Method of recognizing the impingement of a reciprocating armature in an electromagnetic actuator

Abstract

A method of recognizing armature impingement in an electromagnetic actuator having an electromagnet including a solenoid, an armature movable toward and away from the electromagnet and return means for exerting a force on the armature. The method includes the steps of maintaining a solenoid current at a predetermined magnitude I.sub.max during a predetermined period T.sub.A for capturing the armature at the electromagnet; switching off the solenoid current at a moment t.sub.1 upon lapse of the period T.sub.A ; upon lapse of a period T.sub.1 running from moment t.sub.1, oscillating the solenoid current between a lower holding current threshold I.sub.H1 and an upper holding current threshold I.sub.H2 ; detecting a current course from moment t.sub.1 ; and deriving a signal from such current course.

Dependencies are inferred from the claim text.