CONTROL CIRCUIT FOR AIR PURIFYING DEVICE FOR VEHICLE

PURPOSE:To eliminate unnecessary discharge of a battery, by a method wherein the input of an air purifying device is shut off by detecting opening of a door and thereafter, even if the door is closed, an input is kept in a shut off state until a main switch is made again. CONSTITUTION:When the door of an automobile is opened during turning ON of a motor blower 2, a door switch 13 is closed in an earthing state, the base of a transistor 5 is brought into an earthing state, and the transistor 5 is brought into an OFF-state. In which case, the base current of a transistor 4 is stopped, and a blower 2 is brought into an OFF-state. Even if, after that, a door is closed and the door switch 13 is opened, since no collector output from the transistor 4 is provided, a transistor 5 is not turned ON, and the transistor 4 can not be also turned ON. In which case, with a main switch 3 made once, charge accumulated in a capacitor 11 is discharged through a diode 12 and a resistor 9, and the blower 2 is brought into an ON-state by closing the main switch 3 again. This constitution prevents the power source of an air purifying device from being left closed.