| 摘要 |
PROBLEM TO BE SOLVED: To enable only a motor to be replaced and prevent each power supply from fluctuating due to a load current even if the drive circuit of the motor is short-circuited or damaged by outputting the voltage of a detection resistor for limiting current to a power supply side as a signal for indicating the state of the load current. SOLUTION: A drive circuit 10 consists of a logic circuit 12 and a switching circuit 14. By successively turning on or off six transistors Tr1-Tr6 of the switching circuit 14, a drive current flows to motor coil winding 16 through diodes D1-D6, thus rotating a motor by PWM control. A line 18 at the lower stage of the switching circuit 14 is connected to a current-limiting part 20 being provided inside the logic circuit 12 and is further connected to an output terminal 22 for indicating the output of a load state, thus outputting the voltage of a detection resistor R1 for limiting current as a signal for indicating the load current of the motor from the output terminal 22. |
