Patent ID: 11874332
Assignee: DENSO TEN LIMITED
Field: Measurement (Instruments)
Classification: CPC G  B  Y | IPC G

Claim 4:
5. A failure detection apparatus comprising:
a measurement portion that includes a first switch configured to be connected to a positive electrode of a battery, a second switch configured to be connected to a negative electrode of the battery, detection resistances, and a measurement circuit that measures a voltage applied to the detection resistances; and
a controller that (i) turns on one of the first switch and the second switch, and turns off an other one of the first switch and the second switch to form a first series-connected circuit consisting of the battery, insulation resistances of the battery, and the detection resistances, and (ii) calculates the insulation resistances based on the voltage measured by the measurement circuit for the first series-connected circuit, wherein
the controller (a) turns on both the first switch and the second switch to form a failure-detection series-connected circuit consisting of the battery and the detection resistances, and (b) detects a failure of the measurement portion by comparing the voltage measured by the measurement circuit for the failure-detection series-connected circuit to a voltage of the battery received from an external apparatus that is external to the failure detection apparatus, and
the controller calculates a voltage of the battery based on the voltage measured by the measurement circuit for the failure-detection series-connected circuit, and when the calculated voltage of the battery is approximately equal to the voltage of the battery received from the external apparatus, the controller determines that there is no failure of the measurement portion.