Servo Voltage Stabilizer


Servo Voltage Stabilizer

The SERVO CONTROLLED VOLTAGE STABILIZER utilizes a motor driven variable auto transformer & a Buck\Boost transformer, which is connected between the incoming phase supply & the load. The primary winding of the Buck\Boost transformer is connected to the continuously Variable Auto Transformer in such a way that one lead of the winding is connected to a predetermined tap point of the auto transformer, depending on the position of the variable brush arm with respect to the fixed point the voltage applied to the primary winding has addition or subtraction on the supply voltage available on the secondary side.

The autotransformer is driven by an AC synchronous motor to achieve increase or decrease in output set voltage by rotating it in clockwise or anticlockwise direction depending on the input supply voltage.

An electronic control card continuously monitors the output voltage and the same is being compared against the set reference voltage to achieve the desired output voltage. The control card responds to the variation in input voltage in such a way that the motor in voltage correction doesn't overshoot in either direction. This method of correction in output voltage is free from generating waveform distortion & harmonics.


  • Fast corrections rate and very high efficiency.
  • Works over wide input frequency range and no waveform distortion.
  • Specially designed high performance I.C. based control circuit for ultra high reliability.
  • Auto/Manual operation facility.
  • Over voltage and under voltage Indicators.
  • Output voltage adjustability provided on panel.
  • Unaffected by load Power Factor
  • Plug -in type glass-epoxy control cards for easy on line serviceability.
  • All components used are of reputed makes confirming to relevant IS/BS standards.
  • Stabilizer are subject to routine and type tests in accordance with latest IS Standards (IS:9815-94)


  • Automatically corrects voltage on regular intervals.
  • When supplied with constant voltage, synchronous motors operate highly efficiently.
  • Protects expensive electrical equipments from menace of voltage fluctuation thus lowers the cost on maintenance.
  • Better efficiency in plant with less production losses.
  • 100% depreciation as per Income Tax Act.
  • Reduces the electricity bills approximately up to 15%
  • As the generator is not required to run at High/Low input voltage thus it saves on diesel cost.
  • The average pay back period of Servo Controlled Voltage Stabilizer owing to its high energy saving capability, which is approx. 18 months.

Field of Application :

  • Air Conditioning Plants
  • Medical Equipment
  • Offset Printing Machine
  • C.N.C. Machines
  • Escalators & Elevators
  • Mall & Commercial Complex
  • Residences & Offices
  • Telecommunication System
  • Farm House
  • Defense Equipment
  • Information Technology
  • Call Centers
  • Cement Plants
  • Domestics load
  • Hotels
  • Textiles Industries
  • Pharmaceutical Industries
  • R & D Institutions
  • Metrological Department
  • Induction Heating Plant

Three Phase : 3 KVA-25KVA

Single Phase: 2KVA-5KVA

Three Phase - Oil Cooled Stabilizer

Three Phase : 30KVA-40KVA