The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Aug. 20, 1996
Filed:
Apr. 11, 1994
Yasuhito Eguchi, Kanagawa, JP;
Masayuki Sato, Tokyo, JP;
Toshio Narushima, Kanagawa, JP;
Akira Sanpei, Fukushima, JP;
Kanji Murano, Tokyo, JP;
Sony Corporation, Tokyo, JP;
Abstract
Circuit for preventing overcharge and overdischarge of secondary batteries is disclosed. Overcharge detecting comparators COMP2 and COMP4 each having a hysteresis circuit 1 are connected between positive and negative electrodes of series-connected secondary batteries Abat and Bbat, and overdischarge detecting comparators COMP1 and COMP3 each having a hysteresis circuit 2 are connected also between the above electrodes. Transistors T1, T2 and a resistor R are connected between the batteries for overflow of overcharge and balance of overdischarge. Upon detection of any overcharge by the comparator COMP2 or COMP4, the charge current is interrupted by a transistor T6, and simultaneously the overcharge overflow is discharged by the hysteresis circuit until the battery voltage is lowered to the hysteresis voltage. And after the discharge, the transistor T6 is turned on to resume recharging the batteries. Meanwhile, upon detection of any overdischarge by the comparator COMP1 or COMP3, the discharge current is interrupted by a transistor T5. Thus the overcharge and the overdischarge can be balanced by the hysteresis circuits 1 and 2 respectively.