| 摘要 |
PROBLEM TO BE SOLVED: To obtain a control circuit for starting a motor slowly in which a motor drive circuit is not damaged when the motor is stopped. SOLUTION: A transistor Q1 has a base connected with the joint of resistors R1, R2, an emitter connected with a power supply Vcc, and the emitter connected, on the output side thereof, with an output terminal P1 through a time constant circuit 11 comprising a resistor R4 and a capacitor C1. The resistor R4 is connected in parallel with a diode D in the reverse direction. When a switch SW is started, the transistor Q1 is turned on to charge the capacitor C1 transiently and a rotation control signal Vs from the output terminal P1 is boosted transiently. When a switch SW is stopped, the transistor Q1 is turned off to discharge the capacitor C1 through the diode D and a resistor R3 and the rotation control signal Vs from the output terminal P1 is interrupted. |
