Patent ID: 6307376
Filing Date: 2001-10-23
Classification: F16H

Abstract:
A system for sensing faults in a solenoid-controlled actuator assembly, said system comprising:a solenoid;a power supply providing supply voltage;a solenoid driver circuit for selectively energizing and de-energizing said solenoid;a current sense circuit for sensing the current in said solenoid and generating a solenoid current signal;a power supply switching circuit for selectively connecting and disconnecting said supply voltage from said solenoid;a voltage decay detection circuit coupled to said solenoid for generating a voltage signal; anda processing circuit coupled to said solenoid driver circuit, said current sense circuit, said power supply switching circuit, and said voltage decay detection circuit, said processing circuit implementing fault detection logic wherein said processing circuit receives said solenoid current signal and, if said solenoid current signal is below a predetermined current value for a predetermined time period, causes said solenoid driver circuit to energize said solenoid, causes said power supply switching circuit to disconnect said supply voltage from said solenoid, and monitors the rate of voltage decay in said voltage signal to determine if a fault exists.