| 摘要 |
PURPOSE:To shorten the stopping time of an AC motor by providing a capacitor for charging when a triac for controlling the motor is ON, supplying the discharging current to the coil of the motor when the triac is OFF, and braking it. CONSTITUTION:Triacs 17A, 17B are respectively connected to coils 2A, 2B of an AC motor, and a capacitor 24 is connected through a diode 4 to both terminals of a power source 1. An input terminal 15 is set to L level, the triacs 17A is energized, a current is flowed to a coil 2A and a phase advancing capacitor 3 to rotate the motor, the capacitor 24 is simultaneously charged, the input terminal 15 is set to H level, the triac 17A is deenergized, a thyristor 5 is energized by a firing circuit which has a transistor 22, the current of the capacitor 24 is flowed to the coil 2B, thereby braking the motor. Accordingly, the stopping time can be largely shortened, to improve the stopping accuracy of the motor. |
