CONTACTOR CONTROLLING CIRCUIT FOR ELECTRIC CAR

摘要

PURPOSE:To prevent fusing of contactor, by detecting the voltage of DC power source provided in a contactor controlling circuit for driving load driving DC motor, and determining whether or not the contactor is to be turned ON through comparison of the detected voltage with a predetermined reference value. CONSTITUTION:If voltage of battery B is lower than a certain value at the time when closing switch LS of main contactor MSx is turned ON, inversion of operational amplifier OP is not caused since voltage level VD at the voltage dividing point of resistances R2 and R3 is lower than the voltage level VR applied on the inverted input side of operational amplifier OP, so that contact MS of main contactor MSx is not closed. Therefore, it is prevented that contact MS of the main contactor MSx be closed when the battery voltage is lower than a predetermined voltage permitting closing of the contact MS.