Low Voltage LED Decklight problem

[coopersim]

I've fitted some blue led decklights from B&Q in a deck in South Africa, I've had to replace them 4 times now as the led's keep on blowing, it's 240v 50hz as we are here, so I don't understand why there is a problem

So should I replace with like for like and fit some in line power filter? Any suggestions on that?

Or, is there an alternative that is less likely to blow, and where could I buy them from?

They are the small 20 odd mm ones with just one LED in them

Any help much appreciated!

Thanks

 

[joinerjohn]

Long way to go to replace them.

 

[coopersim]

He he, yeah, I installed them first, now I send replacements so the mother in law can replace them herself, it's costing more in postage than in replacement parts!

 

[electronicsuk]

Were they supplied in kit form? I assume they are supplied through a transformer or LED driver? If the latter, not using all the LEDs supplied with the kit could be a problem if the system is designed to be constant current, so that's worth considering.

If the system is constant voltage with a 12v or similar transformer, it may just be that the output voltage isn't particularly stable. This could be especially true if it has an unregulated output and there are large changes in the mains supply voltage.

What exactly are you having to replace? Power supply? Individual LEDs?

 

[coopersim]

First off the transformer died, twice! So I replaced with a locally available 12v downligter transformer, so I could swap that back to a UK style one and put a surge protector in line?

As it stands all the led's slowly die one by one, so there's just two working presently

 

[electronicsuk]

Most likely you have caused this problem by not using the correct transformer. Many LED kits require a constant voltage or constant current supply. As you replaced the original transformer with one designed for downlights, it's a pretty safe bet that you did so because the original transformer was labelled as 12v, so we can assume the kit is designed to be driven by constant voltage.

However, downlight transformers are typically a switch mode power supply with a minimum wattage requirement on the output. Without this, the output voltage could rise to significantly higher than the stated 12v, which would explain the death of the LEDs themselves. The same is true even of a wound transformer - without being loaded down, the output voltage will be higher than the stated voltage of the secondary winding.

If I were you, I'd start again and buy an entire new kit to replace the existing power supply and lights. You can put a surge protector inline if you want, and this might help a little if there is a real problem with voltage spikes on the local mains supply. I'd say it's more likely that the original power supply was just poor quality.

If you can't or don't want to buy the whole lot together (bear in mind that the two remaining LEDs may already be on their way out and may look dim in comparison to new replacements), search 12v LED driver and you'll find plenty of replacement power supplies.

 

[coopersim]

Thanks, I'll take the advice and replace the kit and include a surge protector to be on the safe side.

Thanks,

Simon