Voltage RegulatorsAir Insulated



Regulating transformers are used to provide an adjustable output voltage to increase and decrease the input voltage of high voltage test systems, such as resonant test systems or conventional high voltage transformer test systems. They are equipped with a grounded tank and are also available for outdoor installation.


  • Low weight and foot print
  • Can be connected directly to the feeding LV grid (such as 3x400V)
  • Low noise output (for PD measurement) at high power
  • Rigid and reliable performance at low maintenance effort


Variable column transformers have galvanically refined decks, in order to assure a constant transfer resistance – service life and operation safety are increased thereby. In case of higher powers they are equipped with a compensation winding which results in smaller voltage drops, a smaller power loss and higher operation safety.

With a variable column transformer the voltage adjustment is achieved by means of an adjustment of the amplitude. Variable column transformers do not change the wave shape between input voltage and output voltage. Harmonics and current impulses are not present.

Our variable transformers are developed, manufactured and tested in accordance with relevant EC directives, European standards and VDE regulations, in particular DIN EN 61558-2-14 and VDE 0552.

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