Single Phase Manual Variable Auto Transformer
Variacs or variable auto transformer is a continuously variable voltage transformer, having a single layer winding on a toroidal core of high grade steel.
In a single phase manually operated auto transformer Variac, portions of the same winding act as both the primary and secondary winding. the winding has at least three taps where electrical connections are made. one end of the winding is usually connected in common to both the voltage source and the electrical load. the other end of the source and load are connected to taps along the winding. Different taps on the winding correspond to different voltages, measured from the common end.
On one face of the copped winding, along the periphery, a special durable contact surface is made. a specially designed carbon brush slides smoothly on the surface. a contact arm holding the contact brush is fitted to the central shaft and as the control knob is rotated, the carbon brush slides over the winding and taps off a portion of voltage across the winding. the basic auto transformer is meant for operation off a nominal voltage of 240 v a.c & can give output voltage anywhere between 0 – 240 v or up to 290 v, by a simple transformer action.
We make these 1 Phase Manual Variable Auto Transformer Variac in below ratings.
Variac Rating Available: 2 Amp to 600 Amp