Patent ID: 7049795

Claim:
Single phase under load tapchanging voltage regulating apparatus said apparatus comprising in combination: a) source connection bushing means for connection to sources of electric power, said electric power being capable of flowing in a forward or reverse direction, b) load connection bushing means for connection to loads for electric power, said electric power being capable of flowing in a forward or reverse direction, c) series transformer means for exchanging electric power arising from voltage differences between said source connection bushings and said load connection bushings, d) shunt transformer means for exchanging electric power with loads for electric power, e) connection means for connecting first ends of said series transformer primary windings to said source connection bushings, g) connection means for connecting second ends of said series transformer primary winding to said load connection bushings, h) connection means for connecting first ends of said shunt transformers windings to said load connection bushings, i) series transformer secondary winding means with taps for selecting amounts of power for flowing in either direction through said series transformers, j) switching device means for selecting said taps so as to cause varying amounts of electric power to flow in either direction through said series transformers, k) connection means between said switching device and second ends of said shunt transformer windings for directing said varying levels of electric power to flow from said series transformers in either direction to said shunt transformers and thus to said loads for electric power, and l) tapchanger control device means for sensing the voltage at said load connection bushings and causing said switching devices to select the proper electric power to flow in either direction so as to maintain desired voltages at said load connection bushings.