| 摘要 |
PURPOSE:To turn OFF a driving transistor when a load for disturbing the rotation of a motor is applied and to reduce power consumption by providing a flip-flop, a setter, a controller, a charging/discharging circuit, a second comparator, an invalidating circuit, a resetter, and a varying circuit. CONSTITUTION:If a load for disturbing the rotation of a motor is applied, the terminal voltage Vf of a detecting resistor Rf is raised. When the voltage Rf of the resistor Rf becomes equal to a reference voltage VT1 at a time t0, a set/reset signal of a flip-flop 4 becomes 'L', and control transistors Q16, Q26, Q36 are turned ON. That is, the bases of drive transistors Q13, Q23, Q33 are grounded, and drivers 1U, 1V, 1W are not operated, and the voltage VRf of the resistor Rf becomes zero. Simultaneously, since a transistor Q52 is turned OFF, a capacitor C is started to be charged through a transistor Q49. |
