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:
Nov. 06, 2001
Filed:
May. 24, 2000
Michael R. Mowry, Kenosha, WI (US);
Thomas P. Becker, Kenosha, WI (US);
Snap-on Technologies, Inc., Lincolnshire, IL (US);
Abstract
A lead-acid battery pack has an electronically-controlled power switch connected in series with the battery. A voltage monitor/controller is connected in series with a normally-open ON/OFF switch across the battery, the controller controlling a ramped pulse width modulator which provides a switch control signal to the power switch. The controller is program controlled so that, a fraction of a second after the ON/OFF switch is closed, the modulator will provide a constant DC level control signal to the power switch to hold it closed. If the battery voltage drops below a first level for several seconds, the modulator will produce a PWM switch control signal of gradually decreasing pulse width and duty cycle until the power switch is permanently open. This gradual decrease of power delivered from the battery will occur immediately upon the battery voltage dropping below a second level lower than the first level.