Abnormality detection device

Patent metadata

Field	Value
Publication number	US-11047922-B2
Application number	US-202016788538-A
Country	US
Kind code	B2
Filing date	Feb 12, 2020
Priority date	Sep 15, 2017
Publication date	Jun 29, 2021
Grant date	Jun 29, 2021

Abstract

In a bridge circuit, a series circuit in which a first resistor and a second resistor are connected in series and the second resistor and a fourth resistor are connected in series is formed. In the bridge circuit, the series circuit is connected to a load portion in parallel, one end of a fifth resistor is connected between the second resistor and the fourth resistor, and the other end of the fifth resistor is connected between the first resistor and the load portion. In the bridge circuit, a voltage supply unit is connected between the first resistor and the second resistor. A controller detects an abnormality of the load portion based on a detection voltage of the bridge circuit detected by applying a voltage from the voltage supply unit with a switch turned off. With this configuration, an abnormality detection device can detect abnormality while suppressing an increase in size.

First claim

What is claimed is:

1. An abnormality detection device comprising:
an abnormality detection target connected to a main power source and is supplied with electric power from the main power source;
a bridge circuit including a first resistor, a second resistor, a third resistor that is the abnormality detection target, a fourth resistor, and a fifth resistor;
a voltage supply unit being a power source different from the main power source and configured to apply a voltage to the bridge circuit; and
a controller configured to control the main power source and the voltage supply unit, wherein
in the bridge circuit, a series circuit in which the first resistor and the second resistor are connected in series and in which the second resistor and the fourth resistor are connected in series is formed, the series circuit is connected to the third resistor in parallel, one end of the fifth resistor is connected between the second resistor and the fourth resistor, and the other end of the fifth resistor is connected between the first resistor and the third resistor, and the voltage supply unit is connected between the first resistor and the second resistor, and
the controller is configured to detect an abnormality of the third resistor on a basis of a detection voltage of the bridge circuit detected by applying the voltage from the voltage supply unit in a state where the main power source is turned off.

2. The abnormality detection device according to claim 1 , wherein
the controller is configured to
detect a short circuit of the third resistor on a basis of the detection voltage and a short-circuit reference voltage indicating that the third resistor has short-circuited, and
detect an open circuit of the third resistor on a basis of the detection voltage and an open-circuit reference voltage indicating that the third resistor has been open.

Assignees

• Yazaki Corp

Inventors

• Morimoto Mitsuaki
• Oishi Eiichiro

Classifications

• H02H3/12

  responsive to underload or no-load {(for motors H02H7/0827)} · CPC title

• G01R31/006

  on road vehicles, e.g. automobiles or trucks (testing of ignition installations peculiar to internal combustion engines F02P17/00) · CPC title

• H02H1/003

  Fault detection by injection of an auxiliary voltage (same for detection of earth fault currents H02H3/17; for monitoring earth connection H02H5/105) · CPC title

• G01R31/52 Primary

  Testing for short-circuits, leakage current or ground faults · CPC title

• G01R31/54

  Testing for continuity · CPC title