| 摘要 |
PROBLEM TO BE SOLVED: To prevent a relay contact from fusion attachment, etc., resulting from a charging current to a large capacitance capacitor for noise removal when an ignition key is turned on. SOLUTION: The positive electrode side of a battery 13 is connected normally to a common terminal of a relay 25 directly, and even if an ignition key 12 is off, a capacitor C1 is charged at all times with a comparatively small current through a normal close contact 25y and a resistance R1. When turn-on of the ignition key 12 is sensed, a CPU 11 actuates a relay drive circuit 20, and the normal open contact 25x is closed. The positive electrode side of the battery 13 is connected to a motor drive circuit 21 through the normal open contact 25x, while the capacitor C1 is connected to the battery through the contact 25x. The capacitor C1 is in the charged condition at all times, and no large current will flow to the contact 25x, so that there is no risk of welding. |
