Automatic Voltage Regulating Unit

This comprises basically the following major components: Rolling contact type voltage Regulator, Buck /Boost Transformer, Automatic controlgear comprising Driver motor and Electronic voltage sensing relay. The variable input is boosted up or bucked downto the required level through the series winding of the buck / boost transformer. The primary of the buck / boost transformer is fed from the voltage regulator so that extact magnitude can be injected into the line elther in phase or in antiphase as the case may be. This injected voltage is steplessly variable through the rolling contacts of the voltage regulator. The Electronic voltage sensing relay is connected across netural and one phase on the output side. The relay is preset and remains inoperative at the preset voltage. it sends a signal to the drive motor so as to run it either in the clockwise or anticlockwise direction depending on the deviation of the voltage from the pre-set value. The drive motor is coupled to the rolling contact mechanism by chain & sprockets and its clockwise/ anticlockwise rotation means movemets of the roling contacts up or down the bared face of the regulator coil. This movemnt continues and ceases only when the output voltage comes to the pre-set value making the relay in operative.