Author

Ankita Patil

Publication Date

2015

Document Type

Dissertation/Thesis

First Advisor

Zinger, Donald S.

Degree Name

M.S. (Master of Science)

Department

Department of Electrical Engineering

LCSH

Electrical engineering||Light emitting diodes--Research||Electric apparatus and appliances--Power supply--Research||Voltage regulators--Research||Metal oxide semiconductor field-effect transistors--Research

Abstract

With increasing demand in energy, Light Emitting Diodes (LEDs) are rapidly finding new applications. Parallel combination of LEDs is better than existing solutions for high intensity load requirement than the series combination, as it does not put constriction on number of LEDs to be used. But there are certain discrepancies in using LEDs in parallel combination. Forward voltage change and input voltage drift pose problem in current sharing in parallel branches. This thesis presents a new, cost effective and simple method to design current equalizing circuit that will allow uniform current sharing in parallel LEDs.;The proposed circuit uses magnetically coupled inductors to balance current in parallel branches of unequal loads. The circuit uses a flyback converter to achieve this. High frequency switching used in the circuit helps to minimize visible flicker. The duty cycle of switching MOSFET and inductors of transformer can be used to balance the current in branches along with maintaining the brightness of LEDs. The circuit is tested for larger imbalance in load. Previous work done to reduce current mismatch in loads is discussed. A comparative study is between these methods and the proposed method is presented.

Comments

Advisors: Donald Zinger.||Committee members: Michael Haji-Sheikh; Martin Kocanda.

Extent

56 pages

Language

eng

Publisher

Northern Illinois University

Rights Statement

In Copyright

Rights Statement 2

NIU theses are protected by copyright. They may be viewed from Huskie Commons for any purpose, but reproduction or distribution in any format is prohibited without the written permission of the authors.

Media Type

Text

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