Variable autotransformers​


The BELOTTI autotransformer is an efficient, trouble-free device A.C. voltage control.

Belotti is a manufacturing of VARIAC since 1946, located in ITALY.

Main Features:

–  Easy to control with simple raise-lower switches or standard process controllers. Motor drive control provides complete isolation between power and control circuits.

– Belotti units are immune to power line noise.

– Do not produce harmonic distortion.

-Reduce utility bills.

-Avoid interference with other equipment.

-Produce an adjustable output voltage that is a sine wave. Only the voltage value changed; the shape of the voltage is not distorted.

– Handle all load power factors.

– Can be used to adjust banks of capacitors and/or inductors.

– Versatility of application


  • Regulate voltage (over and under-voltage testing of electrical and electronic equipment).
  • Speed control
  • Used in Laboratory, test rooms, electrical panels or where a voltage variation from zero to line voltage or higher
  • Power supplies
  • Industrial process heating control
  • Source voltage & load banks for electrical testing:
  • circuit breaker, uninterruptible power supplies, generators etc
  • Control of D.C. voltage and current through rectifiers
  • Control of rectifiers in electroplating etc.
  • Supply voltage adjustment (automatic voltage stabilizers)..


Toroidal Variac up to 50kVA

Column Variac up to 500kVA and more


Manual regulation with handle and graduated dial

Motorized regulation with motor AC

230V or DC 24V or 12V

The MOTORIZED REGULATION can be controlled by:

bottom “increase-decrease”

New electronic card RVP-600.

Variable autotransformers

The BELOTTI autotransformer is an efficient, trouble-free device for controlling A.C. voltage. Unlike most transformers, our voltage regulator has a transformation ratio that can be smoothly and continuosly changed so the output of the unit can be controlled from zero to line voltage or even higher.