Electromagnetic valve actuators

摘要

An electromagnetically operated valve assembly 28 is disclosed having a first solenoid 58 and a second solenoid 60 and an armature 56 having a valve stem 54 coupled thereto is positioned between the first solenoid 58 and the second solenoid 60. A controller 12 is coupled to the solenoids 58, 60 and a current sensor 48 is coupled to the one of the solenoids 58, 60 and generates a signal corresponding to the induced current in the respective solenoid 58, 60. The controller 12 is operable to change a voltage applied to one of the solenoids 58, 60 from a first polarity to a second polarity and is further configured to hold the voltage at the second polarity for a predetermined time period and a predetermined amplitude to decrease the induced current. The predetermined time period or the predetermined amplitude is determined based on the first signal.