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:
Feb. 01, 2005
Filed:
Jun. 19, 2003
Seng P. Xiong, Dacula, GA (US);
Martin H. Ramsden, Lawrenceville, GA (US);
Marc B. Riley, Lawrenceville, GA (US);
Seng P. Xiong, Dacula, GA (US);
Martin H. Ramsden, Lawrenceville, GA (US);
Marc B. Riley, Lawrenceville, GA (US);
Motorola, Inc., Schaumburg, IL (US);
Abstract
A circuit and method for charging a rechargeable cell is provided. The circuit includes a voltage regulator coupled serially between a power source and a rechargeable cell. The circuit further comprises a controller capable of both monitoring the power dissipation across the voltage regulator and altering the current flowing through the voltage regulator. When the power dissipation in the voltage regulator exceeds a predetermined threshold, the controller increases the current. Where the power source is a linear transformer, this increase of current will cause the transformer to become loaded. The loading causes the transformer output voltage to fall, thereby reducing the power dissipation in the voltage regulator below the predetermined threshold. If, however, the power dissipation does not fall below the predetermined threshold within a predetermined time following the increase of current, the controller will then reduce the current to a level low enough to cause the power dissipation in the voltage regulator to fall below the predetermined threshold. The circuit and method provide a way to rapidly charge batteries while ensuring that the voltage regulator is not subject to thermal compromise.