Technical Articles
Wirewound Resistors' Application and Characteristics
Date:2019-05-17
A wirewound resistor is an electrical passive device that limits or restricts current flow in a circuit. Wirewound resistors are constructed using a conductive wire. The conductive wire is then wound around a non-conductive core. The conductive wire can be made of varying alloys and thickness to control the resistance value.
 
Microhm offer over different series in wirewound construction. which can be chosen based on mounting, application, and resistance range. Different types of wirewound resistors include Precision, Axial, Tubular and Surfacemount, which all have good stability and resistance range, and are produced in many wattage sizes.

 
Wirewound resistors are typically used in high power and industrial applications such as circuit breakers and fuses. The higher wattage wire wound resistors are used in High Current/Braking applications.
Common in power supplies and other equipment where lots of power is dissipated, a wirewound resistor is made just as you might expect.
 
A high-resistance wire is wound on an insulating form — usually a ceramic tube — and attached to electrodes at each end. These are made to dissipate a lot of power in sizes from one-watt to hundreds of watts! Wirewound resistors are usually intended to be air cooled, but some styles have a metal case that can be attached to a heatsink or metal chassis to get rid of undesired heat.
Because the resistive material in these resistors is wound on a form, they have very high LS. For this reason, wirewound resistors are not used in audio and RF circuits. Be careful when using a resistor from your junk box or a grab bag in such a circuit!
Small wirewound resistors look an awful lot like film or carbon comp resistors. There is usually a wide color band on wirewound resistors, but not always. If you’re in doubt, test the resistor at the frequencies you expect to encounter. There are special versions with windings that cancel most of the inductance, but have a much higher CP that also affects the resistor’s performance above 50 kHz.