Detection of Plunger Movement in DC Solenoids
The detection of the plunger movement in solenoids is required to ensure proper operation of the solenoid actuator. This paper proposes a method to detect the movement of plunger in a solenoid by sensing the solenoid current. The solenoid excitation current have a prominent dip during power up due to the back EMF generated by plunger movement. The solenoid current dip due to back EMF remains constant irrespective of the temperature. The solution proposed in this paper utilizes this characteristic of the solenoid current in detecting the movement of the plunger in the solenoid valve.