LED lamp failure

[Michael GilliganParticipant @michaelgilligan61133]

Posted by Howi on 14/12/2017 09:12:05:

I notice someone has mentioned the 'Blue light ' effect on humans, none of it has been scientifically proved. Just seems to be an excuse not to move to the new technology.

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Here is a very concise description of the two conventional methods of producing white light from LEDs.

**LINK**

http://www.photonstartechnology.com/learn/how_leds_produce_white_light

The problem with the 'Blue' is that it needs to be of sufficiently short wavelength to excite the Yellow phosphor.

… and that lets its emission curve stray into the near-UV band [*], which has the potential to damage the eye.

There is plenty more explanation available, from respectable sources, without having to rely upon internet wackos.

This problem has reduced enormously in recent years, as the technology matured, and especially with the introduction of COB LEDs with their phosphor overcoat.

MichaelG.

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Edit: [*] See the Spectrum plot on page 9 of this spec. [page 10 of the PDF]

http://www.nichia.co.jp/specification/products/led_spec/NSDW510GS-K1-E(2619).pdf

Edited By Michael Gilligan on 14/12/2017 22:34:22

[HowiParticipant @howi]

Posted by XD 351 on 14/12/2017 21:46:58:

Posted by Howi on 14/12/2017 09:12:05:

I think there is an awful lot of rot talked about led bulbs, a bit like the myth that ALL Chinese lathes are rubbish.

In Philips bulbs the electronics are fully potted so unlikely to be affected by moisture. Lets be sensible here, moisture near any type of bulb should be avoided, 240 volts and water don't mix.

I notice someone has mentioned the 'Blue light ' effect on humans, none of it has been scientifically proved. Just seems to be an excuse not to move to the new technology.

Phillips led lights may be potted but the cheaper ones may not be . Mains voltage in the bathroom / shower area is unavoidable unless you use a candle or torch !

My point was that all led bulbs from China are not equal , if the environment is harsh, get a better quality bulb to be on the safe side.

Mains Led's in bathroom lighting can be replaced with 12 volt Led's, no need for candles or torches, let's be sensible here.

[Neil WyattModerator @neilwyatt]

Your bathroom lighting should be waterproof and in the correct 'zone'.

That's how we survived in the days between gas and LEDs

Neil

[Bill DawesParticipant @billdawes]

XD351.

The shower lamp I referred to is still original halogen, hence my reluctance to tempt fate by changing it to LED.

My theory about its longevity is that the water vapour helps to keep it cooler than it would normally be.

Still , when I have finished all my replacements I will swop it for an LED, as I said I have a box full of Halogen GU10's if the LED is no good.

Bill D.

[Anthony KnightsParticipant @anthonyknights16741]

My bathroom light fitting is of the correct type for use in this location, with a rubber seal where the globe screws to the flush fitting ceiling mount. It has worked well over the years with both incandescent and minature fluorescent lamps.

I have cut one of the failed LED lamps open and found what appears to be a minature switched mode PCB which plugs into the LED array. I haven't tested it yet, but I suspect that it is this part of the device which fails.

[Gary WoodingParticipant @garywooding25363]

You might find THIS investigation into the failure of a LED bulb interesting.

[Tim StevensParticipant @timstevens64731]

Bill reminds us:

My theory about its longevity is that the water vapour helps to keep it cooler than it would normally be.

Which reminds me that condensation can be worse – much worse – with LEDs. This is because they only get slightly warm in use. So, the electronics, and the bulb-holder, etc, don't get hot enough to evaporate the dew in a steamy bathroom.

The same effect can cause problems with LEDs on vehicles, especially the outer lamps (as distinct from dashboard and other interior lamps). This is why encapsulation is an advantage, and why the super-cheap (non-coated) stuff can suffer.

Cheers, Tim

[duncan webster 1Participant @duncanwebster1]

Posted by Gary Wooding on 16/12/2017 11:07:58:

You might find THIS investigation into the failure of a LED bulb interesting.

Now if that had been me I'd hve been out with the soldering iron and made 2 good ones out of 3 bad ones!

[modeng2000Participant @modeng2000]

Me too!

[SandgrounderParticipant @sandgrounder]

Posted by Bill Dawes on 15/12/2017 15:28:28:

The shower lamp I referred to is still original halogen, hence my reluctance to tempt fate by changing it to LED.

My theory about its longevity is that the water vapour helps to keep it cooler than it would normally be.

Bill D.

But the halogen bulb is supposed to be run much hotter than ordinary incandescent bulbs, this is so the evaporated tungsten is re-deposited on to the filament increasing bulb life and keeping the bulb free of any blackening.

John

[HacksawParticipant @hacksaw]

I may have asked a similar question before… These newer type Gu10 type , warm white , I'm very happy with.. Not one has popped ! Can you get the same but 12v D.C. for a caravan ?

[Michael GilliganParticipant @michaelgilligan61133]

Posted by Hacksaw on 16/12/2017 23:16:29:

I may have asked a similar question before… These newer type Gu10 type , warm white , I'm very happy with.. Not one has popped ! Can you get the same but 12v D.C. for a caravan ?

.

As you presumably realise: GU10 lamps are, by definition, Mains Voltage

Warm White MR16 lamps would be ideal for caravan spotlighting, and are readily available.

MichaelG.

[Author]

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