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Ⅰ IntroductionPin connectors are made up of various different types of connections. In general, one side is a set of pins soldered to a PCB, and they might be at a right angle to the PCB surface (referred to as "straight") or parallel to the board's surface (referred to as "parallel") (confusingly referred to as "right-angle" pins). These connectors are available in a range of pitches and with any number of separate rows of pins. pin connector A male connector has pins that plug into a female connector. The number of pins in a connector is occasionally used to describe it (for example, "a 25-way D-type connector"). The pinout is a description of the signal associated with each pin. CatalogⅠ IntroductionⅡ 3 pin connector2.1 Basic Information about 3 Pin Connector2.2 Frequently Asked Questions about 3 Pin ConnectorⅢ 4 pin connector3.1 Basic Information about 4 Pin Connector3.2 Frequently Asked Questions about 4 Pin ConnectorⅣ 6 Pin Connector4.1 Basic Information about 6 Pin Connector4.2 Frequently Asked Questions about 6 Pin ConnectorⅤ 7 Pin Trailer Connector5.1 Basic Information about 7 Pin Trailer Connector5.2 Frequently Asked Questions about 7 Pin Trailer ConnectorⅥ 8 Pin Connector6.1 Basic Information about 8 Pin Connector6.2 Frequently Asked Questions about 8 Pin ConnectorⅦ 9 Pin Connector7.1 Basic Information about 9 Pin Connector7.2 Frequently Asked Questions about 9 Pin ConnectorⅧ 12 Pin Connector8.1 Basic Information about 12 Pin Connector8.2 Frequently Asked Questions about 12 Pin ConnectorⅨ 24 Pin Connector9.1 Basic Information about 24 Pin Connector9.2 Frequently Asked Questions about 24 Pin ConnectorⅩ ConclusionⅡ 3 pin connector2.1 Basic Information about 3 Pin ConnectorA three-pin connector consists of three pins: power (5/12 volt), ground, and signal. The signal wire measures how rapidly the fan is moving in the absence of any fan speed controls. The fan speed is normally adjusted by increasing or reducing the voltage across the power wire with this type.  3 pin connector Power connectors for chassis and CPU fans might be 3-pin or 4-pin. 3-pin connectors are typically used for smaller chassis fans that consume less power. CPU fans with significant power consumption typically require 4-pin interfaces. Backwards compatibility exists between fans and on-board fan headers. 2.2 Frequently Asked Questions about 3 Pin Connector1.What to do with 3 pin LED strip connectors?This kit is so well-rounded that it even includes a tool for prying apart connectors without damaging your nails. These connectors are fantastic because they are so easy to use: just position them and snap them together, and you're done! 2.What is a 3 pin socket?The 3-pin plugs are designed to safely supply energy to electrical gadgets. As indicated above, each wire has its own specific color, and each pin must be correctly linked to the three wires in the electrical line. Ⅲ 4 pin connector3.1 Basic Information about 4 Pin ConnectorA four pin connector differs from a three pin connector in that it has an additional (fourth) wire for controlling and sending signals to the fan, which most likely has a chip on it that tells it to slow down or speed up (in addition to the other wires the three pin connector has). 4 pin connector The 4 pin power connector cable (12 volt cable) is intended to provide additional power to the motherboard. These two additional 12 volt cables (two yellow, two black) allow the motherboard to access more power (through these cables). They are typically used to support the CPU, although they can also be employed for other purposes. If your motherboard does not have an extra port, you will not require this additional power. If your motherboard has this port but your power supply does not, you will need to buy a new power supply or an adapter that converts the 4 pin peripheral connector into this 12 volt cable. This cable is sometimes known as the ATX12V or P4 cable, however neither is really valid. 3.2 Frequently Asked Questions about 4 Pin Connector1.What is 4 pin Molex connector?Typically refers to the 4-pin connections used to connect DC power to drives inside a PC cabinet. Molex is a large maker of electrical plugs and sockets that has been in business since the 1940s. 2.Why do you need 4 pin light connectors?They're bright, they're energy efficient, and they're quite simple to use, even when you're creating something from scratch. However, if you require a large number of lights, you will also require something to hold them all together. It's been said that a chain is only as strong as its weakest link, and that anything with LED lights is only as good as its connectors. 3.What is a 4 pin peripheral connector?Peripheral Power Cable (4 Pin) The older IDE hard drives and CD/DVD drives are connected to the power supply through a peripheral power cable. These peripheral power connectors were the original power cables of a computer and were commonly used for hard drives or CD drives. 4.What is the purpose of the 4 pin Molex connector?The 4-pin "Molex" standard connector is a power connector used in computers to power peripheral data drives. It has a 5V and a 12V power supply, as well as ground connections for both. 5.What is a 4 pin auxiliary connector?The 4 pin EPS connector is referred to as the 'tertiary' connector, whereas the 8 pin EPS connector is referred to as the 'auxiliary' connector. In the ATX specification, the 4 pin ATX connector is referred to as the 'auxiliary' connector. Ⅳ 6 Pin Connector4.1 Basic Information about 6 Pin Connector6-pin power connectors are commonly seen in cheap and mid-tier graphics cards. The 6-pin power connector has a 4.2mm pitch and can draw up to 75 watts straight from an external power supply, bypassing the motherboard completely. 6 pin connector When a graphics card requires more power than its PCIe x16 connector can supply, the 6-pin connector serves as a backup power source, allowing the GPU to draw up to 150 watts. 4.2 Frequently Asked Questions about 6 Pin Connector1.What is a 6 pin PCIe power connector?PCI Express (PCIe) 6pin power connector March 1st, 1998 This connector provides additional 12 volt power to PCI Express expansion cards. Because many video cards consume substantially more power than the 75 watts given by the motherboard slot, the 6 pin PCI Express power cable was developed. 2.Do all PSUs have 6 pin connectors?Not all power supplies include PCI-E connectors; some have none, others have one 6/8 pin connector, and some have four or more. When it comes to the PCI-E connector, the simplest rule of thumb to follow is that if the PSU lacks the connector for your card, it was not built to support it. 3.Can you plug a 4 pin into a 6 pin?Everything will be OK. It will be notched in such a way that you can only plug it in one way. 4.What is a 6 pin trailer connector?A 6-way connector provides one wire for trailer brakes and one wire for a battery connection in addition to the basic lighting capabilities of running lights, brake lights, turn signals, and a ground wire. Ⅴ 7 Pin Trailer Connector5.1 Basic Information about 7 Pin Trailer ConnectorTrailer connectors connect the vehicle's electrical systems to those of the trailer or caravan. If you use the indicators, turn on the tail lights, use the brakes, or switch on the fog lights, the trailer or caravan will display the accompanying lights. This is critical for the safety of your driving while towing. 7 pin trailer connector If others behind you are unable to perceive the indications you are providing them, this could result in serious accidents in extreme cases. It is therefore critical to ensure that you have the appropriate fittings and connectors before embarking on a journey with a trailer or a caravan in tow. Trailer connectors are classified into two types: 7 pin and 13 pin. Both are widely used throughout Europe. 5.2 Frequently Asked Questions about 7 Pin Trailer Connector1.What is a 7 pin trailer connector?The 7-Way Trailer Plug is a 2′′ diameter connector with an extra pin for supplemental 12-volt electricity or backup lighting. Towing heavy-duty cargo trailers, aluminum trailers, dump trailers, utility / landscaping trailers, equipment trailers, open car haulers, and enclosed car haulers is common. 2.What is the difference between 4 pin and 7 pin trailer plug?The only real functional difference between them is that the 4-pole trailer connector on part # 37185 is situated to the side of the 7-way, rather than under it, as it is on part # HM47180. Both adapters attach to an existing 4-pole car connector and convert the lighting signals to a 7-way arrangement. 3.Are there different 7 pin trailer connectors?There are two kinds of 7-way connectors: those with flat pins (blades) and those with circular pins. Round pin connectors are extremely rare, although flat pins are popular and frequently found on contemporary SUVs and trucks that come factory equipped with a trailer hitch. Wiring color coding: White = Ground. 4.What is a 7 pole trailer connector?This 7-pole standard RV connector ensures a safe connection between your trailer and tow vehicle. The black plastic construction resists rusting, improves look, and simplifies plug removal. Ⅵ 8 Pin Connector6.1 Basic Information about 8 Pin ConnectorHigh-end graphics cards have 8-pin power connectors. 8-pin connectors have a 4.2mm pitch and can deliver up to 150 watts, which is twice as much as a 6-pin connector. 8 pin connector If a 6-pin connector is inserted into an 8-pin slot, the GPU will attempt to pull more power than the cable is rated for, posing a fire risk. Multiple connections are routinely utilized on high-end GPUs to increase maximum power consumption; the table below illustrates the various 6-pin and 8-pin combinations. Adding more cables has proven less practicable as power needs have increased, as they begin to block air flow and interfere with components in compact places. This is the starting point for the next generation of power connectors. Graphics Card Maximum Power Consumption in WattsPCI Express x166-Pin Connector8-Pin ConnectorTotal Power75W  75W75W1×75W 150W75W 1×150W225W75W2×75W 225W75W1×75W1×150W300W75W 2×150W375W The 8-pin power connector can supply up to 150W to your graphics card. So, if the power usage of your graphics card exceeds 150W, it will almost certainly come with an 8-pin connector or two 6-pin connectors. A graphics card with one 8-pin power connector can receive up to 225W of power, 75W from the PCI Express x16 slot and 150W from the power supply's 8-pin connector. The most recent high-end graphics cards feature an 8-pin power connector, and some of the most power-hungry top-end graphics cards can have both 6-pin and 8-pin connectors, or two 8-pin connectors. A graphics card with both 6-pin and 8-pin connectors can consume up to 300 Watts (75W + 75W + 150W). 6.2 Frequently Asked Questions about 8 Pin Connector1.What is a 8 pin connector called?These are sometimes referred to as "PCI Express cables." They are also sometimes referred to as "PEG cables," where "PEG" refers for PCI Express Graphics. The cable has an 8-pin PCIe power connector. The cable has a 6+2 pin PCIe power connector. 2.What is the 8 pin ATX connector for?An ATX power supply includes a number of peripheral power connectors as well as (in modern systems) two motherboard connectors: an 8-pin (or 4+4-pin) auxiliary connector that provides additional power to the CPU and a main 24-pin power supply connector, which is an extension of the original 20-pin version. 3.Do I need both 8 pin CPU power connector?You must attach the 8 pin connector. If you intend to overclock the CPU, connect both. If you're not using an 8-pin connector. It is not required for normal operation or even a minor overclock. 4.Can you plug an 8 pin into a 4 pin?You can put an 8 pin cable into a 4 pin connector and leave 4 pins hanging over the end, just like you can with a 24 pin cable into a 20 pin motherboard connector, however you may get the same issues with items preventing it from fitting. If it fits, it will be OK. Ⅶ 9 Pin Connector7.1 Basic Information about 9 Pin ConnectorThe word "DB9" refers to a popular connector type, one of the D-Subminiature or D-Sub varieties. The DB9 connector has the smallest "footprint" of the D-Subminiature connectors, with 9 pins (for the male connector) or 9 holes (for the female connector). 9 pin connector The DB9 connector is most commonly seen in serial ports, where it allows for asynchronous data transmission in accordance with the RS-232 standard (RS-232C). It's worth noting that there are DB9-DB25 adapters that can quickly convert a DB9 socket to a DB25 socket and vice versa. 7.2 Frequently Asked Questions about 9 Pin Connector1.Is DB9 and VGA the same?The VGA connector can be a traditional DB9 or (more typically today) a DB15 type connector. While the VGA connector (15 pin) was originally meant to carry a 640 x 480 pixel format, it is now utilized to carry a number of geometries, including HDTV formats. 2.Is there a 9 pin VGA?Pin 9 was deleted from 14-pin cables because the key signal had become obsolete with current computer monitors and was no longer used in the VGA standard's default applications. However, Pin 9 has lately been resurrected as a power supply pin in certain screens to power circuitry. Ⅷ 12 Pin Connector8.1 Basic Information about 12 Pin ConnectorThe 12-pin power connector is the most recent advancement in NVIDIA component power supply. The 12-pin connector has a 3.0mm pitch, hence its overall physical width is the same as that of an 8-pin connector. The connector's architecture has been simplified, with one row for power and the other for ground. 12  pin connector 8.2 Frequently Asked Questions about 12 Pin Connector1. Is there a 12-pin connector?The 12-pin power connector is the most recent advancement in NVIDIA component power supply. The 12-pin connector has a 3.0mm pitch, hence its overall physical width is the same as that of an 8-pin connector. The connector's architecture has been simplified, with one row for power and the other for ground. 2.Does the 3070 require 12-pin?Some board partner 3070s use a six-pin and an eight-pin connector instead of two eight-pins or two eight-pins into the 12-pin adaptor, but this should only be used if your power supply has two eight-pin PCIE connectors. 3.Do I need to buy a 12 pin connector?You are not need to obtain the 12 pin. They are only used by Nvidia Founders Edition cards and come with the video card. Depending on the 3080 you buy, the other brands use two or three 8-pin PCIe cables. 4.Does the 3080 come with a 12-pin connector?You are not need to obtain the 12 pin. They are only used by Nvidia Founders Edition cards and come with the video card. Depending on the 3080 you buy, the other brands use two or three 8-pin PCIe cables. 5.Does the 3080 come with the 12-pin adapter?Yes, Nvidia designed a new proprietary 12-pin power connector to fit on the shortened special PCB inside the GeForce RTX 3080 Founders Edition. The Founders Edition, on the other hand, comes with an adaptor that transforms a pair of 8-pin power cables to the new 12-pin socket. Ⅸ 24 Pin Connector9.1 Basic Information about 24 Pin ConnectorThe ATX 24-pin 12V power supply connector can only be plugged in while the motherboard is pointing in a specified orientation. The original ATX standard included a 20-pin connector with a layout that was very similar to the 24-pin connector but excluded pins 11, 12, 23, and 24. This means that the newer 24-pin power supply is beneficial for motherboards that require more power, eliminating the need for ATX 12V power supplies to include an auxiliary power cord (although some still may). 24 pin connector The extra four pins are often detachable, allowing it to be utilized with a 20-pin motherboard connection. The extra pins simply dangle from the motherboard connector; they do not plug into another slot. Some motherboards allow the older 20-pin power supply cable to be used on a 24-pin motherboard connector. If you need to utilize a 24-pin power supply connector on a motherboard that only supports a 20-pin cable, you can buy a 24-pin to 20-pin converter from a variety of internet suppliers. 9.2 Frequently Asked Questions about 24 Pin Connector1.Can I use a 20 pin connector on a 24 pin motherboard?You can connect a 20-pin cable to a 24-pin motherboard and it will function properly. At least for the time being. They included the extra four pins for a reason. When you insert a 20-pin cable into a 24-pin connector, you are not providing the extra current carrying capacity that the motherboard may require. 2.Do all motherboards have 24 pin connectors?Almost all new power supplies on the market today include a 24-pin power connector for connecting to a computer motherboard. Some motherboards, however, still include a 20-pin ATX power connector. Fortunately, practically all 24-pin power connectors are constructed with four pins that may be disconnected or moved out of the way. 3.How do you remove a 24 pin connector?I did it by pushing the clip, wriggling the connector from side to side, and finally pulling the connector out. If the connector still won't budge, push the clip and wiggle some more. Make certain that you are pushing the clip the entire time. 4.What is the function of 20 24 pin Molex connector?On ATX motherboards, the Mini-Fit Jr. connector can be utilized as the main power connector in 20/24-pin layouts. The same connector design, in single or paired 4-, 6-, or 8-pin combinations, can be used for additional CPU and graphics card power. 5.What is the difference between a 24 pin and a 20 pin motherboard power connector?The 24 pin motherboard connector is essentially a 20 pin connector with four extra pins added to the end. The original 20 pins remained untouched. The additional four pins are not independent rails. They are simply additional lines to give more current to the same rails. Ⅹ ConclusionThere is a wide range of connector types: they can feature holding devices such as pegs, they may require selective soldering, and some are even a "hybrid" of SMT and through-hole. All of these variations can make connectors more difficult to assemble on a PCB, thus it is critical to be aware of potential manufacturing challenges when selecting a connector. When selecting a connector, keep the following points in mind:1) Avoid using through-hole connectors because they have the highest manufacturing costs. Typically, all-SMT designs are less expensive to construct. Even if through-hole components appear to be less expensive, additional production expenses often eat into any savings. 2) Steer clear of connectors that require selective soldering. A connector that requires selective soldering in an otherwise all-SMT design necessitates the assembler doing an SMT/reflow pass, followed by another pass with selective solder. Masking out the components may necessitate additional work. All of this can raise prices and potentially lower yields. 3) Select "pure" SMT connectors devoid of holding features (such as pegs). SMT connectors with retaining components are often more expensive to install. Not all of these components are compatible with all pick and place machines. If using retaining components is required, make the receiving holes as large as possible. Assemblers can and will utilize SMA (surface-mount adhesive) when employing SMT connectors since it is usually strong enough to give more than enough physical strain relief and typically incurs no extra work. 

Introduction RF power amplifier is an important part of various wireless transmitters. In the front-end circuit of the transmitter, the power of the RF signal generated by the modulation oscillator circuit is very small, and it needs to go through a series of amplification-buffer stage, intermediate amplification stage, and final power amplification stage to obtain enough RF power before feeding. In order to obtain a sufficiently large RF output power, a RF power amplifier must be used. RF Power Amplifier Design: The Basics Catalog Introduction Ⅰ Requirements of RF Power Amplifier Ⅱ Types of Power Amplifier in Use Ⅲ Parameters of RF Power Amplifier Design Ⅳ Key Feature: Non-Linearity 4.1 Nonlinear Characteristics 4.2 Influence of Nonlinear Characteristics Ⅴ FAQ Ⅰ Requirements of RF Power Amplifier With the vigorous development of modern digital mobile communication technology, users have more requirements on the performance of wireless communication equipment. To achieve stable and high-speed data transmission in various environments is one of the main goals of future mobile communication system researchers. The RF power amplifier is the last stage of the transmitter. It amplifies the modulated frequency band signal to the required power, ensuring that the receiver in the coverage area can receive a satisfactory signal level, but it cannot interfere too much with the communication of adjacent channels, and meanwhile try to keep the amplified high-power signal without distortion. The requirements of these different aspects make the users of power amplifiers have to consider many factors in all aspects. So you should get a full knowledge of RF power amplifiers. Figure 1. Classic RF Power Amplifier Circuit Ⅱ Types of Power Amplifier in Use What are the main types of RF amplifiers for such an important device?1) According to the operating frequency bandsAccording to the working frequency band, it can be divided into narrowband RF power amplifier and broadband RF power amplifier. The former generally uses frequency selective networks as load circuits, such as LC resonant circuits. The latter does not use the frequency selection network as the load loop, but employs the transmission line with a wide frequency response as the load.2) According to the network propertiesAccording to the nature of the matching network, power amplifiers can be divided into non-resonant power amplifiers and resonant power amplifiers. The matching network of the non-resonant power amplifier is a non-resonant system, such as high-frequency transformers, transmission line transformers and other non-resonant systems, and its load properties are purely resistive, where this is also called reactance properties.3) According to current conduction angleBased on it, RF power amplifiers can be divided into class A, AB, B, C, D, E and so on. The differences between these categories can be seen in the following table: Classification Conduction Angle Efficiency Linearity Application Class A Θ=360° ≤30% Very good Small Signal Low Power Amplification Class B Θ=180° ≤60% Lower than class A For High Power Class C Θ<180° About 60% Nonlinear amplifier For High Power Class AB 180°<Θ<360° 30%~60% Better than class B Small signal works in class A, large signal works in class B Class D Work in switch mode 80% Very good, only good for low frequencies Switch mode amplifier Class E Work in switch mode 90% Completely nonlinear amp Switch mode amplifier In the classification of amplifiers, we often talk about amplifiers of class A to E according to the conduction angle. Class A power amplifier is a linear amplifier, its response to the sine-wave  input is a sine-wave output, generally without distortion amplification, and the output frequency is the same as the input frequency. Since class A amplifiers do not require additional filtering circuitry, their packages can be small and cost less. The output of a class B amplifier is a half sine wave of the input, resulting in half-wave distortion, which produces many harmonics. The output power and efficiency of the class C working state are the highest among these working states, and most of the amplifiers used for radio frequency work in the class C. Figure 2. Class A Amplifier Load Curve   Ⅲ Parameters of RF Power Amplifier Design RF power amplifiers are electronic circuits that comprehensively consider issues such as output power, excitation level, power consumption, distortion, efficiency, size and weight. In the transmitting system, the output power of the RF power amplifier can be as small as mW and as large as several kW, but this refers to the output power of the final power amplifier. In order to achieve high power output, the last stage must have a sufficiently high excitation power level. At the same time, it has other important indicators, as follows:1) Operating FrequencyGenerally speaking, it refers to the linear operating frequency range of the amplifier. If the frequency starts at DC, the amplifier is considered to be a DC amplifier.2) GainThe working gain is the main indicator to measure the amplification ability of the amplifier. Here it is defined as the ratio of the power delivered to the load by the amplifier output port to the power actually delivered by the signal source to the amplifier input port.Gain flatness refers to the variation range of amplifier gain in the entire operating frequency band under a certain temperature, and is also a main indicator of the amplifier. Figure 3. Output Power and 1dB Compression Point (P1dB) Referring to the Figure 3, when the input power exceeds a certain amount, the gain of the transistor begins to decrease, and the end result is that the output power saturates. When the gain of the amplifier deviates from a constant or is 1dB lower than other small signal gains, this point is the famous 1dB compression point (P1dB). Generally speaking, the power capacity of an amplifier is expressed by the 1dB compression point.3) EfficientSince the power amplifier is a power component, it needs to consume the supply current. Therefore, the efficiency of the power amplifier is extremely important to the efficiency of the whole system. Power efficiency is the ratio of the RF output power of the amplifier to the DC power supplied to the transistors.ηp=RF Output Power/DC Input Power4) Intermodulation Distortion (IMD)Intermodulation distortion refers to the mixed components of two or more input signals with different frequencies passing through a power amplifier. This is due to the nonlinear nature of the amplifier. Among them, because the third-order intermodulation product is very close to the fundamental signal, it has the greatest influence, so the third-order intermodulation is the most important consideration for the related products. The lower the third-order intermodulation product, the better.5) Third-order Intermodulation Cut-off Point (IP3)The intersection point of the extension line of the fundamental wave signal output power and the extension line of the third-order intermodulation in Fig is called the third-order intermodulation cut-off point, which is represented by the symbol IP3. It is also an important indicator of nonlinearity. When the output power is constant, the greater the output power of the third-order intermodulation cut-off point, the better the linearity of the power amplifier.6) Dynamic RangeThe dynamic range of a power amplifier generally refers to the difference between the minimum detectable signal and the maximum input power in the linear operating region. Naturally, this value must be as large as possible.7) Harmonic DistortionWhen the input signal increases to a certain level, the power amplifier will generate a series of harmonics due to its work in the nonlinear region. For high-power amplifier systems, filters are generally required to reduce harmonics below 60dBc.8) Input/Output VSWR (Voltage Standing Wave Ratio)This is also a very important indicator of how well the amplifier matches the overall system. The deterioration of the input-output ratio will lead to the deterioration of the gain fluctuation and group delay of the system. However, it is difficult to design a power amplifier with a high VSWR. In general systems, the input VSWR of the power amplifier is required to be lower than 2:1.The main technical indicators of RF power amplifiers are output power and efficiency. Therefore how to improve them is the core of the design goals of RF power amplifiers. Usually in the RF power amplifier, the fundamental frequency or a certain harmonic can be selected by the LC resonant circuit to achieve distortion-free amplification. In addition to this, the harmonic components in the output should be as small as possible to avoid interference with other channels. Figure 4. Increase the Power of the RF Input Signal Ⅳ Key Feature: Non-Linearity In an ideal amplifier, the output signal should faithfully reflect the input signal, that is, the waveform should be the same. But in fact, for many reasons, the input signal cannot be exactly the same waveform as the input signal, which is called amplifier distortion.Amplifier distortion mainly includes frequency distortion (linear distortion) and waveform distortion (non-linear distortion). The former mainly refers to the difference in gain and delay of the amplifier for different frequency components; the latter refers to the same frequency, the output signal and the input signal are not linear. Frequency distortion is represented by spectral changes in the frequency domain, while nonlinear distortion is represented by changes in the time-domain waveform. Non-linear distortion is different from frequency distortion mainly because a large number of new frequency components are generated. The nonlinear distortion of the power amplifier is mainly discussed here. 4.1 Nonlinear Characteristics From the small-signal model and input characteristic curve of an ideal transistor, it can be seen that the transistor amplifier itself is not an ideal linear device, and at the same time, due to the influence of parasitic parameters, the linearity is further reduced. But within a certain power range, the transistor can be regarded as linear amplification. For power amplifier designers, how to obtain higher output power and improve linearity is the key.For a transistor amplifier, its volt-ampere characteristics can be described as follows: A power series expansion can be used to describe the volt-ampere characteristics of the device: In the formula, an(n=0,1,2,3,…) is a coefficient related to the circuit characteristics. Usually, the larger the n, the smaller the value of the coefficient an. When the nonlinear device in the circuit is represented by a power series, the number of series terms taken depends entirely on the magnitude of the signal amplitude and the required precision. 4.2 Influence of Nonlinear Characteristics The influence of the nonlinear characteristics of the device on the amplifier can be discussed in two cases. One is when there is only one signal at the input end, and the other is when the input end has one to two other signals in addition to the useful signal.🔺Only one signal at the inputLet the signal at the input end be , and substitute it into formula 2, at this time there is When the amplitude of the input signal is large and the effect of the cubic term must be considered, the fundamental frequency signal obtained from formula 2 is: Figure 5. 1dB Compression Point (PA) A3 in formula 3 is usually a negative value, that is, y1(t) decreases as the input signal amplitude increases, a phenomenon called gain compression.The "1dB compression point" is often used in engineering to measure the linear performance of the device. The 1dB compression point is defined as the input signal power P1dB that reduces the gain by 1dB from the linear gain. As shown in Figure 5. According to the definition of 1dB compression point and formula 3, we can get 🔺Two signals at the input.The signal amplified at the input end of the amplifier is generally not a single tone signal, but a spectral signal composed of a certain bandwidth. Due to the nonlinearity of the device, a large number of combined interference frequency components other than the useful signal will be generated at the output end. In addition, the combined frequency components of two or more interfering signals may also cause interference to the useful signal. Have an assumption: Substitute into formula 1, where It can be seen from the above formula that the fundamental frequency components of ω1 and ω2 are generated by the first and third power terms: A total of multiple frequency components are generated: ω1 , ω2 , ω1 ± ω2, 2ω1 - ω2, 2ω2 - ω1 , 3ω1 - 2ω2, 3ω2 - 2ω1.The difference frequency 2ω1 - ω2, 2ω2 - ω1 in the combined frequency is generated by the cubic term. The combination of these two signal frequencies is just within the sideband range of the signal frequency, which may cause interference to adjacent channels, and is one of the main indicators of transmission signal. Figure 6. Intermodulation Signal Interference This interference is caused by the mutual modulation of the two signals, so it is called intermodulation interference. At the same time, it is generated by a cubic term, so it is also called third-order intermodulation interference in engineering.When the third-order intermodulation interference is an important indicator of the communication machine, it is often measured by the intermodulation distortion ratio IMR and the third-order intermodulation blocking point IP3 in engineering. IMR is defined as the ratio of the amplitude of the third-order intermodulation product to the amplitude of the fundamental signal at a certain input amplitude. Definition of IP3: When the third-order intermodulation component increases to be equal to the fundamental frequency component, the receiver cannot receive normally, so there is a . Figure 7. Third-order Intermodulation Blocking Point 🔺Sideband Signals Figure 8. Sideband Signals and the Spectrum In fact, most of the sideband signals are generated outside the bandwidth after the useful signals of different frequencies within the bandwidth are modulated with each other. That is, the sideband signal rises faster than the in-band signal, and the spectral mask in the above figure becomes more and more flat. The increase of sideband signals will cause interference to adjacent channels, so the IEEE 802.11 protocol has strict requirements on the spectrum template, as shown in the Figure 9. Figure 9. DSSS Signal Modulation Spectral Mask Figure 10. OFDM 20MHz Bandwidth Signal Spectral Mask For the power amplifier, its nonlinear characteristics will increase the sideband of the modulated signal, and the sideband amplitude is not easily suppressed by other networks such as filters, and it is easy to cause design difficulties. Therefore, when choosing a PA, not only should pay attention to the maximum linear output that it can achieve, but also whether it can meet the sideband spectrum requirements at this output power.🔺Other Effects of NonlinearityIn addition to the previously mentioned gain drop, which generates a large number of harmonic components, as well as third-order intermodulation and sidebands, nonlinearity can also cause signal and EVM to deteriorate, etc.   Ⅴ FAQ 1. What is RF power amplifier?A radio frequency power amplifier (RF power amplifier) is a type of electronic amplifier that converts a low-power radio-frequency signal into a higher power signal. 2. How does RF power amplifier work?An RF amplifier is actually a tuned amplifier that enables the input signal of broadcast or transmitted information to control an output signal. The RF amplifier uses frequency-determining networks to convert the input signal into an output signal that will provide the required response at a given frequency. 3. What is the most efficient class of RF power amplifier?Class C AmplifierThe Class C Amplifier design has the greatest efficiency but the poorest linearity of the classes of amplifiers mentioned here. The previous classes, A, B and AB are considered linear amplifiers, as the output signals amplitude and phase are linearly related to the input signals amplitude and phase. 4. How do I choose an RF power amplifier?Considerations When Choosing An RF Power Amplifier:Gain.Operating Frequency.Output Power Level.Efficiency.Linearity.Mismatch Tolerance.Noise Level. 5. What are the advantages of RF amplifier?Following are the RF Amplifier advantages:The RF amplifier offers greater gain i.e. better sensitivity. It offers better selectivity and hence it has ability to select wanted signals from multiple input signals at the RF receiver. 6. What are the different types of RF amplifiers?Amplifier TypesBroadband AmplifiersGain Block AmplifiersLog AmplifiersVariable Gain AmplifiersLow Noise AmplifiersCoaxial and Waveguide Power AmplifiersLinear AmplifiersBi-Directional Amplifiers 7. What is RF amplifier circuit?A radio frequency power amplifier (RF power amplifier) is a type of electronic circuit that converts a low-power radio-frequency signal into a higher power signal. 8. Is Class D amplifier better than a class AB?The most common audio power amplifier operates in the Class-AB mode. It provides the greatest amount of output power with the least amount of distortion. ... Class-D amplifiers are switches that are more efficient and produce less heat than their Class-AB equivalents. 9. What are RF amplifiers used for?Whenever people need to magnify a radio frequency signal into a higher power signal, the RF amplifier plays a pivotal role. They are used in commercial and defense avionics, space and deep space, electronic warfare, naval applications, mobile internet, satellite communication, and wireless communications. 10. Which amplifier is used in RF amplifier?RF power amplifiers using LDMOS (laterally diffused MOSFET) are the most widely used power semiconductor devices in wireless telecommunication networks, particularly mobile networks. LDMOS-based RF power amplifiers are widely used in digital mobile networks such as 2G, 3G, and 4G.

Introduction IGBT and MOSFET are fully controlled devices and are voltage-driven, that is, the device is turned on or off by controlling the gate voltage. In fact, the structure of the IGBT is an NPN-type MOSFET plus a P-junction, that is, an NPNP structure, which is a P-type BJT driven by MOS in principle. So what is the difference between them? What is the specific connection of them? MOSFET BJT or IGBT - Brief Comparison Catalog Introduction Ⅰ MOSFET & IGBT Review Ⅱ Si IGBT vs SiC MOSFET Ⅲ Different Requirements for Si IGBT and SiC MOSFET 3.1 ON & OFF State 3.2 Short-Circuit Protection 3.3 Interference and Delay Ⅳ IGBT Working Principle by Analogy with MOSFET Ⅴ FAQ Ⅰ MOSFET & IGBT Review MOSFET is a metal-oxide-semiconductor field effect transistor, or metal-insulator-semiconductor. The source and drain of it can be swapped, and they are both N-type regions formed in the P-type backgate. In most cases, these two regions are the same, even if the two ends are reversed, it will not affect the performance of the device. Such devices are considered symmetrical. According to the polarity of its "channel" (working carrier), MOSFET can be divided into two types: N-type and P-type, usually also called NMOSFET and PMOSFET, abbreviations including NMOS, PMOS, etc.IGBT (insulated gate bipolar transistor), is a composite fully controlled voltage-driven power semiconductor device composed of BJT (bipolar transistor) and MOS. Have the advantages of high input impedance of MOSFET and the low on-voltage drop of the GTR. When the GTR saturation voltage is reduced, the current carrying density is large, but the driving current is large; the MOSFET driving power is small, the switching speed is fast, but the on-state voltage drop is large, and the current carrying density is small. The IGBT combines the advantages of the above two devices, and the driving power is small and the saturation voltage is reduced. In simple terms, an IGBT is equivalent to a thick base PNP transistor driven by a MOS. Figure 1. N-MOSFET Architecture Ⅱ Si IGBT vs SiC MOSFET Since the differences between IGBT and MOSFET in structure, working principle and application range are quite detailed, it is impossible to express clearly in one sentence. Next, we will compare the differences between silicon (Si) IGBTs and silicon carbide (SiC) MOSFETs in detail.The electrical parameters and characteristics of Si IGBT and SiC MOS drivers are quite different. The requirements for driving of SiC MOS are also different from those of traditional silicon devices. They have the characteristics of low on-resistance and small switching loss, which can reduce device loss and improve system efficiency, and more suitable for high frequency circuits. It is widely used in new energy vehicle motor controller, vehicle power supply, solar inverter, charging pile, UPS, PFC power supply and other fields.The difference between the two is mainly reflected in the GS turn-on voltage, GS turn-off voltage, short-circuit protection, signal delay and anti-interference, as follows: Characteristic Si IGBT SiC MOSFET Drive Requirements Switching Frequency Low, >30kHz High, 50~500kHz 1) Use high power gate resistors. 2) Optimize the cooling environment. 3) Improve the efficiency of the DC-DC conversion circuit and reduce the overall loss of driving power. Threshold Voltage 5V-6V 1.6V-4.5V Negative pressure shutdown/Miller clamp to prevent false turn-on Switching Time 300ns 50ns 1) Use digital isolation driver chip, the signal transmission delay can reach 50ns, and it has relatively high consistency, and the transmission jitter is less than 5ns. 2) the low transmission delay push-pull chip is selected. Switching-On Time 15V 15V~22V 1) Priority is given to stabilizing the negative voltage to ensure that the shutdown voltage is stable. 2) A negative voltage clamping circuit is added to ensure that it does not exceed the standard during shutdown. Switching-Off voltage -15V~-5V -5V~0V Short-Circuit Withstand Time <10μs 2~5μs A diode or a resistor string is used to detect short circuits, and the shortest short-circuit protection time is limited to about 1.5μs. CMTI 15kV/μs 100kV/μs 1) The common mode anti-interference ability reaches 100kV/μs to transmit the isolation chip for signal transmission. 2) The optimized isolation transformer design is adopted, and its primary side and the secondary side are shielded to reduce mutual crosstalk. 3) The Miller clamp is used to prevent the influence of the switch of the same bridge arm.   Ⅲ Different Requirements for Si IGBT and SiC MOSFET For a fully-controlled switching device, configuring an appropriate on-off voltage is of great significance for the safety and reliability of the device. Due to the difference between IGBT and MOSFET, the requirements for the two are also different.IGBT is a field-controlled device whose turn-on and turn-off are determined by the voltage between the gate(G) and the emitter(E). The working principle of MOS tube (enhancement mode NMOSFET) is to use VGS to control the amount of "induced charges" to change the condition of the conductive channel, and then to control the drain current. 3.1 ON & OFF State 1) Silicon IGBT: Silicon IGBTs of various manufacturers have the same turn-on and turn-off voltage requirements.· The typical turn-on voltage is required to be 15V.· The shutdown voltage value range is -5V~-15V, and customers can choose the appropriate value according to their needs. The common values are -8V, -10V, -15V.· Prioritize stable positive voltage to ensure stable turn-on.2) Silicon carbide MOSFET: Different manufacturers have different switching voltage requirements:· The turn-on voltage is required to be higher than 22V~15V.· The shutdown voltage is required to be higher -5V~-3V.· Prioritize negative voltage stabilization to ensure stable turn-off voltage.· Increase the negative voltage clamping circuit to ensure that it does not exceed the standard when it is turned off. 3.2 Short-Circuit Protection The switching device has the risk of short circuit during operation, and configuring a suitable short circuit protection circuit can effectively reduce the damage caused by the short circuit during the use of the switching device. Compared to Si IGBTs, SiC MOSFETs have shorter short-circuit withstand times.1) Silicon IGBTThe time of surrender and short-circuit of Si IGBT is generally less than 10μs. When designing the short-circuit protection circuit of it, set the detection delay and corresponding time of short-circuit protection to 5-8μs.2) SiC MOSFETGenerally, the short-circuit withstand capability of SiC MOSFET modules is less than 5μs, and short-circuit protection is required to work within 3μs. A diode or a resistor string is used to detect short circuits, and the protection time is limited to about 1.5μs. 3.3 Interference and Delay 1) The impact of high dv/dt and di/dt on the system.When the switching action is performed under the condition of high voltage and high current, the switching of the silicon carbide MOSFET device will generate high dv/dt and di/dt, which will affect the driver circuit. It is very important to improve the anti-interference ability of the driver circuit for the reliable operation of the system. the following way to achieve.· Add common mode choke coil and filter inductor to the input power supply, which reduce the interference of driver EMI to low voltage power supply.· A low-pass filter is added to the rectification part of the secondary side power supply, which reduce the interference of the driver to the high-voltage side.· Use an isolation chip with a common mode immunity of 100kV/μs for signal transmission.· Optimize the isolation transformer design, and use shielding layer on primary side and secondary side to reduce crosstalk between each other.· Use Miller clamp to prevent the influence of the switch of the same bridge arm. 2) Low transmission delayUsually, the application switching frequency of silicon IGBT is less than 40kHZ, and the recommended application switching frequency of SiC MOSFET is greater than 100kHz. The increase of application frequency makes MOS require the driver to provide lower signal delay time. The transmission delay of the SiC MOSFET drive signal should be less than 200ns, and the transmission delay jitter should be less than 20ns, which can be achieved by the following methods.· Using digital isolation driver chip, the signal transmission delay can reach 50ns, and it has relatively high consistency, and the transmission jitter is less than 5ns.· Select push-pull chips with low transmission delay and short rise & fall time. Due to the conductance modulation effect, the on-state specific resistance of high voltage SiC IGBTs is much lower than that of power SiC MOSs, and does not change much as the blocking voltage rating increases. When the conductance modulation effect is fully exerted, the on-state voltage drop of the IGBT drift region is only related to the bipolar diffusion coefficient and bipolar lifetime of the carriers, and will not change with the increase of the on-current. When the operating temperature changes, the on-state voltage drop of the SiC high voltage IGBT decreases with the increase of the junction temperature. This is mainly because the bipolar lifetime of the extra carriers in the SiC epitaxial layer will increase with the increase of temperature. Although the diffusion coefficient will shrink to some extent with the increase of temperature, the greater prolongation of lifetime will eventually make the the bipolar diffusion length increased, thereby reducing the on-state voltage drop. It is especially true in n-channel devices.This is in sharp contrast to the larger increase in the forward voltage drop of the power MOS at high temperature. Silicon carbide p-channel IGBTs have higher on-state voltage drop than n-channel IGBTs at the same current density due to their larger channel resistance, but their volt-ampere characteristics do not change much with temperature. As for the applications, this is undoubtedly an advantage. Figure 2. Comparison of characteristics between SiC IGBT and power MOS under the Same Condition of Withstand Voltage of 20kV. It is not difficult to calculate from the intersection of the equal power consumption curve in the figure and the on-state characteristic curves of these devices: corresponding to the same power consumption of 300W/cm2, the ratio of the on-state current of the silicon carbide IGBT to the silicon carbide power MOS versus p-channel devices and n-channel devices are different, they are 1.5 and 1.8 at room temperature, respectively, and increase to 2.7 and 3.5 at 225°C, indicating that high-voltage and high-current SiC IGBTs are more suitable for high-temperature applications.In a word, compared with Si IGBT, SiC MOSFET not only improves system efficiency, power density and operating temperature, but also puts forward higher requirements for the driver. In order to make silicon carbide MOSFET better in the system, it is necessary to give SiC MOSFET a appropriate driver.   Ⅳ IGBT Working Principle by Analogy with MOSFET IGBT is a Darlington pair composed of GTR and MOSFET: part of which is MOSFET driver, and the other part is thick-base PNP transistor. Figure 3. IGBT Architecture Its simplified equivalent circuit is shown in the figure below, and RN in the figure is the modulation resistance in the base area of the PNP transistor. It can be clearly seen from this circuit that the IGBT is a composite device of Darlington configuration composed of transistors and MOSFET, where the transistor in the figure is a PNP transistor, and the MOSFET is an N-channel field effect transistor, so the IGBT of this structure is called an N-channel IGBT, and its symbol is N-IGBT. Similarly there are P-channel IGBTs, namely P-IGBTs. Figure 4. Simplified Equivalent Circuit The electrical graphic symbols of the IGBT are shown in the figure. IGBT is a field-controlled device, and its turn-on and turn-off are determined by the voltage UGE between the gate and the emitter. When the gate-emitter voltage UCE is positive and greater than the turn-on voltage UCE (th), a channel is formed in the MOSFET and is a PNP. The N-type transistor provides the base current to turn on the IGBT. At this time, the holes (minority carriers) injected into the N- region from the P+ region modulate the conductance of the N- region, reduce the resistance RN of the N- region, and make the IGBT also has a small on-state voltage drop. When no signal or reverse voltage is applied between the gate and emitter, the channel in the MOSFET disappears, the base current of the PNP transistor is cut off, and the IGBT is turned off. It can be seen that the driving principle of IGBT is basically the same as that of MOSFET.① When UCE is negative: J3 junction is in reverse bias state, and the device is in reverse blocking state.② When UCE is positive: UC< UTH, the channel cannot be formed, and the device is in a forward blocking state; UG> UTH, an N-channel is formed under the insulating gate, and conductance is generated in the N- region due to the interaction of carriers modulation so that the device is conducting forward. Figure 5. Hybrid Switch Using Si IGBT and SiC MOSFET 1) ONThe structure of IGBT silicon is very similar to that of power MOSFET, and the main difference is that JGBT adds a P+ substrate and an N+ buffer layer, in terms of it, one MOS drives two bipolar devices (devices with two polarities). The application of the substrate creates a J junction between the P, and N+ regions of the tube. When the positive gate bias causes the inversion of the P base region under the gate, an N-channel is formed, and an electron flow occurs at the same time, and a current is generated exactly in the manner of a power MOSFET. If the voltage produced by this electron flow is in the range of 0.7V, J1 will be forward biased, some holes will be injected into the N- region, and the resistivity between N- and N+ will be adjusted, which reduces the power conduction the total loss of the pass and initiates a second charge flow. The end result is the temporary emergence of two different current topologies within the semiconductor layer: an electron flow (MOSFET current), and a hole current (bipolar). When UCE is greater than the turn-on voltage UCE(th), a channel is formed in the MOSFET to provide base current for the transistor, and the IGBT is turned on. 2) On-State Voltage DropThe conductance modulation effect reduces the resistance RN and reduces the on-state voltage drop. The so-called on-state voltage drop refers to the tube voltage drop UDS when the IGBT enters the on-state, and this voltage decreases with the rise of UCS. 3) Shut DownWhen a negative bias is applied to the gate or the gate voltage is lower than the threshold value, the channel is disabled and no holes are injected into the N-region. In any case, if the current of the MOSFET decreases rapidly during the switching phase, the collector current decreases gradually. This is because there are still minority carriers in the N layer after the commutation starts. This reduction in residual current value (wake) is entirely dependent on the charge density at turn-off, which in turn is related to several factors, such as the number and topology of dopants, layer thickness and temperature. The decay of minority carriers makes the collector current have a wake waveform. Collector current will cause increased power dissipation and cross-conduction problems, especially on devices that use freewheeling diodes.Considering that the wake is related to the recombination of minority carriers, the current value of the wake should be closely related to the Tc, IC of the chip, and has a close relationship with the mobility of holes. Therefore, depending on the temperature reached, it is feasible to reduce the undesirable effects of this current on the end equipment design. When a back pressure or no signal is applied between the gate and the emitter, the channel in the MOS disappears, the base current of the transistor is cut off, and the IGBT is turned off. 4) Reverse BlockingWhen a reverse voltage is applied to the collector, the junction is reverse biased and the depletion layer expands to the N-region. Because the thickness of this layer is reduced too much, an effective blocking ability will not be obtained, so this mechanism is very important. In addition, if the size of this region is increased too much, the voltage drop will continuously increase. 5) Forward BlockingWhen the gate and emitter are shorted and a positive voltage is applied at the collector terminal, the junction is controlled by the reverse voltage. At this time, the depletion layer of the N drift region is still subjected to the externally applied voltage. 6) LatchICBT has a parasitic PNPN thyristor between the collector and the emitter. Under special conditions, this parasitic device will turn on. This phenomenon increases the amount of current between the collector and the emitter, reduces the controllability of the equivalent MOSFET, and often causes device breakdown problems. The thyristor turn-on phenomenon is known as IGBT latch-up. Specifically, the causes of such defects vary, but are closely related to the state of the devices.   Ⅴ FAQ 1. Are there SiC IGBT?Along with the increasing maturity for the material and process of the wide bandgap semiconductor silicon carbide (SiC), the insulated gate bipolar transistor (IGBT) representing the top level of power devices could be fabricated by SiC successfully. 2. Where are SiC MOSFETs used?The primary automotive applications for SiC power MOSFETs, diodes, and modules are onboard electric vehicle (EV) chargers, DC/DC converters, and drivetrain inverters. Plug-in hybrid EVs and battery EVs (BEVs) use onboard chargers to “refuel” the vehicle battery either at home or at a public charging station. 3. What is SiC MOSFET?Silicon Carbide (SiC) MOSFETs exhibit higher blocking voltage, lower on state resistance and higher thermal conductivity than their silicon counterparts. SiC MOSFETs are designed and essentially processed the same way as silicon MOSFETs. 4. Can MOSFET replace IGBT?Due to the higher usable current density of IGBTs, it can usually handle two to three times more current than a typical MOSFET it replaces. This means that a single IGBT device can replace multiple MOSFETs in parallel operation or any of the super-large single power MOSFETs that are available today. 5. What are the advantages of silicon carbide?Silicon carbide MOSFETs have a critical breakdown strength that is 10x of silicon, and silicon carbide MOSFETs can operate at much higher temperatures, provide higher current density, experience reduced switching losses, and support higher switching frequencies. 6. What are the advantages of silicon carbide (SiC) over silicon (Si)?The advantage of SiC starts in the material itself having a 10x higher dielectric breakdown field strength, 2x higher electron saturation velocity, 3x higher energy bad gap and 3x higher thermal conductivity than Silicon. 7. What is the difference between silicon and silicon carbide?Silicon has a breakdown voltage of around 600V, while silicon carbide can withstand voltages 5-10 times higher. ... Silicon carbide can switch at nearly ten times the rate of silicon, which results in smaller control circuitry. 8. What is SiC in semiconductor?SiC (silicon carbide) is a compound semiconductor composed of silicon and carbide. SiC provides a number of advantages over silicon, including 10x the breakdown electric field strength, 3x the band gap, and enabling a wider range of p- and n-type control required for device construction. 9. Which is better MOSFET or IGBT?When compared to the IGBT, a power MOSFET has the advantages of higher commutation speed and greater efficiency during operation at low voltages. What's more, it can sustain a high blocking voltage and maintain a high current. ... The IGBT is also a three terminal (gate, collector, and emitter) full-controlled switch. 10. Why use an IGBT instead of a MOSFET?The main advantages of IGBT over a Power MOSFET and a BJT are: 1. It has a very low on-state voltage drop due to conductivity modulation and has superior on-state current density. ... It canbe easily controlled as compared to current controlled devices (thyristor, BJT) in high voltage and high current applications. 11. Why is MOSFET preferred?Mosfet provides a very good isolation between the gate and the other two terminals compared to bjt. Mosfet can handle more power compared to BJT. The mosfet has a very low power loss and a high speed. Voltage signals can easily operate a mosfet, so it is used in many digital circuits. 12. Where are MOSFETs used?Power MOSFETs are commonly used in automotive electronics, particularly as switching devices in electronic control units, and as power converters in modern electric vehicles. The insulated-gate bipolar transistor (IGBT), a hybrid MOS-bipolar transistor, is also used for a wide variety of applications. 13. Why IGBT is very popular nowadays?With its lower on-state resistance and conduction losses as well as its ability to switch high voltages at high frequencies without damage makes the Insulated Gate Bipolar Transistor ideal for driving inductive loads such as coil windings, electromagnets and DC motors. 14. How many terminals are in a MOSFET?four terminalsThe MOSFET has four terminals: drain, source, gate, and body or substrate. 15. Why is IGBT bipolar?IGBTs is a bipolar device that utilizes two types of carriers, electrons and holes, resulting from the complex configuration that features a MOSFET structure at the input block and bipolar output, making it a transistor that can achieve low saturation voltage (similar to low ON resistance MOSFETs) with relatively fast. 16. How many types of IGBT are there?two typesInsulated Gate Bipolar Junction Transistor (IGBTs) are normally classified into two types. (ii) Punch Through [PT-IGBT]. These IGBTs are also referred to as symmetrical and asymmetrical IGBTs. These varieties of IGBT differ widely with regard to their fabrication technology, structural details etc. 17. What is full MOSFET?MOSFET stands for metal-oxide-semiconductor field-effect transistor. It is a field-effect transistor with a MOS structure. Typically, the MOSFET is a three-terminal device with gate (G), drain (D) and source (S) terminals. 18. How does an IGBT work as a switch?As defined by being a transistor, an IGBT is a semiconductor with three terminals which work as a switch for moving electrical current. Just as the word “gate” suggests, when voltage is applied to the gate, it opens or “turns on” and creates a path for current to flow between the layers. 19. Can I use transistor instead of MOSFET?It very much depends on the application. BJTs can be cheaper than FETs. This is especially true for high voltage switching where the much larger die area of FETs make them much more expensive. 20. Can IGBT conduct in reverse direction?No. The IGBT cannot conduct current in the reverse direction (from emitter to collector) even with a positive Vge applied to it, because it has a bipolar-type structure. ... However, the gate has no control over this reverse current flow; it is simply the forward biasing of the diode that allows it.

Introduction The introduction of grounding technology was originally a protective way to prevent electrical or electronic equipment from being struck by lightning. At the same time, it is also an effective means to protect personal safety. When the phase line (such as poor wire insulation, aging, etc.)  touches the equipment shell for some reason, dangerous voltage will be generated on the equipment shell, thus the generated fault current will flow through the PE line to the ground, thus playing a protective role. With the development of electronic communication and other digital fields, only considering lightning protection and safety in the grounding system is far from meeting the requirements. Electrical Grounding Explained | Basic Concepts Catalog Introduction Ⅰ Basic: Q&A Related to Electrical Ground Ⅱ DC Power Supply Ground 2.1 Basic Overview 2.2 DC Power Supply Ground Analysis with Diagrams 2.3 Ground Bounce for Buck Converters 2.4 Ground Bounce for Boost Converters 2.5 Summery Ⅲ Useful Concepts for Grounding Analysis Ⅳ Conclusion Ⅴ FAQ Ⅰ Basic: Q&A Related to Electrical Ground The signal between each device needs a "ground" as the reference ground of the signal. Moreover, with the complexity of electronic equipment, the signal frequency is getting complicated. Therefore, in the grounding design, special attention must be paid to electromagnetic compatibility issues such as mutual interference between signals. Otherwise, improper grounding will seriously affect the reliability of system operation. Here the following are doubts that may arise in the power grounding. Q1: What is the definition of grounding?A: As for grounding concepts, to line engineers, the term usually means "reference point for line voltage". For system designers, it is often a cabinet or rack. For electrical engineers, it means green safety ground or connection to the earth. A more general definition is "A ground is a low impedance path for current to return to its source", and the key points are "low impedance" and "passage". Q2: What are the common grounding symbols in circuit?A: PE, PGND, FG-protective ground or chassisBGND or DC-RETURN-DC-48V (+24V) power supply (battery) returnGND: working groundDGND: digital groundAGND: analog groundLGND: lightning protection ground Q3: What is the appropriate grounding method?A: There are many ways to ground, including single-point grounding, multi-point grounding and mixed types of grounding. Among them, the single is divided into series single-point grounding and parallel single-point grounding. Generally speaking, single-point grounding is used for simple circuits, while grounding distinction between different functional modules, and multi-point grounding or multi-layer boards (complete ground plane layer) are used in low-frequency (f10MHz) circuits. Q4: Why should the analog ground and digital ground be separated?A: Both the analog signal and the digital signal return to the ground, the digital signal changes fast with large noise, while the analog signal needs a clean ground reference to work. If the analog and digital grounds are mixed, noise can affect the analog signal.According to the above mentioned, the analog ground and the digital ground should be processed separately, and then connected together through thin wires, or together at a single point. The general idea is to try to block the noise on the digital ground from flowing to the analog ground. Of course, this is not a very strict requirement that they must be separated, because it depends on the actual situation. Q5: How to ground the signal on the board?A: Under normal circumstances, it is best to use the nearest ground when designing, and after a complete multi-layer board design, it is very easy to ground common signals. The basic principle is to ensure the continuity of the traces and reduce number of vias, close to ground plane or power plane, etc. Q6: How to ground the interface devices of the board?A: Some single boards have external input and output interfaces, such as serial port connectors, network port connectors, etc, if they are not properly grounded, it will also affect normal work, such as network port interconnection errors, packet loss, etc., and will become an external source of electromagnetic interference, sending the noise inside the board to the outside. Generally speaking, an independent interface ground will be divided, and the connection with the signal ground will be connected by thin traces, and a o small resistance or 0ohm resistor can be connected in series. Thin traces can be used to block signal ground noise from passing to the interface ground. Similarly, the filtering of interface ground and interface power should also be carefully considered. Q7: How to ground the shielding layer in the cable with shielding layer?A: The layer of the shielded cable must be connected to the interface ground of the single board, not the signal ground. This is because there are various noises on the signal ground. If the shielding layer is connected to the signal ground, the noise voltage will drive the common mode current along the shielding. Therefore, cables with unreasonable design are generally the largest noise output source of electromagnetic interference.   Ⅱ DC Power Supply Ground 2.1 Basic Overview In power supply design, safety is often in the first place, and the same is true in switching power supplies. Grounding can protect the personal safety of users and ensure the normal operation of power equipment. So what is the appropriate grounding method in switching power supplies? What are the common ground symbols in circuits? This article will popularize the grounding basic in DC power supplies.DC-DC is a commonly used power supply circuit in electronic hardware design. It has high efficiency in realizing high input voltage and low output voltage. It is widely used, from power adapters, mobile phone chargers, and internal power conversion of electronic equipment to DC-DC circuits. Each semiconductor manufacturer has its own DC-DC chips, and also there are many optional chips. For a well-designed DC-DC circuit, not only the peripheral resistance, capacitance, but also the inductance parameters of the DC-DC circuit should be considered. There are also high requirements for the PCB layout design. This paper proposes a method to guide the grounding in the PCB layout from the perspective of the current flow in DC circuits. 2.2 DC Power Supply Ground Analysis with Diagrams Circuit grounding looks simple in a circuit schematic, but the actual characteristics of a circuit are determined by the layout of its PCB. And the analysis of the grounding point is very difficult, especially for the DC-DC converter circuit, the grounding point of the circuit will gather a large current that changes rapidly. When grounded nodes move, system performance suffers and the system radiates EMI. Here a good understanding of the physical nature of "ground" induced ground noise can provide an intuitive understanding of ground noise reduction problems.The change of the transmission current in the ground loop will generate a magnetic field in the loop. The magnetic field strength is proportional to the current, and the magnetic flux is proportional to the product of the loop area and the magnetic field strength, which is expressed by the formula: Figure 1. Right Hand Rule Suppose there is a sudden break in the current loop, as shown in Figure 2. When the switch is turned off, the magnetic flux disappears, which will generate a large transient voltage along the wire. If part of the wire is a grounding return pin, the voltage referenced to the ground level will have a spike, resulting in a false signal in any circuit that uses that pin as a ground reference. Figure 2. Function of Start Switch The traces on the PCB circuit board are not ideal wires and have resistance. 1 ounce (oz) copper has a resistance of 500 microohms/square, so a 1 amp change in current will only produce a bounce voltage of 500uV/square -- the problem only exists if you use long thin traces or daisy chain grounds or Precision electronic circuits.The best way to reduce ground bounce in a DC-DC switching circuit is to control the magnetic flux variation—minimizing current loop area and loop area variation. The principle of DC-DC circuit buck or boost is to use electronic switches to quickly switch to charge and discharge the energy storage element to achieve voltage conversion, and at the same time change the loop area of the current in the circuit, resulting in ground bounce and electromagnetic radiation.In some cases, as shown in Figure, the current remains constant, while the switching causes a change in the loop area and therefore a change in the magnetic flux. In switching state 1, an ideal voltage source is connected to an ideal current source through an ideal conductor. In addition, current flows in a loop that includes a ground return.In switch state 2, the same current flows in different paths when the switch changes position. The current source is DC and there is no change, but the loop area has changed. A change in the loop area means a change in the magnetic flux, so a voltage is generated. Because the ground loop is part of the change loop. Figure 3. Figure Loop Area In the case of switching changes, the loop area changes. Everywhere along the wire in the lower left, when the current I1 becomes 0, a voltage is generated where the magnetic field disappears. 2.3 Ground Bounce for Buck Converters The buck converter (step-down converter) circuit is very similar to the circuit structure in Figure 3 above, and the circuit of the step-down converter is simplified, as shown in Figure. Figure 4. Step-down Converter Circuit At high frequencies, a large capacitor such as the input capacitor Cin of the step-down converter can be regarded as a DC voltage source. Similarly, an inductor such as the output inductor LBuck can be regarded as a DC current source. These approximations help to visualize understanding and theoretical analysis.As shown in Figure 5, when the switch alternates between the two positions, the change in the path through which the current flows causes a change in the magnetic flux. The large inductor LBuck keeps the output current approximately constant. Similarly, the large capacitor Cin holds the voltage approximately equal to Vin. Since the voltage across the input lead inductance does not change, the input current also remains approximately constant. Figure 5. Effect of Switch on Loop Area Although the input current and output voltage are essentially constant, when the switch is switched from position 1 to position 2, the total loop area rapidly changes by half. Loop area changes imply rapid changes in magnetic flux, causing ground bounce along the loop circuit.In practice, a buck converter consists of a pair of semiconductor electronic switches, as shown in Figure 6. Although the complex procedure increases in each figure, the analysis method for ground bounce caused by changes in magnetic flux remains simple and intuitive. Figure 6. Magnetic Flux Changes Cause Ground Bounce The fact that changes in magnetic flux create voltages along the ground loop raises an interesting question: where is the real ground? Because ground bounce means that, to some ideal point called ground (that point needs to be defined), a bounce voltage is created on the ground return trace. In a power regulator circuit, the real ground should be connected to the low-voltage side of the load. After all, the purpose of a DC-DC converter is to provide a stable voltage and current to the load. All other points on the current loop are not true ground, but the part of ground loop.Since the low-voltage end of the load is grounded and the change in the loop area is the cause of the ground bounce, then reducing the ground bounce and electromagnetic radiation, and optimizing the grounding of the circuit are to minimize the current loop area in the DC-DC circuit. Here is a way to optimize the layout. For example, the location of the input capacitor, output capacitor, and energy storage inductor reduces the current loop area. Figure shows how to carefully place the input capacitor Cin to reduce the loop area and ground bounce. Figure 7. Reduce Ground Bounce Capacitor Cin in Figure bypasses the high-side switch on the top layer of the PCB directly to both ends of the bottom low-side switch, thereby reducing the variation in loop area and isolating it from the ground return. When the switch switches from one state to another, from the bottom of Vin to the bottom of the load, there is no loop area change or switch current change. Therefore no ground bounce occurs in the ground loop.Figure is an unreasonable PCB layout. When the high-side switch is turned on, the DC current flows along the red loop of the outer ring. When the low-side switch is turned on, the DC current flows along the blue loop. It can be seen that this circuit layout produces a large loop change when the switch changes, causing a change in the magnetic flux, resulting in ground bounce and electromagnetic radiation interference. Figure 8. Unreasonable Layout For the clarity, in single-layer PCB routing, even using a second-layer monolithic ground plane cannot solve the bounce caused by grounding. Figure 9 is a simple box to illustrate that the ground plane cannot solve the problem. Here we use a double layer PCB to add a bypass circuit at the top level power line vertical. Figure 9. Ground Floor In the Figure 9 (a), the ground plane is monolithic and uncut. The top layer print current flows through the capacitor, through the via, and to the ground plane. Because AC always flows along the path of least impedance, ground return current returns to the power source around the corners of its path. So when the amplitude or frequency of the current changes, the magnetic field of the current and its loop area change, thereby changing the magnetic flux. The regularity of current flow along the path of least impedance means that ground bounce can occur even with a monolithic ground plane - independent of its conduction.In the Figure 9 (b), a properly cut ground plane limits the return current to minimize loop area, thus greatly reducing ground bounce. Any residual ground bounce voltage developed within the cut return line is isolated from the common ground plane.The PCB layout in Figure 10 uses a double-layer PCB to mount the input capacitor and two switches on islands in the ground plane. This wiring doesn't have to be the best, but it works well and speaks to key points. It should be noted that the loop area surrounded by the red and blue currents is large, but the difference between the two loop areas is small. A small change in loop area means a small change in magnetic flux—small ground bounce. However, in general, keep the loop area small. Figure 10. is just to illustrate the importance of AC current path matching. Figure 10. Converter Layout   Additionally, ground bounce along any ground loop is limited by ground cutting within ground loop islands where magnetic fields and loop areas vary. Also, it may appear at first glance that the input capacitance Cin is not located between the top-level high-side switch and the lower-level low-side switch shown in Figure 10. Although physical proximity can be fine, what really works is the electronic proximity achieved by minimizing the loop area. 2.4 Ground Bounce for Boost Converters A boost converter (step-down converter) is actually a reflection of a buck converter, as shown in Figure 11, where the output capacitor must be placed between the top high-side switch and the bottom low-side switch to minimize loop area change. Figure 11. Changes in Loop Area In the same way that a buck converter places Cvin at a critical position, a boost converter places Cvout at a key position. 2.5 Summery The ground bounce voltage is mainly due to changes in the magnetic flux. In a DC-DC switching power supply, the magnetic flux variation is caused by switching the DC current at high speed between different current loop areas. But careful placement of the buck converter's input capacitors and the boost converter's output capacitors, and a good cut of the ground plane can isolate ground bounce. Pay attention to, it is important to be careful when cutting the ground plane to avoid increasing the loop area for other return currents in the circuit.Another reasonable layout should place the real ground on the bottom layer connecting the load, which will not cause changes in loop area or current. Any other point related to conduction can be called "ground", but it's just a point along the return path.   Ⅲ Useful Concepts for Grounding Analysis If you follow the basic concepts, you will have a clear idea of what will cause ground bounce. Figure 12. shows that two conductors that are perpendicular to each other are not subject to the mutual influence of the magnetic field. Figure 12. Two Conductors Perpendicular to Each Other   The magnetic field lines created around two parallel wires carrying equal currents in the same direction traditionally cancel each other out between the two wires, so the total energy stored by the two wires is less than the energy stored by one wire alone. Therefore, the inductance of PCB wide traces is smaller than that of narrow traces. Figure 13. Two Parallel Wires with Current Flowing in Same Directions   The magnetic field lines generated around two equal conductors carrying equal currents in opposite directions cancel each other out of the two conductors, and strengthen between the two conductors. If the inner loop area is reduced, so does 4the total magnetic flux. This phenomenon can explain why the return current of the AC ground plane always flows under the trace conductors on the top layer of the bath. Figure 14. Two Parallel Wires with Current Flowing in Opposite Directions Figure 15. shows why corners add inductance. A straight wire only sees its own magnetic field, but at the corners, the magnetic field of a vertical wire is also visible. Therefore, the corners store more magnetic field energy, and their inductance is greater than that of straight wires. Figure 15. Add Inductance at the Corners Figure 16. shows that cutting the ground plane under the transmission line conductor increases the loop area by diverting the loop current, thereby increasing the loop size and contributing to ground bounce. Figure 16. Return Current Flows Along the Path of Least Impedance   Figure 17. Effect of Component Orientation   Ⅳ Conclusion Ground bounce has always been a potential problem. For monitors or TVs, it means the image is noisy, for audio equipment it means the noise floor. In digital systems, ground bounce can cause calculation errors -or even system crashes. Careful estimation of parasitic elements and simulation are effective methods for predicting the magnitude of ground bounce.First, when designing the PCB, the low-voltage side of the load should be set to true ground. Then, replace the large inductors and capacitors with current and voltage sources to simplify the circuit dynamics. Observing the current loop under each switch combination, the loops should be made to overlap, and if this is not possible, an island should be carefully cut out in the ground plane to ensure that only islands of DC inflow and outflow are present.In most cases, good grounding performance can be obtained with these efforts. If that doesn't work, the resistance of the ground plane should be considered first, then the displacement currents flowing across all switches and parasitic capacitors entering the return path. In short, no matter what circuit, the principle is the same, that is, to reduce the loop area and its difference when the switch changes.   Ⅴ FAQ 1. Does power supply need to be grounded?While it will likely be fine (I've run many computers in old houses that had no grounding), it's not advised. A static charge will build up, and depending on where it discharges may cause damage to the electronics. 2. What is the purpose of a ground wire?The ground wire offers an additional path for the electrical circuit to flow into the earth so as to not endanger anyone working with the electricity nearby in the event of a short circuit. Without ground wire, your body could instead complete the ground path and may cause shock or electrocution. 3. Which wire is ground on power supply?In a DC circuit, the convention in most of the world is that black is the “ground” and any other color carries a signal or power rail of some sort, with red and yellow being popular for power wiring, but it can really be any color on any particular connector. For example, for a typical PC “ATX” power supply. 4. What is the purpose of a ground?Grounding gives electricity the most effective way to return to the ground via your electrical panel. A grounding wire gives an appliance or electrical device a safe way to discharge excess electricity. 5. Should you ground the negative of a DC power supply?As long as both the negative terminal of the LED and the negative terminal of the battery both have good enough connections to ground then the ground will carry enough current between the two connection to complete the circuit and light the LED. The same applies in the mains electricity supply. 6. How do I know if my power supply is grounded?Insert one probe of the circuit tester into the small slot and the other probe into the large probe. If the circuit tester lights up, you have power to the outlet. Now place one probe in the small slot and the other probe into the "U" shaped ground hole. The indicator should light up if the outlet is grounded. 7. Can you ground yourself by touching PSU?It looks pretty, but it's impossible to ground yourself to a case that has no bare metal. Instead, I just installed my power supply and touched the ground prong every now and then. All that said, if all you're doing is touching a metal part on the computer, you aren't really grounding yourself. 8. Can I tie the neutral and ground together?No, the neutral and ground should never be wired together. This is wrong, and potentially dangerous. When you plug in something in the outlet, the neutral will be live, as it closes the circuit. If the ground is wired to the neutral, the ground of the applicance will also be live. 9. What is ground in DC circuit?Traditionally, "ground" is the lowest potential in a circuit, e.g. the minus side of a battery or DC supply. 10. What happens when electricity goes to ground?The majority of the energy of the lightning discharge is dissipated in the air as it travels from the clouds to the ground through the air. The remainder is dissipated in the ground in the area surrounding the location of the strike, over a fairly short distance. 11. What is difference between earthing and grounding?Earthing and grounding are similar terms. ... The main difference between earthing and grounding is that the earthing refers that the circuit is physically connected to the ground with Zero Volt Potential. But, grounding refers that the circuit is not physically connected to ground, but still has zero potential. 12. Does a DC power supply need a ground?The answer comes from the NEC section 250.162, referring to the grounding of two-wire DC systems, which includes the 5V and 24V outputs, depending on your case. ... So, the short answer for a 24V DC system is no, the output is not required to be connected to ground. 13. How do you ground a DC power supply?You ground the device by connecting a grounding cable to earth ground and then attaching it to the grounding point on the DC power supply. You must provide the grounding cables. The cable lug used on the grounding cable should have a #10 stud hole and accommodate a minimum of 12-AWG wire.

CatalogⅠ IntroductionⅡ DC Power Supply2.1 What is a DC Power Supply?2.2 Types of DC Power Supply2.3 Composition and Operation2.4 Specifications 2.5 Features2.6 Frequently Asked Questions About DC Power SupplyⅢ 5V DC Power Supply3.1 What is the 5V DC Power Supply?3.2 Typical Applications for 5V DC Power Supplies 3.3 Frequently Asked Questions About 5V DC Power SupplyⅣ 12V DC Power Supply4.1 What is the 12V DC power supply?4.2 Typical applications for 12V DC power supplies4.3 Frequently Asked Questions About 12V DC Power SupplyⅤ 24V DC Power Supply5.1 What is the 24V Power Supply? 5.2 What is a 24V Power Supply Used for?5.3 24V Power Supply Requirements & Considerations5.4 What are the Features of a 24V Power Supply?5.5 24V Power Supply Vs. 36V Power Supply5.6 24V Power Supply Problems & Resources5.7 Frequently Asked Questions About 24V DC Power SupplyⅥ Differences Between DC and AC Power Supplies6.1 Characteristics of DC Power Supply6.2 Characteristics of AC power supply6.3 AC Power Supply Vs. DC Power SupplyⅦ How to Choose the Best DC Power SupplyⅠ IntroductionAny electronic system relies on power, and the power supply is what keeps it running. Choosing the correct source can be the difference between a gadget that performs at its best and one that produces inconsistent results. DC to DC converters are available in addition to alternating current (AC) to direct current (DC) power sources. If your system already has DC, a DC to DC converter may be a better design option than the AC mentioned below. There are two types of direct current power supplies: unregulated and regulated. There are various types of regulated supply, including linear, switching, and battery-based. How to Use a Power supplyⅡ DC Power Supply2.1 What is a DC Power Supply?An AC-to-DC converter takes an AC input voltage and converts it to a DC output voltage. The output voltage may contain substantial or negligible quantities of AC frequency components known as ripple voltage, which are connected to the AC input voltage frequency and the power supply's performance, depending on the application requirements. A DC-to-DC converter is a DC power supply that operates on DC input voltage. How to Use a DC Power Supply 2.2 Types of DC Power SupplyThere are mainly four types of DC power supplies: Linear power supply, Switched-mode power supply, Capacitive (transformerless) power supply, Linear regulator. Linear power supplyThe AC input voltage in a linear power supply flows via a power transformer before being rectified and filtered to produce a DC value. Filtering, which can be as simple as a single capacitor or as sophisticated as a pi filter, reduces the amplitude of AC mains frequency present in the rectifier output. The quantity of filtering required by the power supply is determined by the electric load's tolerance for ripple. In other cases, ripple can be completely ignored. In some battery charging applications, for example, the power supply is comprised of a transformer and a diode, with a simple resistor placed at the power supply output to limit the charging current. Figure 1: Simplified block diagram of a programmable linear power supply Switched-mode power supplyThe AC mains input is directly rectified and then filtered to obtain a DC voltage in a switched-mode power supply (SMPS). Electronic switching circuitry switches the resulting DC voltage on and off at a high frequency, producing an AC that passes via a high-frequency transformer or inductor. Switching occurs at a very high frequency (usually 10 kHz — 1 MHz), allowing smaller, lighter, and less expensive transformers and filter capacitors to be used than in linear power supply running at mains frequency. The high-frequency AC is rectified and filtered after the inductor or transformer secondary to create the DC output voltage. The output will be electrically isolated from the mains if the SMPS uses a properly insulated high-frequency transformer; this feature is typically required for safety. Switched-mode power supplies are typically regulated, and a feedback controller monitors the current drawn by the load to keep the output voltage constant. As the power output requirements increase, the switching duty cycle increases. To assist safeguard the device and the user from injury, SMPSs often include safety measures like a current limitation or a crowbar circuit. When a switched-mode supply detects an abnormally high-current power draw, it can presume it's a direct short and shut down before any damage is done. When anomalous supply voltages are present, PC power supplies frequently transmit a power good signal to the motherboard; the absence of this signal prohibits operation. The minimum current output of some SMPSs is set to an absolute maximum. They can only produce electricity above a certain threshold and are unable to function below that threshold. The frequency of the power slicing circuit climbs to a high rate in a no-load condition, leading the isolated transformer to operate as a Tesla coil, causing damage due to the very high voltage power spikes that result. When no load is detected, switched-mode supply with protection circuits may momentarily turn on before shutting off. To allow the supply to run without a primary load, a very modest low-power dummy load, such as a ceramic power resistor or a 10-watt light bulb, can be connected to it. Computer switch-mode power supplies have traditionally had low power factors and have been substantial sources of line interference (due to induced power line harmonics and transients). The input stage of a simple switch-mode power supply can distort the line voltage waveform, causing problems for other loads (and poor power quality for other utility customers), as well as excessive heating in wires and distribution equipment. Customers also pay more for electricity when they use lower power factor loads. Some computer switch-mode power supply conducts power factor adjustment and may use input filters or additional switching stages to prevent line interference to avoid these issues.  Linear DC Power SupplySwitching DC Power SupplySize and WeightLarge transformers are required, which add significant size and weight.If necessary, higher frequencies allow for considerably smaller transformers.EfficiencyTransformer losses are the only important causes of efficiency loss if the system is not regulated. High-power uses, if regulated, will have a significant impact on efficiency.Because they behave like minuscule resistances, transistors have low switching losses. This makes it possible to run high-power applications efficiently.NoiseVoltage ripple can create significant noise in unregulated power supplies, while regulated linear AC DC power systems can have very low noise. They're useful in medical sensing applications because of this.Transistors that switch very quickly produce noise in the circuit. For audio applications, this can be filtered away or the switching frequency can be made exceedingly high, above the limit of human hearing.ComplexityIn comparison to switching DC power supplies, linear DC power supplies feature fewer components and simpler circuits.Because of the additional noise generated by the transformers, massive, complex filters, as well as control and regulation circuitry for the converters, are required. Capacitive (transformerless) power supplyA capacitive power supply (transformerless power supply) reduces the mains voltage to a lower AC voltage by using the reactance of a capacitor. The lowered AC voltage is then typically rectified, filtered, and controlled to produce a steady DC output voltage. The mains voltage is not isolated from the output voltage. As a result, anything connected to the power source must be properly insulated to avoid exposing people and equipment to dangerous high voltage. The voltage reduction capacitor must be able to resist full mains voltage and have sufficient capacitance to handle maximum load current at the rated output voltage. These limits, taken together, limit the practical applicability of this sort of supply to low-power applications. Linear regulatorA linear voltage regulator's job is to convert a fluctuating DC voltage into a fixed, frequently precise, lower DC voltage. They also frequently have a current limiter to safeguard the power source and load from overcurrent (excessive, potentially destructive current). Many power supply applications require a constant output voltage, however the voltage produced by many energy sources varies with changes in load impedance. Furthermore, if the energy source is an unregulated DC power supply, the output voltage will fluctuate with the input voltage. To avoid this, some power supplies use a linear voltage regulator to keep the output voltage constant, regardless of input voltage or load impedance variations. Linear regulators can also lower the magnitude of output voltage ripple and noise. 2.3 Composition and OperationA common DC power supply will be used to demonstrate the general construction of a power supply. As illustrated in the diagram, a basic DC power supply can be constructed using four circuits (or sections), with each block representing a single circuit that performs a certain function. Figure 2: Electrician Training - Integrated Publishing Transformer - The transformer's input is often an AC signal created by a line voltage, such as power from an electric outlet. The primary function of the transformer is to step down (lower the amplitude) or step up (raise the amplitude) the signal to create the necessary DC level at the power supply's output. The transformer can also be used as an isolator. In many applications, it's critical to separate the input AC signal from the device's internal signals. Rectifier - The rectifier receives the signal from the transformer's output. A rectified pulsing DC signal is provided by this device. A half-wave rectifier or a full-wave rectifier can be used. A pulsing DC signal is a voltage or current signal that does not change polarity but has a time-dependent magnitude. Diodes and resistors are commonly used in rectifiers. Filter - A filter is required to transform a pulsing DC signal into a non-pulsating DC signal. In most cases, a simple capacitor filter is sufficient. The filter's output is DC voltage, which typically contains some ripple and slight AC changes. Regulator - The regulator serves two purposes:(1) to smooth the signal from the filter, resulting in a DC signal with no ripples;(2) to maintain a constant voltage at the output.Regardless of changes in the input voltage or the load, the voltage at the regulator's output remains constant (not shown in the diagram). The conversion of a 115 V(RMS) signal to a constant 110 V(DC) voltage is shown in the accompanying image to demonstrate the four steps or blocks required to create a DC voltage from a line voltage. Figure 3: Electrician Training - Integrated Publishing 2.4 SpecificationsMany parameters are required to completely characterize a power supply; nevertheless, there are a set of parameters that are common to most power supply types. Input and output voltages (in volts [V]), output current (in amps [A]), rated output power (in watts [W]), input signal frequency (in Hertz [Hz], kilohertz [kHz], or megahertz [MHz]), and regulation are all examples. Input voltageis the magnitude and type of the voltage applied to the power supply.Input frequencyis the frequency of the input signal.Output voltageis the magnitude of the DC voltage at the output of the device.Output currentis the current associated with the output voltage.Output poweris the power (in watts) delivered to the load.Regulationindicates the stability of the output voltage.Line regulationis the maximum steady-state amount that the output voltage changes as a result of a specified change in input line voltage.Load regulation is the maximum steady-state amount that the output voltage changes as a result of a specified change in load. Mounting requirements are less important, but they should be considered if the power supply is to be appropriately fitted to the application or system. There are several mounting solutions available, including: Board mountCircuit mountWall mountDIN rail mountRack mountDesktop 2.5 FeaturesDC power supplies have extra features like circuit protection and cooling, which might be useful in certain situations. DC power supply' performance and/or physical integrity can be influenced by several factors. Normally, circuits that protect the power supplies are built into the device's design and construction. Here are a few examples: Short circuit protectionOverload protectionOver current protectionOver voltage protectionUnder voltage protectionOver temperature protection Several cooling methods are used to protect DC power supplies: Fan coolingHeat sink coolingWater cooling DC power supplies can also incorporate a number of other features: Battery backupHot swappablePower factor correctionTemperature compensationWeatherproof 2.6 Frequently Asked Questions About DC Power Supply1.What are DC power supplies used for?The main job of an AC/DC power supply is to transform the alternating current (AC) into a stable direct current (DC) voltage, which can then be used to power different electrical devices. Alternating current is used to transport electric power all across the electric grid, from generators to end users. 2.Why is a DC power supply needed?A DC power supply is used by engineers to test a component, circuit or electronic device, such as IoT devices, medical products, mobile phones, and remote industrial sensors. The DC power supply allows engineers to set and supply specific voltages to power the device to confirm it’s working as intended. 3.What is the difference between AC and DC power supply?In direct current (DC), the electric charge (current) only flows in one direction. Electric charge in alternating current (AC), on the other hand, changes direction periodically. 4.How do you use a DC power supply?A DC power supply is easy to use. These instruments connect to a device that’s being tested via leads that are inserted into the DC power supply panel. Using the front panel display, engineers can set voltages or current levels to power the device for testing. 5.How does a DC power supply work?A DC power supply works by providing a regulated direct current to power a component, module, or device. Most DC power supplies have two modes of operation. In Constant Voltage (CV) mode, the power supply controls the output voltage based on the user settings. In Constant Current (CC) mode, the power supply regulates the current. 6.What type of power supply reduces the mains voltage to a lower AC voltage?linear voltage regulator 7.What do linear voltage regulators often have to protect the power source and load from overcurrent?current limiter 8.What do many power supply applications require?constant output voltage 9.What happens when the output voltage fluctuates with the input voltage?if the energy source is an unregulated DC power supply 10.What do some power supplies use to keep the output voltage constant?a linear voltage regulator 11.What can lower the magnitude of output voltage ripple and noise?Linear regulators 12.How can a basic DC power supply be constructed?four circuits (or sections) Ⅲ 5V DC Power Supply3.1 What is the 5V DC Power Supply?One of the most prevalent power sources in use today is the 5V power supply (sometimes known as a 5V DC power supply). Using a mixture of transformers, diodes, and transistors, a 5V DC output can be generated from a 50V AC or 240V AC input. There are two types of 5V power supplies: regulated 5V power supplies and unregulated 5V power supplies. Switching regulated AC to DC, Linear regulated AC to DC, and Switching regulated DC to DC are the three types of 5V regulated power supply. 5V DC power supply Switching regulated 5V DC power supplies, also known as SMPS power supplies, switchers, or switched-mode power supplies, use a complicated high-frequency switching technology that includes pulse width modulation and feedback to regulate the 5V DC output voltage. To reduce common and differential mode noise conveyed to the line and load, switching regulated power supply uses significant EMI filtering and shielding. Our 5V DC switchers come with galvanic isolation as standard, giving our customers input to output and output to ground isolation for optimum versatility. Switching regulated power supplies are very efficient, tiny, and light, and come in AC-DC single and wide-adjust output, as well as DC-DC, variants. Our Low Profile broad adjust output switchers are externally programmed and can be voltage or current regulated. A dissipative regulating circuit regulates the output of linear regulated 5V DC power sources. They are exceedingly stable, have very minimal ripple, and do not create EMI due to switching frequencies. Our 5V DC linears come with galvanic isolation as standard, giving our customers input to output and output to ground isolation for optimum flexibility. AC to DC single and broad adjust output linear regulated power supplies are provided. Basic power sources with an AC input and an unregulated 5V DC output are known as unregulated 5V DC power supplies. The output voltage is affected by the input voltage as well as the load. These power supplies are both affordable and dependable. 3.2 Typical Applications for 5V DC Power Supplies Industrial automationTTL circuit powerPrecision control circuitsResearch projects 3.3 Frequently Asked Questions About 5V DC Power Supply1.What does 5V DC mean?DC 5V/2A, means that the input voltage, to recharge the battery is 5 volts of direct current. It has two outputs, one 2.1A USB (for tablets and Raspberry Pi and high-current devices, the other 1A USB for phones and smaller devices. 2.Can I use a 12V power supply on a 5V device?The device will very likely burn out. In addition, depending on what the device is and the capacity of the 12V supply, connecting a 12V supply to a device rated 5V max could lead to a hazard - fire, explosion, etc. Mostly it will get damaged. 3.What is the difference between 5V and 12V?The main disadvantage of the 5V system is that voltage drop is a more significant limiting factor. However 5V systems are much more power efficient than 12V systems; a 5V linear system will always be 2.4 times more efficient than it's equivalent 12V system. Ⅳ 12V DC Power Supply4.1 What is the 12V DC power supply?One of the most prevalent power sources in use today is 12V power supplies (or 12V DC power supplies). A combination of transformers, diodes, and transistors is used to generate a 12V DC output from a 120V AC or 240V AC input. There are two types of 12V power supplies: 12V regulated power supplies and 12V unregulated power supplies. Switching regulated AC to DC. Linear regulated AC to DC, and Switching regulated DC to DC are the three types of 12V regulated power supply. How does a modern Power Supply work? Switching regulated 12V DC power supplies, also known as SMPS power supplies, switchers, or switched-mode power supplies, use a complicated high-frequency switching technology that includes pulse width modulation and feedback to regulate the 12V DC output voltage. To reduce common and differential mode noise conveyed to the line and load, switching regulated power supply uses significant EMI filtering and shielding. Our 12V DC switchers come with galvanic isolation as standard, giving our customers  input to output and output to ground isolation for optimum versatility. Switching regulated power supplies are very efficient, tiny, and light, and come in  AC-DC single and wide-adjust output, as well as DC-DC variants. Our Low Profile broad adjust output switchers are externally programmed and can be voltage or current-regulated. A dissipative regulating circuit regulates the output of linear regulated 12V DC power sources. They are exceedingly stable, have very minimal ripple, and do not create EMI due to switching frequencies. Our 12V DC linears come with galvanic isolation as standard, giving our customers input to output and output to ground isolation for optimum flexibility. AC to DC single and broad adjust output linear regulated power supplies are provided. Basic power sources with an AC input and an unregulated 12V DC output are known as uncontrolled 12V DC power supplies. The output voltage is affected by the input voltage as well as the load. These power supplies are both affordable and dependable. 4.2 Typical applications for 12V DC power suppliesComputer Peripherals and Networking ApplicationsTelecommunications and Fiber optic NetworkVoice, Data and Analog CommunicationsUniversities and Educational FacilitiesInstrumentation and ElectronicsUtility and Power IndustriesData AcquisitionMedicalMilitaryMotor control 4.3 Frequently Asked Questions About 12V DC Power Supply1.How do you make a 12V DC power supply?Things that you will need to make this power supply is:Piece of veroboardFour 1N4001 diodesLM7812 regulatorTransformer that has an output of 14v - 35v AC with an output current between 100mA to 1A, depending how much power you will need. (I found a 16v 200mA transformer in a broken alarm clock.)1000uF - 4700uF capacitor1uF capacitorTwo 100nF capacitorsJumper wires (I used some plain wire as jumper wires)Heatsink (optional) 2.Is 12V AC the same as 12V DC?12V DC is safer than 12V AC. Body resistance decreased when the 12V AC still may cause the dead, 12V DC will not be in 100%. However, the hazard degree of electric shock to the human body mainly depends on the size of the current passing through the human body and the length of the energization time. 3.What is DC 12V input?12V power supply is one of the most common power supplies in use at present. In general, a 12V DC output is obtained from a 100VAC-277VAC input using a combination of transformers,12V power supplies can be of two types: 12V constant power supplies, and 12V unconstant power supplies. 4.Can I use a 9V power supply on a 12V?It depends on whether your power supply is regulated. If you need regulated (stable) 12V, and the 9V supply is unregulated, it could give you up to 14V or slightly higher when not loaded. 5.Can I use a 12V power supply on a 15V?Assuming the polarity is correct, plugging in a 12V input to a device requiring 15V won't do any damage, however if you undervolt an amplifier, you may get clipping or other distortion. 6.How do you convert 12V DC to 6V DC?It's possible to step 12 volts down to 6 volts by incorporating a pair of 10,000-ohm resistors into the circuit. Cut two lengths of wire, and strip each wire of 1/2 inch of insulation at each end. Attach one end of the first wire to the positive terminal on the power supply. 7.Can I use a 19V power supply on a 12V?Any device that was designed to run at 12V is likely to be fried by 19V. It might catch fire, even though it's not very likely. You must have an equal or higher current rating in order to use an AC adapter. Ⅴ 24V DC Power Supply5.1 What is the 24V Power Supply?A power supply with a voltage of 24 volts can convert AC to DC. The voltage level can be modified at the same time as the AC power is converted to DC power. Some gadgets require DC, although they only have access to AC from the wall. This adjustment is simple to do using the 24V power supply. A DC power supply is an economical and effective alternative in locations where AC power is not available. How to Make 24 Volt Power Supply 5.2 What is a 24V Power Supply Used for?A power supply with a voltage of 24 volts can be utilized in a variety of applications. The 24V supply could be a useful solution whenever an object requires power. Although we usually think of a 24V Power Supply as being utilized on a building site or in the workplace, it has a variety of additional uses. A 24V power source is required in many audio and lighting scenarios. In addition, medical and communication difficulties may necessitate the usage of a 24V power supply. Power supplies are usually compact and can be a relatively portable solution to a problem. The 24V power supply has a wide range of applications. 5.3 24V Power Supply Requirements & ConsiderationsThere are various factors to consider while selecting a 24V Power Supply. Check to see if the device you need to power is compatible with the power supply you buy. Input Voltage & Output VoltageThe output range of a power supply will vary substantially depending on the input voltage. You'll need to make sure you get a 24V power supply with the right voltage range. The longer the range, the more expensive the device will be in general. Power RatingWatts will be used to determine the power rating. Some of the smaller units will have an output of around 80 watts, while the larger ones will be closer to 1000 watts. Keep in mind that certain 24V Power Supplies are designed for light-duty industrial use, while others are designed for heavy-duty industrial use. Make sure you get a power source that meets your requirements. 5.4 What are the Features of a 24V Power Supply?To get the most out of your equipment purchase, it's critical to grasp the features of a 24V power supply. The many output ports and the consistent power supply are three things to be aware of. The 24V power supply's combination of qualities is what makes it so beneficial to its users. Multiple Output PortsThe majority of the 24V power supply includes many outputs. In most cases, one output is insufficient to complete the task. Consider setting up audio equipment with the 24V power supply. One output, without a doubt, will not suffice. The majority of 24V power supplies will offer two or three options. When there are many output ports, you should be able to specify voltage restrictions and even timings to help you regulate whatever is attached to the output ports. Overall, if you're going to buy a 24V power supply, you should go for one that has numerous output ports. ProgrammableMany of the 24V power sources on the market today can be programmed. This implies you can use them with a computer system for product setup and testing. This is critical for medical applications as well as light and audio. With higher-end equipment, the programmability of the 24V power supply will become more sophisticated. Some of the basic programmability is simple enough for a layperson to understand. Constant Voltage Power SupplyA 24V power supply can be mounted to provide backup power to a region that isn't getting enough power. On your power supply, you can choose the required voltage and maximum current for the load. The 24V power supply is an excellent choice in circumstances where steady power is required. Many users consider these to be extremely valuable and dependable pieces of gear. 5.5 24V Power Supply Vs. 36V Power SupplyWhen picking a power source for your project, a higher voltage is usually the better option. The higher voltage can do more and create better outcomes, but your system must be able to manage the additional voltage. When electricity is not restricted, the difference in these additional 12 volts of power might cause damage. Before determining that more is better, make sure that everything will function together well. 5.6 24V Power Supply Problems & ResourcesDamage occurs, but it is frequently repairable. People's largest problem with power supplies is that they aren't installed and put together correctly. You must comprehend what the 24V power source, ground, output, and other components entail. Make sure the process is set up appropriately, and you should have fewer issues with this resource in the long run. If you're having trouble with a 24V power supply, electricians and programmers are usually well-versed on how to get the most out of one. 5.7 Frequently Asked Questions About 24V DC Power Supply1.Can I use a 12V power supply on a 24V?Going the other way - 24V LED strips on a 12V power supplyIf you're trying to go the other way and connect a 12V power supply to operate 24V LED strips, unfortunately, you are out of luck. You'll need to purchase a transformer or voltage booster, or, more straightforwardly, a 24V power supply. 2.Can I use 24V AC for 24V DC?24 volt AC/DC converters with 19 to 28V AC input. These are also known as 24 volt rectifiers, and voltage regulators. They can be used whenever 24V AC power is available and 24V DC power is needed, up to 60 watts. 3.Can I use a 19V power supply on a 24V?As long as the adapter can supply as much or more than the device needs, you're good. Attaching an adapter to a device that needs more current than it can supply will likely damage the adapter. Ⅵ Differences Between DC and AC Power Supplies6.1 Characteristics of DC Power SupplyThe advantages and disadvantages of direct current, in which electricity always flows in the same direction, are as follows. The direction of the current in alternating current is constantly changing. As a result, when a capacitor or inductor is used in the circuit, the current flowing to the load is delayed or advanced in proportion to the voltage behavior. The voltage and direction of the current are always constant with direct current, therefore the behavior of the capacitors and coils is also consistent. As a result, there is no advance or delay in the circuit in DC. Because the direction of the current is shifted in alternating current (AC), not all of the electricity travels through the load, and some power is generated simply passing back and forth between the load and the power source. This is referred to as reactive power. Because the current runs in a consistent direction, all electricity goes through the load in direct current. A scallop is being pushed out in this photograph. As a result, no reactive power is generated, allowing power to be used more efficiently. Another benefit of direct current is that it may be stored in batteries, capacitors, and other devices. Direct current, on the other hand, has several drawbacks. One of them is that interrupting the current is difficult. Because the direct current is always subjected to a constant voltage, particularly when the voltage is high, problems such as arcs (sparks) may arise at the point of interruption, or there may be a risk of electric shock in the immediate vicinity. When the voltage changes from positive to negative or negative to positive in alternating current, the voltage drops to zero for a brief duration. You can interrupt the current more safely than with a direct current if you aim for a time when the voltage is low. In addition, while converting DC voltage, it must first be converted to AC and then back to DC. As a result, DC voltage conversion equipment is larger and more expensive than AC voltage conversion equipment. The severe corrosion of subterranean pipes and insulators necessary for electricity transmission is another downside of direct current. Because DC continually flows in the same direction, electrostatic induction and electrical corrosion cause power transmission equipment to corrode. Direct current is what comes out of batteries, capacitors, and other stored objects. As a result, battery-powered products are compatible with direct current. The power supply in an average home, on the other hand, is AC, while DC is used in electronic equipment like computers and home appliances like televisions. The AC from the outlet is converted to DC using capacitors and other devices to power such devices. However, in data centers where DC is primarily used, the installation of a DC power supply is encouraged to minimize the loss caused by the conversion of AC to DC. 6.2 Characteristics of AC power supplyDirect current is what comes out of batteries, capacitors, and other stored objects. As a result, battery-powered products are compatible with direct current. The power supply in an average home, on the other hand, is AC, while DC is used in electronic equipment like computers and home appliances like televisions. The AC from the outlet is converted to DC using capacitors and other devices to power such devices. However, in data centers where DC is primarily used, the installation of a DC power supply is encouraged to minimize the loss caused by the conversion of AC to DC. For example, if you need 3000W (watts) of power, you'll need 30A (amperes) of current if the voltage is 100V, but only 3A if the voltage is 1000V. In other words, if the voltage is increased by a factor of 10, the current is lowered to 1/10, and the power loss is reduced to 1/100, or the square of 1/10. As a result, for long-distance transmission, extremely high voltages are utilized. Of course, the current-voltage is unsuitable for usage in houses and workplaces. For major factories, the voltage is 100,000 volts, for buildings, it is 6600 volts, and for houses and offices, it is 200 volts or 100 volts. As a result, the voltage of electricity transmitted from a power plant must be reduced to suit the region or location. In comparison to direct current, alternating current can be easily changed by transformers, making it more appropriate for power distribution as infrastructure. Another benefit of AC is that it is simple to shut off while electricity is being delivered, as the voltage lowers to zero at regular intervals. It can also be used like a domestic power supply (outlet) without discriminating between positive and negative, making device connection and operation easier. Because the voltage value is constantly changing and there are periods when the voltage dips to zero, AC requires a higher voltage than the target voltage for the required amount of heat. AC voltage has a sinusoidal waveform with a maximum voltage of 2 times the running value. The effective value must be exceeded by the insulation performance and equipment standards. Another feature of AC is that coils and capacitors have a significant impact on it. Coils and capacitors provide voltages that induce current to flow in the opposite direction of the current flow, causing the current to advance or lag in the circuit. Alternating current electricity is created and sent to a power plant. Three AC waves are sent out at the same time at a power plant, with the waveform of the AC altered by 120 degrees. A three-phase alternating current is a name for this sort of power. There are two types of air conditioners: single-phase and three-phase. A three-phase AC is utilized for high-voltage power transmission in particular. It is converted to one phase, along with the voltage conversion, when it is supplied to a residential outlet. AC is used in standard power outlets and for motors that do not require precise control, such as vacuum cleaners and ventilation fans. Motors for air conditioners, washing machines, refrigerators, and other appliances, on the other hand, do not use AC power as is, but instead need inverters for fine control. 6.3 AC Power Supply Vs. DC Power Supply Alternating Current Direct CurrentAmount of energy that can be carriedIt's safe to transport over greater distances in the city and can deliver more power.DC voltage can only travel so far before it starts to lose energy.Cause of the direction of flow of electronsRotating magnet along the wire.Steady magnetism along the wire.FrequencyDepending on the country, the frequency of alternating current is 50Hz or 60Hz.The frequency of direct current is zero.DirectionWhile passing through a circuit, it reverses its direction.It flows in one direction in the circuit.CurrentIt is the current of magnitude varying with timeIt is the current of constant magnitude.Flow of ElectronsElectrons alternate between forward and backward motion.Electrons move steadily in one direction or 'forward'.Obtained fromA.C Generator and mains.Cell or Battery.Passive ParametersImpedance.Resistance onlyPower FactorLies between 0 & 1.it is always 1.TypesSinusoidal, Trapezoidal, Triangular, Square.Pure and pulsating. Ⅶ How to Choose the Best DC Power SupplyThe most common selection criteria are:Number of output channels (single or multi output)Output voltage, current, and powerSetting resolution and accuracyRipple and noiseFeatures and programmabilityAdvanced features like current measurement with nanoamp resolution, sequencing, analog inputs, digital I/O, and  programming features 

ⅠIntroduction The most common system is single-phase, which is mostly used in homes, whereas three-phase is commonly used in industrial or commercial buildings where heavy loads of power are required. Catalog ⅠIntroduction Ⅱ Three-phase Power Related Video: Ⅲ Single-phase AC Power Basics 3.1 What is Single-phase AC power? 3.2 Advantages of Single-phase 3.3 Disadvantages of Single-phase   Ⅳ 3-phase Power Explained 4.1 What is 3-phase Power? 4.2 Advantages of Three-Phase System 4.3 Disadvantages of Three-Phase System Ⅴ Why We Need 3-phase Power？ Ⅵ What Are the Differences Between Single-Phase Power and Three-Phase Power? Ⅶ FAQ   Ⅱ Three-phase Power Related Video: Three-Phase Power Explained   Three-phase Video Description: This video will take a close look at three-phase power and explain how it works. Three-phase power can be defined as the common method of alternating current power generation, transmission, and distribution. It is a type of polyphase system, and is the most common method used by electric grids worldwide to transfer power.   Ⅲ Single-phase AC Power Basics Single-phase electric power is the distribution of alternating current electric power using a system in which all of the supply voltages vary in unison. When the loads are mostly lighting and heating, with only a few large electric motors, single-phase distribution is used.   3.1 What is Single-phase AC power? Before delving into that topic, it's a good idea to first understand single-phase alternating current (AC). Single-phase alternating current (AC) power is delivered via a three-wire system consisting of one "hot" wire, one neutral wire, and one ground wire. With alternating current power, the power current or voltage reverses on a regular basis, flowing one way on the hot wire that supplies power to the load and the other way on the neutral wire. During a 360-degree phase change, a full power cycle occurs, and the voltage reverses itself 50 or 60 times per second, depending on the system in use in different parts of the world. It is 60 times or 60 hertz in North America (Hz). It is critical to note that the two current-carrying legs are always 180 degrees apart. Consider the power as riding a wave, specifically a sine wave with a defined frequency and amplitude. During each cycle, the waves on each wire pass through zero amplitude twice (see Figure 1). There is no power delivered to the load during these times. Figure1:Single-phase   These brief interruptions have no effect on residential and commercial building applications such as office environments, but they have serious consequences for the motors that power large machinery, as well as computers and other IT equipment.   3.2 Advantages of Single-phase Single-phase connections are designed for household supplies and residential homes. This is due to the fact that most appliances, such as televisions, lights, fans, refrigerators, and so on, require only a small amount of electricity to function.A single-phase connection works in a straightforward manner. It consists of a compact and lightweight unit in which the flow of electricity through the wires is reduced as the voltage increases.Because of the power reduction, it ensures that the power from a single-phase connection operates at peak efficiency and effectively transmits power.A single-phase connection is best suited for units rated up to 5 horsepower.   3.3 Disadvantages of Single-phase     Ⅳ 3-phase Power Explained Three-phase electric power (abbreviated 3), is a type of alternating current that is commonly used in power generation, transmission, and distribution. It is a type of polyphase system that uses three wires (or four if a neutral return wire is used) and is the most common method used by electrical grids around the world to transfer power.   4.1 What is 3-phase Power? As the name implies, three separate currents are provided by three-phase power systems, each separated by one-third of the time it takes to complete a full cycle. However, unlike single-phase, where the two hot legs are always 180 degrees apart, the currents in 3-phase are separated by 120 degrees. Figure 2 shows that when one line is at its peak current, the other two are not. When phase 1 reaches its positive peak, phases 2 and 3 are both at -0.5. In contrast to single-phase current, there is no point at which no power is delivered to the load. In fact, one of the lines is at a peak positive or negative position at six different points in each phase. In practice, this means that the total amount of power supplied by all three currents remains constant; there are no cyclical peaks and valleys as with single-phase. Many computers and motors used in heavy machinery are built with this in mind. Instead of having to account for the variation inherent in single-phase AC power, they can draw a steady stream of constant power. They use less energy as a result. Consider the difference between a single-cylinder and a three-cylinder engine. Both use a four-stroke engine (intake, compression, power, exhaust). With a single-cylinder engine, you only get one "power" cycle for every four-cylinder stroke, resulting in rather uneven power delivery. A three-stroke engine, on the other hand, produces power in three alternating phases (again separated by 120 degrees), resulting in smoother, more consistent, and efficient power. Figure2:Three-phase 4.2 Advantages of Three Phase System There are numerous reasons why this power is preferable to single-phase power. The single phase power equation is   Figure3: single phase power equation Which is a function that changes over time. In contrast, the three-phase power equation is   Figure4: three-phase power equation Which is a constant function that is independent of time. As a result, the single-phase power is pulsing. This has no effect on low-rated motors, but it causes excessive vibration in higher-rated motors. As a result, three-phase power is preferable for high-tension power loads. A three-phase machine has a 1.5 times higher rating than a single-phase machine of the same size. Because single-phase induction motors have no starting torque, we must provide an auxiliary means of starting, whereas three-phase induction motors are self-starting and do not require any auxiliary means. In the case of a three-phase system, the power factor and efficiency are both higher. Which is a constant function that is independent of time. As a result, the single-phase power is pulsing. This has no effect on low-rated motors, but it causes excessive vibration in higher-rated motors. As a result, three-phase power is preferable for high-tension power loads. A three-phase machine has a 1.5 times higher rating than a single-phase machine of the same size. Because single-phase induction motors have no starting torque, we must provide an auxiliary means of starting, whereas three-phase induction motors are self-starting and do not require any auxiliary means. In the case of a three-phase system, the power factor and efficiency are both higher.   4.3 Disadvantages of 3-phase Power The most significant disadvantage of a three-phase connection is that it cannot handle the overload. As a result, it may cause damage to the equipment, increasing the likelihood of costly repairs. This is due to the high cost of individual components. Because the unit voltage is so high, a three-phase power connection necessitates a significant investment in insulation. Insulation varies with voltage, and wire size is determined by power distribution.   Ⅴ Why We Need 3-phase Power？ The ability to deliver ever-increasing amounts of power is especially important as data centers and server rooms become denser. More powerful computing systems are being crammed into the same spaces that once housed servers that used a fraction of the electrical power that today's computers and networks require. Not long ago, a single IT rack of ten servers would consume a total of five kilowatts (kW). Today, that same rack may house dozens of servers, each drawing 20 or 30 kW. At those levels, efficiency is important, as even a small percentage improvement in power consumption will result in significant dollar savings over time. Another issue is wiring. Take a look at a 15 kW rack. Using single-phase power at 120 volts AC (VAC), it takes 125 amps to power the rack, which would necessitate a wire almost one-quarter inch in diameter (AWG 4) — too thick to work with easily, let alone affordably. Because three-phase is more efficient, it can deliver the same amount of power (and more) while using less wiring. To support the same 15 kW rack with 3-phase power, three wires capable of supplying 42 amps (AWG 10) are required, each less than one-tenth of an inch in diameter.   Ⅵ What Are the Differences Between Single-Phase Power and Three-Phase Power? The following are the key distinctions between a single-phase and three-phase connection. Ⅶ FAQ 1. How is 3phase power generated? Electric power is generated as three phase alternating current (AC) by turning mechanical turbines from the forces of water, steam, or other means in order to turn generators, thereby, converting the mechanical energy into electric energy. In the US, generators turn at 60 revolutions per second or at 60 hertz (Hz). 2. Why does three phase not need a neutral? A neutral wire allows the three phase system to use a higher voltage while still supporting lower voltage single phase appliances. In high voltage distribution situations it is common not to have a neutral wire as the loads can simply be connected between phases (phase-phase connection). 3. How many wires does 3 phase have? four wires Three-phase has four wires: three actives (called phases) and one neutral. The neutral wire is earthed at the switchboard. 4. How do you make 3 phase voltage? In a 3 phase system, there are three equal voltages or EMFs of the same frequency having a phase difference of 120 degrees. These voltages can be produced by a three-phase AC generator having three identical windings displaced apart from each other by 120 degrees electrical. 5. Does three-phase need a ground? Does the National Electrical Code (NEC) require a 480-volt (V), three-phase, 3-wire, delta-connected system to be grounded? No, it is optional. This article examines the NEC's electrical-system grounding provision. 6. What is the symbol for 3 phase? A three-phase system may be arranged in delta (∆) or star (Y) (also denoted as wye in some areas). 7.Is 240V single phase or 3 phase? 240V power is used in the US and parts of the world. In the US 120 / 240V 1 Phase 3 Wire is the standard for homes and 240V 3 Phase Open Delta is the standard for small buildings with large loads. In parts of the world 240V Single Phase 2 Wire is the standard for homes. 8. What is the value of 3 phase voltage? 3 phase system is expressed with line voltages. The line votage is 440 volt. Also the voltage between any one phase and neutral for a 3 phase system is 240 volts. 9. What is single-phase power used for? Single-Phase Power generates electricity to residential homes and domestic supplies, since most appliances require only a small amount of power to function, including fans, heaters, television, refrigerator, and lights. 10. Why does single phase have 2 wires? Two hot wires and one neutral wire provide the power. Each hot wire provides 120 volts of electricity. The neutral is tapped off from the transformer. A two-phase circuit probably exists because most water heaters, stoves and clothes dryers require 240 volts to operate. 11. Can we use 2 AC in single phase? You can, yes. The main MCB has a current rating of at least 25 ampere. If you use 1.5 ac, it has max load current of 7 to 8 amperes for a single ac, and the MCB size is to be selected. 12.Is 240 volt single-phase? Single Phase 120/240 It may also be called Split Phase 240. This configuration consists of 2 voltage legs that are 180 degrees apart. The voltage between the two legs (called phase to phase or line to line) is 240V and the phase to neutral voltage is 120V.