Patent ID: 8599530
Filing Date: 2013-12-03
Classification: F02D

Abstract:
1. An electromagnetic valve driving circuit, comprising: a booster circuit for generating a high voltage from a power supply; a first switching element connected to a route formed between the booster circuit and a first terminal of an electromagnetic valve; a second switching element connected to a positive-polarity side of the power supply; a first diode connected to a route formed between a negative-polarity side of the second switching element and the first terminal of the electromagnetic valve; a second diode with a first terminal connected to a portion between the first terminal of the electromagnetic valve and the first diode, and a second terminal connected to an electrical grounding side of the power supply; a third switching element connected to a route formed between a second terminal of the electromagnetic valve and the grounding side of the power supply; and control means for operating appropriately the first switching element, the second switching element, and the third switching element, according to a level of a current which flows through the electromagnetic valve; wherein the control means includes peak-hold assist means for activating the second switching element during a period in which the first switching means repeats on/off switching control a plurality of times; wherein, by activating/deactivating the first switching element, the control means holds the current that flows through the electromagnetic valve to a first current level; and wherein, during a period of holding the current, which energizes the electromagnetic valve, to the first current level, when the current through the electromagnetic valve increases in level while the control means is deactivating the first switching element and activating the second switching element, the control means re-deactivates the second switching element.