Resistor

What is Resistor

A resistor is a passive two-terminal electrical component that implements electrical resistance as a circuit element. In electronic circuits, resistors are used to reduce current flow, adjust signal levels, to divide voltages, bias active elements, and terminate transmission lines, among other uses. High-power resistors that can dissipate many watts of electrical power as heat may be used as part of motor controls, in power distribution systems, or as test loads for generators. Fixed resistors have resistances that only change slightly with temperature, time or operating voltage. Variable resistors can be used to adjust circuit elements (such as a volume control or a lamp dimmer), or as sensing devices for heat, light, humidity, force, or chemical activity.

First 12 Last

Advantages of Resistor

Voltage and current control
Resistors are commonly used to control the flow of current and voltage in a circuit. By adjusting the resistance value, you can regulate the amount of current flowing through a circuit or the voltage across specific components.

Dividing voltage
Resistors are often used in voltage divider circuits to divide the input voltage into smaller voltages. This is useful in various applications where you need to obtain a fraction of the input voltage.

Limiting current
Resistors can be used to limit the current flowing through a circuit to protect components from damage due to excessive current. They act as current-limiting devices in such situations.

Temperature stability
Some types of resistors exhibit good temperature stability, which means their resistance values remain relatively constant over a wide range of temperatures. This property is important in applications where temperature variations can affect circuit performance.

Matching impedances
In some cases, resistors are used to match the impedance between different components in a circuit. This helps in maximizing power transfer and minimizing signal reflections.

Protection
Resistors can also be used for protection purposes, such as in current-limiting circuits or voltage clamping circuits, to protect sensitive components from overvoltage or overcurrent conditions.

Why Choose Us

Company Honor
The company has obtained more than 80 patent authorizations, covering aspects such as invention patents, design patents, and utility model patents.

Corporate Strategy
Expand more market shares in oversea market shares, then estabilish new company for passive components,improving prefer supply chain system, provide more best service to customer.

Products Applications
Products widely applied in many areas such as power supply and adapters (customer: SUNGROW power supply), green lighting (customers: MLS, TOSPO lighting), router (customer: Huawei), smart phone (customers: Huawei, Xiaomi, OPPO) and communication products, automobile electrics (customer: SAIC General Motors), frequency transformer, big and small household electrical appliances (customer: Gree), safety guard area (HIKVISION, DAHUA) and other areas.

R&D Capability
According to the actual management requirements, the company has independently built a TRR office management system for many years, incorporating most functions such as production, sales, finance, personnel, and administration into the system management, promoting the company's management informationization, and realizing the production and demand database management mode , Improve the quality and efficiency of production and management, better achieve the management of complex products, complex production, and meet the different needs of customers.

Types of Resistor

Linear resistors
The resistors whose value changes when temperature and voltage values are changed are known as linear resistors. These are further of two types- Fixed and variable resistors.
Fixed resistors- These resistors have a fixed value that cannot be changed. Some examples of fixed resistors are- thin-film resistors, wire-wound resistors, carbon composition resistors, etc.
Variable resistors–These resistors do not possess a fixed value but values that can be changed using a knob, dial etc. Some examples of variable resistors are- rheostats, potentiometers, etc.

Non-Linear resistors
The resistors whose value changes when temperature and voltage values are changed but do not follow ohm's law are known as non-linear resistors. For e.g. Thermistor, Varistor, Photo resistors etc.
Thermistor-A thermistor is a type of resistor whose resistance is strongly dependent on temperature in standard resistors.
Varistor- A varistor is a resistor whose resistance varies with the applied voltage.
Photoresistors- A photoresistor is a resistor, also a sensor that changes its resistance when light shines on it.

Resistor Materials

Wirewound (WW) Resistors
The process of creating Wire Wound Resistors involves spiraling resistance wire around a non-conductive core. Usually, they are made for applications requiring a high degree of precision and power. Typically, the resistance wire is composed of an alloy of nickel and chromium, while the core is constructed of ceramic or fiberglass. Applications involving frequencies more than 50 kHz are not appropriate for them.

Metal Film Resistors
The resistive substance is usually composed of a mixture of metal and ceramic. Although they are better at handling higher frequencies, metal film resistors are typically less stable with temperature than wire wound resistors.

Metal Oxide Film Resistors
Compared to metal film resistors, these resistors function at greater temperatures and are dependable and stable. For this reason, applications requiring great durability employ metal oxide film resistors.

Carbon Film Resistors
Carbon film resistors consist of an insulating cylindrical core covered in a thin layer of carbon with a spiral cut in it to improve the resistive path. This raises the resistance value and makes it possible for the resistance value to be more precise. Resistors made of carbon composition are not nearly as accurate as carbon film resistors. Applications requiring strong pulse stability employ special carbon film resistors.
The process of creating Wire Wound Resistors involves spiraling resistance wire around a non-conductive core. Usually, they are made for applications requiring a high degree of precision and power. Typically, the resistance wire is composed of an alloy of nickel and chromium, while the core is constructed of ceramic or fiberglass. Applications involving frequencies more than 50 kHz are not appropriate for them.

Working Principle of Resistor

Atomic structure
The behavior of resistors is rooted in the atomic structure of the materials they are made of. Most common resistors are made from materials like carbon, metal films, or metal wire. These materials have electrons that are somewhat loosely bound, allowing them to move relatively freely through the material.

Electric field and electrons
When a voltage (potential difference) is applied across the ends of a resistor, an electric field is established within the material. This electric field exerts a force on the loosely bound electrons, causing them to move through the material in response to the voltage.

Resistance
As the electrons pass through the conductor, they encounter resistance due to collisions with atoms and other electrons within the material. These collisions slow down the electron flow, transforming some of the electrical energy into heat energy. This heat dissipation is why resistors get warm when current passes through them.

Ohm's law
Ohm's law is a fundamental principle in electronics that describes the relationship between voltage, current, and resistance in a conductor, such as a resistor. It was named after the german physicist georg simon ohm, who first formulated this law in the 1820s.

The relationship between voltage, current, and resistance in a resistor is described by ohm's law, which states that the current passing through a resistor (i) is directly proportional to the voltage across the resistor (v) and inversely proportional to its resistance (r).

How To Choose the Right Resistor for Your Project

Resistance
The basic criterion for selecting your resistor is its resistance value. Resistors are sold in standardized value ranges set by the IEC (International Electrotechnical Commission). The values in each range follow an exponential curve, keeping the tolerance within a designated percentage.

Tolerance
Tolerance is the amount that the resistance of a specified resistor can vary from its target value. Most resistors have a 5% tolerance, though 1% tolerances are readily available. Large “power” resistors tend to have a tolerance of 10% or even 20%, though precision models are available. High-precision resistors, with tolerances of 0.1% to 0.01% and lower are available, but tend to be a little more pricey when compared to the basic 5% resistor. The resistors with high-precision tolerances are highly useful for instrumentation, precision measuring devices, and reference applications to name a few.

Package and Mounting
Resistors are packaged in different ways and have different mounting styles. For one-off, hand-soldered applications, this is not necessarily a big concern. If you are mass producing computer chips, the packaging and mounting style could become a primary consideration.

Power Dissipation Rating
Since the function of a resistor is to impede current flow, some power is dissipated as heat. Whether this matters depends on the size of the resistor, the size of the device in which it is placed, and the heat tolerance of the device. A tiny single resistor in an analog device is unlikely to dissipate enough power to be noticeable, while a bank of large resistors working at their maximum capacity can put out significant heat.

Voltage Rating
In physically small devices, the voltage ratings tend to be low. In large, high voltage systems, it is generally better and safer to raise the voltage of the circuit by connecting multiple resistors in series rather than using a single resistor at its max voltage rating.

Resistive Material
Not counting semiconductors, there are three basic types of resistive materials: composition, metal film, and wire-wound. Each has its own unique properties:
Film Resistors are made of conductive metal oxide paste on a ceramic substrate, and are laser cut to create tight tolerances. Due to their low noise and temperature stability, film resistors are ideal for radio frequency or high frequency applications.

Temperature Range
In normal ambient temperatures, checking the power dissipation of the resistor is fine. If the resistor will operate in significantly elevated temperatures, though, it is important to look at the power dissipation derating curve. As the resistor gets closer to its maximum allowable temperature, the less power can be dissipated. This puts the resistor, and ultimate the entire device, at risk for overheating and failure.

Noise
Resistors can put out three types of noise: shot noise, flicker noise, and thermal noise. Shot noise sounds something like a rushing river, but it is generally an extremely low level of not-unpleasant white noise. Flicker noise is more random and can be far more annoying. Composition resistors have the most flicker noise, and larger resistors have less than smaller ones of the same type. Thermal noise becomes a problem at higher temperatures, and metal film resistors tend to have the least. Overall, lower-value resistors create less noise than higher-value resistors.

Use of Resistor

In every life, the gazettes use the resistors to operate easily without damaging itself. Today's life depends upon lots of electrical and electronic applications.

These applications use resistors in several ways. To heat the water, you need geysers, to watch a movie, the requirement of TVs/mobiles are a must. To do any kind of work in today's life, electronic gazettes are need of the hour. All these equipment being used are having resistors in some way or other.

In electronic components, sometimes a single resistor does not give the desired result. To get the desirable results, resistors are in use in series or parallel pattern.

To enhance the value of resistance, resistors are in use in the series pattern. When the resistors are arranged in the series pattern, the total resistance of the connected resistors is the summation of individual resistances.

For this arrangement of resistors, the total equivalent resistance RTotal is RTotal=R1+R2+R3.

To reduce the value of resistance, the use of resistors in a parallel pattern is recommended. When the resistors are used in the parallel pattern, the reciprocal total resistance of the connected resistors is the reciprocal summation of individual resistances. For this arrangement of resistors, the total equivalent resistance RTotal is 1RTotal =1R1+1R2+1R3.

How Can I Prevent a Resistor from Losing Power

Resistors are passive electronic components that dissipate power in the form of heat when current flows through them. This power dissipation is an inherent characteristic of resistors and is determined by the current passing through them and the voltage across them, according to Ohm's Law (P = I^2 * R or P = V^2 / R, where P is power, I is current, V is voltage, and R is resistance).

To prevent a resistor from losing power and overheating, you can take several measures:

Choose the Right Wattage Rating: Use a resistor with a wattage rating that is higher than the calculated power dissipation. This ensures that the resistor can safely handle the heat generated without getting damaged.

Use Multiple Resistors in Series or Parallel: Distribute the power dissipation among multiple resistors connected in series or parallel. By doing this, each resistor will dissipate less power compared to a single resistor carrying the entire load.

Heat Sinks: For high-power resistors or applications where power dissipation is significant, consider using a heat sink to dissipate heat more effectively. Heat sinks help to transfer heat away from the resistor and improve thermal performance.

Airflow and Ventilation: Ensure that there is adequate airflow around the resistor to help dissipate heat. Good ventilation can prevent the resistor from overheating.

Derating: Operating a resistor below its maximum power rating can increase its reliability and lifespan. Derating involves using a resistor at a lower power level than its maximum rating to ensure it operates within safe limits.

Use Pulse Withstanding Resistors: For applications involving high-energy pulses or transient conditions, consider using pulse-withstanding resistors designed to handle short bursts of high power without damage.

Temperature Monitoring: Implement temperature monitoring to keep track of the resistor's temperature. If the temperature exceeds safe limits, appropriate measures can be taken to prevent overheating.

FAQ

Q: What is the purpose of the resistor?

A: The name itself mention it's function. Resistor is used to resistance the flow of current. When resistor is placed in a circuit, the current flow decreases when current passes through the resistor. The part of current energy dissipate in the form of heat in resistor, thus decrease the total current.

Q: How do resistors work?

A: A resistor works by restricting the flow of current, it can do this in one of three ways: firstly, by using a less conductive material, secondly by making the conductive material thinner and finally by making the conductive material longer.

Q: Why are resistors important to us?

A: They may be small and often built-in to other components, but resistors are essential to almost every electrical circuit. These hidden resistors are essential because they control the flow of the electrical current to sensitive components, and they protect components from voltage spikes.

Q: Do resistors reduce voltage?

A: “Resistors do just what their name says; they resist. You can use them to limit either current or voltage, depending upon whether they are wired in series (one after the other), or parallel (sharing the same connection points, side-by-side” .

Q: What happens if I use a higher ohm resistor?

A: The basic principle that can guide you is; The higher the resistance, the lower the current. At the end of it all, the choice of resistor value depends on the current you want to pass or you want your circuit to deliver. In most cases Ohms law may help in determining the value of resistor to use.

Q: How does resistance affect current?

A: As the resistance increases, the current decreases, provided all other factors are kept constant. Materials with low resistance, metals for example, are called electrical conductors and allow electricity to flow easily. Those materials with high resistance, like plastics, are called electrical insulators.

Q: Where are resistors used?

A: The main use of resistors is to control the flow of electric current. Resistors are used in heaters, toasters, microwaves, electric stoves, and other household heating appliances. Electrons in a resistor collide with ions slowing down the flow of electricity. It lowers the current and also produces heat.

Q: Why do resistors resist?

A: The resistance of a resistor is dependent on its material and shape. Some materials have a higher resistivity, thereby resulting in a higher resistance value. The resistance value is often printed on the resistor with a alphanumeric code for SMD resistors or in the form of a color code for through-hole resistors.

Q: How do resistors affect voltage?

A: Voltage applied to a series circuit is equal to the sum of the individual voltage drops. The voltage drop across a resistor in a series circuit is directly proportional to the size of the resistor.

Q: Can resistors increase voltage?

A: Adding an extra resistor to the circuit increases the resistance of the circuit. As resistance increases the current decreases. The equal increase in resistance and decrease in current results in the voltage remaining constant. The voltage is shared evenly across all resistors present in the circuit.

Q: Do resistors add voltage?

A: Voltage varies directly with current. "R" is the constant of proportionality telling how much it varies. If I add in a resistor to a circuit, the voltage decreases. If you have a resistor in a circuit, with a current flowing through it, there will be a voltage dropped across the resistor (as given by Ohm's law).

Q: Do resistors reduce power?

A: The fact remains that all resistors that are part of a circuit and has a voltage drop across it will dissipate electrical power. Moreover, this electrical power converts into heat energy, and therefore all resistors have a (power) rating.

Q: Why do resistors drop voltage?

A: When current is flowing, components such as resistors consume energy, and the amount of work per unit charge associated with the current flowing through a given component is the component's voltage drop. The voltage dropped by a component accounts for a portion of the voltage generated by the battery.

Q: Why do resistors heat up?

A: When electricity is conducted through a resistor, heat is generated and dissipated through the surrounding air. Under excessive voltage, a resistor generates so much heat that it cannot dissipate the heat quickly enough to prevent burning.

Q: Do resistors slow down current?

A: The resistor moderates the flow of electrons, so the current doesn't move too quickly and cause damage to the breadboard, wires, battery, etc. The second reason to use a resistor is to slow the current flow to a component. Components like LED's, fans, light bulbs, etc.

Q: What is the mostly used resistor?

A: The fixed resistor type is the most common resistor. When people talk about a resistor, they most likely mean a fixed resistor. The carbon film resistor, the most common type on older printed circuit boards (PCBs) that used through-hold components.

Q: Are resistors always positive?

A: Even though it doesn't matter which way you place your resistor, current flows from positive to negative. While resistors don't have their own polarity they will typically be part of a circuit that does, thanks to other components like capacitors. In a DC circuit, the current will always flow in only one direction.

Q: Do resistors have positive or negative voltage?

A: Resistors don't have positive or negative terminal. However, when current flows through a resistor then the voltage drop across the resistor do have a polarity. Polarity of voltage drop depends upon the direction of current.

Q: What's inside a resistor?

A: Resistors can be constructed out of a variety of materials. Most common, modern resistors are made out of either a carbon, metal, or metal-oxide film. In these resistors, a thin film of conductive (though still resistive) material is wrapped in a helix around and covered by an insulating material.

Q: Do resistors decrease charge?

A: With less voltage being dropped across the resistor, the current drops off. With less current, the rate at which charge goes onto the capacitor decreases. The charge continues to build up, but the rate of that build up continues to decrease.

We're well-known as one of the leading resistor manufacturers and suppliers in Shenzhen, China. If you're going to buy high quality resistor in stock, welcome to get quotation from our factory. Also, OEM service is available.