| 摘要 |
PURPOSE: To make it possible to detect a lock current accurately by adjusting the setting of reference voltage and a compensation factor of temperature compensation means respectively by electrical trimming and by detecting a lock current of a motor by a voltage drop. CONSTITUTION: Voltage drop detecting means 111 and 112 detect the voltage drop between two points on a conductor through which a drive current for a motor flows. A temperature sensor 130 detects a temperature change on the conductor. A temperature compensating means 140 and 150 compensate the outputs of voltage drop detecting means 111 and 112 based on the output from a temperature sensor 130. Adjusting means 142, 143 and 162 adjust the setting of reference voltage and the compensation factor of temperature compensating means 140 and 150 respectively by electrical trimming. A lock state detecting means 170 compare the voltage drop in a motor current to a reference voltage after the adjustment by adjusting means 142, 143 and 162 and outputs a signal showing the motor in lock state when the voltage drop exceeds the reference voltage. By doing this, the lock current of the motor can be detected highly accurately. |
