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. 19, 1997
Filed:
Sep. 28, 1995
Deepakraj M Divan, Madison, WI (US);
Nasser H Kutkut, Madison, WI (US);
Donald W Novotny, Madison, WI (US);
Herman L Wiegman, Madison, WI (US);
Wisconsin Alumni Research Foundation, Madison, WI (US);
Abstract
A simple, low-cost technique for charge equalization of a series connected string of battery cells is provided. The secondary windings of a transformer having a single primary winding and multiple secondary windings are connected across each battery cell to be equalized. A single power converter applies a charging signal to the primary of the transformer, inducing a charging current in each secondary which is inversely related to the charge on the battery cells to be equalized. The transformer is preferably implemented as a coaxial winding transformer having low secondary-to-secondary winding coupling. The power converter is preferably implemented as a forward converter supplied with DC power from an adjustable DC power source. A source voltage provided by the DC source may preferably be adjusted during the course of charge equalization to preferentially direct charge to weaker cells. The charge equalization system may be used in combination with a bulk charging system to provide for both rapid charging of a battery string as well as equalization of the battery cells within the string.