DC ELECTRICAL MACHINE Russian patent published in 1994 - IPC

FIELD: commutator machines. SUBSTANCE: electrical machine has commutator with alternating conducting laminations 1 and insulating strips 2 which are in contact with unlike-polarity groups of brushes, each group having main brush 3 and auxiliary brush 4 arranged on trailing edge side of main brush and insulated from the latter. Main brush 3 of positive-polarity group is connected directly to positive terminal 6 of power supply. Nonlinear resistor unit 9 is inserted between leads of main brush 3 and auxiliary brush 4; primary winding 10 of pulse transformer 11 is connected in series with resistor unit 9; output of pulse transformer 11 is connected via rectifier 13 to terminals 6 and 8 of DC power supply. If universal power supply is used, transformerless bridge-type polarity switch is inserted between it and rectifier. EFFECT: improved design. 2 dwg