| 摘要 |
PURPOSE:To enhance performance by detecting the voltage drop and current of a motor driving coil, and limiting a motor current flowing to a driving transistor. CONSTITUTION:Driving coils 1a-1c are controlled to be energized by driving transistors(Tr) 2a-2c in a motor to be driven. The common emitter of the Trs 2a-2c is connected to a negative terminal 50 of a power source in the driving circuit, connectors are connected to the input terminal of a conduction switching circuit 3, and connected to a positive terminal 30 of the power source through the coils 1. Bases are connected to the output terminal of the circuit 3, and connected to Trs 7a-7c of a current limiter 4. It has motor driving coil voltage drop detecting means 5, and motor current/voltage signal converting means 6, detects and outputs a motor current. Thus, the conduction signals of the phases are combined to detect the motor current, and if it becomes larger than a reference voltage signal, it limits the motor currents flowing to the Trs 2a-2c. |
