Dimming LED’s

Singapore 28th June 2011

It has been kind of a hot topic these last couple of weeks, the dimming of LED’s. Our first 100% LED project was launched today with a big advertorial in the local Straits Times newpaper. But it has been quite an educational ride, specifically when it coms to the dimming aspect of the LED’s. I blogged my frustration in an previous blog and it has been an ongoing story till today.

What did we learn? First of all that dimming LED as a stand alone system is much easier then dimming retrofit LED. Retro fit LEDs have the “driver” build into the lamp itself contrary to standalone systems where the “driver” is outside the system. In our case, for cost reasons, we opted for standard fittings with retrofit options except for the linear lighting. In other words we used standard halogen down lights but retrofitted with the latest (Philips) LED MR 16 master lamps. A few issues here…first the LED lamps are supposed to be able to retro fit directly onto conventional transformers, but as it turned out only very selected transformers actually work with LED. Only testing and manufacturers advise gave us guidance in which one to use. Secondly the dimming respnse curve for LED is different from halogen (not linear) so we had to play around to find the right balance and response. There is also a minimum level of dimming as below a certain level (10% for us) the occasional light start to flicker, not really nice.

All decorative items such as pendants were fitted out with the latest 3W LED candle lamps. Contrary to the halogen LED retrofits these operate on direct mains voltage and as we found out the dimming modules need roughly about 40W minimum in the circuit to properly dim. Our pendants had only about 18 to 24W LED load in them and the result was noticable humming. Not really nice…so we had to find ways to increase the load through some creative thinking. But considering that the whole idea is to minimise energy, it is somehow ironic that we need to resort to increasing the electrical loads to compensate and allow proper dimming…

In Light Watch today some self promotion. Man Fu Yuan Restaurant in  Singapore’s iconic Intercontinental Hotel was officially opened today after a complete make over. A couple of months design and installation work finally found its culmination in the grand opening. More to follow as the rest of the hotel continues on its renovation path. Meanwhile the restaurant is a first 100% LED restaurant within the IHG group. The warmwhite light however does not reveal that as the overall ambiance feels just like the good old halogen days.

Light Watch 120: Man Fu Yuan Restaurant

28. June 2011 by Martin Klaasen
Categories: Education, light watch, lighting applications, lighting design | 1 comment

One Comment

  1. Great blog look forward to reading more

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