Constant Voltage Transformer (Magnetic Voltage Stabilizer)
are separating transformers according to EN 61558/ VDE 0570; equipped with some special characteristics.

They generate within the permissible operation range a stabilized output voltage with an open-loop circuit only by vectorial addition or subtraction of partial voltages.

Fluctuations of a 50 cps input voltage up to +10/-20% are reduced in 40...60 ms to about +/- 1%; presupposing a constant loading with power-factor cos φ≈1 .
Constant Voltage transformers regenerate the sinusoidal shape of distorted mains voltages, suppress glitches, attenuate high- frequency voltages in both directions, and shunt-out short-breaks of up to 10 ms.

Constant Voltage Transformers are short-circuit proof and require no maintenance ; neither radio interference nor additional harmonics occur within the permissible operation range.

Constant Voltage Transformers regenerate, clear up and stabilize the operation voltage of appliances for
  • Data processing
  • Test equipment
  • Measuring and control engineering
  • Film and photo
  • Optical illumination systems
  • Audio equipment , etc.

What Constant Voltage Transformers can not do:
  • Constant Voltage transformers are not able to regenerate the voltage at the end of long dead- end lines when conductor cross section and system impedance are too high.
  • A reliable stabilization is only possible when lines are so dimensioned, that the voltage drop between feeding and consumers point even by inrush reaches no more than 4% of the rated voltage.
  • Constant Voltage Transformers are short- circuit proof and therefore, they are not able to accept high inrush currents. Depending on transformer size, the output voltage collapses to zero with currents of approx. 1.3 ...1.5 times of the rated current. Inrush currents are only accepted with Constant Voltage Transformers dimensioned for at least 90% of the inrush power.
  • Constant Voltage Transformers cannot regenerate frequency deviations or stabilize the rated frequency.

For detailed information, please see our publication "Magnetic Voltage Stabilizer" .