Giving LED lights a good life

[bernardgreen]

Two articles from Power Systems Design newsletter, although the articles are primarily related to industrial and commercial lighting the basic principals of protection apply to domestic lighting as well. Many LED drivers produced for the domestic market have little if any circuit protection for the LED elements

How to protect LEDS HERE

In conclusion, although LEDs can exhibit much higher lifetimes than traditional lighting solutions, they need adequate circuit protection to ensure they can deliver on their promise. By focusing on the three key elements of a luminaire’s electrical designs, LEDs will live longer and, increasingly, will be able to move into increasingly harsh environments.

and the problems that the ultra violet light from "ordinary" (*) LEDs can cause HERE

(*) ordinary in that the LED element(s) produce UV energy to excite the phosphers that produce the visible light. The UV that escapes can be harmful to eyes and bleach out colours in paint and other items that are illuminated by the LED light source.

 

[JohnW2]

... In conclusion, although LEDs can exhibit much higher lifetimes than traditional lighting solutions, they need adequate circuit protection to ensure they can deliver on their promise. By focusing on the three key elements of a luminaire’s electrical designs, LEDs will live longer and, increasingly, will be able to move into increasingly harsh environments.

Thanks, but I'm not quite sure that this article is quite what one might at first think.

Of the "three key elements" they mention, two ('surge' etc. protection and over-current protection) really apply to anything electronic, not just "LEDs". It appears that the third (the first they discuss, and the one they say most about) is not aimed at providing a 'longer life' at full performance but, rather, seeks to minimise the number of LED elements which are 'lost' (hence reduction in light output) if one LED element fails. Furthermore, this one is not really anything to do with "circuit protection" (in the sense that one might expect of that phrase) or drivers etc. - but, rather, is about the design of the electronic bits of the light-producing components.

Kind Regards, John

 

[ericmark]

In theroy cheap LED units where a simple capacitor is used for current control should be more susceptible to over voltage to one with a switched mode power supply where the voltage range it can cope will is far higher.

Yet with all LED lighting I have had just one failure, and that was a fluorescent tube replacement one of the few units to use switch mode control, and every LED failed together, clearly the driver failed rather than the LED's.

I am sure one can fit surge protection in domestic premises, however the big question is if its cost effective? Will the surge protection fail at a rate to save or waste money spent?

 

[JohnW2]

In theroy cheap LED units where a simple capacitor is used for current control should be more susceptible to over voltage to one with a switched mode power supply where the voltage range it can cope will is far higher.

It looks as if that article is talking about things far more sophisticated (and expensive) than "cheap LED units where a simple capacitor is used for current control".

Yet with all LED lighting I have had just one failure, and that was a fluorescent tube replacement one of the few units to use switch mode control, and every LED failed together, clearly the driver failed rather than the LED's.

I wouldn't be so sure about that. In the couple of LED tubes I have taken apart (because they arrived mechanically damaged), whilst they did, indeed, have some sort of SMPSU, although I may be wrong, the LED elements all appeared to be connected in series. If that was the case, then o/c failure of just one of those elements would obviously cause all the LED elements to 'fail' simultaneously.

I am sure one can fit surge protection in domestic premises, however the big question is if its cost effective? Will the surge protection fail at a rate to save or waste money spent?

Quite so.

Kind Regards, John