• Donut Technologies

Auto Variable Transformers

Donut Technologies manufacturers of Open-table and Motorized Auto Variable Transformers (Variac) in India. Auto Variable Transformers are electrical Transformers with only one winding, wherein, a part of the winding is exposed and the secondary connection is made through a sliding brush. This way, a continuously variable turns ratio is obtained, allowing for very smooth and more accurate (±1%) control of output voltage. This output voltage adjustment can be done manually or automatic.

Auto Variable Transformers (Variac) is generally used to maintain a steady voltage at the Output terminals, during a wide range of line and load conditions. It is also being used successfully as lighting dimmer that doesn't produce the EMI typical of most thyristor dimmers.