To realize compaction and cost reduction and to drive another driven body interlocked with a main body being driven through a motor by obtaining a detection voltage regardless of the quantity of motor current.

When a motor current is fed to a motor M, a motor current detection circuit 3 detects a forward voltage, i.e., a voltage drop across diodes D1, D2 connected in series on a feeder line 5, and determines the presence of motor current. Based on the motor current detection timing, another driven body (e.g. illumination or fan) is driven while being interlocked with a main body being driven through the motor M.