Rugged Construction: "VARIVOLT" Auto Transformers are designed for heavy duty trouble free operation. All components are designed to give maximum life to the unit under extreme operating conditions. Except for carbon tips, no other parts need any specific maintenance. Even the carbon tips are not required to be changed frequently. This practically makes "VARIVOLT" a maintenance free electrical equipment.

Excellent Regulation: The drop in voltage from "no load to full load" is minimal in "VARIVOLT" Auto-transformers (See fig. II for regulation characteristics.)

High Efficiency: Careful copper, core selection and design assures the user of low watt loss, as compared to other controllers. (See fig. III for efficiency characteristics.)

No Waveform Distortion: "VARIVOLT" provides an output voltage wave-form, which is a distortionless replica of the input voltage wave-form.

Silver Plated Commutator: A special silver plating technique is used on the commutator, enabling it to withstand high overloads and maintain constant contact drop. It also ensures smooth operation, long life and increased resistance to corrosion.

Overload Capacity: Because of its careful designing, "VARIVOLT" can withstand many overloads, Fig...I gives an idea of the maximum overloading with its relevant time limits. When repeated overloading takes place, care has to be taken to provide sufficient off time in order to reduce the temperature build up.

Low Operating Torque: A glass smooth commutator, special sintered bushings for the shaft and perfect assembling of coils results in low operating torque for all "VARIVOLT" Auto Transformers.

Smooth and Linear Output: As the voltage between turns is small and as the brush arm is in constant contact with more than one turn, harmful sparking is avoided and output voltage can be set to a fraction of a volt from zero onwards.

Negligible Maintenance and Trouble-Free Long Life: "VARIVOLT" has been carefully designed so that no special care has to be taken for its maintenance in normal working environments. The only components that need inspection and maintenance are the carbon tips and the commutator. Timely replacement of carbon tips and cleaning off foreign particles and accumulated dust from the surface of the commutator, will ensure a considerably long, maintenance-free, and uninterrupted life of the unit. Normally "VARIVOLT" Auto Transformers, up to 28 Amps., are offered in air cooled or oil cooled construction and models of 40 Amps. & above are offered in oil cooled construction. In very special cases "VARIVOLT", above 40 Amps., can be offered in air cooled construction. This is possible due to the new paralleling techniques adopted by us.