摘要 |
Unnecessary power is not supplied to a driver built-in motor when the driver built-in motor does not substantially rotate, without having a microcomputer unit to perform determination processing for confirming stop of the motor, or processing for blocking a relay in a manner of an interrupt action. To a fan driver 91 built within a fan motor unit 9, power is supplied through a power line L1 having a switch K1. An analog command value V sp according to a rotation speed command V spp is outputted from the DA conversion circuit 8. When the analog command value V sp is smaller than a predetermined value Vs pb , a voltage control circuit 10 makes the switch K1 nonconductive. |