| 摘要 |
PROBLEM TO BE SOLVED: To provide a motor control circuit provided with an overload protection function to which a transistor of a low current capacity is applicable in order to control the driving current of a motor. SOLUTION: A speed command signal Vs is compared with a reference signal Vsr through a comparator circuit CM1 to generate a PWM control signal Vp . A transistor Tr1 is turned on/off by means of the control signal Vp to control the driving current of a motor 1. A transistor Tr2 for overload protection which is turned on if the motor is overloaded and an interruption command signal Vc is generated, is placed between the non-inverting input terminal of the comparison circuit CM1 and the ground. The transistor Tr2 is brought in conduction, and the output of the comparison circuit CM1 is thereby instantaneously brought to a zero level to reduce a time when unsaturated state is generated when the transistor Tr1 is turned off. |
