D C ELECTRIC MOTOR DRIVE Russian patent published in 1994 - IPC

FIELD: electrical engineering. SUBSTANCE: invention deals with control over rotational speed of D C motors supplied from A C network. For provision of inphase operation or lead current consumed from feeding voltage network there are inserted unblanking unit per each power thyristor of controlled rectifier for feeding of signal synchronized with network with preset time delay with reference to start of half-period which output is coupled to lead of controlling electrode of power thyristor and blanking unit which first input is connected to first unit of phase control. Second input is linked to one of free leads of phase of supply network and first and second outputs are connected accordingly to anode and cathode of thyristor. EFFECT: improved operational reliability and stability. 4 cl, 4 dwg