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:
Jun. 11, 1996
Filed:
Jul. 25, 1995
Yasuhisa Higashijima, Atsugi, JP;
Masaru Takeuchi, Atsugi, JP;
Mitsumi Electric Co., Ltd., Tokyo, JP;
Abstract
A secondary battery protection unit comprises a discharge switch (41) and a charge switch (42) inserted in an electric path between a positive terminal (B1) and a negative terminal (B2) together with secondary cells (1 and 2) connected in cascade to the discharge and the charge switches (41 and 42), overcharge detection circuits (45 and 46), and an activation control circuit (17) including a current mirror circuit. The activation control circuit (17) detects a voltage difference between both ends of a combination or one of the discharge and the charge switches (41 and 42) to judge whether or not the secondary cells perform a charging operation or a discharging operation. Only during the charging operation, the activation control circuit (17) makes the current mirror circuit supply a bias voltage to the overcharge detection circuits (45 and 46) to allow activation thereof. During the discharging operation, supply of the bias voltage is inhibited to save excessive power consumption.