| 摘要 |
PROBLEM TO BE SOLVED: To prevent a situation where charging of a capacitor to a target voltage is not done in time and there occurs a delay in opening of an injector valve.SOLUTION: A step-up power supply device provided for a control device 31, which drives an injector 41, includes: an output capacitor 34 in which electric energy discharged to a valve opening electric load 41a of the injector 41 is accumulated; a charge circuit 35 that charges the output capacitor 34 by stepping up a battery voltage VB; and a charge control circuit 36 that causes the charge circuit 35 to operate so that a charge voltage VC of the output capacitor 34 becomes a target voltage. The output capacitor 34 includes a plurality of parallel capacitors C0 and C1, with a switch T1 being connected to the capacitor C1 in series. When a microcomputer 38 turns on the switch T1, the capacitor C1 is connected to the capacitor C0 in parallel, and when the microcomputer 38 turns off the switch T1, the capacitor C1 is nullified and an electrostatic capacitance of the output capacitor 34 decreases. |
