Patent ID: 6017017
Filing Date: 2000-01-25
Classification: B60T,F01L,F02D,H01H,Y02T,Y10T

Abstract:
A method for the recognition of the state of an electromagnetically controlled valve, comprising the steps of:a) supplying a first magnitude regulated switching current to a coil of said electromagnetically controlled valve to achieve switch on of an armature of said valve,b) reducing said first magnitude of said switching current to a second magnitude level sufficient to hold said armature in said switch on position, wherein said second magnitude level is less than said first magnitude level,c) monitoring the frequency of said second magnitude switching current with a frequency detection device,d) comparing said detected second magnitude switching current frequency with a predetermined threshold value, said threshold value representing a second magnitude switching current frequency upper limit attributable to a drop off of said armature from said switch on position,e) wherein when said armature of said electromagnetically controlled valve drops off from said switch on position, the resulting increase in said second magnitude switching current frequency exceeds said predetermined threshold value, and an error signal is generated.