Variable Laboratory Autotransfomer (Variac 500VA 0-260VAC)The variable autotransformer (Variac is the trade name of a popular brand) is one of the most useful and efficient devices ever invented for the control of AC votage and of voltage dependent parameters such as current, power, temperature, light intensity, motor speed etc. It enables the AC input to a mains powered appliance to be easily varied from 0 to full line voltage (or greater). Encased in heavy duty steel housing it also features on off switch,