Secondary battery protection device

• US 20030169021A1
• Filed: 03/04/2003
• Published: 09/11/2003
• Est. Priority Date: 03/08/2002
• Status: Active Grant

• Current Assignee: Seiko Epson Corporation (Seiko Group)
• Original Assignee: Seiko Epson Corporation (Seiko Group)
• Inventors: Kashine, Takashi
• Granted Patent: US 7,068,484 B2
• Time in Patent Office: Days
• US Class Current: 320/148
• CPC Class Codes: G06F 1/263 Arrangements for using multiple switchable power supplies, e.g. battery and AC G06F1/30 takes precedence
• CPC Class Codes: G06F 1/28 Supervision thereof, e.g. detecting power-supply failure by out of limits supervision
• CPC Class Codes: G06F 1/305 in the event of power-supply fluctuations
• CPC Class Codes: H02J 7/00302 Overcharge protection
• CPC Class Codes: H02J 7/00304 Overcurrent protection
• CPC Class Codes: H02J 7/00308 Overvoltage protection
• CPC Class Codes: H02J 7/0031 using battery or load disconnect circuits H02J9/002 takes precedence

Abstract

Device miniaturization is made possible by building a battery protection circuit in a microcomputer. A secondary battery protection device comprises a voltage detection means 7 that detects a voltage of a power supply circuit 6 including a secondary battery 1, a current detection means 8 that detects a current of the power supply circuit, and a battery protection circuit 10 that shuts off the power supply circuit 6 based on a signal representing a detection made by the voltage detection means 7 or the current detection means 8 of an excess current that is generated in the power supply circuit 6, wherein the protection circuit 10 is built in a microcomputer 13.

Claims

1. A secondary battery protection device comprising:

a voltage detection means that detects a voltage of a power supply circuit including a secondary battery;

a current detection means that detects a current of the power supply circuit; and

a protection circuit that shuts off the power supply circuit based on a signal representing a detection made by the voltage detection means or the current detection means of an excess current that is generated in the power supply circuit, the secondary battery protection device characterized in that the protection circuit is built in a microcomputer.

2. A secondary battery protection device according to claim 1, characterized in further comprising a latch that holds an input signal from the current detection means or the voltage detection means as is.

3. A secondary battery protection device according to claim 1, wherein an output of the latch defines an interrupt request flag to the microcomputer.

4. A secondary battery protection device according to claim 1, wherein an output of the voltage detection means or the current detection means is directly inputted in an I/O register of the microcomputer to conduct an on-operation of the power supply circuit based on a judgment of the microcomputer.