What brand is TNR rheostat?

Rheostat is a kind of voltage limiting protection device. Based on the nonlinear characteristics of the varistor, overvoltage occurs between the two electrodes of the varistor, and the varistor can clamp the voltage at a relatively fixed voltage value, thus realizing the protection of the later circuit.

Varistors can be mainly used in DC power supply, AC power supply, low-frequency signal line and antenna feeder with feed.