Resistors and Potentiometers

Resistors and potentiometers are passive electronic components that oppose the flow of either alternating current (AC) or direct current (DC). Fixed resistors have a fixed resistance value. Variable resistors have a resistance value that can be adjusted or changed by the user. For both types of resistors and potentiometers, device types include attenuator, chip, and shunt resistors, as well as load banks and voltage dividers. Attenuator resistors reduce the power of a signal by a determined factor without distortion. Chip resistors are passive devices with a form factor of an integrated circuit (IC) chip. Shunts resistors are connected in parallel with an instrument or component to divert electrical current. They provide an alternate path for current in case of failure. Load banks are fixed and variable resistors that provide resistive electrical loads for testing purposes. Similarly, voltage dividers produce highly-accurate reference voltages for both calibration and testing. Potentiometers, trimmers and rheostats are additional device types for variable resistors. 

There are many different categories of resistors and potentiometers. Current sensing fixed resistors convert flow-through current to a voltage drop. By monitoring or measuring the voltage drop, current flowing through the resistor can be measured. Dynamic braking resistors (DBR) produce braking torque and absorb the high amounts of energy generated by stopping electric motors. They are used in variable-speed drive systems such as elevators, cranes, and trains. Fusible resistors are made of a partially-organic film. The flow of high-current melts the film, opening the circuit and stopping the flow of current through the resistor. Harmonic filter resistors are used in power electronics and solid-state devices which generate harmonic voltages. They dissipate harmonic currents as heat. High current, high frequency, and high voltage fixed and variable resistors are also available. Specialized resistors and potentiometers include medical resistors, motor-starting resistors, neutral grounding resistors, precision resistors, power resistors, railways resistors, surge resistors, and telecom resistors. 

Resistors and potentiometers carry specifications for configuration style and product performance. There are two main configurations: single resistor and resistor array. Single resistors are standard, passive devices with a single resistance value. Resistor arrays contain several fixed resistors and/or variable resistors housed in a single package. Performance specifications for resistors and potentiometers include tolerance, resistance range, temperature coefficient of resistance (TCR), power rating, operating alternating current (AC) voltage, operating direct current (DC) voltage, and operating temperature. For arrays of fixed and variable resistors, the number of resistors in the package is also an important consideration.

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Part Numbers for Resistors and Potentiometers