The Kynix Blog

What is a coupling capacitor?In electronics, capacitive coupling is a type of electronic coupling, which uses capacitance between circuits to transfer energy. This coupling design can produce expected effects, and may also produce some accidental effects. Capacitive coupling usually involves placing capacitors in series circuits to achieve signal coupling.Next, this blog will briefly introduce you the basic information of coupling capacitors, mainly from the following six aspects: definition, coupling, decoupling, coupling mode, principle, and function.What is Coupling Capacitor?CatalogI Definition of coupling capacitorII CouplingIII DecouplingIV Coupling method4.1 Direct coupling4.2 Common impedance coupling4.3 Capacitive coupling4.4 Electromagnetic induction coupling4.5 Radiation coupling4.6 Leakage couplingV Working Principle of Coupling CapacitorVI The role of capacitive couplingFAQI Definition of coupling capacitorCoupling capacitance, also known as electric field coupling or electrostatic coupling, is a coupling method due to the existence of distributed capacitance.Coupling capacitors make the two systems of strong and weak currents coupled and isolated by capacitors, provide high-frequency signal paths, prevent low-frequency currents from entering the weak current system, and ensure personal safety. In addition to the above functions, the coupling capacitor with voltage extraction device can also extract power frequency voltage for protection and reclosing use, and play the role of a voltage transformer.Coupling capacitor II CouplingCoupling refers to the process of signal transmission from the first stage to the second stage, and usually refers to AC coupling when it is not specified.From the circuit point of view, it can always be divided into the driving power supply and the driven load. If the load capacitance is relatively large, the drive circuit must charge and discharge the capacitance to complete the signal jump. When the rising edge is relatively steep, the current is relatively large, so that the drive current will absorb a large power supply current. The inductance and resistance (especially the inductance on the chip pins will bounce). Compared with normal conditions, this current is actually a kind of noise, which will affect the normal operation of the previous stage. This is coupling.Red WIMA CAPIII DecouplingDecoupling refers to taking further filtering measures to the power supply to remove the influence of mutual interference between the two levels of signals through the power supply.The coupling constant refers to the time constant corresponding to the product of the coupling capacitance value and the second-stage input impedance value.The purpose of decoupling1. Remove the high-frequency ripple in the power supply, and cut off the high-frequency signal of the multi-stage amplifier through the crosstalk path of the power supply;2. When working with a large signal, the circuit's demand for power increases, causing power fluctuations, and the influence of power fluctuations on the input stage/high voltage gain stage when the large signal is reduced by decoupling;3. Form a floating ground or floating power supply, and complete the coordination of each part of the ground or power supply in a complex system. The high-frequency switching noise generated by the active device during switching will propagate along the power line. The main function of the decoupling capacitor is to provide a local DC power supply to the active device to reduce the propagation of switching noise on the board and to guide the noise to the ground.WEST-CAPIV Coupling methodThe interference signal generated by the interference source causes electromagnetic interference to the electronic control system through a certain coupling channel. The coupling method of interference is nothing more than acting on the electronic control system through wires, spaces, common lines, etc. There are mainly the following:4.1 Direct couplingDirect coupling is the most direct way of interference intrusion, and it is also the most common way in the system. For example, interference signals directly invade the system through wires and cause interference to the system. For this coupling method, filtering and decoupling can be used to effectively suppress the introduction of electromagnetic interference signals. 4.2 Common impedance couplingCommon impedance coupling is a common coupling method. It often happens when the currents of two circuits have a common path. Common impedance coupling has two types: common ground and power supply impedance. To prevent this coupling, the coupling impedance should be close to zero, so that there is no common impedance between the interference source and the interfered object. 4.3 Capacitive couplingCapacitive coupling, also known as electric field coupling or electrostatic coupling, is a coupling method due to the existence of distributed capacitance. 4.4 Electromagnetic induction couplingElectromagnetic induction coupling is also called magnetic field coupling. It is a coupling method induced by the electromagnetic field in the internal or external space. The common method to prevent this coupling is to shield devices or circuits that are susceptible to interference. 4.5 Radiation couplingThe electromagnetic field radiation can also cause interference coupling, which is an irregular interference. This kind of interference is easily transmitted to the system through the power line. In addition, when the signal transmission line is long, they can radiate and receive interference waves, which is called the antenna effect. 4.6 Leakage couplingThe so-called leakage coupling is resistive coupling. This interference often occurs when the insulation is reduced.Black beautyV Working Principle of Coupling CapacitorWhen the capacitor is connected to the AC circuit, the voltage of the circuit connected to a pin gradually rises, and gradually accumulates charge on the plate where it is located. When the voltage of the circuit connected to the pin drops, the charge accumulated when the potential is high returns to the circuit.TCC V-CAPThe same goes for the other end. The capacitor is insulated, and no current flows through the entire capacitor, but the phenomenon that it accumulates and releases charges as the potential rises and falls, which makes people mistakenly believe that there is current passing. Therefore, it can isolate the DC.The AC signal is coupled to the following circuit components in the form of increasing and decreasing potential at both ends. Capacitors have the characteristics of passing AC and blocking DC. As a coupling capacitor, its function is to allow AC signals to pass normally, while blocking the DC current of the previous amplifier circuit, so that it will not affect the operating point of the next amplifier circuit.Why can the capacitor make the AC current flow and the DC current cannot flow? The two plates of the capacitor can store charge but do not form a loop. The DC current can charge the capacitor, but when the voltage across the capacitor is the same as the power supply voltage, the circuit stabilizes. Therefore, no current will flow; the positive half cycle of the alternating current charges the capacitor, and the negative half cycle first discharges the capacitor. Such continuous charging and discharging are equivalent to current flowing through the capacitor to form a path. VI The role of capacitive couplingThe function of capacitive coupling is to transfer the AC signal from the previous stage to the next stage.Coupling methods include direct coupling and transformer coupling. The direct coupling efficiency is the highest, and the signal is not distorted. However, the adjustment of the working points of the front and rear stages is more complicated and involves each other. In order to prevent the working point of the latter stage from being affected by the previous stage, it is necessary to separate the former stage from the latter stage in terms of direct current.SPRAGUE VQ V-CAPAt the same time, the AC signal can be smoothly transmitted from the previous stage to the next stage. At the same time, the way to accomplish this task is to use capacitor transmission or transformer transmission to achieve. They can transmit AC signals and block DC, so that the working points of the front and rear stages are not involved in each other. But the difference is that when using a capacitor to transmit, the phase of the signal will be delayed, and when using a transformer, the high-frequency component of the signal will be lost.In general, capacitors are often used as coupling elements for small signal transmission, and transformers are often used as coupling elements for large signal or strong signal transmission. FAQ 1. What is meant by coupling capacitor?Coupling capacitors (or dc blocking capacitors) are use to decouple ac and dc signals so as not to disturb the quiescent point of the circuit when ac signals are injected at the input. Bypass capacitors are used to force signal currents around elements by providing a low impedance path at the frequency.2. How does a coupling capacitor work?Definition: A capacitor that is used to connect the AC signal of one circuit to another circuit is known as a coupling capacitor. ... On the o/p end, we get the AC signal. So a coupling capacitor is placed between two circuits so that AC signals supplies while the DC signal is blocked.3. What is the need of coupling capacitor?Coupling capacitors are essential components in amplifier circuits. They are used to prevent interference of a transistor's bias voltage by AC signals. In most amplifier circuits, this is achieved by driving the signal to the base terminal of a transistor through a coupling capacitor.4. What is coupling and decoupling capacitor?A decoupling capacitor is a capacitor used to decouple one part of an electrical network (circuit) from another. ... In analog circuits, a coupling capacitor is used to connect two circuits such that only the AC signal from the first circuit can pass through to the next while DC is blocked.5. Why decoupling capacitor is used?A decoupling capacitor acts as a local electrical energy reservoir. Capacitors, like batteries, need time to charge and discharge. When used as decoupling capacitors, they oppose quick changes of voltage. ... Decoupling capacitors are used to filter out voltage spikes and pass through only the DC component of the signal. 6. How do I choose a coupling capacitor?A coupling capacitor is best selected so that its impedance is as low as possible at the frequency of interest. The impedance magnitude at any frequency is easily calcu- lated as: Since the net reactance is zero at the capaci- tor's FSR, the total impedance will be equal to the ESR at this frequency. 7. What is the value of coupling capacitor?C is the coupling cap value, w is the angular frequency 2*pi*f with f the frequency in Hertz. Units of resistance Ohms, capacitance Farads. The reason for this is because the three components form a voltage divider and the output only appears across R2 the output resistor. 8. What is coupling capacitor and bypass capacitor?Coupling capacitors (or dc blocking capacitors) are use to decouple ac and dc signals so as not to disturb the quiescent point of the circuit when ac signals are injected at the input. Bypass capacitors are used to force signal currents around elements by providing a low impedance path at the frequency. 9. What happens when coupling capacitor is removed?Since capacitor blocks DC, former stage do not affect DC biasing of succeeding stage. Disadvantage of coupling capacitor is, it put limit on low frequency response of the amplifier. Another disadvantage is, capacitor coupled amplifier, can not be used for amplifying DC signal. 10. How do you calculate the value of coupling capacitor?Measure, calculate or determine from a manufacturer's data sheet the input impedance of the circuit to which the coupling capacitor is connected. Multiply this number by 1/10 to find the minimum value of the coupling capacitor's impedance.

CatalogⅠ What is a Repeater?Ⅱ Types of Repeater2.1 Telephone Repeater2.2 Optical Communications Repeater2.3 Radio RepeaterⅢ How Does a Repeater Work?Ⅳ Features of RepeaterⅤ Advantages of RepeatersⅥ Disadvantages of RepeatersⅦ Use of Repeaters in Ethernet Ⅷ Frequently Asked Questions About Repeater Ⅰ What is a Repeater?A repeater is a network device that retransmits a received signal with greater strength and to a larger geographical or topological network boundary than the original signal could.  A repeater is used in computer networks to increase network coverage, replicate a weak or broken signal, and/or support remote nodes. Repeaters amplify the received/input signal to a higher frequency domain, allowing it to be reused, scalable, and available. Repeaters were first used in wired data transmission networks to overcome the limitation of a signal propagating over a greater distance, and they are now widely used in wireless networks to increase cell size. Repeaters are frequently referred to as signal enhancers. Ⅱ Types of Repeater2.1 Telephone Repeater  This is used to extend the transmission range of telephone signals in a telephone connection. Land Line RepeaterThey are most commonly found on trunklines that transport long-distance calls. An analog telephone line is made up of two wires and an amplifier circuit constructed of transistors that uses power from a DC current source to boost the power of the alternating current audio signal on the line. The wire pair carries two audio signals, one in each direction, because the telephone is a duplex (bidirectional) communication device. As a result, telephone repeaters must be bilateral, amplifying the signal in both directions without creating feedback, which significantly complicates their construction. Telephone repeaters were the first sort of repeater, and they were used in some of the first amplification applications. Between 1900 and 1915, the introduction of telephone repeaters enabled long-distance phone service. The majority of telecommunications cables are now fiber optic cables with optical repeaters (below). Mechanically connected carbon microphones were utilized as amplifiers in telephone repeaters prior to the invention of electronic amplifiers. It was discovered after the turn of the twentieth century that negative resistance mercury lamps could magnify, and they were utilized. Around 1916, the advent of audion tube repeaters made transcontinental telecommunications feasible. In the 1930s, vacuum tube repeaters with hybrid coils were prevalent, allowing thinner cables to be used. In the 1950s, negative impedance gain devices were more prevalent, and the E6 repeater, a transistorized form, was the last major type employed in the Bell System until the low cost of digital transmission rendered all voiceband repeaters obsolete. From the mid to late twentieth century, frequency frogging repeaters were common in frequency-division multiplexing systems. Submarine Cable RepeaterThis is a telephone repeater that is used in submarine telecommunications cables. 2.2 Optical Communications Repeater  This is used to extend the signal range of a fiber optic cable. Short pulses of light carry digital information across a fiber optic cable. Light is composed of particles known as photons, which can be absorbed or scattered in the fiber. A phototransistor transforms light pulses to an electrical signal, an amplifier amplifies the signal, an electronic filter reshapes the pulses, and a laser converts the electrical signal to light again and sends it out the other fiber in an optical communications repeater. However, optical amplifiers for repeaters are being created to magnify light without first converting it to an electric signal. 2.3 Radio Repeater  This is used to increase the range of a radio signal's coverage. The history of radio relay repeaters began in 1898, with Johann Mattausch's publication in the Austrian journal Zeitschrift für Elektrotechnik (v. 16, 35 - 36). However, his "Translator" concept was crude and unsuitable for usage. Emile Guarini-Foresio designed the first relay system with radio repeaters that actually worked in 1899. A radio repeater is typically made up of a radio receiver and a radio transmitter. To offer coverage beyond the blockage, the received signal is amplified and retransmitted, generally on a different frequency. The installation of a duplexer allows the repeater to use one antenna for both receive and transmit. Broadcast relay station, rebroadcastoror translator: A repeater is a device that extends the coverage of a radio or television transmitting station. It is made up of a second radio or television transmitter. The signal from the main transmitter is frequently transmitted via leased telephone lines or microwave relay. Microwave relay: This is a specialized point-to-point telecommunications link that consists of a microwave receiver that receives information from another relay station in line-of-sight distance via a microwave beam and a microwave transmitter that transmits the information to the next station via another microwave beam. Microwave relay networks deliver phone conversations, television shows, and computer data from one city to another across continents. Passive repeater: This is a microwave relay that is merely a flat metal surface that reflects the microwave beam in a different direction. It is used to send microwave relay signals over hills and mountains when amplification is not required. Cellular repeater: This is a radio repeater used to improve cell phone reception in a small region. The gadget works like a miniature cellular base station, including a directional antenna for receiving signals from neighboring cell towers, an amplifier, and a local antenna for rebroadcasting the signal to adjacent cell phones. It's common in downtown office buildings. Digipeater: A packet radio network repeater node. It performs a store and forward function, sending information packets from one node to another. Amateur radio repeater: Amateur radio operators use it to provide two-way communication across an area that would otherwise be difficult to cover using point-to-point on VHF and UHF. Individual operators or clubs put up and maintain these repeaters, which are normally available for use by any licensed amateur. A hill or mountaintop position is desirable for constructing a repeater since it maximizes usage across a vast area. Radio repeaters improve communication coverage in systems that normally use frequencies with line-of-sight propagation. Without a repeater, the curvature of the Earth and the blocking effect of terrain or tall buildings limit the range of these devices. A repeater on a hilltop or tall building can allow stations that are not in line of sight with each other to communicate consistently. Radio repeaters may also allow translation from one set of radio frequencies to another, allowing two separate public service agencies to communicate with one another (say, police and fire services of a city, or neighboring police departments). They may also provide connections to the public switched telephone network or satellite networks (BGAN, INMARSAT, MSAT) as an alternate way from the source to the destination. A repeater station typically listens on one frequency, A, and transmits on another, B. All mobile stations listen on channel B for signals and transmit on channel A. The difference between the two frequencies may be negligible in comparison to the frequency of operation, say 1%. The repeater station will frequently utilize the same antenna for transmission and receiving; highly selective filters known as "duplexers" separate the feeble incoming received signal from the billions of times stronger outbound sent signal. Separate sending and receiving stations are often employed, linked by a wire line or a radio link. While the repeater station is designed for simultaneous receipt and transmission, mobile units do not need bulky and expensive duplexers because they only transmit or receive at any one time. A "talkaround" channel may be given to mobile units in a repeater system, allowing direct mobile-to-mobile operation on a single channel. This may be utilized if the repeater system is out of range, or for communications that do not require the attention of all mobiles. The repeater output frequency could be the "talkaround" channel; the repeater will not retransmit any signals on its output frequency. An engineer will examine the intended coverage area and pick repeater locations, altitudes, antennas, operating frequencies, and power levels to provide a predictable degree of reliable communication over the designed coverage area. Ⅲ How Does a Repeater Work?The repeater action is analogous to a relay race. The transmitting station passes the signal to the repeater, which receives it and sends it to the receiving station. Because you press the transmit button to communicate and the release button to receive, only one side of the conversation is heard at a time. The diagram below depicts the gear used to operate a repeater as well as the path the signals take. Here's a quick rundown of the components: How Does a Repeater Work? Antenna: The majority of repeaters employ a single antenna for both transmit and receive. In general, it's a high-performance, long-lasting, and efficient omnidirectional antenna. They are elevated as much as possible above ground level. Feedline: Repeaters employ hardline, a tough, low-loss cable. Actually, it resembles a flexible pipe with a central conductor rather than a cable. Because hardline has lower signal loss than traditional coax, more transmit power reaches the antenna and weaker signals can be received by the repeater. Duplexer: The duplexer distinguishes and isolates the incoming and outgoing signals. It keeps the receiver and transmitter from interfering with one another and aids in the rejection of particularly powerful adjacent frequencies or other RF interference entering the repeater system. A duplexer is often made up of two parallel bandpass filters. There is no direct connection between the transmitter and the receiver since one filter offers a road between the transmitter and the antenna and the other provides a way between the antenna and the receiver. Receiver: Repeater receivers are often exceedingly sensitive and selective, capturing signals that would be lost if sent directly from radio to radio. It is configured to receive input frequencies from radio transceivers. Controller: This is the repeater's brain and is effectively a dedicated computer. It manages repeater station ID via CW or voice and activates the repeater as necessary. It also serves a variety of other purposes, such as making pre-programmed announcements or connecting many repeaters. Transmitter: The transmitting section of most repeaters includes an exciter and a power amplifier. The exciter retransmits the received audio at the correct frequency, while the power amplifier amplifies its output. Repeaters are network devices that retransmit data and divert signals to weak network access points. Data transmission and reception have various frequencies on both the sender and receiver sides. When the sender's and receiver's frequencies are matched, the Repeater operates. Let us look at an example to learn more about Repeators. Many of you have probably heard of the term Walkie Talkie. A Walkie Talkie has a straightforward connection. The data can be transferred to the receiver without any congestion or error. Only if there are no barriers in the middle of the transmission may data be transferred. Allow us to get into the subject in depth. Assume one person communicates with another via a one-to-one communication device, such as a walkie talkie. If there is a clear path between the distances, the data can be successfully sent. If there is a peak or hill in the way, the data cannot be delivered precisely. An Antenna is installed between the two devices to avoid this problem. This device retransmits data to the receiver side and directs signals to weak spots. This is referred to as the repeater's primary function. Please let us know how the repeater system is working. The data delivered from the sender to the receptor is referred to as an uplink, whereas the receptor that retransmits the same data in the other way and sends it to the receiver is referred to as a downlink. These repeaters, however, can also be employed in areas where there are no mountains or hills in the Way. We consider reports to be incredibly strong radios. We have various portable repeaters that are more powerful than the 25 Watt mobile devices. These repeaters are stationed in specific geographic locations. The range of these routers is mostly 50 to 100 watts, and there are certain cable connectors that link to repeaters at fixed locations such as building towers or the tops of residential buildings. Because of the presence of repeaters, all mobile or portable devices have access to a wide range of communication signals in all directions. These receptors provide a broad spectrum of communication for greater areas. Ⅳ Features of RepeaterThese repeaters are linked together at the physical layer.It transmits signals to weaker places in order to boost the system signals.These receptors connect the various network signals in order to convey data between the two devices.These Repeaters can bridge the gap between two devices.The Repeaters are capable of continuously monitoring the signals generated between the two LANs.Electrical signals become weaker as they travel a greater distance. These Repeaters arrived at the location to strengthen the weak signals used in data transfer.Repeaters can help with flexible networking.The 30 repeaters attached to it are supported by multi-site connectivity options.All of the Repeaters are linked together via an IP site connection network.This IP network can respond quickly to any problem in the repeater network.These receptors are capable of providing 100 percent digital communication. thus they don't have to wait for analog voice calls. Ⅴ Advantages of RepeatersRepeaters are easy to set up and can be used to extend the length or coverage area of networks.They are inexpensive.Repeaters do not necessitate any processing overhead. The only time they need to be investigated is when performance suffers.They can connect signals with various sorts of cables. Ⅵ Disadvantages of RepeatersRepeaters are unable to connect disparate networks.They are unable to distinguish between true signal and noise.They are unable to minimize network traffic or congestion.Most networks restrict the number of repeaters that can be deployed. Ⅶ Use  of Repeaters in EthernetRepeaters are used to increase signal length and efficiency, hence they are utilized more in Ethernet. An Ethernet repeater's primary role is to transmit a signal from one Ethernet cable to another without signal attenuation or loss of signal strength. Whereas repeater systems aid in the detection of collisions. If a repeater detects a collision, it sends the signal to all associated ports. A repeater is a device that connects many Ethernet segments together. This is usually done with a multiport repeater. If there are more than five segments between two host devices, repeaters frequently identify incorrect links; in such a case, the data flow is interrupted until the Jat's data is correct or repaired. Repeaters are intelligent devices that regulate and control signal flow. In order to protect the wires from damage or breaking. Repeaters also allow network segments to continue operating even if one of them breaks or becomes unable to perform any function. As a result, repeaters are extremely beneficial to the seamless operation of wired networks. Ⅷ Frequently Asked Questions  About Repeater1. What is the Function of Repeater in Network?A repeater is used to extend the signal over great distances in order to transmit it. It is able to reach the destination by extending the signal's range, which was not achievable with a router alone. 2. What is the Meaning of Repeater in Computer?A repeater is used in computer networks to increase coverage, repair weak or broken signals, and service faraway nodes. The received/input signal is amplified to a higher frequency domain in a repeater, making it reusable, scalable, and available at any moment. 3. What is Repeaters in Networking?Extenders (also known as repeaters) are devices that improve your network's signal intensity so that it can travel further. When utilized in this manner, the repeater divides the cable into two segments. There is a limit on the cable length in addition to the length limit on each side of the repeater. 4. Where is Repeater Use  d in a Network?The physical layer is where a repeater functions. To increase the amount of time a signal can be transmitted over the same network, it regenerates the signal before it gets weak or garbled. 5. How Do Repeaters Work in Networking?When a wireless repeater receives radio signals from a WAP, it regenerates and distributes them as frames. Wireless repeaters can improve wireless signal coverage. A repeater is installed in remote regions where network signals can travel but become feeble. 6. What Are the Main Functions of Repeater?A repeater's role in telecommunications is to retransmit a signal. A repeater is used to send signals over extended distances or to receive signals on the other side of an obstruction. 7. What is the Function of Switch And Repeater on Network?A network switch learns the identity of the connected devices and passes the data to the port corresponding to the device, as opposed to repeater hubs, which broadcast the same data out of each port and let the devices select out the data targeted to them. 8. What is the Purpose of Using a Repeater in Network Environment?In networking repeaters, incoming electrical, wireless, or optical signals are regenerated in order to maintain signal integrity and extend data transmission range. 9. What is a Repeater Station And How Does It Work?Resounding is an automated radio station that expands communication range. An integrated controller is connected to a receiver tuned to one frequency and a transmitter tuned to another. 10. What’s the Optimal Location to Mount a Repeater?The best mounting site is determined by your structure and surroundings. Before installing the repeater, we recommend doing a radio coverage site survey to ensure optimal radio range and coverage. This entails positioning the antenna in an optimal central place and replicating the coverage that would be expected if the antenna were put in this location. 11. How is a Repeater Made?A typical repeater is made up of five parts: an antenna, a duplexer, a receiver, a baseband processor, and a transmitter. The duplexer allows a single antenna to receive and transmit signals on several frequencies. A low-level signal is filtered and amplified by the receiver before it is processed and delivered to the transmitter. 12. How Does a Digital Repeater Differ From an Analog Repeater?The primary distinction is in the baseband processor. The receiver voice is filtered and delivered directly to the transmitter modulator in an analog repeater. Any noise picked up will be transmitted to the transmitter. This repeater downlink will have noise increases from both the uplink to the repeater and the downlink from the repeater, regardless of what a radio receives. The baseband processor in the digital repeater transforms to binary bits, which are then error corrected and supplied to the transmitter. This downlink signal will be error corrected by the radio receiving the repeater, resulting in noise-free voice. Only when the signal in either the uplink or downlink becomes too weak does the voice decode begin to break up and drop out. 13. How Can I Improve the Range of a Repeater?By increasing antenna gain, increasing transmitter power, or improving antenna placement. Ascertain that the coaxial cable connecting the repeater duplexer to the antenna is of high quality, low loss, and in good working order. Additionally, ensure that no interfering signals are jamming the receiver. When the channel is busy with a signal, the receiver squelch LED indicator might help. 14. Can I Link Repeaters Together?This is feasible, but it becomes complex. On another site, you cannot simply invert the repeater pair. The frequency of a repeater downlink output cannot be the same as the frequency of a repeater uplink receiver input. To extend the range using only repeaters, you would need two more repeaters with two more sets of repeater pairs. 

 CatalogInstructionRelated VideoHow to Use SD Card ReaderSD Card Reader Not WorkingExampleFAQInstructionAs a base device, the SD card reader is lightweight and compact. You only need to insert the SD card into the SD card reader in the correct direction to connect successfully and start using it. For some SD card readers, you need to insert the SD card upside down. After that,the device is connected to another electronic terminal (such as a laptop) where the files in the SD card can be viewed. The card reader is similar to a USB floppy drive for a computer; the only difference is that the card reader reads a variety of flash memory cards, whereas the USB floppy drive only reads floppy disk. Related VideoVideo: How to Use an SD Card ReaderVideo Description:If you need to get files off your camera and onto your computer, you might need to know how to use an SD card reader. How to Use SD Card Reader1: Insert the card into the reader. Insert the SD card into the reader.2: Insert the card into the USB drive. Connect the card reader to any USB drive on your computer.3: Choose View in New Window. When prompted by the computer, select View in New Window.4: Choose DCIM DCIM should be double-clicked.5: Emphasize files Select all of the files you want to copy to your computer.6: Transfer files Move your files wherever you want by right-clicking and selecting Move To.7: Disconnect the card reader. Remove the card reader by clicking the Safely Remove Hardware icon in the bottom right corner of the screen. SD Card Reader Not WorkingHere are the steps for resolving the SD card reader not working problem. If your SD card reader isn't working on Windows, try these fixes:Clean the slot on the SD card reader.In Device Manager, look at the SD card reader's hardware information.In Device Manager, update the SD card reader driver. If your SD card reader isn't working on Mac OS, try these solutions:Check to see if the SD card reader has any limitations.In System information, look for SD card reader.In System Preferences, look for software updates. ExampleUSB 3.0 SuperSpeed Multi-Drive Memory Card ReaderSystem RequirementsTablet, laptop, Ultrabook,Chromebook or computer withUSB port (USB 3.0 port requiredfor USB 3.0 speeds) FeaturesHigh-Speed Data TransferIdeal for transferring photos, documents, hi-def audio and video, and other files between a memory card and your tablet, laptop, Ultrabook, Chromebook or computerBuilt-in 6 in. USB cable connects to device’s USB portSupports USB 3.0 data transfer rates up to 5 GbpsBackward compatible with previous USB generations Plug-and-Play ConvenienceNo software, drivers or external power supply requiredCompact case made from lightweight aluminumFits easily into your pocket, backpack, briefcase or laptop bagCompatible with all USB-enabled operating systems Compatible with Wide Range of Memory CardsSD Cards: Secure Digital (SD), Elite Pro SD, Extreme III SD, Gaming Edition SD, Platinum II SD, SD Pro, SDHC, SDXC, SD-Max, SD-Pleomax, SD-Pro C, Super SD, Turbo SD, Ultima I SD, Ultima II SD, Ultimate SD, Ultra High Speed SD, Ultra II SD, Ultra II SD Plus, Ultra SD, Ultra-X SD, DV-RS MMC, High Speed MMC/RS-MMC, MCCmobile, MMC Pro, MMCplus, MMCplus Turbo, RS-MMC Micro SD Cards: MicroSD (TransFlash), microSDHCCF Cards: CompactFlash Type I/II, CF Elite Pro, CF PRO I, CF PRO II, CF Turbo, CF Ultima I, CF Ultima II, Extreme CF, Extreme III CF, HS CF, Ultra II CF FAQ1. Why do you need a card reader?A card reader is a security device that all customers who want to use Online Banking must have. It works in conjunction with your Online Banking service to provide an additional layer of security against online fraud. 2. Are all SD card readers the same?Card readers come in a variety of shapes and sizes, with various connectors. They can read more than just SD cards; some can also read microSD cards, CompactFlash (CF) cards, and Sony's Memory Stick Pro Duo. We tested SD readers that connect via USB or USB Type-C to find the best one for your machine. 3. Does SD card reader matter?In summary, transfer speed does matter. To professional users, both write and read speed matter. To consumers, read speed is generally the most important measure of performance. For all users, a fast memory card reader is essential to ensure that the least amount of time is required during the post-capture workflow. 4. How do I use my SD card reader on my laptop?Insert your SD card into the card reader and connect it to the appropriate port on your laptop. Then, using the Windows key + E, open File Explorer and navigate to This PC. Your SD card should be listed in the right pane. To browse or access the content on your SD card, double-click it. 5. How do I use SD card reader on Android?Head to Settings > Storage & USB, and you'll be able to see the microSD cards you've installed. If your microSD card is configured as portable storage and you want to switch to internal storage, select the drive and then tap the menu button in the top right corner of the screen. Then, go to Settings and select Format as Internal. 6. Can you read an SD card on an iPhone?You can use the Files app and other supported apps to access files stored on external devices connected to your iPhone, such as USB drives and SD cards. 7. Do Macs have SD card readers?The MacBook Pro comes with a built-in SD card reader, so you can insert compatible SD cards and view their contents using the Media Reader. The cards must conform to SD 1. x, 2. x, and 3. 8. How do I get drivers for my SD card reader?You can use the Files app and other supported apps to access files stored on external devices connected to your iPhone, such as USB drives and SD cards. 9. What does a USB SD card reader do?A memory card reader is a device used to read data from a memory card such as a CompactFlash (CF), Secure Digital (SD), or MultiMediaCard (MMC). Most card readers have write capability, and when combined with a card, this can function as a pen drive. 10. Why do I need an SD card reader?SD card readers enable you to view and transfer files from the card. If your computer lacks one, you may be able to connect an external SD card reader. It is simple to transfer these files to your computer. First, remove the card from the device where it was collecting data. 

RFID is the abbreviation of Radio Frequency Identification.Its principle is the contactless data communication between the reader and the tag to achieve the purpose of identifying the target. RFID has a wide range of applications, typical applications include animal chip, car chip immobilizer, access control, parking control, production line automation, and material management.What is RFID? How RFID works? RFID Explained in DetailCatalogI Overview of RFIDII Working principle of RFIDIII How RFID system is composed?3.1 About the reader3.2 About electronic tagsIV Features4.1 Applicability4.2 High efficiency4.3 Uniqueness4.4 SimplicityFAQI Overview of RFIDRadio frequency identification, or radio frequency identification technology, is a type of automatic identification technology that uses wireless radio frequency for non-contact two-way data communication. It uses radio frequency to read and write recording media (electronic tags or radio frequency cards) to achieve the purpose of identification and data exchange. It is considered to be one of the most promising information technologies in the 21st century.Radio frequency identification technology uses radio waves without contact with fast information exchange and storage technology, combines wireless communication with data access technology, and then connects to the database system to achieve non-contact two-way communication. In this way, the purpose of identification is achieved, and it can be used for data exchange, connecting an extremely complex system in series.In the identification system, the reading and writing and communication of electronic tags are realized through electromagnetic waves. According to the communication distance, it can be divided into near-field and far-field. For this reason, the data exchange mode between the read/write device and the electronic tag is correspondingly divided into load modulation and backscatter modulation.  II Working principle of RFIDThe basic working principle of RFID technology is not complicated: After the tag enters the reader, it receives the radio frequency signal from the reader, and uses the energy obtained by the induced current to send out the product information stored in the chip (Passive Tag, passive tag or passive tag). ), or the tag actively sends a signal of a certain frequency (Active Tag, active tag or active tag). After the reader reads and decodes the information, it is sent to the central information system for relevant data processing.A complete RFID system is composed of three parts: a reader, an electronic tag, a so-called transponder, and an application software system. Its working principle is that the reader emits radio wave energy of a specific frequency to drive the circuit to send out the internal data. At this time, the Reader receives the interpretation data in order and sends it to the application program for corresponding processing.From the perspective of the communication and energy sensing methods between the RFID card reader and the electronic tag, it can be roughly divided into two types: inductive coupling and backscatter coupling. Generally, low-frequency RFID mostly adopts the first method, and high-frequency RFID mostly adopts the second method.The reader can be a read or read/write device depending on the structure and technology used, and it is the information control and processing center of the RFID system. The reader usually consists of a coupling module, a transceiver module, a control module and an interface unit.The reader and the tag generally adopt a half-duplex communication mode for information exchange, and the reader provides energy and timing to the passive tag through coupling. In practical applications, management functions such as the collection, processing and remote transmission of object identification information can be further realized through Ethernet or WLAN. III How RFID system is composed?The complete RFID system consists of three parts: Reader, Tag and data management system. 3.1 About the readerThe reader is a device that reads the information in the tag or writes the information that the tag needs to store into the tag. Depending on the structure and technology used, the reader can be a read/write device, which is the information control and processing center of the RFID system. When the RFID system is working, the reader sends radio frequency energy in an area to form an electromagnetic field, and the size of the area depends on the transmit power.The tag in the coverage area of the reader is triggered to send the data stored in it, or modify the data stored in it according to the instructions of the reader, and can communicate with the computer network through the interface. The basic composition of the reader usually includes: transceiver antenna, frequency generator, phase-locked loop, modulation circuit, microprocessor, memory, demodulation circuit and peripheral interface composition.(1) Transceiver antenna: Send radio frequency signals to the tag, and receive the response signal and tag information returned by the tag.(2) Frequency generator: Generates the operating frequency of the system.(3) Phase-locked loop: Generate the required carrier signal.(4) Modulation circuit: Load the signal sent to the tag to the carrier wave and send it out by the radio frequency circuit.(5) Microprocessor: Generates the signal to be sent to the label, decodes the signal returned by the label, and sends the decoded data back to the application program. If it is an encrypted system, a decryption operation is also required.(6) Memory: store user programs and data.(7) Demodulation circuit: demodulate the signal returned by the tag and deliver it to the microprocessor for processing.(8) Peripheral interface: to communicate with the computer.3.2 About electronic tagsThe electronic tag consists of a transceiver antenna, AC/DC circuit, demodulation circuit, logic control circuit, memory and modulation circuit.(1) Transceiver antenna: Receive the signal from the reader and send the required data back to the reader.(2) AC/DC circuit: Utilize the electromagnetic field energy emitted by the reader, output by the voltage regulator circuit to provide a stable power supply for other circuits.(3) Demodulation circuit: Remove the carrier from the received signal and demodulate the original signal.(4) Logic control circuit: decode the signal from the reader, and send back the signal according to the requirements of the reader.(5) Memory: As a location for system operation and storage of identification data.(6) Modulation circuit: The data sent by the logic control circuit is loaded to the antenna and sent to the reader after the modulation circuit.IV FeaturesGenerally speaking, the radio frequency identification technology has the following characteristics.  4.1 ApplicabilityRFID technology relies on electromagnetic waves and does not require physical contact between the connecting parties. This makes it possible to establish connections without regard to dust, fog, plastic, paper, wood and various obstacles, and to complete communications directly. 4.2 High efficiencyRFID system read and write speed is extremely fast, a typical RFID transmission process is usually less than 100 milliseconds. RFID readers in the high frequency band can even identify and read the contents of multiple tags simultaneously, greatly improving the efficiency of information transmission.  4.3 Uniquenesseach RFID tag is unique, through the RFID tag and product one-to-one correspondence, you can clearly track the subsequent circulation of each product. 4.4 SimplicityRFID tag structure is simple, high recognition rate, the required reading equipment is simple. Especially with the gradual popularization of NFC technology on smart phones, each user's cell phone will become the simplest RFID reader.FAQ 1. What is RFID used for?Radio Frequency Identification (RFID) is the wireless non-contact use of radio frequency waves to transfer data. Tagging items with RFID tags allows users to automatically and uniquely identify and track inventory and assets.2. What is RFID and how it works?RFID is a method of data collection that involves automatically identifying objects through low-power radio waves. Data is sent and received with a system consisting of RFID tags, an antenna, an RFID reader, and a transceiver.3. What RFID means?Radio Frequency Identification (RFID) refers to a wireless system comprised of two components: tags and readers. The reader is a device that has one or more antennas that emit radio waves and receive signals back from the RFID tag.4. Is RFID harmful to human?It is a non-ionizing type of radiation, but some researches show that it could have a negative impact on the human body in a long-term period [11, 12]. So, for the safety reasons, manufacturers of the RFID systems have limited the range of the RFID antennas used in their systems.5. Is RFID tag and FASTag same?FASTag is a device that employs Radio Frequency Identification (RFID) technology for making toll payments directly while the vehicle is in motion. FASTag (RFID Tag) is affixed on the windscreen of the vehicle and enables a customer to make the toll payments directly from the account which is linked to FASTag.6.What is RFID and its advantages?RFID technology automates data collection and vastly reduces human effort and error. RFID supports tag reading with no line-of-sight or item-by-item scans required. RFID readers can read multiple RFID tags simultaneously, offering increases in efficiency.7. Why is RFID bad?Some negative effects are that its deadly, if RFID tags combine with static electricity you can die. Another negative effect is that the government is slowly taking away surviving resources and giving ultimatums, such as if you don't get the RFID tracking chip your public assistance will be terminated.8.What are the disadvantages of RFID?a. Materials like metal & liquid can impact signal.b. Sometimes not as accurate or reliable as barcode scanners.c. Cost – RFID readers can be 10x more expensive than barcode readers.d. Implementation can be difficult & time consuming.9.How do I charge my RFID FASTag?In order to recharge your FASTag sticker, just hit the Add Money option in your Paytm app. FASTag will automatically reserve some amount from your wallet, which can be used at toll plazas later. Do note that FASTag can be used only after 20 mins of adding money to the Paytm Wallet.10. Can I use existing RFID for FASTag?If a vehicle already has an RFID tag, it might already be activated. When you buy the vehicle, RFID tag payment was also done. It might also have a minimum balance of INR 100 or 200 as is required by the bank. You can recharge it with your Customer ID or Wallet ID of FASTag.11. How does RFID work without power?Passive RFID tags have no power of their own and are powered by the radio frequency energy transmitted from RFID readers/antennas. The signal sent by the reader and antenna is used to power on the tag and reflect the energy back to the reader.12. What are the types of RFID tags?RFID tags can be grouped into three categories based on the range of frequencies they use to communicate data: low frequency (LF), high frequency (HF) and ultra-high frequency (UHF). Generally speaking, the lower the frequency of the RFID system, the shorter the read range and slower the data read rate.13.How do I know if I have an RFID chip?The best way to check for an implant would be to have an X-ray performed. RFID transponders have metal antennas that would show up in an X-ray. You could also look for a scar on the skin. Because the needle used to inject the transponder under the skin would be quite large, it would leave a small but noticeable scar.14. Does RFID require power?Active RFID tags possess their own power source – an internal battery that enables them to have extremely long read ranges as well as large memory banks. Typically, active RFID tags are powered by a battery that will last between 3 - 5 years, but when the battery fails, the active tag will need to be replaced.15. What is the difference between a QR code and RFID?QR codes must always be “read-only”, whereas RFID tags can be “read-write”, depending on the radio frequency that's being used. ... So, not only are RFID tags futuristic and have more uses than QR tags, they also have many more applications. The read range is far superior for an RFID tag. 

CatalogⅠ What Is a Thyristor？Ⅱ How Does a Thyristor Work?Ⅲ Thyristor I-V Characteristics Curves3.1 Thyristor turn-on3.2 Thyristor turn-offⅣ Thyristor Phase ControlⅤ Applications of ThyristorsⅥ Different Types of Thyristors and Their Uses6.1 Thyristors with turn-on capability (Unidirectional control)6.2 Thyristors with turn-off capability (Unidirectional control)6.3 Bidirectional controlⅦ Thyristor VS TransistorsⅧ ConclusionⅨ Frequently Asked Questions about Thyristor Ⅰ What Is a Thyristor？A thyristor is a four-layer solid-state semiconductor device having alternating P- and N-type materials. It only functions as a bistable switch, conducting when the Gate gets a current trigger and continuing to conduct until the voltage across the device is reversed biased or removed (by some other means). There are two designs, which differ in what causes the conducting state to occur. A modest current on the Gate lead of a three-lead thyristor regulates the larger current of the Anode to Cathode circuit. Conduction begins in a two-lead thyristor when the potential difference between the Anode and Cathode is sufficiently large (breakdown voltage). this video shows what a thyristor is  The first thyristor devices were commercially available in 1956. Because thyristors can handle a relatively significant quantity of power and voltage with a compact device, they have a wide range of applications in power control, from light dimmers and electric motor speed control to high-voltage direct-current power transmission. Thyristors can be found in power-switching circuits, relay-replacement circuits, inverter circuits, oscillator circuits, level-detector circuits, chopper circuits, light-dimming circuits, low-cost timer circuits, logic circuits, speed-control circuits, phase-control circuits, and many other applications. Originally, thyristors could only be turned off by reversing the current, making them impractical to use for direct current; later device types can be turned on and off via the control gate signal. The latter is referred to as a gate turn-off thyristor (GTO thyristor). Thyristors, unlike transistors, have a two-valued switching characteristic, which means that they can only be fully on or off, whereas transistors can be in between on and off states. As a result, a thyristor is ineffective as an analog amplifier but beneficial as a switch. Ⅱ How Does a Thyristor Work?A P-N-P-N-P-N thyristor has three junctions: PN, NP, and PN. If the cathode is a positive terminal, the outer junctions, PN and PN, are forward-biased, while the center NP junction is reverse-biased. As a result, the NP junction prevents positive current from flowing from anode to cathode. In a forward blocking state, the thyristor is said to be. Similarly, the outer PN junctions prevent the flow of a negative current. The thyristor is currently in reverse blocking mode. this video shows how a thyristor works A thyristor can also be in the forward conducting condition, which occurs when it gets a sufficient signal to turn on and begin conducting. Ⅲ Thyristor I-V Characteristics Curvesthyristor I-V characteristics curves3.1 Thyristor turn-onThe gate signal loses all control once the thyristor is turned "ON" and passing current in the forward direction (anode positive). This is due to the regenerative latching action of the two internal transistors. Any gate signals or pulses applied after regeneration has begun will have no effect because the thyristor is already conducting and fully-ON. The SCR, unlike the transistor, cannot be biased to remain in an active zone along a load line between its blocking and saturation states. Because conduction is controlled internally, the magnitude and duration of the gate "turn-on" pulse have no effect on the device's operation. Then, delivering a brief gate pulse to the device is enough to cause it to conduct, and it will remain permanently "ON" even if the gate signal is removed completely. As a result, the thyristor can be thought of as a Bistable Latch with two stable states: "OFF" or "ON." This is because, in the absence of a gate signal, a silicon controlled rectifier blocks current in both directions of an alternating current waveform, and once triggered into conduction, the regenerative latching mechanism means that it cannot be turned "OFF" simply by using its Gate. 3.2 Thyristor turn-offOnce the thyristor has self-latched into its "ON" state and is passing a current, it can only be turned "OFF" by either completely removing the supply voltage and thus the Anode (IA) current, or by reducing its Anode to Cathode current by some external means (the opening of a switch, for example) to below a value commonly known as the "minimum holding current," IH. The anode current must thus be lowered below this minimum holding level for the thyristors' internally latched pn-junctions to regain their blocking condition before a forward voltage is given to the device again without it instantly self-conducting. To conduct in the first place, a thyristor's anode current, which is also its load current, IL, must be greater than its holding current value. That would be IL > IH. Since the thyristor has the ability to turn "OFF" whenever the Anode current is reduced below this minimum holding value, it follows that when used on a sinusoidal AC supply, the SCR will automatically turn "OFF" at some value near the cross over point of each half cycle, and will remain "OFF" until the next Gate trigger pulse is applied. Because an alternating current sinusoidal voltage constantly switches polarity from positive to negative on every half-cycle, the thyristor can be turned "OFF" at the 180o zero point of the positive waveform. This effect is known as "natural commutation," and it is a crucial feature of the silicon controlled rectifier. Thyristors used in circuits fed by DC sources cannot have this natural commutation condition since the DC supply voltage is continuous, hence another mechanism to turn "OFF" the thyristor at the proper moment must be given because once triggered, it will stay conducting. Natural commutation, on the other hand, occurs every half cycle in AC sinusoidal circuits. The thyristor is thus forward biased (anode positive) during the positive half cycle of an AC sinusoidal waveform and can be triggered "ON" using a Gate signal or pulse. The Anode becomes negative throughout the negative half cycle, whereas the Cathode remains positive. This voltage reverse biases the thyristor, preventing it from conducting even while a Gate signal is present. So, by applying a Gate signal at the proper point during the positive half of an AC waveform, the thyristor can be triggered into conduction until the positive half cycle is completed. Thus, phase control (as it is known) may be used to trigger the thyristor at any position along the positive half of the AC waveform, and power control of AC systems is one of the numerous applications of a Silicon Controlled Rectifier, as shown. Ⅳ Thyristor Phase ControlThe SCR is "OFF" at the start of each positive half-cycle. When the gate pulse is applied, the SCR enters conduction and remains fully latched "ON" for the duration of the positive cycle. If the thyristor is triggered at the half-cycle start ( Θ= 0°), the load (a light) will be "ON" throughout the entire positive cycle of the AC waveform (half-wave rectified AC) at a high average voltage of 0.318 x Vp. Thyristor Phase Control The lamp is lighted for less time as the application of the gate trigger pulse increases along the half cycle ( Θ= 0° to 90°), and the average voltage given to the lamp is proportionally smaller, diminishing its brightness. A silicon controlled rectifier can thus be used as an AC light dimmer as well as in a range of other AC power applications such as AC motor-speed control, temperature control systems, and power regulator circuits, among others. So far, we've learned that a thyristor is simply a half-wave device that conducts only in the positive half of the cycle when the Anode is positive and inhibits current flow like a diode when the Anode is negative, regardless of the Gate signal. However, there are other semiconductor devices known as "Thyristors" that can conduct in both directions, are full-wave devices, or can be turned "OFF" by the Gate signal. To name a few, these devices include "Gate Turn-OFF Thyristors" (GTO), "Static Induction Thyristors" (SITH), "MOS Controlled Thyristors" (MCT), "Silicon Controlled Switch" (SCS), "Triode Thyristors" (TRIAC), and "Light Activated Thyristors" (LASCR), with all of these devices available in a variety of voltage. Ⅴ Applications of ThyristorsThyristors are primarily used to regulate high currents and voltages, and are frequently used to control alternating currents, where a change in polarity of the current causes the device to automatically turn off, a process known as "zero cross" operation. The device is considered to work synchronously because, once triggered, it conducts current in phase with the voltage provided across its cathode to anode junction with no further gate modulation necessary, i.e., the device is fully biased on. This is not to be confused with asymmetrical operation because the output is unidirectional, flowing exclusively from cathode to anode, and hence asymmetrical. Thyristors can be used to control phase angle triggered controllers, also known as phase fired controllers. They can also be found in digital circuit power supplies, where they act as a form of "improved circuit breaker" to prevent a power supply failure from damaging downstream components. A thyristor is used in conjunction with a Zener diode coupled to its gate, and if the power supply output voltage exceeds the Zener voltage, the thyristor will conduct and short-circuit the power supply output to ground (in general also tripping an upstream breaker or fuse). In the early 1970s, the first large-scale application of thyristors, with associated triggering diac, in consumer devices linked to stable power supplies within color television sets. The stable high voltage DC supply for the receiver was generated by changing the switching point of the thyristor device up and down the falling slope of the positive going half of the AC supply input (if the rising slope was used the output voltage would always rise towards the peak input voltage when the device was triggered and thus defeat the aim of regulation). The precise switching point was decided by the load on the DC output supply as well as AC input fluctuations. Thyristors have been utilized as light dimmers in television, film, and theater for decades, replacing inferior technology such as autotransformers and rheostats. They have also been utilized in photography as an important component of flashes (strobes). Ⅵ Different Types of Thyristors and Their UsesThyristors are classified based on their voltage and current characteristics, as well as their on/off behavior. 6.1 Thyristors with turn-on capability (Unidirectional control)1. Silicon controlled rectifier (SCR)SCRs are the most well-known type of thyristor. An SCR remains latched on even when the gate current is released, as indicated in the general thyristor description above. To unlatch, either the anode to cathode current must be removed or the anode must be reset to a negative voltage relative to the cathode. This property is ideal for phase control. When the anode current reaches zero, the SCR stops conducting and the reverse voltage is blocked. Switching circuits, DC motor drives, AC/DC static switches, and inverting circuits all require SCRs. 2. Reverse conducting thyristor (RCT)Thyristors often allow current solely in one direction while blocking current in the other. An RCT, on the other hand, is made up of an SCR integrated with a reverse diode, which avoids unwanted loop inductance and lowers reverse voltage transients. The RCT enables electric conduction in the opposite direction, resulting in enhanced commutation. RCTs are utilized in high-power choppers' inverters and DC drives. 3.Light-activated silicon-controlled rectifier (LASCR)These are also referred to as light-triggered thyristors (LTT). When light particles reach the reverse-biased junction of these devices, the number of electron-hole pairs in the thyristor increases. The thyristor will turn on if the intensity of the light exceeds a specific value. An LASCR provides total electrical isolation between the light source and the power converter's switching component. LASCRs are found in high-voltage direct current transmission equipment, reactive power compensators, and high-power pulse generators. 6.2 Thyristors with turn-off capability (Unidirectional control)When a sufficient gate pulse is supplied, traditional thyristors, such as SCRs, turn on. To turn them off, the main current must be cut. This is troublesome in DC to AC and DC to DC conversion circuits where current does not naturally zero out. 1. Gate turn-off thyristor (GTO)A GTO varies from a typical thyristor in that it can be turned off by applying a negative current (voltage) to the gate without requiring the current between the anode and cathode to be removed (forced commutation). This means that a gate signal with a negative polarity can turn off the GTO, making it a fully controlled switch. It is also known as a Gate-Controlled Switch, or GCS. A GTO's turn off time is approximately ten times faster than that of a similar SCR. Symmetric GTOs have reverse blocking abilities that are comparable to their forward voltage ratings. Asymmetric GTOs lack significant reverse voltage blocking capacity. Reverse conducting GTOs are made up of a GTO and an anti-parallel diode. Asymmetric GTOs are the most common type on the market. 2.MOS turn–off thyristor (MTO)An MTO is a combination of a GTO and a MOSFET that improves the turn-off capability of the GTO. GTOs require a high gate turn off current with a peak amplitude of 20-35 percent of the anode to cathode current (current to be controlled). An MTO contains two control terminals, one for the turn-on gate and one for the turn-off gate, also known as the MOSFET gate. To activate an MTO, a sufficiently large gate pulse is given, causing the thyristor to latch on (similar to SCR and GTO). A voltage pulse is applied to the MOSFET gate to turn off the MTO. When the MOSFET switches on, it shorts the NPN transistor's emitter and base, preventing latching. It's a considerably faster operation than a GTO (around 1-2 s), in which the huge negative pulse sent to the GTO's gate seeks to extract enough current from the NPN transistor's base. Furthermore, the shorter time (MTO) eliminates the losses associated with current transfer. MTOs are employed in high voltage applications ranging from 20 MVA to motor drives, flexible AC line transmissions (FACTs), and high power voltage source inverters. GTOs are utilized in DC and alternating current motor drives, high power inverters, and alternating current stabilizing power. 3.Emitter turn off thyristors (ETO)The ETO, like the MTO, has two terminals, one for a regular gate and one for a second gate connected in series with a MOSFET.Positive voltages are provided to both gates to turn on an ETO, which causes NMOS to turn on and PMOS to switch off. The ETO turns on when a positive current is introduced into the usual gate.NMOS turns off and transfers all current away from the cathode when a negative voltage signal is supplied to the MOSFET gate. The latching process is terminated, and the ETO is turned off.ETOs are used in high-power voltage source inverters, Flexible AC line Transmissions (FACTs), and Static Synchronous Compensators (STATCOM). 6.3 Bidirectional controlSo far, the thyristors that have been discussed have been unidirectional and have been employed as rectifiers, DC-DC converters, and inverters. To use these thyristors for AC voltage control, two of them must be coupled in anti-parallel, resulting in two independent control circuits with extra wire connections. Bidirectional thyristors, which can conduct current in both directions when triggered, were created expressly to address this issue. 1. Triode for alternating current (TRIAC)After SCRs, TRIACS are the most often utilized thyristors. They can regulate both half of the alternating waveform, allowing for more efficient use of available power. TRIACs, on the other hand, are normally only employed for low power applications due to their inherent non-symmetrical structure. When switching at various gate voltages throughout each half cycle, TRIACs have some drawbacks in high power applications. This generates more harmonics in the system, causing an imbalance and affecting EMC performance.Low-power TRIACs are utilized in light dimmers, speed controllers for electric fans and other electric motors, and computerized control circuits for household appliances. 2. Diode for alternating current (DIAC)DIACS are low-power devices that are typically used in tandem with TRIACS (placed in series with the gate terminal of a TRIAC). Because TRIACS are inherently unsymmetrical, a DIAC stops any current from flowing through the TRIAC's gate until the DIAC reaches its trigger voltage in either direction. This guarantees that TRIACS used in AC switches trigger in both directions uniformly. Light bulb dimmers contain DIACs. 3. Silicon Diode for Alternating Current (SIDAC)Electrically, a SIDAC behaves similarly to a DIAC. SIDACs offer a higher breakover voltage and stronger power handling capabilities than DIACs. A SIDAC is a five-layer device that can be used as a switch on its own rather than as a trigger for another switching device (like DIACs are for TRIACS). A SIDAC begins to conduct current if the applied voltage matches or exceeds the breakover voltage. Even if the applied voltage changes, it remains in this conducting state until the current can be decreased below the rated holding current. The SIDAC then returns to its nonconductive condition to begin the cycle again. SIDACs are found in relaxation oscillators and other specialized devices. Ⅶ Thyristor VS TransistorsBoth thyristors and transistors are electrical switches, however thyristors have a much higher power handling capacity than transistors. Because of the Thyristor's high rating in kilowatts, whereas transistor power ranges in watts. In this analysis, a Thyristor is modeled as a closed couple pair of transistors. The major difference between a transistor and a thyristor is that a transistor requires constant switching power to stay on, but a thyristor requires only a single trigger to stay on. Transistors cannot be used in applications such as alarm circuits that must activate once and remain ON indefinitely. To address these issues, we employ the Thyristor. More distinctions between Thyristor and Transistor are listed in the table below: PropertyThyristorTransistorLayerFour LayersThree LayersTerminalsAnode, Cathode and GateEmitter, Collector, and BaseOperation over-voltage and currentHigherLower than thyristorTurning ONJust required a gate pulse to turn ONRequired continuous supply of the controlling currentInternal power lossLower than transistorhigher Ⅷ ConclusionSilicon Controlled Rectifiers, also known as Thyristors, are three-junction PNPN semiconductor devices that can be thought of as two interconnected transistors capable of switching high electrical loads. They can be latched-"ON" with a single positive current pulse delivered to their Gate terminal and will remain "ON" endlessly until the Anode to Cathode current falls below their minimum latching level. Thyristors are high-speed switches that can be used to replace electromechanical relays in a variety of circuits since they have no moving components, no contact arcing, and are not affected by corrosion or dirt. However, in addition to merely switching big currents "ON" and "OFF," thyristors can be used to adjust the mean value of an alternating current load current without dissipating large quantities of electricity. The regulation of electric lighting, heaters, and motor speed is a good example of thyristor power control. Ⅸ Frequently Asked Questions about Thyristor1. What is the difference between SCR and thyristor?A thyristor is a four-layer semiconductor device with three PN junctions. It is also referred to as "SCR" (Silicon Control Rectifier). The phrase "Thyristor" is a combination of the words thyratron (a gas fluid tube that functions as an SCR) and transistor. Thyristors are also referred to as PN PN Devices. 2. Why SCR is called thyristor?A silicon controlled rectifier (SCR) is a unidirectional silicon semiconductor device. Because this device is the solid-state analogue of a thyratron, it is also known as a thyristor or thyroid transistor. 3. Is thyristor a semiconductor device?A thyristor is a four-layer semiconductor device that alternates between P-type and N-type materials (PNPN). A thyristor is typically composed of three electrodes: an anode, a cathode, and a gate (control electrode). 4. What is the symbol for a thyristor?The silicon-controlled rectifier, SCR, or thyristor symbol used in circuit designs or circuits aims to highlight the rectifier properties while also displaying the control gate. As a result, the thyristor symbol resembles a typical diode with a control gate entering at the junction. 5. What is the difference between diode and thyristor?The primary distinction between a diode and a thyristor is that a diode has two terminals and is employed as a rectifier for converting AC to DC as well as a switch. The thyristor, on the other hand, has two terminals and functions as a switch. Both a diode and a thyristor are semiconductor devices made of a combination of p and n materials. 6. How is thyristor measured?In general, the multimeter is used to measure the DC resistance between the anode and cathode of thyristors and diodes, as well as the gate to the cathode on thyristors. These data are of the device's "off state" or blocking voltage. "Open circuit" and "short circuit" are the only valid readings. 7. How to Check a Thyristor?1)Connect the anode (entry terminal) of the thyristor to the multimeter's positive (red) lead.2)Place the multimeter in the high resistance mode.3)Replace the leads in their original placements, adding the gate terminal to the positive lead this time. 8. How do I know if my thyristor is bad?Connect the negative lead of your ohmmeter to the SCR's anode and the positive lead to the SCR's cathode. Take note of the resistance value displayed on the ohmmeter. It should display a very high resistance value. If it reads an extremely low value, the SCR is shorted and needs to be replaced. 9. Which is better IGBT or thyristor?IGBTs are much faster than typical thyristors and can be controlled by toggling an on/off gate signal with a digital signal processor and a field-programmable gate array rather than waiting for a zero crossing. The conduction losses and switching losses are the two primary losses for the IGBT. 10. What is the purpose of a thyristor in a circuit?A thyristor's principal function is to control electric power and current by acting as a switch. It provides adequate protection to circuits with high voltages and currents for such a compact and lightweight component (up to 6000 V, 4500 A). 

2026 Executive Summary: Reading SMD Resistor CodesHow do you read SMD resistor codes? For standard 3-digit codes, the first two numbers are significant digits, and the third is the multiplier (10^x). For 4-digit codes (precision), the first three are significant. The EIA-96 system uses a two-digit code and a letter multiplier. This authoritative guide covers all calculation methods, updated for 2026 industry standards.What are SMD Resistors? (2026 Overview)SMD Resistor, also known as a Chip Resistor, is a surface-mount passive component essential for modern high-density electronics. Manufactured by sintering metal powder and glass glaze on a ceramic substrate, these components offer superior resistance to humidity, high temperatures, and vibration compared to legacy through-hole parts. As of 2026, they are the industry standard for everything from AI hardware to smartphones. While different resistors feature varied specifications, the critical question remains: how are these microscopic resistance values marked and decoded? Figure 1. Structure of SMD ResistorsⅠ How to Read Resistor Markings: 4 Key MethodsTo master resistor identification, one must understand the four global standards used to denote resistance values. These methods are governed by IEC 60062 standards:1. Direct Marking MethodThis method prints the actual numbers and unit symbols directly on the resistor surface. The allowable error (tolerance) is expressed as a percentage. If no deviation is marked, the standard tolerance is typically ±20%.2. Text Symbol MethodThis approach uses a combination of Arabic numerals and text symbols to indicate the nominal resistance and tolerance. The number preceding the symbol represents the integer value, while the number following represents the decimal. Tolerance characters are standardized: D (±0.5%), F (±1%), G (±2%), J (±5%), K (±10%), M (±20%).3. Digital Method (Most Common for SMD)This method uses a 3-digit or 4-digit code. Read from left to right, the initial digits represent the significant figures (effective values), and the final digit is the exponent (multiplier), indicating the number of zeros to add. The unit is always Ohms (Ω).4. Color Code Marking MethodWhile rare on modern SMDs (except MELF packages), color bands are the standard for through-hole resistors. The bands represent values and multipliers:Black (0), Brown (1), Red (2), Orange (3), Yellow (4)Green (5), Blue (6), Violet (7), Gray (8), White (9)Tolerance: Gold (±5%), Silver (±10%), Colorless (±20%)Figure 2. Universal Resistor Color Code DiagramReading Tip: For a four-band resistor, the last band (usually gold/silver) is the tolerance. The first two bands are digits, and the third is the multiplier. For five-band precision resistors, the first three are digits, the fourth is the multiplier, and the fifth is the tolerance. Ⅱ Calculating SMD Resistor Values (Step-by-Step)2.1 Understanding Character Code MarkingsVideo: SMD Resistor Coding ExplainedMarking chip resistors requires a compact system due to the component's microscopic size. While large packages may use full numbers, 0603, 0805, and 1206 packages use coded systems. Here is the 2026 standard breakdown for decoding these values:The 3-Digit System (Standard Tolerance ±5%):1. The first and second digits represent the significant resistance figures.2. The third digit is the multiplier (10^x).Decoding Guide by Third Digit:• Ends in 0: No extra zeros. Example: 100 = 10 Ω.• Ends in 1: Add one zero (x10). Example: 101 = 100 Ω.• Ends in 2: Add two zeros (x100). Example: 102 = 1,000 Ω (1 kΩ).• Ends in 3: Add three zeros (x1,000). Example: 103 = 10,000 Ω (10 kΩ).• Ends in 4: Add four zeros. Example: 104 = 100 kΩ.• Ends in 5: Add five zeros. Example: 105 = 1 MΩ.• Ends in 6: Add six zeros. Example: 106 = 10 MΩ.The 4-Digit System (Precision Tolerance ±1%):For higher precision, three significant digits are used. Example: 1001 means 100 + one zero = 1000 Ω (1 kΩ).Note: Ultra-small packages like 01005, 0201, and 0402 are physically too small for markings. These must be measured with a multimeter or tracked via reel tape labeling.2.2 Real-World Calculation ExamplesCase 1: 3-Digit Code (±5% Tolerance)This uses two significant digits followed by a multiplier.Calculation: 153 → 15 followed by 3 zeros → 15,000 Ω = 15 kΩDecimal Values: "R" represents the decimal point. Code 6R8 → 6.8 ΩCase 2: 4-Digit Code (±1% Tolerance)Common on packages like 0805, 1206, and 2512. The first three digits are significant.Calculation: 2372 → 237 followed by 2 zeros → 23,700 Ω = 23.7 kΩDecimal Values: 3R24 → 3.24 ΩCase 3: EIA-96 System (The "Cryptic" Code)Used for 1% tolerance resistors on small 0603 packages where 4 digits won't fit. This system uses a two-digit code (referencing a lookup table) and a letter multiplier.Format: [Code] [Letter]Example Multipliers: Y=0.01, X=0.1, A=1, B=10, C=100, D=1000, E=10000.E-96 Series Standard Resistance Lookup Table (Partial)ValueCodeValueCodeValueCode100011471721533102021501822134105031541922635107041582023236110051622123737113061652224338115071692324939118081742425540121091782526141124101822626742127111872727443130121912828044133131962928745137142003029446140152053130147143162103230948 ValueCodeValueCodeValueCode316494646568181324504756669882332514876771583340524996873284348535116975085357545237076886365555367178787374565497280688383575627382589392585767484590402595907586681412606047688792422616197790993432626347893194442636497995395453646658097696EIA-96 Calculation Examples:Code 29B: Lookup "29" in table → Value 196.Multiplier "B" → x10.Result: 196 × 10 = 1.96 kΩCode 10X: Lookup "10" in table → Value 124.Multiplier "X" → x0.1.Result: 124 × 0.1 = 12.4 ΩCase 4: The Underlined Code (Special 0603 Case)Sometimes you see a standard 3-digit code with a line under it on an 0603 package. This usually indicates the manufacturer uses the E-24 series values (loose tolerance) rather than E-96, but the calculation is standard.122 = 12 × 100 = 1.2 kΩ680 = 68 × 1 = 68 Ω (Note: 680 does not mean 680 ohms here, it means 68 and zero extra zeros). Ⅲ How to Identify Damaged SMD Resistor Values?When a resistor is burned or the marking is unreadable, use these four forensic engineering methods to deduce the value:1. Parallel Circuit ComparisonPCB designs, especially in power supplies and audio amplifiers, often use symmetrical channels. • Example: In an LCD backlight driver, if the resistor in Channel A is burnt, check the corresponding position in Channel B. Often R17 = R51, or R23 = R48. Measure the intact sibling component to find the value.2. Circuit Context Analysis (Pull-Up/Pull-Down)For Microcontroller (MCU) circuits, resistors connected to GPIO pins are typically "pull-up" or "pull-down" resistors used to stabilize logic levels.• Common Values: 3.3kΩ, 4.7kΩ, 10kΩ.• Deduction: If the resistor connects a data line to VCC or GND, replacing it with a 10kΩ resistor is a safe starting point for testing.3. Reference Similar SchematicsIf the exact schematic is unavailable, search for schematics of devices using the same main IC. Manufacturers often use the "Reference Design" provided by the chipmaker, meaning the peripheral resistor values will be identical across different brands.4. The Potentiometer Test (Advanced)If all else fails, trace the circuit diagram. Temporarily solder a high-value potentiometer (variable resistor) in place of the damaged part. Power on the device and slowly adjust the resistance while monitoring voltage levels until the circuit functions correctly. Remove the potentiometer, measure its set resistance, and replace it with the closest standard fixed resistor.  Ⅳ Top SMD Resistor Manufacturers (2026 Updated)Reliability is paramount in 2026 electronics. The following brands are currently recognized as Tier-1 manufacturers for automotive, industrial, and consumer electronics:YAGEO: Global leader in chip resistors (acquired KEMET).Vishay: Known for high-precision, military-grade foil resistors.Panasonic: Industry standard for high-reliability automotive parts.KOA Speer: Major supplier for automotive and industrial markets.Bourns: Famous for circuit protection and resistors.TE Connectivity: Specialist in harsh environment resistors.Other Notable Brands: ROHM, Ohmite, Welwyn, TT Electronics, UNI-ROYAL (Uniohm). ⅴ Frequently Asked Questions (FAQ)1. What is an SMD resistor used for?SMD (Surface Mount Device) resistors limit current, divide voltage, and stabilize signal lines in compact electronic circuits. They are essential for miniaturizing devices like smartphones, wearables, and IoT sensors where traditional through-hole components would be too bulky. 2. How do I calculate the value of a 3-digit SMD resistor?Use the formula: [1st Digit][2nd Digit] x 10^[3rd Digit]. For example, "103" means 10 x 10^3 (1000) = 10,000 Ohms or 10kΩ. 3. What does "R" mean in a resistor code like 4R7?The letter "R" represents the decimal point. It is used when the resistance value is too small to use a multiplier code. Therefore, 4R7 equals 4.7 Ohms. 4. What is the difference between 103 and 1002 markings?Both equal 10kΩ, but the marking indicates tolerance. "103" (3-digit) typically indicates ±5% tolerance. "1002" (4-digit) indicates higher precision, typically ±1% tolerance. 5. How do I read the cryptic "01A" or "29B" codes?These are EIA-96 codes for 1% precision resistors on small 0603 parts. You cannot read them directly; you must use an EIA-96 lookup table. The number refers to a value code, and the letter is the multiplier. 6. Why do some SMD resistors have no markings?Resistors in package sizes 0402, 0201, and 01005 are physically too small to print legible text. To identify these, you must measure them with a multimeter or refer to the manufacturer's reel tape packaging. 7. What does SMD stand for?SMD stands for Surface Mounted Device. It refers to the component itself. SMT (Surface Mount Technology) refers to the manufacturing process of placing these components onto a PCB. 8. What materials are SMD resistors made of?Most SMD resistors are "Thick Film" or "Thin Film" types. They consist of a ceramic substrate (alumina) coated with a resistive paste (metal oxides and glass). This is fired in a kiln, laser-trimmed to the exact value, and then coated with a protective layer.{ "@context": "https://schema.org", "@type": "Article", "mainEntityOfPage": { "@type": "WebPage", "@id": "https://www.kynix.com/Blog/How-to-Read-the-Value-of-SMD-Resistor-Example-Explained.html" }, "headline": "How to Read SMD Resistor Codes: The 2026 Guide to 3-Digit, 4-Digit & EIA-96 Markings", "image": "https://www.kynix.com/editor_u/image/20211027/2021102711243403.jpg", "author": { "@type": "Organization", "name": "Kynix Electronics" }, "publisher": { "@type": "Organization", "name": "Kynix Electronics", "logo": { "@type": "ImageObject", "url": "https://www.kynix.com/logo.png" } }, "datePublished": "2021-10-27", "dateModified": "2026-01-08", "description": "Learn how to calculate SMD resistor values using 3-digit, 4-digit, and EIA-96 codes. Includes updated 2026 lookup tables and troubleshooting steps for damaged components.", "articleBody": "SMD Resistor, called Chip Resistor, is one type of resistors..."}{ "@context": "https://schema.org", "@type": "FAQPage", "mainEntity": [{ "@type": "Question", "name": "What is an SMD resistor used for?", "acceptedAnswer": { "@type": "Answer", "text": "SMD (Surface Mount Device) resistors limit current, divide voltage, and stabilize signal lines in compact electronic circuits like smartphones and IoT devices." } }, { "@type": "Question", "name": "How do I calculate the value of a 3-digit SMD resistor?", "acceptedAnswer": { "@type": "Answer", "text": "Use the formula: [1st Digit][2nd Digit] x 10^[3rd Digit]. For example, 103 means 10 x 1000 = 10,000 Ohms (10kΩ)." } }, { "@type": "Question", "name": "What does 'R' mean in a resistor code like 4R7?", "acceptedAnswer": { "@type": "Answer", "text": "The letter 'R' acts as a decimal point. 4R7 represents 4.7 Ohms." } }, { "@type": "Question", "name": "How do I read EIA-96 codes like 01A?", "acceptedAnswer": { "@type": "Answer", "text": "EIA-96 codes require a lookup table. The number represents a significant value, and the letter represents a multiplier. For '01A', 01 is 100 and A is x1, resulting in 100 Ohms." } }]}{ "@context": "https://schema.org", "@type": "HowTo", "name": "How to Read a 3-Digit SMD Resistor Code", "description": "Step-by-step guide to calculating resistance from standard 3-digit markings found on most chip resistors.", "step": [{ "@type": "HowToStep", "name": "Identify the Significant Digits", "text": "Read the first two numbers on the resistor. These are your significant digits (e.g., in '103', the significant digits are '10')." }, { "@type": "HowToStep", "name": "Identify the Multiplier", "text": "Read the third number. This indicates the power of 10 to multiply by (or how many zeros to add). In '103', the multiplier is 3 (10^3 or 1000)." }, { "@type": "HowToStep", "name": "Calculate the Result", "text": "Multiply the significant digits by the multiplier. 10 x 1000 = 10,000 Ohms (10kΩ)." }]}