Method and device for testing solenoid valves
A device for testing a solenoid valve includes: a voltage generator for applying a short pulse of voltage, which is not long enough to open the solenoid valve, to the windings of the solenoid valve; a current meter configured for measuring the current flowing through the windings of the solenoid valve; and an analysis device which is configured for analysing the current measured by the current meter for detecting a potential fault of the solenoid valve.
1. A method for testing a solenoid valve, comprising:
applying a voltage to a winding of the solenoid valve for a period of time which is not long enough to open the solenoid valve;
obtaining a current waveform flowing through the winding that results from the applied voltage; and
analysing both of a form and an amplitude of the current waveform to identify faults of the solenoid valve.
2. The method of claim 1 , wherein the voltage is applied for less than 50 ms.
3. The method of claim 2 , wherein the voltage is applied in the form of a square pulse.
4. The method of claim 2 , wherein a disconnection is detected if the form of the current waveform indicates that no current is flowing through the winding.
5. The method of claim 2 , wherein a mechanical pin of the solenoid valve being stuck in an open position is detected if the amplitude of the current waveform is below a first threshold.
6. The method of claim 2 , wherein a mechanical pin of the solenoid valve being stuck in a closed position is detected if the amplitude of the current waveform exceeds a second threshold.
7. The method of claim 2 , wherein the step of analysing includes analysing the form of the current waveform over time.
8. The method of claim 7 , wherein a short circuit is detected if the amplitude of the current waveform is a square wave which exceeds a predetermined third threshold.
9. A device for testing a solenoid valve, comprising:
a voltage generator for applying a short pulse of voltage, which is not long enough to open the solenoid valve, to a winding of the solenoid valve;
a voltage meter configured for measuring a current waveform flowing through the winding of the solenoid valve; and
an analysis device configured for analysing both of a form and an amplitude of the current waveform to detect a fault of the solenoid valve;
wherein the current waveform is measured via components that include:
a shunt connected serially to the winding of the solenoid valve; and
the voltage meter configured to measure the current waveform via voltage caused by the current flowing through the shunt.