• Cosmostat Industries

Variable Auto Transformer

Variac is continuously variable autotransformer having a single layer winding on a toridol core of high-grade cold rolled grain oriented (CRGO) steel. On one face of the copper winding along the periphery, a special durable contact surface is made. A Specially finished carbon brush slide smoothly on the surface. A contact arm holding the carbon brush fitted on the centre shaft and as the control knob is rotated the carbon brush slides over the winding and taps of a portion of voltage across the winding. The calibrated dial show approximately output voltage at no load, when the input is at its rated value. The rotation of the arm by manual or motor drive delivers an output voltage from 0 to above line voltage.