CFL failures

Dec 09, 2020 Last reply: 5 years ago 18 Replies

AIUI, the Compact Fluorescent Lamps, which have replaced the incandescent Edison / Swann inventions consist, of an inert tube driven by high voltage electronics in the base.



When they fail, is it then likely to be a fault in the electronics rather than the tube itself, as was the case with the double filament fluorescent tubes with starters and chokes?



Finally, has anyone here dabbled in mending the electronics?



Could be either, but more usually ageing of the tube IME.

Why anyone would *want* to repair one given the superiority of LED replacements is my challenge.

Yes

Yes.

Most have given up on them and use LEDs now instead.

glass tube with mercury & phosphor mainly.

I forget the exact figures, but IIRC there were more tube failures than electronics, but not by a huge margin. In most cases one of the tube filaments goes oc.

It was easier to swap the base or tube with another lamp of the same rating. The circuits are simple enough though, and spares can be had from most CFLs. Transistors were the prime failure IIRC. There are also some IC based ballasts, but few - and of course the early iron choke ballasts.

NT

Most CFLs I have come across use an old fashioned choke, like ballasts in convention fluorescent tube fittings.

I have seen others where the failed component is a polyester capacitor of the self healing type[1].

[1] Every time it self heals the capacitance drops. Enough healing events and it's toast.

I have an American Coleman lantern with one of those. The CFL is dead, and even Coleman cannot supply me with a replacement. So I now have an expensive but useless dust-gatherer.

Usually the electronics, which get too hot packed into such a small space.

Why bother? If you really want to BigClive on Youtube has a lot of reversed engineered circuits from the strip downs of such items.

More likely to be the tube itself that has failed. They tend to light up ever more feebly as the mercury becomes unavailable in their electrodes. I have a couple on their last legs right now - they become very slow to start and have a purple glow and visible darkening near the electrodes.

IME Somehow the curvy spiral ones seem to fail more spectacularly than the linear folded ones.

If you need to ask then you shouldn't even be thinking about trying. There are dangerous voltages involved in them and they are designed to fail safe. They can cook their capacitors in some enclosures (as do the PSUs on some LED lamps).

Sorry, lazy question; electronics degree 1972, licensed radio ham since

1970.

Yes but otherwise a wise caveat for hoi polloi.

Aren't those called 'D type' (or D something anyway)? We had one in our bathroom until quite recently.

The first CFLs I saw were in hotel rooms in the mid 1980s, the ballast was firmly attached to the luminaire, and the CFL itself had four pins that plugged in. Expensive, but rarely got stolen.

They're not what is usually referred to as CFLs which means fluorescent lamps which you can plug/screw into a fitting which usually has an incandescent.

Most of the ones I had go fell into two categories. The heat glue and solder holding the tube in failed resulting in no light or the tube on the floor. The other way is much like the old fashioned ones, flickery and won't start in the cold. Bit boring. I suppose some may fail electronically, but my main gripe is the nasty interference they kick out, LEDs seem to do much the same, or some of them do. Bah Humbug. I luckily do not need the light myself, but you cannot expect a visitor to fiddle about in the pitch black. Brian

You'll find those tubes at car boot sales fwiw. Whether it's worth dicing with covid for...

NT

Not really anything hazardous in the ballast. The mercury in the fragile tubes is the main issue.

NT

Hmm. I don't normally frequent car boot sales, but it's worth knowing. How come those specific tubes are available here? The impression I got from Coleman was that this particular model had only ever been sold in the US, never in the UK, and wasn't even available over there now. But as you suggest, car boot sales and covid are a bad combination. Are they even holding them now?

Around my way all car boot sales have disappeared during these covid times.

I think you would have a safer chance on eBay? If it's not on eBay best not bother!!

no idea. I can only say that the odd one now & then I've been to has featured these & other obsolete bulbs aplenty.

NT

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