High-pressure fuel pump drive circuit for engine

摘要

There is provided a high-pressure fuel pump drive circuit for manipulating the electric current to be passed to a solenoid coil for controlling a high-pressure pump. This circuit is characterized in that a first switching element, the solenoid coil and a second switching element are connected in series with each other in a rout from a source voltage side to the ground side, that a flywheel diode for passing electric current to a power source is disposed parallel with the solenoid and with the first switching element, and that a Zener diode connected with the power source is disposed parallel with the second switching element, wherein a counter electromotive force to be developed at the opposite ends of solenoid coil on the occasion when the second switching element is changed from ON to OFF is consumed by the flywheel diode provided that the first switching element is in a state of ON, and the counter electromotive force is more rapidly consumed by the Zener diode provided that the first switching element is turned OFF.