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:
Jul. 21, 1998
Filed:
Jan. 15, 1997
Larry T Albert, Abingdon, MD (US);
Frank Faez Athari, Baltimore, MD (US);
Black & Decker Inc., Newark, DE (US);
Abstract
A self-oscillating buck mode battery charger apparatus 10. The apparatus 10 includes a main switching transistor 22, a first control transistor 34 and a second control transistor 36. The control transistors 34 and 36 are arranged such that neither control transistor sees the full input mains voltage across input terminals 12 of the apparatus 10 when the switching transistor 22 is turned off. An alternative embodiment of the invention includes a high and low main sensing circuit 102 in which a controller 120 is used to detect an excessively high mains voltage condition as well as an undesirably low mains voltage condition. The controller 120 turns off a PWM control circuit 104 when either condition is present for a predetermined length of time. Turning off the PWM control circuit 104 causes the main switching transistor 106 to be turned off, thereby preventing damage to the components of the charger apparatus 100. The charger apparatus is especially well-suited for applications where a rectified DC mains voltage is used to provide a charging current to a rechargeable battery.