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. 04, 1986
Filed:
Feb. 06, 1984
Daniel J Birk, Aurora, IL (US);
Pittway Corporation, Aurora, IL (US);
Abstract
A flashlight battery charging circuit includes a diode bridge which full-wave rectifies an AC voltage supplied from a 120 VAC supply through a coupling capacitor. The output terminals of the bridge are coupled to the battery through a Zener diode circuit which terminates current flow from the bridge to the battery when the battery voltage reaches a predetermined level. A storage capacitor has one terminal thereof connected to the coupling capacitor and the other terminal thereof connected to the output of the rectifying bridge through a diode and to the battery through a current-limiting resistor and an LED. The storage capacitor is charged during alternate half cycles of the AC supply voltage to a relatively high voltage and on the remaining half cycles is discharged through the current-limiting resistor and the LED to supply to the battery a limited current at a relatively high voltage.