Open Type Variable Autotransformer

• VARISTAT continuously variable Auto Transformers have many operating advantages and conveniences over other manually operated voltage control devices for alternating current use
• Smooth Control: The VARISTAT can be set to any output voltage within its range. Output voltage is continuously adjustable from zero to maximum.
• Small Size: The variable Auto Transformers is much smaller than any other type of control of equal rating.
• Better Efficiency: Very low losses under all loud conditions. Toroidal VARISTAT have low-loss grain oriented strip wound cores.
• Better Regulation: Output voltage is substantially independent of  loud.
• Linear Output Volts: Output Voltage varies linearly with angle of rotation of control knob.
• Temperature rise: Less than 50 deg.C for continuous duty.
• Advanced Design: Excellent electrical specification is matched by rugged, compact construction. Brush replacement is simple and convenient.Two,Three or more units can be ganged on one shaft for series,parallel or three-phase operation.
• Long Life: When used correctly the VARISTAT has a very long operating life.The life of a VARISTAT is essentially the same as that of any standard fixed ratio power transformer.
  

• Easily Read Dials: Dials are single - reading with large, clear numerals, easy to read at a distance.
• Wide range of models: VARISTAT are available in a wide range of models to suit various requirements. These include
• Open - for panel mounting purpose
• Enclosed - Suitable for table mounting
• Portable - with or without meters
• Oil Cooled - for increased ratings
• Double Wound - Where the primary is isolated from the secondary prominant for manufacturer of servo-control voltage stabilizer
• High Frequency - for various louds
• Special Voltage - 120v, 240v, 400v,etc.
  

• Supply Voltage Correction, Boosting of low lines and line voltage stabilisation, either manually or automatically in automatic voltage stabilizers
• Control of D.C. voltage and current through rectifiers. Control of rectifiers in electroplating, battery chargers etc.
• Motor speed control in textile machines, blow moulding machines, injection moulding machines,printing and packaging machineries etc.
• Testing and calibration of voltmeters, ammeters, wattmeters, power-factor meters etc.
• Voltage and current control in development and experimental  works
• Heating control of ovens,furnaces, infra-red heaters etc. in production and experimental works
• Lighting control in theaters, auditorium, hotels, restaurant, photographic studios and dark-rooms, reading houses,etc.
  

• Input Voltage: The voltage that should be applied to the input terminals to make the dial calibration correct is 240v, 50Hz, 415v, 50Hz
• Output Voltage: The output voltage from the varistat is continuously adjustable from zero to 12.5% above the line voltage (i.e. 270V or 470V). The dial reads the approximate voltage.
• No load current: Less than 2% of full load
  

Construction: Both single and three phase units are supplied enclosed in sheet metal covers, unless asked  for open type construction for panel mounting,oil cooled units are supplied in sheet-metal tanks with or without cooling radiators.

Current ratings: (single wound type)

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