| 摘要 |
PURPOSE:To improve the detecting accuracy by superposing the dither currents, of which amplitude and frequency are within a range that a load does not follow, to the load driving current, and inputting the driving current with dither from a harness to detect a fail on the basis of the existence of dither. CONSTITUTION:The dither current, of which amplitude and frequency are within a range that a load (b) does not follow, is superposed to the driving current command signal from a driving current command signal output circuit (a) in a load drive control circuit (c), and this driving current with dither is given to the load (b) through a harness. At the time of detecting a fail such as disconnection and short of a harness of a car, the driving current with dither is input to a load drive control system fail detecting means (d) from the harness connected to the load (b), and a fail is detected by monitoring the existence of dither. With the advantage in cost in comparison with the case that multiple comparing circuits are used, fail of a load drive control system can be always detected at high detecting accuracy independently of the current value of the driving current. |
