The control of any luminaire should be considered early in the design phase, and LED luminaires are no exception. How the user may want to change the light level can impact the mechanical design of the fixture, the specification of the LEDs, and the nature of the optical and thermal systems. Providing for control options in the design phase can reduce the burden of standards, as well as costly last-minute design changes. Furthermore, the ability to provide control options allows for significant product differentiation, which brings value to the customer, the market and the manufacturer. Incandescent lamps controlled by quality dimmers are able to easily dim well below a 1% light output, which has set a customer expectation for high performance dimming, especially in high-end applications. This means that dimmable LED drivers need to provide smooth, continuous, and flicker-free performance to 5% light output or less.
A primary component in any LED lighting system is the driver. Regardless of whether it comes in one module, or several, the LED driver is a power supply and a power regulation device for the LEDs. By construction, each LED can pass current in only one direction, which means that there must be some means of converting the AC power source to DC.
This article was published in the July/August 2009 issue of LEDs Magazine.
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