Secondary battery protection device

• US 7,068,484 B2
• Filed: 03/04/2003
• Issued: 06/27/2006
• Est. Priority Date: 03/08/2002
• Status: Expired due to Fees

• Current Assignee: Seiko Epson Corporation (Seiko Group)
• Original Assignee: Seiko Epson Corporation (Seiko Group)
• Inventors: Kashine, Takashi
• Primary Examiner(s): Jackson, Stephen W.
• Application Number:
  US10/377,889
• Publication Number:
  US 20030169021A1
• Time in Patent Office: 1,211 Days
• Field of Search: 361/90, 361/118, 361/91.1, 361/93.1, 361/78, 361/79, 361/18, 361/92
• US Class Current: 361/79
• 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 device that detects a voltage of a power supply circuit including a secondary battery;

a current detection device 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 device or the current detection device of an excess current that is generated in the power supply circuit, the protection circuit being built in a microcomputer, an output of the voltage detection device or the current detection device being 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.

2. A secondary battery protection

device, comprising:

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

a current detection device 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 device or the current detection device of an excess current that is generated in the power supply circuit, the protection circuit being built in a microcomputer;

a latch that holds an input signal from the current detection device or the voltage detection device as is, an output of the latch defining an interrupt request flag to the microcomputer so that a state after a discharge path of the secondary battery is shut off is judged by software.