ABSTRACT
A linear light emitting diode (LED) module with multiple parallel LED strings driven by a constant current source could display luminous flux variations along its length. This effect is caused by current imbalance among LED strings. Three commonly used electrical connection methods were compared and analyzed with computer simulations and actual experiments. Recommendations are made on how to minimize the imbalance.
Additional information
Notes on contributors
Ming Li
Ming Li is Global System Architect in Osram’s LED Lamps & Systems (LLS) Business Unit. Prior to this position, he was an engineering manager within OSRAM. He received a Ph.D. from UCONN and holds 25 U.S. patents. He has published 20+ journal papers. Additionally, he has cochaired symposia in MRS and ICALEO conferences.
Keng Chen
Keng Chen is a senior power electrical engineer in OSRAM’s LLS Business Unit. He received his M.S. in lighting and M.S. in electrical engineering from Rensselaer Polytechnic Institute and Columbia University, respectively. He holds two U.S. patents.
Arnulf Rupp
Arnulf Rupp is the Global R&D Head of the LEM division in the Osram’s LED Lamps & Systems (LLS) Business Unit.
Daniel Chu
Daniel Chu is Director of Product Portfolio for Osram’s SSL light engines for the North/South American Region.
Divya Vangari
Divya Vangari is an applications engineer in OSRAM’s LLS Business Unit. She received her M.S. in electrical engineering from Northern Illinois University.