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. 26, 1997
Filed:
Apr. 03, 1995
Upal Sengupta, Oregon, WI (US);
Rayovac Corporation, Madison, WI (US);
Abstract
A circuit and method for detecting and indicating the state of charge of an electrochemical cell or battery are disclosed. The invention finds particular application in the field of battery chargers for alkaline manganese dioxide cells, but may also be used in other types of chargers and electrochemical cells or batteries. In one preferred feature of the invention, a circuit low-pass filters or time-averages a charge enable control or transistor base drive signal, and provides the filtered or averaged signal as a first input to a comparator. The second input to the comparator is a predetermined reference voltage. When the voltage of the low-pass filtered or time-averaged signal becomes less than the reference voltage, the output of the comparator changes state. The change in state indicates that the cell has attained a full state of charge. Microprocessor means for accomplishing the same state of charge detection function are also disclosed.