| 摘要 |
<p>PURPOSE:To prevent the spreading of trouble even if a gate control circuit is erroneously operated, by noise, by always applying voltage into the contact point between the terminal of a motor and the contact of a normal/reverse revolution relay through a resistor having a prescribed resistance value. CONSTITUTION:A transistor 21 is biased in the normal direction by resistors 37 and 38, and when a key switch 2 is turned ON, the transistor 21 is put into electric conduction, and a relay 20 is closed to supply electric power for a power steering system. When anomaly is generated in the contacts 4-7 of a normal/reverse revolution switching relay, and a trouble due to welding etc. is generated among said contacts, the relay 20 is necessarily put inoperative, and a contact 2a is opened to cut-off the supply of electric power. Therefore, the spreading of the trouble such as destruction of a power transistor 8 is prevented.</p> |
