| 摘要 |
PURPOSE:To accurately detect a load current by controlling a timing for switching a switch for turning ON and OFF the current based on a gate signal and a timing for detecting monitoring means. CONSTITUTION:A controller 54 has a closed circuit formed of a motor 22 and a battery 52 together with a switching circuit 60 as a main circuit 62, and monitor control means 78 outputs timing signals t1, t2 for indicating a timing for detecting a load current I of the circuit 62 together with a switching signal (q) for indicating a timing for switching a changeover switch 74. The signals t1, t2 are input to monitoring means 80 for monitoring a malfunction of the current I from a shunt 66, the t1 is output at a center of an ON time width when the signal (q) selects a fixed pulse p2, and the t2 is output at a center of an OFF time width. The means 80 detects the current I from the shunt 66 based on the signals t1, t2. As a result, the current can be accurately detected. |
