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Resistors

What the Function of Resistors in Transistor Circuits?

Introduction A resistor is a passive two-terminal electrical component. After it is connected to the circuit, the resistance is fixed, which can limit the current through the branch connected to it. On one hand, the resistance that cannot be changed is called a fixed resistor, on the other hand, the resistances of potentiometers or variable resistors are changeable. The main physical characteristic of a resistor is to transform electrical energy into thermal energy. It can also be said that it is an energy-consuming element, because internal energy is generated when current passes through it. Figure 1. Use Resistor in Circuit Catalog Introduction Ⅰ Functions of Resistor Ⅱ Three Basic Principles for Resistor Selection Ⅲ The Role of Resistors in Transistor Circuits 3.1 Why Should a Resistor Be Added to the Base of the Transistor? 3.2 Pull-down Resistor in Transistor Circuits Ⅳ FAQ Ⅰ Functions of Resistor In short, the function of resistance is to limit current, divide current, divide voltage, and convert electric energy into internal energy (heating) in the circuit. According to Ohm's law, through calculations, resistors in parallel and series connections can be used to achieve the desired current and voltage. Also there are different resistors and switches combined to produce voice-activated switches, photosensitive switches, infrared switches and so on. How to Use Resistors in circuits? 1) Limit CurrentIn order to prevent the components connected in series from being burnt out by the excessive current and to ensure the normal operation of the electrical appliances, a variable resistor can usually be connected in series in the circuit.2) Current DiversionThe resistor is connected in parallel to the component or circuit that needs to be shunted, and the voltage does not change. The function of this resistor is to divide current.3) Voltage DiversionGenerally, electrical appliances are marked with a rated voltage value. If the power supply is higher than it, the electrical appliance cannot be directly connected to the power supply for a normal operation. In this case, a resistor with suitable resistance can be connected in series in the circuit to share a part of the voltage, therefore the electrical appliance can work at the rated voltage. At this time, the role of the resistor is to divide the voltage.4) Provide Bias VoltageIn the transistor circuit, the resistor is connected between the base of it and the working voltage. At this time, the power supply provides a bias voltage to the base through the resistor, and the resistance can determine the bias voltage. The role of the resistor in the circuit at this time is to provide a bias voltage.5) Negative FeedbackUsed in the resistance between the base and collector of the transistor, then the feedback branch of the negative feedback circuit is formed in the circuit. At this time, the resistor plays a negative feedback role in the circuit.6) OscillationResistor and capacitor form an RC circuit, which can be combined in parallel and in series.7) Damping EffectConnecting a resistor in parallel in the LC resonant circuit can reduce the Q value, at this time, resistor plays a damping effect.8) DecouplingThe use of resistors in multi-stage amplifier circuits can prevent harmful low-frequency interference, which play a decoupling effect.9) Convert Electrical Energy into Internal Energy (Heating)When the current passes through the resistor, it will convert all (or part) of the electrical energy into internal energy, which will generate heat. This principle is often used in electric stoves and heaters in our lives.10) Convert Current into VoltageWhen current flows through the resistor, a voltage will be generated across the resistor. As shown in the figure below, the collector load resistor R2 plays this role, converting the current flowing through the resistor R2 into a voltage and outputting it from U0. Figure 2. Resistor Circuit   Ⅱ Three Basic Principles for Resistor Selection 1) Choose resistors that are manufactured by a certification body that implement high-level standards.2) Choose resistors produced by manufacturers with functional advantages, quality advantages, efficiency advantages, price advantages, and service advantages.3) Choose a manufacturer that can meet the above-mentioned requirements in the model catalog.   Ⅲ The Role of Resistors in Transistor Circuits 3.1 Why Should a Resistor Be Added to the Base of the Transistor? First of all, we must understand the basic principle of the transistor. It is a current-controlled element, which is different from the MOFET, a voltage-controlled element. The transistor has three working areas: cut-off area, amplification area and saturation area. Take NPN transistor as an example, the voltage difference(UBE)of BE is about 0.6V (the actual size depends on the model of the component). When UBE<0.6V , the transistor is off; when UBE=0.6V, the transistor is in the amplification or saturation region. Figure 3. Schematic Diagram of the NPN Transistor Current When the transistor is in the amplification area, the added resistance between the base and VCC is a bias resistance. The following explains why the base should be added when the transistor is used as a switch. What is the difference between transistor and MOSFET circuits when adding a resistor.The following figure is the most commonly used circuit diagram of NPN transistors. The common input terminal is the I/O port of the microprocessor (microcontroller, DSP, ARM, etc.). Figure 4.  NPN Transistor Take the microcontroller I/O port with 0/5V input as an example. Why must a resistor be connected in series with the base? Can it work without a resistor? Here the resistor is a current control element. When the transistor is in an amplified or saturated state, the voltage of the UBE is 0.6V, and the base current can be calculated according to the input voltage U. The calculation formula is Ib=(U-0.6 )/R1. It can also be seen from the formula that if the current limiting resistor R1 is not connected, when the input voltage is greater than 0.6V, the base current will be very large to burn the tube.Moreover, the resistor cannot be used casually. It needs to be calculated according to the input voltage and the characteristics of the tube. For example, the amplification factor β of the transistor is 50, the maximum current of the collector is 500mA, and the input voltage is 5V. If the design requires the transistor to be in a saturated state, then Ic=500mA, Ib=Ic/β=10M=mA, where the current-limiting resistance R1=(5V-0.6V)/Ib=430Ω. If it is required to input 5V, the collector current is about 200mA, then Ib=Ic/β=200mA/50=4mA can be calculated, finally the current-limiting resistance R1=(5V-0.6V)/Ib=1075Ω (1K can be selected Standard resistance). Note: The above figure is used to explain the example, but it is not very reliable. A more reliable connection method should be to connect a large resistor (such as 10K, or 20K) between the base and the ground. When there is no input, pull the base down quickly to ensure that the tube is in a stable cut-off state.If the NPN transistor in the figure above is replaced with an N-channel MOS tube, the principle is the same. When a high level is input, the tube is turned on, and when a low level is input, the tube is turned off. Figure 5. MOSFET Circuit Since the MOSFET is a voltage-controlled device, the current of the gate (G) is very small and can be ignored, so it can work normally without connecting the resistor R1.The figure after remove the resistor is shown in the below: Figure 6. MOSFET Circuit without Resistor Note: In actual applications, a resistor is generally connected in series to improve reliability. The product reliability is very important. Without current-limiting resistor, when the MOS is   damaged by voltage breakdown, the components on the control terminal will be affected easily, especially the processor, is easily damaged by high current. 3.2 Pull-down Resistor in Transistor Circuits 🔺For TransistorsThe transistor is a current-type driving component, so a current-limiting resistor is connected to the base, generally less than 10K, and the typical values are 3.3K, 4.7K, 5.1K, 6.8K, etc. What is the function of this pull-down resistor?The following figure shows the transistor 8050 switching circuit. The transistor will be turned on when the I/O port outputs a high level, and the transistor will not be turned on. If the I/O port does not output a high level, the base will always be pulled low without a 68K pull-down resistor, that is to say it is in the cut-off state. The circuit may be in an unstable state, especially when it is initialized at the moment of power-on. It is easy to generate noise and easily cause the transistor to malfunction, especially for some general input/output ports. Therefore, this resistor is actually a bias resistor, which makes the base to be pulled down when there is no driving signal, making the circuit more reliable. Figure 7.  Pull-down Resistor in Transistor Circuit Although the pull-down resistor can make the circuit more reliable, tit cannot be too large or too small. If the resistance too large, the base current will not be enough to drive the transistor. On the contrary, if it is too small, the bias voltage will be less than the transistor conduction voltage. In general, this resistance is not more than 100K.Sometimes we see that a capacitor is connected in parallel with this resistor. In fact, this is generally designed in high-speed signal switching circuits. Adding a capacitor can improve performance, as shown below: Figure 8.  RC Circuit 🔺For MOSFETUnlike transistors, MOS transistors are voltage-controlled components, which are driven by voltage. We all know that there is parasitic capacitance between the two pins of MOS transistors. In fact, the key of MOS transistors’ conduction is the charging and discharging of capacitors. Therefore, for the N-type MOS, it will be turned on when Vgs is greater than a certain value, but for the P-type MOS, it will be turned on when the value of Vgs is less than a certain value.Therefore, due to the capacitive effect between the three pins, when the MOS is constantly turned off, the parasitic capacitance voltage can be properly discharged, which is similar to the role of a bleeder resistor and is a kind of protection for the MOS. Figure 9.  MOSFET Circuit Ⅳ FAQ 1. What is the function of the resistor?A resistor has the ability to reduce voltage and current when used in a circuit. The main function of a resistor is to limit current flow. Ohm's law tells us that an increase in a resistors value will see a decrease in current.   2. How do resistors work?A conductor has low resistance, while an insulator has much higher resistance. Devices called resistors let us introduce precisely controlled amounts of resistance into electrical circuits. ... A resistor works by converting electrical energy into heat, which is dissipated into the air.   3. Why do you need resistors?A resistor controls the flow of the electrical current within a circuit. ... Resistors are essential to many electoral circuits, and they can be applied to a myriad of different applications. Protect against voltage spikes. Resistors also protect components against voltage spikes.   4. What role do resistors play in electronic devices?A resistor is a passive two-terminal electrical device that resists the flow of current. It is probably the simplest element in an electronic circuit. It is also one of the most common components as resistance is an inherent element of nearly all electronic circuits. They are usually color-coded.   5. What is a good example of a resistor?A few examples include limiting electric current, voltage division, heat generation, matching and loading circuits, gain control, and setting time constants. They are commercially available with resistance values over a range of more than nine orders of magnitude.   6. What happens if I use a higher ohm resistor?The cases where using a higher value resistor will damage a circuit exist, but are a bit less usual than the cases where it may simply produce a weaker result than desired, or a different frequency response than desired.   7. What is a resistor simple explanation?A resistor is an electrical component that limits or regulates the flow of electrical current in an electronic circuit. Resistors can also be used to provide a specific voltage for an active device such as a transistor. ... The most common type in electronic devices and systems is the carbon-composition resistor.   8. What happens when a resistor blows?Blowing Up a Resistor. By applying too high a voltage to a resistor, the resistor will draw too much current. This causes excessive power to be dissipated in the resistor which makes it go up in flames and a cloud of smoke as this video shows.   9. How is a resistor connected in a circuit?Resistors are said to be connected in “Series”, when they are daisy chained together in a single line. Since all the current flowing through the first resistor has no other way to go it must also pass through the second resistor and the third and so on.   10. Do resistors change voltage?The larger the resistor, the more energy used by that resistor, and the bigger the voltage drop across that resistor. Ohm's Law can be used to verify voltage drop. In a DC circuit, voltage equals current multiplied by resistance. V = I R.
kynix On 2021-09-24   3231
Resistors

The Best Guide to Capacitor Code

Ⅰ IntroductionWhen connected to a voltage source, capacitors are basic passive devices that can store an electrical charge on their plates. The capacitor, like a miniature rechargeable battery, has the ability or "capacity" to store energy in the form of an electrical charge, producing a potential difference (Static Voltage) across its plates. Capacitors come in a variety of sizes and shapes, ranging from tiny capacitor beads used in resonance circuits to enormous power factor correction capacitors, but they always store charge. this video shows how capacitors work CatalogⅠ IntroductionⅡ Types of Capacitor2.1 Dielectric Capacitor2.2 Variable Capacitor Symbol2.3 Film Capacitor Type2.4 Axial Lead Type2.5 Ceramic Capacitors2.6 Electrolytic Capacitors2.7 Aluminium Electrolytic Capacitors2.8 Tantalum Electrolytic Capacitors2.9 Frequently Asked Questions About Different Types Of CapacitorⅢ The Capacitance of a Capacitor3.1 SI Unit of Capacitance3.2 μF vs. nF vs. pF3.3 Frequently Asked Questions about the Capacitance of a CapacitorⅣ Capacitor Conversion: µF-nF-pF 4.1 Capacitor Conversion Chart4.2 Popular Capacitor Conversions4.3 Frequently Asked Questions about Capacitor ConversionⅤ Capacitor Color Code5.1 Capacitor Colour Code Tables5.2 Color Codes of Different Capacitors5.3 Frequently Asked Questions about Capacitor Color CodeⅥ Capacitor Code6.1 Types of Capacitor Code6.2 Frequently Asked Questions about Capacitor CodeⅦ Capacitor Code Calculator7.1 Capacitor Safety Discharge Calculator Tool7.2 Series and Parallel Capacitance Calculator Ⅱ Types of CapacitorFrom very small delicate trimming capacitors used in oscillator or radio circuits to enormous power metal-can type capacitors used in high voltage power correction and smoothing circuits, capacitors are available. The dielectric used between the plates is commonly used to make comparisons between different types of capacitors. There are variable varieties of capacitors, just like resistors, that allow us to adjust their capacitance value for use in radio or "frequency tuning" circuits. Metallic foil is interwoven with thin sheets of either paraffin-impregnated paper or Mylar as the dielectric material in commercial capacitors. Because the metal foil plates are rolled up into a cylinder to produce a compact box with the insulating dielectric material sandwiched in between, some capacitors resemble tubes. Ceramic materials are frequently used to make small capacitors, which are subsequently sealed with epoxy resin. Capacitors play a crucial role in electronic circuits in any case, therefore here are a few of the most "common" capacitor types available. 2.1 Dielectric CapacitorWhen a constant variation in capacitance is necessary for tuning transmitters, receivers, and transistor radios, dielectric capacitors are normally of the variable variety. Multi-plate air-spaced variable dielectric capacitors have a set of fixed plates (the stator vanes) and a set of movable plates (the rotor vanes) that move in between the fixed plates. The overall capacitance value is determined by the position of the moving plates concerning the fixed plates. When the two sets of plates have entirely meshed together, the capacitance is usually at its highest. With breakdown voltages in the thousands of volts, high voltage tuning capacitors have relatively large spacings or air gaps between the plates. 2.2 Variable Capacitor SymbolTrimmers are pre-set type variable capacitors that are available in addition to continuously variable varieties. These are typically small devices that may be modified or "pre-set" to a specific capacitance value with a small screwdriver, and are available in very low capacitances of 500pF or less, and are non-polarized. variable capacitor symbol 2.4 Axial Lead TypeLong thin strips of thin metal foil with the dielectric material sandwiched between them are twisted into a tight roll and then sealed in paper or metal tubes for film and foil capacitors. To lessen the possibility of tears or punctures in the film, these film types require a significantly thicker dielectric film and are thus better suited to lower capacitance values and bigger case sizes. axial-lead-type Metalized foil capacitors have the conductive film metalized sprayed directly onto each side of the dielectric, giving the capacitor self-healing capabilities and allowing thinner dielectric films to be used. For a given capacitance, this enables for larger capacitance values and smaller case sizes. Film and foil capacitors are typically employed in situations that require more power and precision. 2.5 Ceramic CapacitorsCeramic capacitors, also known as Disc capacitors, are created by coating two sides of tiny porcelain or ceramic disc with silver and stacking them together to form a capacitor. A single ceramic disc of roughly 3-6mm is utilized for very low capacitance values. Ceramic capacitors have a high dielectric constant (High-K) and are available in tiny physical sizes, allowing for relatively high capacitances. ceramic capacitor Because they are non-polarized and exhibit huge non-linear changes in capacitance with temperature, they are employed as de-coupling or by-pass capacitors. Ceramic capacitors range in size from a few picofarads to one or two microfarads, but their voltage ratings are often modest. A three-digit code is usually inscribed on the body of ceramic capacitors to identify their capacitance value in pico-farads. The first two digits usually represent the capacitor's value, while the third digit represents the number of zeros to be added. A ceramic disc capacitor marked 103, for example, would indicate 10 and 3 zeros in pico-farads, which is equal to 10,000 pF or 10nF. The numerals 104, for example, represent 10 and 4 zeros in pico-farads, which is comparable to 100,000 pF or 100nF, and so on. The digits 154 on the ceramic capacitor image above represent 15 and 4 zeros in pico-farads, which is comparable to 150,000 pF, 150nF, or 0.15F. To signify their tolerance value, letter codes are occasionally employed, such as J = 5%, K = 10%, M = 20%, and so on. 2.6 Electrolytic CapacitorsWhen very large capacitance values are required, electrolytic capacitors are typically utilized. Instead of employing a very thin metallic film layer for one of the electrodes, a semi-liquid electrolyte solution in the form of jelly or paste is employed (usually the cathode). The dielectric is a very thin layer of oxide that is produced electrochemically in the manufacturing process and has a thickness of fewer than ten microns. Because the insulating layer is so thin, capacitors with a big capacitance value can be made in a small physical size because the distance between the plates, d, is so short. electrolytic capacitor The majority of electrolytic capacitors are polarized, which means that the DC voltage applied to the capacitor terminals must be of the correct polarity, i.e. positive to the positive terminal and negative to the negative terminal, or the insulating oxide layer will be broken down and permanent damage may result. The polarity of all polarized electrolytic capacitors is indicated with a negative sign to signify the negative terminal, which must be followed. Due to their huge capacitance and small size, electrolytic capacitors are commonly employed in DC power supply circuits to help reduce ripple voltage or for coupling and decoupling applications. Electrolytic capacitors have a low voltage rating, which means that they can't be utilized on AC supply because of their polarization. Aluminium Electrolytic Capacitors and Tantalum Electrolytic Capacitors are the two most common types of electrolytes. 2.7 Aluminium Electrolytic CapacitorsThe plain foil type and the etched foil type are the two varieties of Aluminum Electrolytic capacitors. These capacitors have extremely high capacitance values for their size due to the thickness of the aluminum oxide coating and the high breakdown voltage.aluminium electrolytic capacitor A DC current is used to anodize the capacitor's foil plates. The polarity of the plate material is established during the anodizing process, which defines which side of the plate is positive and which side is negative. The aluminum oxide on the anode and cathode foils has been chemically etched to increase surface area and permittivity, which makes the etched foil type different from the plain foil type. This results in a smaller capacitor than a normal foil type of comparable value, but it has the disadvantage of not being able to handle strong DC currents. Their tolerance range is also fairly high, reaching up to 20%. Capacitance values for aluminum electrolytic capacitors typically range from 1uF to 47,000uF. Plain foil electrolytes are better suited as smoothing capacitors in power supply, while etched foil electrolytes are best employed in the coupling, DC blocking, and by-pass circuits. However, because aluminum electrolytes are “polarized” devices, inverting the applied voltage on the leads will damage the insulating layer within the capacitor, as well as the capacitor itself. The capacitor's electrolyte, on the other hand, aids in the healing of a damaged plate if the damage is minor. The electrolyte has the power to re-anodize the foil plate since it can self-heal a damaged plate. The electrolyte can remove the oxide layer from the foil if the anodizing process is reversed, as it would if the capacitor was connected with reverse polarity. Because the electrolyte can conduct electricity, if the aluminum oxide layer is removed or destroyed, current can flow from one plate to the other, causing the capacitor to fail, "so be alert." 2.8 Tantalum Electrolytic CapacitorsTantalum Electrolytic Capacitors and Tantalum Beads come in both wet (foil) and dry (solid) electrolytic varieties, with dry tantalum being the most prevalent. Solid tantalum capacitors have a second terminal of manganese dioxide and are physically smaller than analogous aluminum capacitors. Tantalum oxide's dielectric characteristics are superior to those of aluminum oxide, resulting in reduced leakage currents and greater capacitance stability, making it ideal for blocking, by-passing, decoupling, filtering, and timing applications. Tantalum capacitors, although being polarized, can withstand being linked to a reverse voltage considerably better than aluminum capacitors, but they are rated at much lower operating voltages. Solid tantalum capacitors are commonly employed in circuits with low AC voltages compared to DC voltages. Some tantalum capacitors, on the other hand, comprise two capacitors in one, connected negative-to-negative to make a “non-polarized” capacitor for use in low voltage AC circuits. The positive lead of a tantalum bead capacitor is usually identifiable by a polarity mark on the capacitor body, which has an oval geometrical shape. Capacitance values typically vary from 47nF to 470F. 2.9 Frequently Asked Questions About Different Types Of Capacitor1. Which type of capacitor is best?Class 1 ceramic capacitors offer the highest stability and lowest losses. They have high tolerance and accuracy and are more stable with changes in voltage and temperature. Class 1 capacitors are suitable for use as oscillators, filters, and demanding audio applications. 2. Does the type of capacitor matter?Yes, the type of capacitor can matter. Different types of capacitor have different properties. Some of the properties that vary between capacitor types: polarized vs unpolarized. 3. Are all capacitors the same?Not all capacitors are created equal. Each capacitor is built to have a specific amount of capacitance. The capacitance of a capacitor tells you how much charge it can store, more capacitance means more capacity to store charge. 4. Which type of capacitor is known as Polarised capacitor?Electrolytic Capacitors. The Electrolytic Capacitors are the capacitors which indicate by the name that some electrolyte is used in it. They are polarized capacitors which have anode + and cathode − with particular polarities. A metal on which insulating oxide layer forms by anodizing is called as an Anode. 5.Which capacitors are not polarized?Ceramic, mica and some electrolytic capacitors are non-polarized. You'll also sometimes hear people call them "bipolar" capacitors. A polarized ("polar") capacitor is a type of capacitor that have implicit polarity -- it can only be connected one way in a circuit. Ⅲ The Capacitance of a CapacitorThe Farad (abbreviated to F) is the unit of capacitance and is named after the British physicist Michael Faraday. Capacitance is the electrical property of a capacitor and is the measure of a capacitor's ability to store an electrical charge onto its two plates. When a charge of One Coulomb is stored on the plates by a voltage of One volt, a capacitor has a capacitance of One Farad. It's worth noting that capacitance, or C, is always positive and has no negative units. However, because the Farad is a relatively big unit of measurement on its own, sub-multiples such as micro-farads, nano-farads, and pico-farads are commonly used. 3.1 SI Unit of CapacitanceCapacitors are a common type of electrical component, and their values are usually stated in microfarads, F (or uF if a micro character is not available), nanofarads, nF, or picofarads, pF. Microfarad (μF)  1μF = 1/1,000,000 = 0.000001 = 10-6 FNanofarad (nF)  1nF = 1/1,000,000,000 = 0.000000001 = 10-9 FPicofarad (pF) 1pF=1/1,000,000,000,000 = 0.000000000001 = 10-12 F 3.2 μF vs. nF vs. pFAlthough most current circuits and component descriptions use the nomenclature F, nF, and pF to specify capacitor values, older circuit designs, circuit descriptions, and even the components themselves may employ a variety of non-standard acronyms that aren't always evident. The following are the main changes for the various capacitance sub-multiples: Micro-Farad, µF: Larger value capacitors, such as electrolytic capacitors, tantalum capacitors, and even some paper capacitors measured in micro-Farads, may have been labeled with uF, mfd, MFD, MF, or UF. All of these terms refer to the value in µF. Electrolytic and tantalum capacitors are commonly connected with this nomenclature. Nano-Farad, nF: Because nF or nano-Farads nomenclature was not frequently used prior to terminology standardization, this submultiple lacked a variety of abbreviations. The term nanofarad has gained in popularity in recent years, while it is still not widely used in some countries, with values given in huge numbers of picofarads, such as 1000pF for 1 nF, or fractions of a microfarad, such as 0.001 µF for a nanofarad. Ceramic capacitors, metalized film capacitors, including surface mount multilayer ceramic capacitors, and even some modern silver mica capacitors all use this terminology. Pico-Farad, pF: The value in picoFarads, pF, was again indicated using a variety of acronyms.  MicroromicroFarads, mmfd, MMFD, uff, µµFwere among the terms used. All of these numbers are in pF. Picofarad capacitor values are commonly employed in radio frequency, RF circuits, and equipment. As a result, this nomenclature is most commonly associated with ceramic capacitors, however, it is also applied to silver mica capacitors and some film capacitors. The conversion of values from one submultiple to the next has been aided by the standardization of terminology. It has resulted in a significant reduction in the potential for misunderstanding. Converting from µF to nF and pF is simpler. This is important when a capacitor value is listed in one way on a circuit diagram and another way on a list of electronic components distributors. Because different electrical component manufacturers label components differently, the capacitance conversion table is highly useful. For example, some manufacturers label their equivalent capacitors as a fraction of a microfarad, while others label them as a fraction of a nanofarad, and so on. Electrical component wholesalers and retailers will prefer to adopt the manufacturer's nomenclature. Similarly, circuit diagrams may use different symbols to represent components to maintain commonality, etc. As a result, being able to convert between picofarads, nanofarads, and microfarads, as well as vice versa, is beneficial. When the bill of materials or parts list for the circuit has values expressed in microfarads, µF, and picofarads, pF, this can aid identify components labeled in nanofarad values. It is generally useful to be able to utilize a capacitance conversion calculator like the one above, but it is also important to be familiar with the conversions and popular equivalents, such as 1000pF = nanofarad and 100nF = 0.1µF. These conversions become second nature while working with electrical components and designing electronic circuits, but the capacitance conversion tables and calculators can still be quite useful. Capacitors, as well as other electronic components like inductors, benefit from these conversions. 3.3 Frequently Asked Questions about the Capacitance of a Capacitor1. What is capacitance in simple terms?Capacitance is the ability of a system of electrical conductors and insulators to store electric charge when a potential difference exists between the conductors. Capacitance is expressed as a ratio of the electrical charge stored to the voltage across the conductors. 2.What is C in capacitance?The capacitance C is the ratio of the amount of charge q on either conductor to the potential difference V between the conductors, or simply C = q/V. 3.What is difference between capacitor and capacitance?Capacitance is nothing but the ability of a capacitor to store the energy in form of electric charge. In other words, the capacitance is the storing ability of a capacitor. It is measured in farads. 4.What is the formula of capacitor?The governing equation for capacitor design is: C = εA/d, In this equation, C is capacitance; ε is permittivity, a term for how well dielectric material stores an electric field; A is the parallel plate area; and d is the distance between the two conductive plates. 5.What four factors affect capacitance?The capacitance of a capacitor is affected by the area of the plates, the distance between the plates, and the ability of the dielectric to support electrostatic forces. Ⅳ Capacitor Conversion: µF-nF-pF  The use of the nanofarad (nF) is less common in some fields, with values stated in fractions of a µF and huge multiples of picofarads (pF). When components marked in nanofarad are available, it may be necessary to convert to nanofards, nF in these circumstances. When a circuit diagram or electronic components list mentions the value in picofarads, for example, and listings for an electronic component distributor or electronic components store state it in another way, it can be confusing. Capacitor values can be in the 109 range or even higher, thanks to the introduction of supercapacitors. The common prefixes pico (10-12), nano (10-9), and micro (10-6) are often used to avoid misunderstanding with high numbers of zeros connected to the values of different capacitors. When converting between them, a capacitor conversion chart or capacitor conversion table for the various capacitor values can be useful. Another requirement for capacitance conversion is that the actual capacitance value is reported in picofarads in some capacitor marking systems, therefore the value must be converted to the more common nanofarads or microfarads. 4.1 Capacitor Conversion ChartMicrofarads ( µF)Nanofarads(nF)Picofarads(pF)0.0000010.00110.000010.01100.00010.11000.001110000.0110100000.11001000001100010000001010000100000001001000001000000004.2 Popular Capacitor ConversionsCapacitor values can be written in a few different ways. A ceramic capacitor, for example, is frequently assigned a value of 100nF. It is often interesting to realize that this is 0.1µF when utilized in circuits with electrolytic capacitors. These handy conversions can aid in the design, construction, and maintenance of circuits. When building circuits or employing capacitors in any fashion, keeping these capacitor conversions in mind when values migrate from picofarads to nanofarads and then nanofarads to microfarads is typically beneficial. A more comprehensive table of conversion factors to convert between the different values, nF to pF, µF to nF etc is given below.Table of Conversion Factors to Convert between µF,nF and pF convertmultiply by:pF     to     nF1 x 10-3pF     to     µF1 x 10-6nF     to     pF1 x 103nF     to     µF1 x 10-3µF     to     pF1 x 106µF     to     nF1 x 103 4.3 Frequently Asked Questions about Capacitor Conversion1. Can I replace a capacitor with a higher uF?An electric motor start capacitors can be replaced with a micro-farad or UF equal to or up to 20% higher UF than the original capacitor serving the motor. 2.What happens if I use a higher uF capacitor?The higher the number of micro-farads, the more energy the capacitor can hold. In theory, if a device has a high uF, it will last longer in a power outage.3.What happens if you use the wrong size capacitor?If the wrong run capacitor is installed, the motor will not have an even magnetic field. This will cause the rotor to hesitate at those spots that are uneven. This hesitation will cause the motor to become noisy, increase energy consumption, cause performance to drop, and cause the motor to overheat. 4.Can I replace a capacitor with a lower capacitance?Yes, it's possible given the necessary skills and tools. Yes, it's safe. The only rating that matters for safety is the rated voltage: if you put a higher voltage than the maximum you might see your cap explode. 5.Can I use a run capacitor in place of a start capacitor?The capacitance and voltage ratings would have to match the original start capacitor specification. A start capacitor can never be used as a run capacitor, because it cannot not handle current continuously. Ⅴ Capacitor Color Code5.1 Capacitor Colour Code TablesWhen the capacitance value is a decimal value, problems with the marking of the "Decimal Point" arise since it is easily overlooked, leading to a misunderstanding of the real capacitance value. Instead of the decimal point, letters like p (pico) or n (nano) are used to indicate the position and weight of the number. A capacitor might be labeled as n47 = 0.47nF, 4n7 = 4.7nF, or 47n = 47nF, for example. Also, capacitors are occasionally labeled with the capital letter K to indicate a value of one thousand pico-Farads, thus a capacitor marked 100K would be 100 x 1000pF or 100nF. An International color-coding scheme was devised many years ago as a simple manner of identifying capacitor values and tolerances to reduce the confusion regarding letters, numbers, and decimal points. The Capacitor Colour Code system, which consists of colored bands (in spectral order) and whose meanings are given below, is a system that consists of colored bands (in spectral order). Band ColourDigit ADigit BMultiplier DTolerance (T) > 10pfTolerance (T) < 10pfTemperature Coefficient (TC)Black00x1± 20%± 2.0pF Brown11x10± 1%± 0.1pF-33×10-6Red22x100± 2%± 0.25pF-75×10-6Orange33x1,000± 3% -150×10-6Yellow44x10,000± 4% -220×10-6Green55x100,000± 5%± 0.5pF-330×10-6Blue66x1,000,000  -470×10-6Violet77   -750×10-6Grey88x0.01+80%,-20%  White99x0.1± 10%± 1.0pF Gold  x0.1± 5%  Silver  x0.01± 10%  Capacitor Colour Code Table Band ColourVoltage Rating (V) Type JType KType LType MType NBlack4100 1010Brown62001001.6 Red10300250435Orange15400 40 Yellow205004006.36Green25600 1615Blue35700630 20Violet50800   Grey 900 2525White31000 2.53Gold 2000   Silver     Capacitor Voltage Colour Code Table Capacitor Voltage ReferenceType J–  Dipped Tantalum Capacitors.Type K–  Mica Capacitors.Type L–  Polyester/Polystyrene Capacitors.Type M–  Electrolytic 4 Band Capacitors.Type N–  Electrolytic 3 Band Capacitors. 5.2 Color Codes of Different Capacitors 1.Metalised Polyester Capacitor  2. Disc & Ceramic Capacitor  For many years, unpolarized polyester and mica molded capacitors were coded using the Capacitor Colour Code system. Although this color coding method is no longer in use, many “old” capacitors can still be found. Small capacitors, such as film or disk kinds, now comply with the BS1852 Standard and its new replacement, BS EN 60062, which replaces the colors with a letter or number coding system. 5.3 Frequently Asked Questions about Capacitor Color Code1. What do capacitor colors mean?All the color bands painted on the capacitors body are used to indicate the capacitance value and capacitance tolerance. The color codes used to represent the capacitance values and capacitance tolerance is similar to that used to represent resistance values and resistance tolerance. 2.How do you read a capacitor code?If you have a capacitor that has nothing other than a three-digit number printed on it, the third digit represents the number of zeros to add to the end of the first two digits. The resulting number is the capacitance in pF. For example, 101 represents 100 pF: the digits 10 followed by one additional zero. 3.Which type of capacitor is available in color code?A color code was used on polyester capacitors for many years. It is now obsolete, but of course there are many still around. The colors should be read like the resistor code, the top three color bands giving the value in pF. Ignore the 4th band (tolerance) and 5th band (voltage rating). 4.Are capacitors color coded?The capacitors use a capacitor color code similar to the resistors color code (3, 4 or 5 bands). The first two colors indicate significant digits of the value of the capacity (in pF), the next colour is the corresponding power of 10, the other two colors are optional and indicate tolerance and maximum voltage. Ⅵ Capacitor Code6.1 Types of Capacitor CodeFor example, a capacitor labeled 474J should be read as 47 times the value listed in Table 1 corresponding to the third number, in this case, 10000: 47 * 10000 = 470000 pF = 470 nF = 0.47µF, with the J indicating a 5% tolerance. If a temperature coefficient is present, the second letter will be it. You'll rapidly learn to tell whether a capacitor's value is expressed in pF, nF, or µF based on its size and kind. The capacitance of a capacitor designated 2A474J is encoded as mentioned above; the two initial signs are the voltage rating, which can be decoded from table 2 below. According to the EIA standard, 2A is a 100V DC rating. Some capacitors are only marked 0.1 or 0.01, mostly in these cases the values are given in µF. Some small capacitance capacitors contain an R between the numbers, such as 3R9, which indicates that the value is less than 10pF and has nothing to do with resistance. 3R9 has a 3.9pF value. Table 1 – Capacitor codes with letters and tolerances3rd numberMultiply withLetterTolerance01D0.5pF110F1%2100G2%31,000H3%410,000J5%5100,000K10%61,000,000M20%7Not usedM20%80.01P+100%/-0%90.1Z+80%/-20% Table 2A – Electronic Industries Alliance (EIA) – DC voltage code table0E = 2.5 VDC2A = 100 VDC3A = 1 kVDC0G = 4.0 VDC2Q = 110 VDC3L = 1.2 kVDC0L = 5.5 VDC2B = 125 VDC3B = 1.25 kVDC0J = 6.3 VDC2C = 160 VDC3N = 1.5 kVDC1A = 10 VDC2Z = 180 VDC3C = 1.6 kVDC1C = 16 VDC2D = 200 VDC3D = 2 kVDC1D = 20 VDC2P = 220 VDC3E = 2.5 kVDC1E = 25 VDC2E = 250 VDC3F = 3 kVDC1V = 35 VDC2F = 315 VDC3G = 4 kVDC1G = 40 VDC2V = 350 VDC3H = 5 kVDC1H = 50 VDC2G = 400 VDC3I = 6 kVDC1J = 63 VDC2W = 450 VDC3J = 6.3 kVDC1M = 70 VDC2J = 630 VDC3U = 7.5 kVDC1U = 75 VDC2I = 650 VDC3K = 8 kVDC1K = 80 VDC2K = 800 VDC  Table 2B – Electronic Industries Alliance (EIA) – AC voltage code table2Q = 125 VAC2T = 250 VAC2S = 275 VAC2X = 280 VAC2F = 300 VACI0 = 305 VACL0 = 350 VAC2Y = 400 VACP0 = 440 VACQ0 = 450 VACV0 = 630 VAC  Table 3 – Capacitor code tablepico-farad (pF)nano-farad (nF)micro-farad (µF) Capacitor Code1 pF capacitor code0.001 nF capacitor code0.000001 µF capacitor code101.5 pF capacitor code0.0015 nF capacitor code0.0000015 µF capacitor code1R52.2 pF capacitor code0.0022 nF capacitor code0.0000022 µF capacitor code2R23.3 pF capacitor code0.0033 nF capacitor code0.0000033 µF capacitor code3R33.4 pF capacitor code0.0039 nF capacitor code0.0000039 µF capacitor code3R93.5 pF capacitor code0.0047 nF capacitor code0.0000047 µF capacitor code4R75.6 pF capacitor code0.0056 nF capacitor code0.0000056 µF capacitor code5R66.8 pF capacitor code0.0068 nF capacitor code0.0000068 µF capacitor code6R88.2 pF capacitor code0.0082 nF capacitor code0.0000082 µF capacitor code8R210 pF capacitor code0.01 nF capacitor code0.00001 µF capacitor code10015 pF capacitor code0.015 nF capacitor code0.000015 µF capacitor code15022 pF capacitor code0.022 nF capacitor code0.000022 µF capacitor code22033 pF capacitor code0.033 nF capacitor code0.000033 µF capacitor code33047 pF capacitor code0.047 nF capacitor code0.000047µF capacitor code47056 pF capacitor code0.056 nF capacitor code0.000056 µF capacitor code56068 pF capacitor code0.068 nF capacitor code0.000068 µF capacitor code68082 pF capacitor code0.082 nF capacitor code0.000082 µF capacitor code820100 pF capacitor code0.1 nF capacitor code0.0001 µF capacitor code101120 pF capacitor code0.12 nF capacitor code0.00012 µF capacitor code121130 pF capacitor code0.13 nF capacitor code0.00013µF capacitor code131150 pF capacitor code0.15 nF capacitor code0.00015 µF capacitor code151180 pF capacitor code0.18 nF capacitor code0.00018 µF capacitor code181220 pF capacitor code0.22 nF capacitor code0.00022 µF capacitor code221330 pF capacitor code0.33 nF capacitor code0.00033 µF capacitor code331470 pF capacitor code0.47 nF capacitor code0.00047 µF capacitor code471560 pF capacitor code0.56 nF capacitor code0.00056 µF capacitor code561680 pF capacitor code0.68 nF capacitor code0.00068 µF capacitor code681750 pF capacitor code0.75 nF capacitor code0.00075 µF capacitor code751820 pF capacitor code0.82 nF capacitor code0.00082 µF capacitor code8211000 pF capacitor code1 / 1n / 1 nF capacitor code0.001 µF capacitor code1021500 pF capacitor code1.5 / 1n5 / 1.5 nF capacitor code0.0015 µF capacitor code1522000 pF capacitor code2 / 2n / 2 nF capacitor code0.002 µF capacitor code2022200 pF capacitor code2.2 / 2n2 / 2.2 nF capacitor code0.0022 µF capacitor code2223300 pF capacitor code3.3 / 3n3 / 3.3 nF capacitor code0.0033 µF capacitor code3324700 pF capacitor code4.7 / 4n7 / 4.7 nF capacitor code0.0047 µF capacitor code4725000 pF capacitor code5 / 5n / 5 nF capacitor code0.005 µF capacitor code5025600 pF capacitor code5.6 / 5n6 / 5.6 nF capacitor code0.0056 µF capacitor code5626800 pF capacitor code6.8 / 6n8 / 6.8 nF capacitor code0.0068 µF capacitor code68210000 pF capacitor code10 / 10n / 10 nF capacitor code0.01 µF capacitor code10315000 pF capacitor code15 / 15n / 15 nF capacitor code0.015 µF capacitor code15322000 pF capacitor code22 / 22n / 22 nF capacitor code0.022 µF capacitor code22333000 pF capacitor code33 / 33n / 33 nF capacitor code0.033 µF capacitor code33347000 pF capacitor code47 / 47n / 47 nF capacitor code0.047 µF capacitor code47368000 pF capacitor code68 / 68n / 68 nF capacitor code0.068 µF capacitor code683100000 pF capacitor code100 / 100n / 100 nF capacitor code0.1 µF capacitor code104150000 pF capacitor code150 / 150n / 150 nF capacitor code0.15 µF capacitor code154200000 pF capacitor code200 / 200n / 200 nF capacitor code0.20 µF capacitor code204220000 pF capacitor code220 / 220n / 220 nF capacitor code0.22 µF capacitor code224330000 pF capacitor code330 / 330n / 330nF capacitor code0.33 µF capacitor code334470000 pF capacitor code470 / 470n / 470nF capacitor code0.47 µF capacitor code474680000 pF capacitor code680 nF capacitor code0.68 µF capacitor code6841000000 pF capacitor code1000 nF capacitor code1.0 µF capacitor code1051500000 pF capacitor code1500 nF capacitor code1.5 µF capacitor code1552000000 pF capacitor code2000 nF capacitor code2.0 µF capacitor code2052200000 pF capacitor code2200 nF capacitor code2.2 µF capacitor code2253300000 pF capacitor code3300 nF capacitor code3.3 µF capacitor code3354700000 pF capacitor code4700 nF capacitor code4.7 µF capacitor code4756800000 pF capacitor code6800 nF capacitor code6.8 µF capacitor code68510000000 pF capacitor code10000 nF capacitor code10 µF capacitor code10615000000 pF capacitor code15000 nF capacitor code15 µF capacitor code15620000000 pF capacitor code20000 nF capacitor code20 µF capacitor code20622000000 pF capacitor code22000 nF capacitor code22 µF capacitor code22633000000 pF capacitor code33000 nF capacitor code33 µF capacitor code33647000000 pF capacitor code47000 nF capacitor code47 µF capacitor code47668000000 pF capacitor code68000 nF capacitor code68 µF capacitor code686100000000 pF capacitor code100000 nF capacitor code100 µF capacitor code107330000000 pF capacitor code330000 nF capacitor code330 µF capacitor code337470000000 pF capacitor code470000 nF capacitor code470 µF capacitor code477680000000 pF capacitor code680000 nF capacitor code680 µF capacitor code6871000000000 pF capacitor code1000000 nF capacitor code1000 µF capacitor code1086.2 Frequently Asked Questions about Capacitor Code1. What is the code of a capacitor?Generally, the actual values of Capacitance, Voltage or Tolerance are marked onto the body of the capacitors in the form of alphanumeric characters. For example, a capacitor can be labeled as, n47 = 0.47nF, 4n7 = 4.7nF or 47n = 47nF and so on. 2.What does the numbers on a capacitor mean?The first two numbers represent the value in picofarads, while the third number is the number of zeroes to be added to the first two. For example, a 4.7 μF capacitor with a voltage rating of 25 volts would bear the marking E476. 3.What is the value of a capacitor?Capacitor values can be of over 109 range, and even more as super capacitors are now being used. To prevent confusion with large numbers of zeros attached to the values of the different capacitors the common prefixes pico (10 -12 ), nano (10 -9) and micro (10 -6) are widely used. 4.How can you determine the value of a capacitor?The value of capacitors can be determined by several ways depending up on the type of capacitor like electrolytic, disc, film capacitors, etc. These methods include value or number printed on the body of the capacitor or color coding of the capacitor. 5.How can I determine the capacitance of an unknown capacitor?To determine an unknown capacitance using an oscilloscope , a dc power source such as a 9-V battery, a known resistance, a switch and the capacitor are all connected in series. An oscilloscope probe tip and ground lead are connected across the capacitor. Additionally, you need a short wire jumper to shunt across the capacitor. Ⅶ Capacitor Code Calculator7.1 Capacitor Safety Discharge Calculator ToolThis Capacitor Safety Discharge Calculator helps to determine the discharge rate of a capacitor at known capacitance and charge through a fixed-value resistor. Enter the initial voltage, time, resistance, and capacitance into the calculator. The calculator will display the total voltage discharged and remaining. Many factors need to be considered when choosing a discharge resistor. Safety standards require the voltage across a capacitor to reach a safe voltage before a person is able to touch it. In the USA, standards such as UL, OSHA, NTA, ETL, MET, etc. will have the requirements available for the needs of your product.Capacitor Safety Discharge Calculator Tool 7.2 Series and Parallel Capacitance CalculatorThis tool calculates the overall capacitance value for multiple capacitors connected either in series or in parallel.Series and Parallel Capacitance Calculator 
kynix On 2021-09-14   14067
Resistors

A Guide to Color Code of Resistor

IntroductionIn 2025, while surface mount technology (SMT) dominates mass production, the ability to read resistor color codes remains a fundamental skill for electronics prototyping, repairs, and education. Color bands are used to identify leaded resistors, typically with a power rating of up to one watt. The international standard IEC 60062 specifies this coding system, which applies to both resistors and capacitors.This system allows engineers and hobbyists to quickly identify resistance values without a multimeter. While digital marking codes are common on SMD resistors, the color band system remains the global standard for through-hole components.Figure: A guide to the resistor color code standard. Several bands provide the complete data for the component. They indicate the resistance value, tolerance, and sometimes the failure rate (reliability). Resistors typically have between three and six bands. The first two (or three) bands represent the significant digits of the resistance value, followed by a multiplier band. Resistance levels are standardized into specific series (E-series) of preferred values.Video: Visual guide to understanding resistor color codes.Ⅰ 1 Ohm Resistor Color Code1.1 Color Code Of 1 Ohm 4-Band ResistorThe resistor color code table is used to determine the value. Below is the breakdown for a 1 Ohm, 4-band resistor:Figure: Color code of 1Ω 4-band resistor.BandColorValue1st BandBrown 12nd BandBlack 03rd Band (Multiplier)Gold x 0.14th Band (Tolerance)Gold ±5%Calculation1st digit: 12nd digit: 0Multiplier: 0.11 OhmTolerance: ±5% Calculation logic:1st-band = Brown = 1 (1st digit)2nd-band = Black = 0 (2nd digit)3rd-band = Gold = 0.1 (Multiplier)4th-band = Gold = ±5% (Tolerance) Formula: $10 \times 0.1 = 1 \Omega$.Tolerance range: 5% of 1Ω is 0.05Ω. Theoretically, the actual resistance of a 1Ω resistor lies between 0.95Ω and 1.05Ω. Note on Low Values: For low-value resistors (under 10 Ohms), the multiplier band is often Gold (x0.1) or Silver (x0.01). In modern IEC 60062 standards, a Pink band is sometimes used for x0.001 multipliers in high-precision shunts. In 4- and 5-band resistors, the last band indicates tolerance. Gold indicates ±5%, Silver ±10%, Brown ±1%, and Red ±2%. If the fourth band is missing, the tolerance is standardized at ±20% (rare in 2025). 1.2 Color Code Of 1 Ohm 5-Band ResistorThe 1 Ohm 5-band resistor color code is Brown, Black, Black, Silver, Black:Figure: Color code of 1Ω 5-band resistor.1st-band = Brown = 1 (1st Digit)2nd-band = Black = 0 (2nd Digit)3rd-band = Black = 0 (3rd Digit)4th-band = Silver = x 0.01 (Multiplier)5th-band = Black = ±1% (Tolerance) For a 1 Ohm 5-band precision resistor, the calculation is $100 \times 0.01 = 1 \Omega$. The tighter tolerance (Black band = 1%) makes these ideal for current sensing applications. 1.3 Frequently Asked Questions about 1 Ohm Resistor1. What does a 1 ohm resistor do?A 1 Ohm resistor is often used as a current sense resistor (shunt) to measure current flow or to simulate a specific load. In power supplies, it can also act to simulate the ESR (Equivalent Series Resistance) of a large capacitor. 2. What is the definition of 1 ohm?The Ohm is the SI unit of electrical resistance. 1 Ohm is defined as the resistance between two points of a conductor when a constant potential difference of 1 volt applied between these points produces a current of 1 ampere. 3. Is 1 ohm a lot of resistance?No, 1 Ω is a very small amount of resistance. It is close to a short circuit. Resistances in electronic circuits usually range from hundreds (Ohms) to millions (Megaohms). 4. What is the formula for resistance?Rearranging Ohm's Law ($V = I \times R$) gives $R = V / I$. Therefore, 1 Ohm = 1 Volt per Ampere. Ⅱ 10 Ohm Resistor Color Code2.1 Color Code of 10 Ohm 4-Band ResistorThe 4-band 10 Ohm resistor color code is shown below:Figure: Color code of 10Ω 4-band resistor. BandColorValue1st BandBrown 12nd BandBlack 03rd Band (Multiplier)Black x 1 ($10^0$)4th Band (Tolerance)Gold ±5% Calculation:1st band = Brown = 12nd band = Black = 03rd band = Black = Multiplier $10^0$ = 1Result: $10 \times 1 = 10 \Omega$.With ±5% tolerance (0.5Ω), the actual value lies between 9.5Ω and 10.5Ω. Pro Tip: Be careful not to confuse Brown (1st band) and Red bands under poor lighting, as a "Red-Black-Black" sequence would read 20 Ohms. 2.2 Frequently Asked Questions about 10 Ohm Resistor1. What is the power consumed by a 10 ohm resistor with no current?If no current flows (open circuit), the power consumed is zero. 2. What is the current through a 10 ohm resistor in a circuit?Current depends on voltage. For example, if a 10 Ohm resistor is connected to a 6V source with some internal resistance (total circuit resistance 10.8Ω), the current is $I = V/R = 6 / 10.8 \approx 0.55$ Amps. 3. What is the voltage across the 10 ohm resistor?Ohm's Law states $V = I \times R$. If 1.2 Amps flows through a 10 Ohm resistor, the voltage drop is $1.2 \times 10 = 12$ Volts. 4. How much power is dissipated by a 10 ohm resistor?Power is calculated as $P = I^2R$ or $P = V^2/R$.Example: If 12 Volts is applied directly across a 10 Ohm resistor, the current is 1.2A. The power is $P = 1.2^2 \times 10 = 14.4$ Watts. Warning: A standard 1/4 Watt resistor would burn instantly in this scenario. You would need a high-power ceramic resistor. 5. What is a 10 ohm resistor used for?Low-value resistors like 10 Ohms are often used as current limiters in power circuits, in voltage dividers, or as part of RC filters (snubbers) to suppress voltage spikes. Ⅲ 100 Ohm Resistor Color Code3.1 Color Code of 100 Ohm 4-Band ResistorFor a 100 Ohm resistor, the bands are Brown, Black, Brown, Gold.Figure: Color code of 100Ω 4-band resistor. BandColorValue1st BandBrown12nd BandBlack03rd Band (Multiplier)Brownx 10 ($10^1$)4th Band (Tolerance)Gold±5% Calculation:1st digit (Brown) = 12nd digit (Black) = 0Multiplier (Brown) = 10Result: $10 \times 10 = 100 \Omega$.With ±5% tolerance, the resistance ranges from 95Ω to 105Ω. 3.2 Color Code of 100 Ohm 5-Band ResistorA 5-band 100 Ohm resistor allows for higher precision. The sequence is Brown, Black, Black, Black, Gold (or Brown/Red for tolerance).Figure: Color code of 100Ω 5-band resistor.1st-band = Brown = 12nd-band = Black = 03rd-band = Black = 04th-band (Multiplier) = Black = x 1 ($10^0$)5th-band (Tolerance) = Gold (±5%)Calculation: $100 \times 1 = 100 \Omega$. 3.3 Frequently Asked Questions about 100 Ohm Resistor1. What is a 100 ohm resistor used for?It is commonly used for LED protection, gate drive resistance in MOSFET circuits, and signal termination. It fits perfectly into breadboards for prototyping. 2. How can you tell if a resistor is 100 ohm?Look for the color bands: Brown-Black-Brown (4-band) or Brown-Black-Black-Black (5-band). 3. What is the value of 100 ohm in Megaohms?100 Ohms is $0.0001 M\Omega$ ($100 \times 10^{-6}$). 4. What is the actual range of a 100 ohm resistor?With standard ±5% tolerance, it measures between 95Ω and 105Ω. An older ±20% resistor (rare today) would measure between 80Ω and 120Ω. Ⅳ 120 Ohm Resistor Color Code4.1 Color Code of 120 Ohm 4-Band ResistorThe 120 Ohm resistor is famously used in CAN Bus termination. The color code is Brown, Red, Brown, Gold.Figure: Color code of 120Ω 4-band resistor. BandColorValue1st BandBrown12nd BandRed23rd Band (Multiplier)Brownx 104th Band (Tolerance)Gold±5% Calculation:Digits: 1, 2Multiplier: x 10Result: $12 \times 10 = 120 \Omega$.Tolerance range (±5%): 114Ω to 126Ω. 4.2 Frequently Asked Questions about 120 Ohm Resistor1. Why is 120 Ohm the standard for CAN Bus?The characteristic impedance of twisted pair cables used in automotive CAN networks is approximately 120 Ohms. Placing a 120Ω resistor at each end of the bus prevents signal reflections (ringing), ensuring data integrity. 2. Where do you place the 120 Ohm resistor?It is placed between CAN High (pin 7) and CAN Low (pin 2) at the two physical ends of the bus network. 3. Can I measure 120 Ohms on a live CAN bus?If the system is powered down, measuring resistance between CAN High and CAN Low should yield 60 Ohms. This is because there are two 120Ω terminating resistors in parallel ($120 / 2 = 60$). Ⅴ 150 Ohm Resistor Color Code5.1 Color Code of 150 Ohm 4-Band ResistorThe sequence for 150 Ohms is Brown, Green, Brown, Gold.Figure: Color code of 150Ω 4-band resistor. BandColorValue1st BandBrown12nd BandGreen53rd Band (Multiplier)Brownx 104th Band (Tolerance)Gold±5% Calculation:Digits: 1, 5Multiplier: x 10Result: $15 \times 10 = 150 \Omega$.Tolerance range: 142.5Ω to 157.5Ω. 5.2 Frequently Asked Questions about 150 Ohm Resistor1. How do I identify a 150 ohm resistor?Look for the Green band in the second position (representing 5) and the Brown band in the third position (representing x10 multiplier). Ⅵ 220 Ohm Resistor Color Code6.1 220 Ohm Resistor Color Code (5% Tolerance)This is extremely common for driving LEDs from 5V logic.Figure: 220 ohm resistor color code (Red-Red-Brown-Gold). BandColorValue1st BandRed22nd BandRed23rd Band (Multiplier)Brownx 104th Band (Tolerance)Gold±5% Calculation:Digits: 2, 2Multiplier: x 10Result: $22 \times 10 = 220 \Omega$. 6.2 220 Ohm Resistor Color Code (10% Tolerance)If the last band is Silver, the tolerance is ±10%. This means the resistor could be anywhere between 198Ω and 242Ω. 6.3 Frequently Asked Questions about 220 Ohm Resistor1. What does a 220 ohm resistor do?It resists current flow. In 2025, it is the standard "go-to" resistor for limiting current to standard LEDs when powered by USB (5V) or microcontrollers like Arduino or ESP32. 2. Will a 5 volt LED with a 220 ohm resistor run safely?Yes. If a red LED drops 2.0V, the resistor drops the remaining 3.0V. Using Ohm's Law ($I = V/R$), $3.0V / 220\Omega \approx 13.6 mA$, which is a safe and bright current for most indicator LEDs. Power dissipation is minimal ($0.04W$), so a 1/8W or 1/4W resistor is perfect. Ⅶ 330 Ohm Resistor Color Code7.1 Color Code of 330 Ohm 4-Band ResistorSequence: Orange, Orange, Brown, Gold.Figure: Color code of 330Ω 4-band resistor. BandColorValue1st BandOrange32nd BandOrange33rd Band (Multiplier)Brownx 104th Band (Tolerance)Gold±5% Calculation:Digits: 3, 3Multiplier: x 10Result: $33 \times 10 = 330 \Omega$. 7.2 Frequently Asked Questions about 330 Ohm Resistor1. Why use a 330 ohm resistor for an LED?If you need slightly less brightness or are using a 3.3V power supply (common in modern electronics like Raspberry Pi), a 330Ω resistor offers a good balance of brightness and protection. 2. What is the real value of a 330 ohm resistor?With 5% tolerance, it falls between 313.5Ω and 346.5Ω. Ⅷ 470 Ohm Resistor Color Code8.1 Color Code of 470 Ohm 4-Band ResistorSequence: Yellow, Violet, Brown, Gold.Figure: Color code of 470Ω 4-band resistor. BandColorValue1st BandYellow42nd BandViolet73rd Band (Multiplier)Brownx 104th Band (Tolerance)Gold±5% Calculation:Digits: 4, 7Multiplier: x 10Result: $47 \times 10 = 470 \Omega$. 8.2 Frequently Asked Questions about 470 Ohm Resistor1. What is a 470 ohm resistor used for?It is often used to drive blue or white LEDs (which have higher forward voltages) from higher voltage sources like 9V batteries or 12V automotive systems. 2. How do I know if I have a 470 ohm resistor?Look for the distinct Yellow (4) and Violet (7) starting bands. Ⅸ 500 (510) Ohm Resistor Color Code9.1 Color Code of 510 Ohm 4-Band ResistorNote: 500 Ohms is not a standard "E24 series" value. The closest standard value is 510 Ohms. In 99% of circuits, a 510Ω resistor is a perfect substitute for a 500Ω requirement.Figure: Color code of 510Ω 4-band resistor (Green-Brown-Brown-Gold). BandColorValue1st BandGreen52nd BandBrown13rd Band (Multiplier)Brownx 104th Band (Tolerance)Gold±5% Calculation:Digits: 5, 1Multiplier: x 10Result: $51 \times 10 = 510 \Omega$. 9.2 Frequently Asked Questions about 510 Ohm Resistor1. Can you substitute 500 ohm for 510 ohm?Yes. The error is only 2%. Given that standard resistors have a 5% tolerance, 510 Ohms is well within the acceptable range for a "500 Ohm" design. Alternatively, you can place two 1kΩ resistors in parallel to get exactly 500Ω. Ⅹ 1k Ohm Resistor Color Code10.1 Color Code of 1k Ohm 4-Band ResistorThe 1kΩ (1000 Ohm) resistor is arguably the most common resistor in electronics, used extensively for pull-up and pull-down logic circuits.Figure: Color code of 1kΩ 4-band resistor (Brown-Black-Red-Gold). BandColorValue1st BandBrown12nd BandBlack03rd Band (Multiplier)Redx 100 ($10^2$)4th Band (Tolerance)Gold±5% Calculation:Digits: 1, 0Multiplier: Red = x 100Result: $10 \times 100 = 1000 \Omega = 1 k\Omega$. 10.2 Frequently Asked Questions about 1k Ohm Resistor1. What is a 1k ohm resistor used for?It is the industry standard for pull-up resistors on microcontroller pins (like Arduino inputs) to prevent floating signals. 2. What is 1k ohm?"k" stands for Kilo (1000). Thus, 1k Ohm is 1000 Ohms. Ⅺ 2k Ohm Resistor Color Code11.1 Color Code of 2k Ohm 4-Band ResistorSequence: Red, Black, Red, Gold.Figure: Color code of 2kΩ 4-band resistor. BandColorValue1st BandRed22nd BandBlack03rd Band (Multiplier)Redx 1004th Band (Tolerance)Gold±5% Calculation:Digits: 2, 0Multiplier: Red = x 100Result: $20 \times 100 = 2000 \Omega = 2 k\Omega$. Ⅻ 2.2k Ohm Resistor Color Code12.1 Color Code of 2.2k Ohm 4-Band ResistorFamous for the "Three Reds" pattern.Figure: Color code of 2.2kΩ 4-band resistor (Red-Red-Red-Gold). BandColorValue1st BandRed22nd BandRed23rd Band (Multiplier)Redx 100 ($10^2$)4th Band (Tolerance)Gold±5% Calculation:Digits: 2, 2Multiplier: Red = x 100Result: $22 \times 100 = 2200 \Omega = 2.2 k\Omega$. 12.2 Frequently Asked Questions about 2.2k Ohm Resistor1. What does a 2.2k resistor do?It is commonly used in voltage dividers, particularly with LDRs (Light Dependent Resistors) to read ambient light levels with a microcontroller. 2. Calculating Current for a 1/2 Watt 2.2k ResistorIf you have a 1/2 Watt (0.5W) resistor, the maximum current it can handle is calculated using the power formula $P = I^2 \times R$.Rearranging for current ($I$):$I = \sqrt{P / R}$$I = \sqrt{0.5 / 2200}$$I \approx 0.015$ AmperesConclusion: A 2.2kΩ 1/2W resistor can safely handle approximately 15 milliamperes (mA). XIII Resistor Color Code Calculator13.1 4 Band Resistor Color Code CalculatorNeed to double-check your work? Use this tool to instantly decode 4-band axial lead resistors. Open 4 Band Resistor Color Code Calculator13.2 5 Band Resistor Color Code CalculatorFor high-precision 5-band resistors, use the calculator below: Open 5 Band Resistor Color Code Calculator 13.3 6 Band Resistor Color Code CalculatorIncludes the 6th band for Temperature Coefficient (PPM). Open 6 Band Resistor Color Code Calculator
Kynix On 2021-09-08   28028
Resistors

What is a Shunt Resistor?

Ⅰ IntroductionA shunt is an electrical device that creates a low-resistance route for a current to flow through. This allows the current to flow to a different part of the circuit. Ammeter shunts and current shunt resistors are two terms for shunts. A shunt resistor is used to measure alternating or direct electric current. The voltage drop across the resistor is used to determine this. Shunt resistors were once used to describe a resistor connected in parallel to an ammeter as a shunt to increase the current measurement range, but in recent years, all resistors used to detect circuit current have been referred to as shunt resistors (current sense shunt resistor). This vedio shows a shunt resistor CatalogⅠ IntroductionⅡ What Does a Shunt Resistor Do?Ⅲ How Does a Shunt Resistor Work?Ⅳ How to Measure Current by a Shunt Resistor?Ⅴ Position of the Shunt Resistor in the Circuit When Measuring CurrentⅥ How to Select a Shunt Resistor?6.1 How to Calculate Shunt Resistance?6.2 Shunt Resistor ParametersⅦ How to Wire a Shunt Resistor?Ⅷ Frequently Asked Questions about Shunt Resistor Ⅱ What Does a Shunt Resistor Do?The electrical shunt is a device that creates a low-resistance route that allows electricity to travel through or be redirected past a defined point in a circuit. Some meters have built-in precision current shunts that allow measurements in terms of DC and Watts to be taken. Electrical shunts can also be used to measure the flow of DC. The formula for Ohm's law is as follows: V = I × R This equation applies to the voltage (V) created across the resistance (R in ohms) as a function of the resistance and the current (I in amps) flowing through it. A current shunt with a resistance of 0.002 ohms and a current of 30 amps, for example, will generate 0.002 x 30 = 0.06 volts or 60 millivolts (milliVolts). By including a current shunt into a measurement circuit, you can determine the voltage drop across the shunt. The calculation of current measurement using Ohm's law will be possible thanks to the assessment of current shunt resistance. The current shunt resistance can also be calibrated using Ohm's law. Shunt resistors are commonly used in the following applications:Current circulating through a battery is measured, and power output is monitored.Before the signal reaches the circuit elements, high-frequency noise is redistributed (this requires a shunt with a capacitator).Installation in a DC connects the container with a negative conductor connecting the batteries to the inverter.Control equipment, such as battery chargers and power sources, provides overload protection. Ⅲ How Does a Shunt Resistor Work?The technological limits of a shunt resistor differ from those of a conventional resistor. Shunt resistors allow for high precision while maintaining a low ohmic value. To reach such great precision, a Kelvin connection is recommended. This connection eliminates difficulties like lead sensitivity and resistance. The value of a shunt resistor can be influenced by several reversible and irreversible causes. Long-term stability and irreversible change in resistance are ensured by the accompanying mechanical, electrical, and thermal stresses. The Temperature Coefficient of Resistance (TCR) is measured in ppm/ and represents the drift caused by the transistor cooling or heating due to changes in ambient temperature. The Power Coefficient of Resistance (PCR) or ppm/W is used to express the amount of power that the resistor must dissipate. Electrical shunts are commonly used to safeguard the speed controller from a load that consumes too much current or to limit the motor's speed. By disconnecting the shunt from the sense line, the controller's speed can be increased. After that, the sense line must be linked to the ground. Because there will be no voltage drop, the speed controller will generate the maximum amount of power feasible. However, if the load on the controller transistors is too great, this could be dangerous. A high-precision current shunt can also be utilized for equipment bench testing. This current shunt can be used in conjunction with a voltmeter to determine the amount of current flowing through the circuit. The use of a sensitive voltmeter ensures a high level of safety in the measurement of greater currents than can be achieved with a regular multimeter. Ⅳ How to Measure Current by a Shunt Resistor?An ammeter is a device that measures electric current. The voltage drop across a precision resistor with a known resistance is measured by most modern ammeters. Ohm's law is used to calculate current flow:  To measure current, most ammeters feature a built-in resistor. When the current is too high for the ammeter, however, a different configuration is required. The solution is to connect the ammeter to a precise shunt resistor in parallel. Ammeter shunt is a name that is sometimes used to describe this sort of resistor. This is usually a low resistance manganin resistor with great accuracy. Only a small (known) amount of the current travels through the ammeter after it is divided between the shunt resistor and the ammeter. The remaining current travels through the shunt resistor, bypassing the ammeter. Large currents can still be measured this way. The actual amperage can be measured by accurately scaling the ammeter. The greatest amperage that can be measured using this arrangement is theoretically limitless. However, the measurement device's voltage rating must not be exceeded. As a result, the maximum current multiplied by the ammeter resistance value cannot exceed the voltage rating. To minimize circuit interference, the ammeter resistance should be as low as feasible. A smaller ammeter, on the other hand, creates a smaller voltage drop, which results in a lesser resolution. Example of calculationA series resistor in an ammeter, for example, is a shunt resistor with a resistance of 1 mΩ. A voltage drop of 30 mV is observed across the resistor after it is inserted in a circuit. The current is equal to the voltage divided by the resistance in this case, or:I=V/R=0.030/0.001=30A. With the resistance value unknown and the voltage and current known, the same calculation might be performed. This is how shunt resistance is measured. Ⅴ Position of the Shunt Resistor in the Circuit When Measuring CurrentA.To eliminate the common-mode voltage, the shunt is frequently put on the grounded side. However, there are certain drawbacks.B.The common-mode voltage may be too high for the ammeter in this arrangement. Position of the Shunt Resistor in the Circuit The placement of the shunt resistor in the circuit must be carefully considered. When the circuit and the measurement instrument share a common ground, the shunt is frequently put as close to the ground as practicable. The rationale for this is to safeguard the ammeter from excessive common-mode voltage, which could harm the instrument or cause incorrect results. One downside of this configuration is that leakage currents through the shunt may go undetected. To protect the instrument, the shunt must be isolated from the ground or incorporate a voltage divider or an isolation amplifier if it is put in the ungrounded leg. Other options include employing a Hall Effect sensor instead of directly attaching the measurement instrument to the high voltage circuit. Current shunts, on the other hand, are frequently cheaper. Ⅵ How to Select a Shunt Resistor?Shunt resistors are a type of resistor that creates a low resistance route. Because of their low resistance, they are commonly employed to detect high currents. Many applications necessitate current measuring. Overcurrent protection, 4-20mA systems, battery chargers, high-brightness LED control, H-bridge motor control, and metrology, for example, all require current monitoring. Shunt sensors are simpler to develop and less expensive than magnetic current sensors. They do not, however, afford any seclusion. A Rogowski coil, also known as a Hall effect sensor, is a noninvasive measurement in which the detecting circuitry is not electrically coupled to the monitored system and subsequently isolated. 6.1 How to Calculate Shunt Resistance?Shunt resistors have different technological limits than normal resistors. They have a low ohmic value and are high-precision resistors (they can be expressed in microOhm when several hundreds of Amper currents must be measured). Because accuracy is crucial, current sensing is best accomplished via a Kelvin connection (or four-terminal connection), which eliminates the undesired effects of lead resistance and temperature sensitivity. Four-terminal connection equation A shunt resistor's value can be changed by a variety of causes, which are divided into reversible and irreversible effects. A change in resistance that is irreversible owing to mechanical, electrical, or thermal stresses is referred to as long-term stability. There are two fundamental components to reversible effects:Temperature Coefficient of Resistance (TCR): TCR is measured in parts per million and describes how the resistor drifts as the ambient temperature changes.The Power Coefficient of Resistance (PCR) is a unit of measurement for the amount of power a resistor must dissipate. It is given in ppm/W. 6.2 Shunt Resistor ParametersThe thermal EMF is an important metric for shunt resistors that isn't as critical for ordinary resistors. A voltage changeable with temperature appears at the junction of two different conducting materials (explaining why it's termed thermal EMF or thermocouple effect and expressed in µV/). An intermetallic junction's rate of change of voltage with temperature is a function of the metallic combination. Depending on whether side of the combination is regarded as the input, the voltage produced is either positive or negative. All resistors are assumed to be soldered to copper at some point, and copper becomes the reference metal. Some Thermal EMF values are shown in the table below. Table 1: Thermal EMF of the Metal vs. CopperMetal / AlloyThermal EMF vs copper in μV/°CEvanohm2Cupron-45Manganin-3Zeranin-1.3Nickel-22Gold0.2Silver-0.2Aluminum-4 Table 2. TCR, ppm/  of various Resistor Element MaterialsTemperature range-55°C to +25°C0°C to +25°C+25°C to +60°C+25°C to +125°CManganin5010-5-80Zeranin20±2.5±510Evanohm52.5-2.5-5Foil (Vishay proprietary)-1-0.30.31Thin Film-10-5510Thick Film-100-2550100 Manganin is the preferred material for shunts with exposed blades based on thermal EMF, TCR, and cost. Zeranin, a cousin of Manganin with a lower temperature coefficient, is used to make shunts with exposed parallel wires. Evanohm, which has a near-zero temperature coefficient and a high sensitivity to strain, is commonly used to make shunts contained in heat sinks. Ⅶ How to Wire a Shunt Resistor?First, read and follow any manufacturer's instructions. It will be required to make sure that the ammeter and the shunt can handle the same mV levels. The shunt must then be connected to the negative connection that runs from the battery bank to the electrical circuits. Following the negative lead from the battery to the circuits or fuse box will reveal this. Adjust the negative connections on the battery to the corresponding side of the battery and shunt if you want to measure the current consumed by the connected device and supplied by the alternator. The other side of the shunt should be linked to the battery's negative terminal with a sufficiently thick cable. The shunt resistor must be installed in a location where there is no possibility of shorting cables. The negative cables can be shortened to make the installation process easier. It is also necessary to drill a suitable hole for the ammeter to mount on the panel. The hole must be large enough to connect the meter firmly. The plus and minus pins on the connection between the leads and the DC  or voltage should be properly fitted. You must also confirm that the meter is correctly set (the current can be measured in AC, DC, ohms etc). The wiring procedure should start with a simple check to confirm that the shunt is connected to the load in series. You'll also need to hook up a battery pack and make sure it's linked to the right side of the shunt. The wiring from the shunt should then be fed to the load. The ammeter and the ground should not be connected in any way. The ammeter, on the other hand, should be wired in parallel with the shunt, with the shunt connected to the load in series. The powering of the circuit should be the first step in measuring the current or voltage. After that, you can take the meter reading. When measuring the level of resistance, however, you should not turn on the electricity. Ⅷ Frequently Asked Questions about Shunt Resistor1.What is the meaning of shunt resistor?A resistor having a very low value of resistance such type of resistor is called shunt resistance. The shunt is used in the galvanometer for measuring the large current. It is connected in parallel to the circuit of the galvanometer. 2.Why is it called a shunt resistor?In electronics, a shunt is a device that creates a low-resistance path for electric current, to allow it to pass around another point in the circuit. The origin of the term is in the verb 'to shunt' meaning to turn away or follow a different path. 3.Why a shunt resistor is connected in parallel?A shunt resistor is connected in parallel to the galvanometer so as to keep the resistance low. Such low resistance galvanometer is used in series with the circuit to measure the strength of current through the circuit. 
kynix On 2021-09-06   9656
Resistors

The Best Electronics Tutorial for Colpitts Oscillator

Ⅰ IntroductionA Colpitts oscillator is one of several designs for LC oscillators, which employ a combination of inductors (L) and capacitors (C) to produce an oscillation at a specific frequency. It was invented in 1918 by American engineer Edwin H. Colpitts. The voltage divider made up of two capacitors in series across the inductor serves as feedback for the active device in the Colpitts oscillator.   CatalogⅠ IntroductionⅡ What a Colpitts Oscillator Contains?Ⅲ How the Colpitts Oscillator Works?Ⅳ Colpitts Oscillator vs Hartley OscillatorⅤ Types of Colpitts Oscillator5.1 Common Base Colpitts Oscillator5.2 Common Emitter Colpitts Oscillator5.3 Buffered Colpitts OscillatorⅥ Advantages of Colpitts OscillatorⅦ Applications of Colpitts OscillatorⅧ ConclusionⅨ Frequently Asked Questions about Colpitts OscillatorⅡ What a Colpitts Oscillator Contains?The Colpitts circuit, like other LC oscillators, is made up of a gain device (such as a bipolar junction transistor, field-effect transistor, operational amplifier, or vacuum tube) with its output connected to its input in a feedback loop containing a parallel LC circuit (tuned circuit) that serves as a bandpass filter to set the oscillation frequency. The amplifier's input and output impedances will be different, and these must be linked into the LC circuit without overdamping it. Ⅲ How the Colpitts Oscillator Works?The Colpitts oscillator is commonly used in RF applications, with a frequency range of 20KHz to 300MHz. The capacitive voltage divider configuration in the tank circuit serves as the feedback source in the Colpitts oscillator, and this arrangement provides superior frequency stability than the Hartley oscillator, which uses an inductive voltage divider system for feedback. The circuit diagram of a typical transistor-based Colpitts oscillator is shown below. Colpitts oscillator The resistors R1 and R2 in the circuit schematic provide a voltage divider biasing for the transistor. The transistor's collector current is limited by the resistor R4. The input DC decoupling capacitor is Cin, and the output decoupling capacitor is Cout. The emitter resistor, Re, is used to ensure thermal stability. The emitter by-pass capacitor is denoted by Ce. The emitter by-pass capacitor's job is to keep the amplified AC signals from crossing Re. If the emitter by-pass capacitor is missing, the amplified AC signal will drop across Re, causing the transistor's DC biasing conditions to change, resulting in lower gain. The tank circuit is made up of capacitors C1, C2, and inductor L1. Tank circuit in a Colpitts oscillator When the power source is turned on, the capacitors C1 and C2 begin to charge. They start discharging through the inductor L1 when they are completely charged. The electrostatic energy stored in the capacitors is transmitted to the inductor as magnetic flux when the capacitors are fully drained. The inductor begins to discharge and the capacitors are re-charged. Oscillation is caused by energy being transferred back and forth between capacitors and inductors. The voltage across C2 is in phase opposite that of C1, and the voltage across C2 is sent back to the transistor. The enhanced feedback signal at the transistor's base emerges across the collector and emitter. The transistor compensates for the energy lost in the tank circuit, maintaining the oscillations. One 180° phase shift is produced by the tank circuit, and the other 180° phase shift is produced by the transistor. That means the input and output are in phase, and positive feedback requires to keep oscillations going for long periods. The equation below can be used to calculate the frequency of the Colpitts oscillator's oscillations. Where L is the inductance of the tank circuit's inductor and C is the effective capacitance of the tank circuit's capacitors. The effective capacitance of the serial combination C= (C1C2)/(C1+C2) if C1 and C2 are independent capacitances. The Colpitts oscillator can be made variable by utilizing ganged variable capacitors in place of C1 and C2. Ⅳ Colpitts Oscillator vs Hartley OscillatorThe Colpitts oscillator is extremely similar to the Hartley oscillator, however they are constructed differently. The Colpitts oscillator employs a single inductor in parallel with two capacitors in series, whereas the Hartley oscillator utilizes the exact opposite, one single capacitor in parallel with two inductors in series. In high-frequency operation, the Colpitts oscillator is more stable than the Hartley oscillator. Colpitts Oscillator vs Hartley Oscillator In high-frequency operation, the Colpitts oscillator is an ideal choice. It can generate output frequencies in the Megahertz and Kilohertz ranges. Ⅴ Types of Colpitts Oscillator5.1 Common Base Colpitts OscillatorA typical Colpitts oscillator design is shown below. The Colpitts LC tank circuit operates similarly to the Hartley oscillator, however it only has a single inductor and two capacitors. Instead of the tapped inductor used in the Hartley, the capacitors create a single 'tapped' capacitor. The total capacitance in series (CTOT) of the two capacitors (connected in series) is calculated as follows: common base Colpitts oscillator The total capacitance required for the tank circuit to achieve parallel resonance at the specified frequency is given. The oscillation frequency is calculated using the same formula as the Hartley oscillator. However, in this case, the number C is the sum of the values C2 and C3 in order (CTOT). C2 and C3's values are chosen so that their ratio delivers the required proportion of feedback signal. The ratio of voltages across two capacitors in series, on the other hand, is inversely proportional to the ratio of their values, implying that the smaller capacitor has a higher signal voltage across it. The fundamental advantage of the Colpitts design is that the single inductor in the tuned circuit eliminates any mutual inductance between two coils, where the alternating magnetic field generated up around one inductor drives a current into the inductor of the other coil. This alters the resonance frequency of the tuned circuit by changing the total inductance of the coils. 5.2 Common Emitter Colpitts OscillatorThe Colpitts analog of the Common Emitter Hartley Oscillator is shown below.                              common emitter Colpitts oscillator It employs a common emitter amplifier, and because the tuned (tank) circuit tapping point is connected to the ground in this design, the tank circuit generates anti-phase waves at the top and bottom of L2, ensuring proper phase relationships for positive feedback between collector and base. The feedback is delivered to the base via C1, which also functions as a DC block, preventing the greater voltage on L1 from causing the base bias voltage to be thrown off. The supply rail (+Vcc) is connected to the tank circuit (L2, C2, and C3) through L1. Because the DC supply is significantly decoupled by huge capacitors in the DC Power supply, if the tank circuit were connected directly to the supply, there would be no anti-phase AC signal present at the top of the tank circuit. As a result, between the tuned circuit and the supply, an RF choke (L1) with a high impedance at the oscillation frequency is provided. This permits the development of a signal voltage across L1 for feedback purposes. Automatic class C bias is utilized, with the emitter only partially disconnected by a small amount of C5 to provide the previously mentioned "slide bias." The Colpitts oscillator, like the Hartley, can produce an excellent sine wave shape and has the added benefit of improved stability at very high frequencies. It's easy to spot because it's always got a "tapped capacitor" on it. The fact that any load placed on the output by circuits that the output is supplying essentially inserts a dampening resistance across the tank circuit complicates the design of a sine wave oscillator. This can have an adverse influence on both the wave shape and frequency stability of the oscillator waveform, as well as lowering the amplitude of the oscillator output by lowering the Q factor of the tuned tank circuit. 5.3 Buffered Colpitts OscillatorAs demonstrated below, feeding the oscillator output into an emitter follower buffer amplifier is a standard technique. buffered Colpitts oscillator TR1's load impedance has been changed to the RF choke, and the tank circuit is now isolated from TR1 by two DC blocking capacitors, C1 and C4. As a result, instead of a tuned amplifier, this variant of the Colpitts oscillator uses a tuned feedback channel. The emitter follower stage (R4, TR2 and R5) has a very high input impedance, which has no effect on the oscillator, and a very low output impedance, which allows it to drive loads with impedances as low as a few tens of ohms. Variations in supply voltage can also affect the frequency stability of oscillators. When good frequency stability is required, it is typical to use a stabilized power supply. Extra decoupling capacitors may be required for oscillator supplies to reduce undesired 'noise.' Automatic class C bias, which is given in this circuit by only partially disconnecting the emitter of TR1 by C5, is generally used to achieve stable amplitude. Ⅵ Advantages of Colpitts OscillatorThe Colpitts oscillator may produce very high-frequency sinusoidal pulses.It can tolerate extreme heat and cold.There is a lot of frequency stability.Both variable capacitors can be used to change the frequency.A small number of components is all that is required.Over a certain frequency range, the output amplitude remains constant.The Colpitts oscillator was created to address the shortcomings of the Hartley oscillator and is known to have no unique flaws. As a result, a Colpitts oscillator has a wide range of uses. Ⅶ Applications of Colpitts OscillatorThe Colpitts oscillator is mostly employed for fixed frequency generation due to the challenges in achieving a smooth variation of inductor and capacitor.The Colpitts oscillator is most commonly found in mobile phones and other radio frequency-controlled communications devices.The Colpitts oscillator is a great choice for high-frequency oscillation. Colpitts Oscillator is used in high-frequency oscillator-based systems.Colpitts Oscillator is utilized in a few applications where continuous and undamped oscillation is required as well as thermal stability.For applications that require a broad range of frequencies with minimal noise.Colpitts oscillator is used in a variety of SAW-based sensors.The Colpitts oscillator is used in a variety of metal detectors.A Colpitts oscillator is used in frequency modulation radio frequency transmitters.It has a wide range of uses in both military and commercial items.Signal masking-related chaotic circuits are also required in microwave applications Colpitts oscillator in various frequency ranges. Ⅷ ConclusionTo summarise, the Colpitts Oscillator consists of a parallel LC resonator tank circuit whose feedback is achieved by way of a capacitive divider. The Colpitts oscillator exists in several forms like most oscillator circuits, and the most common form is the transistor circuit. The tank sub-center circuit's tap is made at the junction of a "capacitive voltage divider" network, which feeds a fraction of the output signal back to the transistor's emitter. The 180o phase shift produced by the two capacitors in series is inverted by another 180o to produce the requisite positive feedback. The resonance frequency of the tank circuit determines the oscillation frequency, which is a purer sine-wave voltage. Ⅸ Frequently Asked Questions about Colpitts Oscillator1.What is the use of Colpitts oscillator?It is used for generation of sinusoidal output signals with very high frequencies. The Colpitts oscillator using SAW device can be used as the different type of sensors such as temperature sensor. As the device used in this circuit is highly sensitive to perturbations, it senses directly from its surface. 2.What is the basic principle of oscillator?There are many types of electronic oscillators, but they all operate according to the same basic principle: an oscillator always employs a sensitive amplifier whose output is fed back to the input in phase. Thus, the signal regenerates and sustains itself. This is known as positive feedback. 3.What is meant by Colpitts oscillator?A Colpitts oscillator, invented in 1918 by American engineer Edwin H. Colpitts, is one of a number of designs for LC oscillators, electronic oscillators that use a combination of inductors (L) and capacitors (C) to produce an oscillation at a certain frequency. 
kynix On 2021-09-01   6408
Resistors

What is the Blower Motor Resistor?

ⅠIntroduction Resistor is commonly used in our daily life. There are all kinds of resistor in a vehicle. As we know ,the air conditioning is very important for a car . One of the most essential components is blower motor resistor. This article embodies basic knowledge about blower motor resistor.Figure1: the location of Blower Motor Resistor ⅠIntroductionⅡDefinition and Function of Blower Motor Resistor2.1 Definition of Blower Motor Resistor2.2 Function in a CarⅢ How the Blower Motor Resistor Works?Ⅳ Symptons of Faulty Blower Motor ResistorⅤ Blower Motor Resistor TestⅥ How to Replace Blower Motor Resistor6.1 DIY Jobs Related to the Blower Motor Resistor6.2 Details of Replacing Blower Motor ResistorⅦ Frequently Question Asked about Blower Motor Resistor ⅡDefinition and Function of Blower Motor Resistor 2.1 Definition of Blower Motor ResistorThe heating and air conditioning system in your vehicle is made up of many parts that work together to produce the desired air temperature. Some of these parts will (hopefully) last the life of your vehicle, but others will wear out and need to be replaced.The blower motor resistor is a small electrical component that, if it fails, can cause noticeable problems with the air in the passenger compartment. Understanding how it works can assist you in identifying the symptoms of a faulty resistor.This vedio shows a circuit of a blower motor  2.2 Function in a CarA blower motor is a device that drives the fan in a car's heating and air conditioning system. It's usually found inside the dash, on the opposite side of the steering wheel, or on the firewall inside the engine compartment. A blower motor resistor, also known as a blower motor control module, is the component that regulates the speed of the blower motor.An electronic blower motor control module is fixed in cars with automatic climate control systems and vehicles where the blower speed can be gradually adjusted.  Figure2: the control module The blower motor resistor or control module is usually installed inside one of the ducts in the HVAC system, close to the blower motor, in most modern vehicles. This is done so that the resistor or control module can be cooled by passing air. A blower motor resistor was installed on the firewall of some older vehicles, with access from under the hood. Ⅲ How the Blower Motor Resistor Works?Blower motor resistor diagram depicts how the blower motor resistor is connected in a typical automobile. The resistor is bypassed in this car at the highest "4" fan speed setting, and the blower motor is powered directly by the fan switch. As a result, even if the resistor is faulty, the blower motor in some vehicles may continue to operate at a "High" speed.The fan switch is set to "1" in this diagram, so the blower motor current is reduced by three resistors (R2 + R3 + R4) connected in series. The flow of current is depicted in blue and red.Two resistors are connected in series when the setting is 2.  Whereas, in setting "3," there is only one resistor. When resistance is added to an electric circuit, the current in the circuit is reduced. When multiple resistors are connected in series, the total resistance rises and equals the sum of the individual resistances. Figure3: how the blower motor resistor works  Ⅳ Symptons of Faulty Blower Motor ResistorA faulty blower motor resistor can disrupt the operation of the entire heating and cooling system. A bad or failing blower motor resistor will usually cause a few symptoms that will alert the driver to a potential problem. It is critical to understand the symptoms of a faulty motor resistor. 1. The blower motor is stuck at one speed.A blower motor that is stuck on one setting is a common symptom of a faulty blower motor resistor. The blower motor resistor is the component directly responsible for controlling the fan speed of the blower motor. If the resistor shorts or fails, the blower motor may become stuck at one fan speed. The heating and air conditioning systems may continue to operate at one speed, but the resistor has to be replaced before full functionality can be restored. 2. The blower motor does not operate in certain settings.A blower motor that does not function in certain settings is another common symptom of a faulty blower motor resistor. If the internal components of the blower motor resistors fail, the blower motor may malfunction or not function at all on one or more of the settings. Perhaps, a faulty blower motor switch can lead to the same situation, so a proper diagnosis is highly recommended if you are unsure of the problem. 3.There is no air coming from the vehicle's vents.Another sign of a faulty blower motor resistor is the absence of any air from the vehicle's vents. Power to the blower motor is routed through the blower motor resistor, so if it fails or has any problems, power to the motor can be cut off. A blower motor that is not powered will not have the capacity to produce any air pressure, leaving the heating and air conditioning system with no air coming from the vents.Because the blower motor resistor is the component directly responsible for powering the blower motor, when it fails, dangerous problems with the blower motor and the heating and air conditioning system can occur. If your vehicle exhibits any of the symptoms listed above, or you suspect that your blower motor resistor is malfunctioning, have it inspected by a professional technician, such as one from YourMechanic, to determine if the component needs to be replaced. Ⅴ Blower Motor Resistor TestFirstly, if the blower motor does not work at all, it is necessary to test the motor. When the blower motor is turned on, the voltage at the blower motor connector is typically measured. If there is a voltage at the motor (at least 4-6 Volts at low speed and 12 Volts at high speed), but the motor does not run, the motor is defective or jammed. Voltage testing of the blower motor The voltage at the blower motor is being tested. If there is a voltage at the motor (at least 4-6 Volts at low speed and 12 Volts at high speed), but the motor does not run, the motor is defective.Figure4: how to test the blower motor resistor Leaves, twigs, nuts, and pieces of a ripped cabin filter can jam the blower motor's blade. This is a common occurrence in many automobiles.The entire blower motor circuit, beginning with a fuse, has to be tested if the motor is in the case of no voltage. See also: how to test a fuse in a car.If a blower motor fails, it must be replaced. Depending on the vehicle, the cost of replacing the blower motor ranges from $320 to $650. In many cars, the blower motor is located behind the glove box and is held in place by 3-4 screws. In others, it may be located inside the dash (as in the Mazda 5), making replacement difficult. Ⅵ How to Replace Blower Motor Resistor6.1 DIY Jobs Related to the Blower Motor ResistorWhile you're under the hood working around the HVAC housing, here are some related tasks you should complete for preventative maintenance or to avoid future HVAC system problems.Take out and clean the blower motor fan.Replace the cabin air filter. Figure5: the blower fan 6.2 Details of Replacing Blower Motor ResistorThe following are the simple steps to replacing a blower motor resistor: 1.Locate the Blower Motor ResistorObviously, the first thing you had better do is locate the blower motor resistor so that you determine which component will be taken out. It is directly next to the blower motor. The latter, on the other hand, is commonly found underneath the passenger side dash or in the engine compartment. 2.Take out the Blower Motor ResistorRemove the blower motor resistor now that you know where it is. To begin, remove the components surrounding the blower motor resistor, including the pigtail connected to the AC and the blower motor cooling duct. You can now easily access the blower motor resistor at this point.All that remains is to unscrew the bolts that hold the blower motor resistor in place. Using a ratchet with a short extension, tighten the screw. Once the bolts are taken out, all that remains is to remove the blower motor resistor. 3.Disconnect the WiresAfter removing the blower motor resistor, cut the wires that connect to the component. Cut the wires with a stripper or scissors designed for cutting through wires. 4.Install the New Blower ResistorApply dielectric grease to the housing of the blower motor resistor before proceeding with the installation. It will keep water out of the vehicle, which is a common issue when driving off-road. Apply a coating around the plastic to create a seal that will protect the component.Replace the blower motor resistor in the same location where it was previously removed. Replace the screws to secure them in place. Connect the pigtail when you are finished with the job. However, there are some cases in which the pigtail has already worn out. Proceed to the next step if this is the case.Disconnect the old wires and reconnect the new ones. Because the wires are probably color-coded, this should be simple. Connect the new wires with the connectors. Return the pigtail to its original position, and you fulfill the task.Ⅶ Frequently Question Asked about Blower Motor Resistor1.What does a resistor do for a blower motor?Blower resistors are resistors which are used to control the fan speed of automotive blowers. The fan speed can be changed either by switching the blower resistor resistance mechanically using a rotating lever, or electronically by the air conditioning system. 2.Why do blower motor resistors fail?In most cases, a blower motor resistor fails due to corrosion or overheating. Sometimes, the mechanical resistance to the motor rotation causes an excessive electric current that can overheat and prematurely damage the blower motor resistor. 3.Can you fix a blower motor resistor?The resistor module is easy and inexpensive to replace. It's then typically installed in the ductwork, near the car blower—either under the dash or under the hood. (Refer to a service manual to locate yours.) Purchase a new resistor module at the auto parts store (usually less than $25). 4.Can you drive with a bad blower motor?A bad heater blower motor will not affect the safety of your car, with the possible exception of you not being able to clear the windshield of snow, ice, or condensation if the defrosters don't work. But you won't be comfortable inside your car, especially during the cold of winter and the heat of summer. 5.How do I know if my blower motor has power?Check for power at the motor itself. Using a test light or a multimeter set on volts, unplug the blower motor. Keeping the black lead on a good ground, usually a bolt on the engine block, and the blower switch turned on, use the red lead to probe the plug that usually attaches to the blower motor.  
kynix On 2021-08-27   8784

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