Patent ID: 7859211

Claim:
A method for continuously controlling the firing angle of a single-phase electric motor supplied with alternating current, by way of at least one locking electronic switch (T 2 , T 3 ) between the supply voltage (U v ) and at least one motor winding (A, B), wherein the switch or switches (T 2 , T 3 ) are switched according to the following conditions: a) the instantaneous voltage (U EMK ) induced in the winding (A, B) to be connected has the same polarity as the instantaneous supply voltage (U v ), b) the instantaneous voltage (U EMK ) induced in the winding (A, B) to be connected given the same polarity is smaller than the instantaneous supply voltage (U v ) with regard to magnitude, and c) the instantaneous voltage (U EMK ) induced in the winding to be connected, with respect to its zero-crossing, is located in a predefined angular range, assuming the same polarity of the induced voltage and the supply voltage (U v ), wherein the predefined angular range is determined by a time measurement in one of the previous half periods of the instantaneous voltage (U EMK ) induced in the winding (A, B) to be connected.