| Engineers, Scientists, Technicians working in laboratories on sensitive equipments have a need for Isolated mains supply, with a variable output Voltage. This facilitates them in testing various devices demanding different voltages & currents. It is also an Electrical Engg. practice to test devices by applying steadily
increasing voltage from 0 V to the device rated voltage. To
achieve the above objective, it is normal practice to use a Variac followed by a 1: 1 Isolation transformer or
vice versa as shown in figure 1. This combination becomes very
bulky (heavy) with two separate transformers, wiring or a combined bulky box. occupying much of test test bench space. This is more so as the current rating or VA increasing. It looses its mobility.
Radio Electric has solved this problem by designing a "Double Wound Isolated Variac". This
elegant & compact arrangement uses only ONE Transformer on a Single torroidal Core. This provides 2.5 kv Isolation between prim & sec, prim & body with a Variable Output Voltage from 0V to the required voltage. Various models are as Illustrated in table 1.This concept can also be used very effectively in DC power supplies with Variable
output (eg. Input 230V / 110 V, Output 0 to 25 V, 5A or 0 to 15V, 8 Amp.