High Power Voltage Variators 
The variable transformers allows to obtain an alternating voltage smoothly and continously variabIe from zero to the line voltage or even higher.
All described models are for laboratory use, are closed and realised into a metallic box with output on security terminals and protected against short circuits and overcharge.

Motor drive System 290kW

Motor drive System 50kW

Single phase voltage variators


Output V


Power VA


0-220V a 0-260V

0,9A a 2A

0,18k a 0,45k

Three phase voltage variators


Output V

Current A

Power VA


0-220V a 0-450V

0,9A a 2,4A

0,9k a 1,4k


0-200V a 0-480V

1,8A a 5,6A

0,9k a 2,7k

Manufacturing standards designed and tested according to VDE-0552 EN 61010, EN 50081-1, EN 50082 and IEC 61558-2-14; designed as toroidal auto transformer under quality system UNI EN ISO 900

All regulators use grain-oriented strip would silicon steel cores ensuring low losses and reduce magnetising current.

The windings, which is insulated from the core by precision moulded winding formers, comprises a single layer (class H wire) carefully wound to provide a flat surface for the brushgear.

Easily replaceable carbon units are used, the resistance of the brush being carefully calculated to limit the current circulating in the bridged turns.
It is therefore most important that only the correct replacement brush is used in any particular Brushes are mounted in robust brush carriers insulated from the shaft, and designed so that metal parts cannot come into contact with the winding in the event of brush fracture.

Rated Current:
output current that can be draw at any brush setting for a continous duty.

Ambient temperature:
current ratings apply up to 45C ambient.

kVA Rating:
the maximum output current at maximum output line voltage multiplied by that max voltage and divided by 1000 for single-phase. Divide by 577 for three-phase (1000/V3)

Line-Voltage and over-Voltage connection:
with line-voltage connections, the supply is connected across the whole winding, and the maximum output equals the applied voltage.
In over-voltage connection, the supply is applied to a tapping provide instead of to the whole winding, giving e.g.:0-280 Volt from a 220 Volt supply.

All variable transformers are flash-tested at 2,5KV.rms 50 Hz.

Copyright © 1995, italtec srl.