Electronic apparatus incorporating battery

• US 6,016,018 A
• Filed: 11/21/1997
• Issued: 01/18/2000
• Est. Priority Date: 11/22/1996
• Status: Expired due to Fees

• Current Assignee: ALPS Electric Company Limited (Alps Alpine Co., Ltd.)
• Original Assignee: ALPS Electric Company Limited (Alps Alpine Co., Ltd.)
• Inventors: Hasegawa, Kazuo, Takai, Daisuke
• Primary Examiner(s): Gaffin, Jeffrey
• Assistant Examiner(s): Zura, Peter
• Application Number:
  US08/975,954
• Time in Patent Office: 788 Days
• Field of Search: 327/551-555, 327/221, 327/344, 257/533, 333/172, 307/9.1-10.51, 307/109, 307/116, 307/125, 307/131, 340/310.01-310.07, 340/636, 320/106
• US Class Current: 307/109
• CPC Class Codes: G01R 19/16542 for batteries charge condition monitoring in G01R31/36
• CPC Class Codes: G01R 31/3648 comprising digital calculation means, e.g. for performing an algorithm
• CPC Class Codes: G01R 31/374 with means for correcting the measurement for temperature or ageing

Abstract

An battery-driven electronic apparatus incorporating battery has a source battery, a driven circuit driven by the battery, a pair of external terminals connected to the both ends of the source battery and a capacitor provided between the source battery and the external terminals. A circuit for identifying voltage of a battery having a pair of checking terminals, a resistor, a transistor, a peak hold circuit, a multiplexor, a temperature measuring circuit, an A/D converter and an identification control circuit including an arithmetic circuit and an identification circuit is employed to identify voltage of the source battery of the electronic apparatus incorporating battery by coupling the pair of the checking terminals with the pair of the external terminals of the electronic apparatus incorporating battery, measuring voltages of the source battery repeatedly and calculating voltage differences by the arithmetic circuit for identifying whether the battery is usable or not by comparing voltage differences with predetermined values in the identification circuit without removing the source battery with minimal power consumption.

Claims

1. An electronic apparatus incorporating battery comprising:

a source battery for generating a DC voltage, said source battery having a positive terminal and a negative terminal;

a driven circuit connected to one of said terminals of said source battery such that said driven circuit is driven by said source battery;

two external terminals, one of the external terminals connected to the positive terminal of said source battery, the other of the external terminals connected to the negative terminal of said source battery;

a capacitor connected in series between one of the positive terminal and the negative terminal of said source battery and one of said external terminals,

a battery voltage identification circuit having a detection circuit to detect a current of said capacitor; and

wherein said two external terminals are connected and disconnected by said battery voltage identification circuit.

2. The electronic apparatus incorporating battery of claim 1, wherein a resistor is connected in parallel to said capacitor.

3. The electronic apparatus incorporating battery of claim 1, wherein a diode is connected between a second capacitor in said driven circuit and said source battery.

4. The electronic apparatus incorporating battery of claim 3, wherein said diode is a Schottky barrier diode.