초록 ▼

A method and apparatus for the recognition of the state of a solenoid valve supplies an on/off control switching current to the coil of the solenoid valve. A high level of current is caused to flow through the coil for switching the device on, and a reduced level of current is applied to the coil fo

A method and apparatus for the recognition of the state of a solenoid valve supplies an on/off control switching current to the coil of the solenoid valve. A high level of current is caused to flow through the coil for switching the device on, and a reduced level of current is applied to the coil for holding the solenoid armature in its on position. If the armature should be caused to drop off from its on position by a mechanical shock, an increase in the frequency of the switching current occurs, due to the decrease in magnetic circuit inductance. This frequency increase is detected and compared to a predetermined threshold value. If the detected frequency exceeds the threshold value, it is recognized as an armature drop off, and corrective action can be taken immediately.

대표청구항 ▼

[ We claim:] [1.] 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) reduc

[ We claim:] [1.] 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.