Express Transformers & Controls (2015) Limited manufactures a broad range of durable, wire-wound power resistors to suit a variety of applications.
What is a Resistor?
A resistor is a passive component that creates electrical resistance as a circuit element. Fixed resistors have resistances that only change slightly with temperature, time or operating voltage. A fixed resistor fitted with a tapping band becomes a variable resistors.
What is a resistor used for?
In electronic/electrical circuits, resistors are used to reduce current flow, adjust voltage levels 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.
A variable resistor can be used to adjust circuit elements (such as a volume control or a lamp dimmer). It can also be used to obtain intermediate values of resistance compared with fixed resistors ratings.
Wire wound power resistors
Wire wound power resistors are made by winding a metal wire, usually nichrome, around a ceramic tube. The ends of the wire are fastened to two clips, attached to the ends of the tube. The assembly is protected with a layer of ceramic cement that is baked at a high temperature. These resistors are designed to withstand unusually high temperatures of up to 300 °C.
The standard resistors we supply are rated from 130 watts up to 750 watts and are designed to radiate excess heat. Larger wire wound resistors are possible to special order.
Custom resistors and how to order
To quote we would need to know the rating in ohms and the throughput power of the resistor required.
Examples of our work can be seen in the gallery.