Brighter, More Energy Efficient LEDs Thanks To New High-Performance LED Driver

September 9th, 2013 by James Ayre

Brighter, more energy-efficient LED light bulbs are in the near-future, thanks to a new high-performance LED driver that’s been developed by researchers from the Department of Electronic and Information Engineering. The newly designed LED driver provides power to the light bulbs via a rather innovative new approach that’s been dubbed “multi-level PWM” (Pulse-Width Modulation).

The new approach has yielded substantial improvements with regard to light quality and energy efficiency — as compared with the “pulse width modulation” and “linear driver” methods that are currently in wide use.

“The newly invented technology can be applied in many areas, like LED billboard, it can achieve additional energy saving by up to 15%.”
Image Credit: The Hong Kong Polytechnic University

The press release from Hong Kong Polytechnic University explains:

By traditional method of pulse width modulation, LEDs are fed pulsed current instead of steady DC. The drive current is turned ON and OFF at a rate faster than being perceptible by human eyes. Powering LEDs in pulses makes their light output easily controllable.

The research team, formed by Dr Lai Yuk Ming, Dr Loo Ka Hong and Prof. Michael Tse, gives the PWM method a new twist. The pulsed operation is redesigned in a way to maximize light output while minimizing wasted energy in the form of heat. The result is higher lumen per watt. Dr Loo Ka Hong said they achieved additional energy saving by up to 15%.

When used in a large scale application, it can save a lot of energy. The LED billboard on One Times Square in New York is a good example. The math goes like this: The giant display uses 12 million bulbs and 250 KW of power. If the billboard is on for 16 hours a day, the energy bill comes to US$18,000 a month. A 12% drop in energy consumption means US$2,160 in energy savings. That’s something to roll your eyes at.

Those are significant savings — and in addition to those improvements, the new driver also has lowered cooling requirements, and thus can function well with a smaller heat sink — meaning that the whole LED system can be made significantly smaller, reducing costs. When coupled with the new MPWM driver’s excellent dimming capability, this makes for a “brighter, smarter and more versatile LED lighting solution”.

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Tags: China, Department of Electronic and Information Engineering, high-performance LEDs, Hong Kong Polytechnic University, LED MPWM driver, LED research, LEDs energy efficiency, Pulse-Width Modulation, Pulse-Width Modulation LEDs, PWM

About the Author

James Ayre 's background is predominantly in geopolitics and history, but he has an obsessive interest in pretty much everything. After an early life spent in the Imperial Free City of Dortmund, James followed the river Ruhr to Cofbuokheim, where he attended the University of Astnide. And where he also briefly considered entering the coal mining business. He currently writes for a living, on a broad variety of subjects, ranging from science, to politics, to military history, to renewable energy. You can follow his work on Google+.

Wayne Williamson

Cool…that being said, just wondering why the “stop lights” that have been converted to led are having large patches of failures…what happened to 40k hours….