Driving circuit for commutatorless dc motor

Abstract

Abstract PURPOSE:To improve the starting performance of a driving circuit for a self-control type commutatorless DC motor by automatically switching the current flowing angle of a 3-phase half-wave rectifying circuit for driving the motor at 180 deg. at the starting time and at 120 deg. at the ordinarily operating time, thereby reducing the variation width of the starting torque. CONSTITUTION:The rotary position detection signals detected by Hall elements 1A-1C are shaped and amplified in a rectangular waveform by arithmetic amplifiers 2A-2C, and the signals from the amplifiers are inputted to driving transistors 3A-3C and switching circuits 5A-5C respectively. The switching circuits 5A- 5C close at the prescribed delay time with respect to a power swich, and have functions to be OFF at the starting time and ON at the ordinarily operating time, and performs 3-phase half-wave rectification of 120 deg. of current flowing angle at the ordinarily operating time and 3-phase half-wave rectification of 180 deg. of current flowing angle at the starting time.

Inventors

• 👤 Masayuki Shizuka

Bibliographic Details