Abstract: A method of polarity-independent reduction of feedback from a complex consumer or consumers periodically connected to an A.C. line is of the type involving disconnection of the consumer or consumers from the line during each half wave of the A.C. line voltage. The consumer or consumers are damped and discharged during each half wave of the A.C. line voltage by a power switching device, the power switching device being rendered operative whenever the connection between the consumer or consumers and the line is interrupted. A power switching device includes the collector-emitter leads of a pair of transistors and a set of rectifiers, preferably in the form of a bridge circuit, supplies voltage at the proper polarity for the consumer or consumers to the transistors. The secondary windings of respective transformers are connected to the base-emitter circuit of the respective transistors.

Abstract: A method of regulating electrical power supplied via a current path to a consumer in an A.C. network involves setting a desired current flow angle using a power switching device connected in the current path to the consumer. The method includes cutting the switching device ON at the beginning of each half-wave of the line voltage substantially at a phase angle of zero degrees, and cutting the power switching device off at a phase angle corresponding to the desired current flow angle. A power switching device for carrying out the method includes at least one set of two transistors having their respective collector-emitter leads connected in parallel to define a current path. Rectifier means are provided in series with the consuming means and the transistors. Secondary winding means of transformer means are connected in respective base-emitter circuits of the transistors, while primary winding means of the transformer means are connected to a source of switching voltages which drive the transistors.