Method for detecting failure of a relay
AssigneeVisteon Global Technologies, Inc.
InventorsPaul Thomas Jordan, John Harry Floros
Life of this patent
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Abstract
A method for detecting failure of a relay operating in a vehicle having an ignition switch, a power supply, a capacitor, and a pre-charge circuit to pre-charge the capacitor with the relay switching power from the power supply to the pre-charged capacitor, the method comprising the steps of: performing a capacitor pre-charge test; and performing a capacitor discharge test. Preferably, the capacitor pre-charge test is performed when the ignition is switched ON and the capacitor discharge test is performed when the ignition is switched OFF.
Claims9
A method for detecting failure of a relay operating in a vehicle having an ignition switch, a power supply, a capacitor, and a pre-charge circuit to pre-charge the capacitor with the relay switching power from the power supply to the pre-charged capacitor, the method comprising the step of:
- performing a capacitor discharge test, wherein the step of performing a capacitor discharge test includes the steps of:
- opening the relay to disconnect the power supply from the capacitor;
- checking the capacitor for a discharged over-voltage condition;
- and
- delaying opening the relay to disconnect the power supply from the capacitor for a predetermined discharge time period and wherein the step of checking the capacitor for a discharged over-voltage condition is performed after the predetermined discharge time period has elapsed.
A method for detecting failure of a relay operating in a vehicle having an ignition switch, a power supply, a capacitor, and a pre-charge circuit to pre-charge the capacitor with the relay switching power from the power supply to the pre-charged capacitor, the method comprising the steps of:
- performing a capacitor discharge test, and
- performing a capacitor pre-charge test, wherein the step of performing a capacitor pre-charge test includes the steps of:
- activating the pre-charge circuit to initiate pre-charging of the capacitor;
- checking the capacitor for a pre-charge over-voltage condition;
- checking the capacitor for a pre-charge under-voltage condition;
- deactivating the pre-charge circuit;
- closing the relay to provide power from the power supply to the capacitor;
- and
- checking the capacitor for a post-charged under-voltage condition.
A method for detecting failure of a relay operating in a vehicle having an ignition switch, a power supply, a capacitor, and a pre-charge circuit to pre-charge the capacitor with the relay switching power from the power supply to the pre-charged capacitor, the method comprising the steps of:
- performing a capacitor discharge test;
- activating the pre-charge circuit to initiate pre-charging of the capacitor;
- deactivating the pre-charge circuit;
- closing the relay to provide power from the power supply to the capacitor;
- checking the capacitor for a post-charged under-voltage condition;
- checking the capacitor for a pre-charge over-voltage condition;
- and
- checking the capacitor for a pre-charge under-voltage condition,
- wherein the step of checking the capacitor for a pre-charge over-voltage condition further includes repetitively checking the capacitor for a pre-charge over-voltage condition for a predetermined pre-charging time period.
Dependencies are inferred from the claim text.