LED panel lights

[tabbypurr]

They're very different animals. It's easy to make LEDs run on an iron ballast, but not so easy to make LEDs run on either type.

NT

[Dave Plowman (News)]

The small ones - like say in a 12v hand lamp or caravan light, may well have the usual two pins at either end, but both pins paralleled.

A fluorescent tube can light with no connection at all in the presence of a strong RF field.

[The Natural Philosopher]

Well they have never been wired that way of course.

Live at one end, neutral at the other. Otherwise how could you get a voltage across them?

Perhaps a simple diagram will clear up your confusion

[Scott]

Philips seem to have achieved this?

[GB]

I hadn't thought about how they worked.

I had thought the starter built up then dropped the current through the inductor so as to create a voltage spike, like a Ruhmkorff Coil. But it also allows the filaments to heat up electrically for a short time? How clever!

[tabbypurr]

A quick look says electronic ballasts only, not both types. Anyway it is doable, just more complication & expense.

NT

[Scott]

That's because I sent the link for the HF version. There is also an EM version. I accept it appears the same tube cannot run on either type of ballast but it seems tubes (in the plural) can run on either type.

'More complication and expense' - compared to what?. I suggest it would be less complication and cheaper for someone to replace the tubes themselves rather than employ an electrician to rewire every lighting unit.

[tabbypurr]

You're either trolling or complaining about a statement you haven't understood.

[DerbyBorn]

Fairly enlightening:

[Huge]

All things considered, I prefer Big Clive's accent;

[DerbyBorn]

Huge wrote in news:eht3lhFiihjU8 @mid.individual.net:

Agree - but the video is about low voltage fittings.

[Scott]

Neither actually - just responding to your attempt to drive discussion down a pedantic route.

My point was - and is - that 'retrofit' tubes are available for those who want to swap over without rewiring the internals. It is also possible to bypass the ballast for those who wish to do so. I thought this information would be of practical assistance.

Your point seems to be which type of ballast is easier to remove and the levels of technical skill needed. Probably of interest to somebody but not to me. Remember the original question was about replacing fluorescent lights with LED panel lights

[Huge]

But first he explains how fluorescent lights work.

[tabbypurr]

My point had nothing to do with that whatsoever. I won't be continuing this discussion.

NT

[Scott]

Good because I have no idea what your point was. You seem to have something against 'retrofit' tubes that you are having difficulty articulating. .

[ARW]

Did they slowly dim or suddenly dim?

[The Natural Philosopher]

All semiconductors age. They age faster at high temperatures.

Performance generally changes gradually.

If you are interested this is MOSFET oriented, but still relevant

As for LEDS..

"In conclusion, commercially available blue LEDs have been subject to accelerated DC ageing process and their electrical and optical characteristics are measured. It is found that both characteristics are degraded after each ageing cycle: the ideality factor and the reverse saturation current in I-V characteristics increase while the peak wavelength intensity in the electroluminescence characteristic decreases. We attribute the degraded characteristics to the formation (or activation) of mid-gap energy levels which can effectively function as non- radiative recombination centres in the forward-biased mode, and generation centres in the reverse-biased mode."

In other words, electricity starts to be used to do other stuff than emit light, over time.

[Andy Burns]

[snip]

Add to that the degradation of the phosphor(s).

[Dave Plowman (News)]

Slowly. And over quite a longish period. From more than adequate for the job to useless. The replacements from the same batch have started to do the same. They were just generic bought from Ebay - but not the very cheapest. First time I've seen this happen.

[ARW]

I suppose time will tell on the ones I have fitted.

An awful lot of them were supplied for us to fit (we quoted a price for installation only). That's a lot of hospitals and schools.