Voltage detector of battery assembly

• US 20050083015A1
• Filed: 08/27/2004
• Published: 04/21/2005
• Est. Priority Date: 08/29/2003
• Status: Active Grant

• Current Assignee: Yazaki Corporation
• Original Assignee: Yazaki Corporation
• Inventors: Adachi, Hideomi
• Granted Patent: US 7,282,890 B2
• Time in Patent Office: Days
• US Class Current: 320/116
• CPC Class Codes: G01R 31/396 Acquisition or processing of data for testing or for monitoring individual cells or groups of cells within a battery

Abstract

A voltage detector for a battery assembly having unit cells, the voltage detector includes a low voltage system circuit and a high voltage system circuit. The low voltage system circuit includes an enable pulse output unit which outputs an enable pulse to command detection of a voltage across both terminals of the unit cell. The high voltage system circuit includes a voltage pulse output unit which output a voltage pulse showing a voltage across both terminals of the unit cell, a switch which is provided between each unit cell of the battery assembly and the voltage pulse output unit and a switch controller which conducts ON-OFF control of the switch so that the each unit cell is successively connected to the voltage pulse output unit according to the enable pulse inputted from the pulse output unit.

Claims

1. A voltage detector for a battery assembly having a plurality of unit cells which are connected to each other, the voltage detector comprising:

a low voltage system circuit, which is supplied with electric power from a low voltage power source different from the battery assembly, the low voltage system circuit including;

an enable pulse output unit which outputs an enable pulse to command detection of a voltage across both terminals of the unit cell; and

a high voltage system circuit, which is supplied with electric power from the battery assembly, the high voltage system circuit including;

a voltage pulse output unit which output a voltage pulse showing a voltage across both terminals of the unit cell;

a switch, which is provided between each unit cell of the battery assembly and the voltage pulse output unit; and

a switch controller, which conducts ON-OFF control of the switch so that the each unit cell is successively connected to the voltage pulse output unit according to the enable pulse inputted from the pulse output unit,

2. The voltage detector as set forth in claim 1, wherein the voltage pulse output unit outputs a voltage pulse according to a period of time from the start of integration of one of a first voltage and a second voltage to when a value of integration of the one of the first voltage and the second voltage becomes equal to an integration value obtained when the other of the first voltage and the second voltage is integrated for a predetermined period of time;

wherein the first voltage is a voltage across both terminals of the unit cell; and

wherein the second voltage is a reference voltage.

3. The voltage detector as set forth in claim 2, wherein the voltage pulse output unit has an integration circuit to integrate an input voltage;

wherein the switch changes the input voltage of the integration circuit between the first voltage and the second voltage which is a reverse polarity with respect to the first voltage;

wherein the switch controller controls so as to inputs the other of the first voltage and the second voltage after inputting one of the first voltage and the second voltage for a predetermined period of tine; and

wherein the voltage pulse output unit outputs a voltage pulse according to, a period of time from when the input of the integration circuit is changed from one to the other to when an output of the integration circuit becomes equal to the output of the integration circuit before the one is inputted.

4. The voltage detector as set forth in claim 2, wherein the voltage pulse output unit outputs a voltage pulse of either level H or L for a period of time from when the input of the integration circuit is changed from one to the other to when the output of the integration circuit becomes equal to the output of the integration circuit before one is inputted;

and

wherein the low voltage system circuit further includes a count pulse generator which generates a count pulse while a voltage pulse of either level H or L is outputted.

5. The voltage detector as set forth in claim 2, wherein the high voltage system circuit further includes a counter which counts the predetermined period of time.

6. A voltage detector for a battery assembly having a plurality of unit cells which are connected to each other, the voltage detector comprising:

a detector, which detects a voltage across both terminals of the unit cell according to a period of time from the start of integration of one of a first voltage and a second voltage to when a value of integration of the one of the first voltage and the second voltage becomes equal to an integration value obtained when the other of the first voltage and the second voltage is integrated for a predetermined period of time,

wherein the first voltage is a voltage across the both terminals of the unit cell; and

wherein the second voltage is a reference voltage.

7. The voltage detector as set forth in claim 6, further comprising:

an integration circuit, which integrates an input voltage;

a switch, which changes the input voltage of the integration circuit between the first voltage and the second voltage which is a reverse polarity with respect to the first voltage; and

a switch controller, which control so as to change the input between the first voltage and the second voltage,

wherein the switch controller change one of the first voltage and the second voltage to the other of the first voltage and the second voltage after the one is inputted for a predetermined period of time; and

wherein the first voltage is detected according to a period of time from when one of the first voltage and the second voltage is changed to the other of the first voltage and the second voltage to when the output of the integration circuit becomes equal to the output of the integration circuit before the one is inputted.