| 摘要 |
<p>PURPOSE:To surely detect the ground of an assist motor at the hot side by extracting terminal voltage at the hot side in response to polarity out of terminal voltages at the both sides of the assist motor, and thereby comparing the extracted terminal voltage with a specified threshold voltage. CONSTITUTION:A detection device for the ground of motor wires is equipped with a signal output circuit 46 which outputs signals based on the output from a polarity judging circuit 76 when a motor 20 is normally rotated, a signal output circuit 47 which outputs signals when the motor 20 is reversely rotated, and is also equipped with a signal output circuit 43 which outputs signals when PWM pulse signals driving the motor 20 are outputted. Terminal voltage VM1 is outputted with No.1 analogue switch 36 turned on when the motor 20 is normally rotated, meanwhile, terminal voltage VM2 is outputted with No.2 analogue switch 37 turned on when the motor 20 is reversely rotated so that the respective voltages are applied to the negative input terminal of a comparator 42 via a LPF 41. This thereby permits a ground detection signal to be outputted when the aforesaid input voltage is lower than a threshold voltage.</p> |
