| 摘要 |
<p>PURPOSE:To provide an electric current driving means which can accurately detect initial grounding during engine start-up, by turning off all switching elements when detection of motor grounding is permitted during controlling the switching elements. CONSTITUTION:Grounding of a motor 6 is detected by a motor line grounding detecting circuit 38, and the result of this grounding detection is inputted to a CPU 30. Outputs of an overcurrent detecting circuit 37 and the motor line grounding detecting circuit 38 are inputted to a driving control circuit 31 through an OR-gate 39. When overcurrent or grounding of a motor 6 is detected, the driving of the motor 6 is prohibited. The algorithm of processing of motor line grounding detection compares the sum of voltages at both ends (detected voltages) and a predetermined value (reference voltage) and, if the detected voltage is not higher than the reference voltage, it is determined that motor line grounding exists. This makes a power relay 36 immediately turned off to shut off motor driving output, resulting in all the gates for four switching elements SW1 to SW4 turned off.</p> |
