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. 29, 2003
Filed:
Dec. 14, 2001
Craig E. Hughes, Oviedo, FL (US);
DME Corporation, Fort Lauderdale, FL (US);
Abstract
An improved LED current regulation circuit for providing continuous electrical current to one or more Light Emitting Diodes (LEDs) in an aircraft illumination system, in particular, an aircraft emergency evacuation system, through a varying voltage source. The circuit comprises a DC voltage source and a current regulation circuit electrically coupled to the one or more light sources, preferably, LEDS. The current regulation circuit comprises a transistor, a collector of which is electrically coupled to the one or more light sources, a zener diode electrically coupled to a base of the transistor, an emitter resistor having a first terminal electrically coupled to an emitter of the transistor and a second terminal electrically coupled to ground, the emitter resistor in parallel connection with the zener diode, wherein the current through each LED is maintained at a constant predetermined level based upon the summation of voltage drops across the zener diode, the transistor and the emitter resistor. In this fashion, each LED will illuminate a desired area on an aircraft despite wide fluctuations in input voltage.