Title:
SLOW STARTER FOR AC MOTOR
Document Type and Number:
Japanese Patent JPS55109179
Kind Code:
A
Abstract:
PURPOSE:To lower the residual voltage produced by a voltage regulator for an AC motor after completing the starting of the motor by applying the logic product signal of the output signal of a start completion signal generator and the output signal of a power supply synchronization detector to a pulse generator. CONSTITUTION:A voltage waveform VS synchronized with the voltage waveform VO applied between the terminals of a voltage regulator 5 from a synchronization detector 1 is converted through a sawtooth wave generator 2 into a sawtooth wave V2 when starting an AC motor. When the sawtooth wave V2 reaches the pulse voltage VP, a pulse generator 4 produces a firing pulse to the voltage regulator 5 to apply lowered voltage to the motor 6. Since the outputs of a timer 3 and the detector 1 are applied to a logic multiplier 7 before the generator 2 produces a sawtooth wave V1 when a starting time setting timer 3 is operated, the pulse generator 4 produces a firing pulse at the time of a voltage restricting angle alpha0. Accordingly, the residual voltage produced by a voltage regulator 5 after completing the starting of the motor is lowered in the amount corresponding to the differential voltage restricting angle alpha1-alpha0 as compared with the conventional case.
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Inventors:
SANAKA YOUZOU
Application Number:
JP1545879A
Publication Date:
August 22, 1980
Filing Date:
February 15, 1979
Export Citation:
Assignee:
TOKYO SHIBAURA ELECTRIC CO
International Classes:
H02P1/28; (IPC1-7): H02P1/28