VARIAC / AUTO TRANSFORMER:
“VARIAC” Auto Transformer:-
Is a continuously variable voltage auto transformer, having a movable carbon tip, fixed to a brush arm sliding on a silver plated commutator. Rotation of the brush-arm by either manual or motor drive, delivers-an output voltage from zero to or above line voltage. Variac conforms to I. S. 5142 of 1969.
“VARIAC” Auto Transformers 1 Ph. (Closed / Open type) are designed to give output voltage of 260-270 Volts for the input voltage of 240 Volts. 3 Phase “VARIAC” Auto Transformers are designed to give output voltage of 470 Volts for input 415 Volts. These are available in manual and motorised operating type.
1. RUGGED CONSTRUCTION: Variac 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 part needs any specific maintenance. Even carbon tips do not require to be changed frequently. This practically makes the VARIAC maintenance free electrical equipment.
2. EXCELLENT REGULATION: The drop in voltage from "no load to full load" is minimal in Variac Auto-transformers.
3. HIGH EFFICIENCY: Careful copper, core selection and design assures the user of low watt loss, as compared to other types of controllers.
4. NO WAVE FORM DISTORTION: VARIAC provides an output voltage wave-form, which is a faithful and distortion less replica of the input voltage wave-form.
5. 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.
6. LOW OPERATING TORQUE: A glass smooth commutator, special sintered bushings for the shaft and perfect assembling of the coils, results in low operating torque for all Variac Auto-transformers.
7. SMOOTH AND LINEAR OUTPUT: As 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 very easily to a fraction of a volt from zero onwards by rotation of the knob.
8. LOW MAGNETIZING CURRENT: By using an adequate section of high quality grain oriented silicon steel, the iron losses in Variac, are controlled to the minimum, The no-load current in all Variac transformers, is invariably less than 5% of the rated current.
9. NEGLIGIBLE MAINTENANCE AND TROUBLE-FREE LONG LIFE: Variac has been carefully designed. No special care has to be taken to maintain Variac Auto-transformers in-normal- working environments. The only components needing inspection and maintenance are the carbon tips and the commutator. Timely replacement of carbon tips and cleaning of the commutator surface of foreign