| 摘要 |
<P>PROBLEM TO BE SOLVED: To prevent degradation in startability of an engine caused by a decrease in battery voltage to decrease the drive voltage of a switching element, in a boosting circuit generating voltage for driving a fuel injection valve. Ž<P>SOLUTION: In the boosting circuit, an application current to a boosting coil 12 is detected by a resistor 16, the switching element 14 is turned on until a current value thereof reaches a threshold, and is turned off when the current value reaches the threshold, so that high voltage is generated in the boosting coil 12 and a capacitor 18 is charged with high voltage to generate the voltage for driving the fuel injection valve. Battery voltage+B and power supply voltage that is generated from boosted voltage in a power supply 30 are supplied to a buffer circuit 26 driving the switching element 14. Therefore, even if the battery voltage is extremely low, a threshold current is applied to the boosting coil 12 when the switching element 14 is turned on to prevent elongation of time required for the generation of the boosted voltage and thereby to ensure the startability of the engine. Ž<P>COPYRIGHT: (C)2010,JPO&INPIT Ž
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