What Is a Rheostat?

Rheostat can adjust the resistance of the device, connected in the circuit can adjust the size of the current. A general varistor is composed of a large resistance wire (resistance wire) and a device that can change the contact point to adjust the effective length of the resistance wire. Function: 1. Limit the current and protect the circuit; 2. Change the voltage distribution in the circuit.

As a special kind of resistance, the sliding line varistor is widely used in ordinary physical tests. Many circuits use the sliding line varistor to achieve the function of the control circuit, and it can be used to control the change of current and voltage in the circuit. ^[1]

The knob on the Walkman to adjust the volume; the knob to adjust the light on and off on the desk lamp; the knob to adjust the brightness on the monitor on the computer; Both are varistor applications.