DC motor drive circuit

Abstract

Abstract PURPOSE:To enable to use low withstand voltage transistor by converting a rectangular wave output from a position detector of a rotor to a trapezoidal wave, altering the slope due to the magnitude of the motor current and switching and energizing the coil. CONSTITUTION:A DC motor is formed of a disc-shaped yoke 1, an energizing coil 3 and a disc-shaped magnet 2 of a rotor. The rotor position is detected by a Hall element 6, is applied to a trapezoidal wave generator 14A, the current from a control current generator 11 is alternately switched by energization switching means 7 to energize the coils 3, 4, the control voltage from motor speed detecting means is inputted from a terminal 48, the constant-current sources 43, 45 are varied with the value to control the charging of a condenser 47, thereby varying the slope of the trapezoidal wave. Accordingly, the slope of the trapezoidal wave at the starting and ordinary times is maintained constantly, thereby preventing the large counterelectromotive force generated in the coil and eliminating the damage of the elements.

Inventors

• 👤 Takayasu Ito
• 👤 隆康 伊藤
• 👤 Hideo Nishijima
• 👤 英男 西島
• 👤 Isao Fukushima
• 👤 福島　勇夫

Bibliographic Details