Method and apparatus for controlling a duty ratio - solenoid valve

摘要

The method involves feeding an additional pulse to the solenoid valve after expiry of a defined time following the on/off switching point. This varies the level of a drive pulse so as to drive the valve body in a direction to close the valve and to reduce the speed of the valve body when it comes into contact with the valve seat. The additional pulse has the same phase as the drive pulse applied before the on/off switching point and has a pulse width which is smaller than that of the drive pulse with the same phase.