Published on September 9th, 2013 | by Nathan1
Brighter, More Energy Efficient LEDs Thanks To New High-Performance LED Driver
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 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”.