Another day…

Singapore, 28th September 2012

Another day, another time spent on LED dimming issues…a continuing saga. I am starting to be convinced now that dimming retrofit lamps should be avoided at all cost, at least in commercial or public applications. I guess in residential and home applications it may not be such a big deal, but in a professional environment failing lights and lighting effects are noticed immediately and affect the image, mood and ambiance of the space that is being lit. With all due respect to all the great LED lamp manufacturers out there, we have still some way to go before we can confidently specify LED retrofit lamps for dimming, specifically the MR16 halogen types.

I am continuing my quest in finding the origins of the faltering LED performance when it comes to dimming. Again this week we had tests carried out to determine where in the chain of lighting components the possible cause could be identified and after another meeting today I have to conclude with more and more certainty that the retro fit lamp itself is at fault. The tests included testing current and voltage in various parts of the circuit starting from the dimmer system, testing with leading and trailing edge dimming, adding active loads (to simulate a “conventional” incandescent lamp in the circuit) and bypassing the electrical wiring and cabling all together by pulling a new cable with a complete new transformer and LED lamp.

In the original situation shimmering (light flickering) can be observed when dimming specifically at lower levels. But any of the above tests did not result in any change of situation, except in the newly pulled cable with new lamps which seemed to resolve the issue. When one of the (flickering) LED bulbs from the original situation was interchanged with the new lamp in the new circuit, the problem shifted to the new circuit. The new lamp in the old circuit did not flicker, the old lamp in the new one kept flickering even in the new set up. It has to benoted that the original LED retrofit lamp did not flicker when dimmed on installation!

This begs the question whether retrofit LED lamps (MR16 types specifically) age with prolonged use of dimming. Possibly the stronger the dimming level over longer duration, the faster these LED lamps start to depreciate …and flicker. Surely the LED manufacturers must know something about this? Can someone enlighten me?

Light Watch 3-147: No comments…:)
Have a great weekend!

28. September 2012 by Martin Klaasen
Categories: Light & Learn, light watch, lighting applications, lighting design | Leave a comment

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