System for predicting or detecting a fault in a solenoid utilization

Abstract

A system for detecting the occurrence of a fault in a solenoid utilization system when the fault is manifested by the solenoid armature or plunger being seated either too early or too late. A predetermined time interval is established such that the seating of the solenoid armature or plunger during this time interval is regarded as acceptable. A cusp detector circuit detects the point in time at which the solenoid plunger or armature seats and if it is within this predetermined time interval, it is recognized as acceptable, but if it is detected either too early or too late, an indication is generated that a fault exists and the occurrence and probable nature of the fault may be flagged. A test mode is provided whereby the predetermined established time interval can be considerably narrowed so that maintenance can be performed on the system so as to insure that the solenoid armature or plunger seats at exactly the proper time. As the predetermined time interval is narrowed, the acceptable range is narrowed and if the solenoid armature or plunger is found to seat a little too early or too late, it can be taken as an indication that a future failure is to be anticipated unless maintenance is performed. The system can then be recalibrated to insure that the solenoid armature or plunger seats at the proper time thereby averting a future failure.