Potentiometers are a form of electrical resistors. While not designed to carry a great deal of electrical current, they are often ideal for small jobs. A potentiometer is helpful in such common tasks as adjusting the volume level on a radio, or changing channels on some types of television sets.
In construction, a potentiometer uses either a two or three terminal configuration. A slide-wire contact is used to create a voltage divider that can be adjusted to different settings as needed. It is this ability to make an adjustment in position that makes it possible for the resistor to be useful in simple management tasks associated with the operation of small electrical devices.
The amount of power controlled by a potentiometer is very small. In most cases, the voltage output and input is no more than a single watt, but this is enough power to allow simple manipulation of many electrical devices. Along with the volume control on a radio, this resistor provides enough power control to trigger the on/off function on a number of devices, as well as increase of decrease the flow of current to a given device. Light fixtures and lamps that have a dimmer control are able to brighten and dim the output of light with the aid of a potentiometer.
A potentiometer may be activated with the use of a knob that is turned to various settings, a slide control, or even a simple switch. In all cases, the movement of the outward mechanism activates the function of the resistor and helps to achieve the desired effect. The range of movement allowed will depend on the construction of the electrical device and the exact configuration of the potentiometer. In many cases, one complete circle or turn is permitted among a limited amount of selections along a scale. Some devices use a model that allows for multiple revolutions around the range, however, increasing the number of settings that may be chosen. This is particularly true when the resistor is used to control volume levels.