Long Island and New York

Dimming Circuit With Reference Control - 2

United States Patent    Fred Katz     Patent Number: US11026305B1     


A balance circuit includes a reference circuit configured to generate current through strings of light emitting diodes (LEDs). The reference circuit includes a first string of LEDs in series coupled to a collector node of a first transistor. A base drive current resistor is connected between the collector node and a base node of the first transistor. A base emitter resistor is connected between the base node and an emitter of the first transistor such that a reference voltage is generated on the base node during operation. Another stage receives the reference voltage to generate a tracking current through a second transistor and a second string of LEDs connected to a base of the second transistor, wherein a current through the first string of LEDs is uniformly tracked by the tracking current through the second string of LEDs.
Assignee Name:  
US Patent Application No.:

Frank Zarcone, James D. Chermak, Fred Katz
Apogee Lighting Holdings, LLC
April 29,2020
Patent Granted
June 2, 2021

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Last modified: 10/03/23 İFred Katz March 2008