This is also a three phase transformer, however with each limb having one winding inside. The top winding is connected in series with inside winding. The Carbon brushes are on the outer load winding. This VARIAUTO has special application in Servo controlled Voltage Stabiliser with balanced loads & balanced input conditions. It can be also used for unbalanced load conditions upto a certain extent. This eliminates the 3 phase buck boost transformer thus making the TANK SIZE very compact. Presently ready model is suitable for 45 KV A, 3 PhStabiliser. Further models are under development.