To secure circuit design which is fault-tolerant even when circuit operation is impaired due to a short-circuit or the like and a high fail-safe function as a circuit for driving a shut-off valve on a fuel supply path.
The drive control circuit device of the shut-off valve comprises a control device 4 whose internal circuit is equipped with a high-side switch 7 and low-side switches 8 and 9, a load coil 5 connected to the control device to drive the shut-off valve, and a power supply relay 6 for switch-controlling a power supply state, wherein an electric path 16 passing the contact 15 of the power supply relay 6 and an electric path 18 passing the coil 17 of the power supply relay 6 are distributedly connected to the high-side switch 7 and the low-side switches 8 and 9, the load coil 5 for driving the shut-off valve is connected in series to the electric path 16 passing the contact 15 of the power supply relay 6 and the two electric paths including the high-side path 18 and the low-side path 16 are connected through corresponding connectors 19 of the control device 4 to the high-side switch 7 and low-side switches 8 and 9.
IDENO YOSHIYUKI