Variable Voltage Transformer

Autovolt Variacs or variable auto-transformer is a continuously variable voltage transformer, having a single layer winding on a toroidal core of high grade Cold Rolled Grain Oriented Steel. 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. Any desired voltage within the maximum range can be obtained by adjusting the position of the brush. The calibrated dial reads approximately the output voltage at no-load, when the input is at its rated value. Rotation of the brush arm by manual of motor drive delivers an output voltage from zero to or above line voltage. APPLICATIONS:Supply voltage adjustment, boosting of low lines and line voltage stabilization, either manually or automatically in automatic voltage stabilizers. Voltage and current control in development and experimental work. Over and under voltage testing of electrical and electronic equipment. Heat control of ovens, furnaces, infra-red heaters etc& Testing and calibration of voltmeters, ammeters, watt meters etc& Built in as an integral control element in electrical, electronic and automatic control and process equipment. Lighting control in theatres, auditoriums, hotels. Restaurants, photographic studios and darkrooms etc... Motor speed control either direct or through suitable circuits. Control of DC voltage and current through rectifiers. Control of rectifiers in electroplating etc& Various Models available are:Single Phase Open Type Model Single Phase Motorised Model Single Phase Portable Model Three Phase Open Type Model Three Phase Enclosed Model Three Phase Oil Cooled Model