Re: Dissecting CFLs

[andrew@xxxxxxxxxxxxxxxxxxxx (Andrew Gabriel)]

In article <092dnYPZgpxGlfnbnZ2dnUVZ_oytnZ2d@xxxxxxx>,
	"Robert Green" <ROBERT_GREEN1963@xxxxxxxxx> writes:
> "Andrew Gabriel" <andrew@xxxxxxxxxxxxxxxxxxxx> wrote in message
> news:466316a2$0$644$5a6aecb4@xxxxxxxxxxxxxxxxxxxx
>> In article <6sCdnUss9fNcTf_bnZ2dnUVZ_hqdnZ2d@xxxxxxx>,
>> "Robert Green" <ROBERT_GREEN1963@xxxxxxxxx> writes:
>> >
>> > Has anyone cut open a CFL before?  Any pointers?
>>
>> Yes, and I've reused the control gear...
>> http://www.cucumber.demon.co.uk/lights/diy/
>
> Very interesting.  I notice some of the bulbs really discolored at the base
> in your "fanned out" photo.

Many of them weren't new, but borrowed from around the house in order
to take the photo.

> I've never seen a bulb twist like the Ikea's.
> I assume these are all 220VAC units from the UK addy. I don't see any
> helical bulbs which appear to use narrower tubes.  Is that just a
> coincidence or are they not available for 220VAC?

Bare in mind I wrote that article over 5 years ago.
I don't think helical tubes existed back then.
The largest Ikea one is interesting in that it has a
clear dog-leg which you can just about see right in the
middle, extending half way up the tube. This is a cold
chamber which is used to regulate the mercury vapour
pressure.

> It looks as if you've opened them in a number of different ways.  What tool
> did you use?  I think I seen the tell-tale curves left behind by a small
> grinding wheel on some of the bases where you cut away the shell.

Nothing that fancy -- just a screwdriver, knife, and pliers.
Some come apart along the seams, others are solvent welded.

I bought several of those large Ikea lamps at the time. One
had an early electronics failure. The case quite easily unclips
so I saved the almost new tube and chucked the rest. Of the
remaining ones, some ~7 years later, the second one just died
of old age (worn out tube electrodes). I uncliped and chucked
the tube, and refitted the tube saved from the early electronics
failure, and it works again. Don't know if I'll get another 7
years from it -- the electronics might not last that long as it
runs quite hot in an enclosed fitting.

>> At the time I wrote that article, low power electronic control
>> gear was somewhere between expensive and unavailable. Now that
>> it's more readily available, I wouldn't actually suggest reusing
>> it from dead lamps, although the downlighters covered at the
>> end of that article are all still running from the original
>> 8 year old control gear from some Philips PL Electronic CFLs.
>
> This is just an R&D exercise.  (Rip open and Destroy, in the best Brainiac
> tradition. (-:  )
>
> From what you've written, I'm expecting to see a dead capacitor in the GE.

It could be just about any component.
Resistors are good at smoke too. Semiconductors
usually just go pop and crack the case if you
look carefully. Some electronic control gear
deliberately burns itself out when the tube
dies so it doesn't keep trying to restart it,
although that normally happens without any
smoke.

> What worries me is that it could come from the era when all that bad
> electrolyte was floating around.

Do you mean the chinese ones made with a stolen formula from
a taiwanese factory (which they had discarded as not viable)?
I thought those mostly ended up on computer motherboards.

>> They've probably had about 4 lamp changes over that period.
>
> Are there any interesting uses for the electronics other than driving lamp
> tubes?  Tesla coils or bug zappers?  (-:  Recycling should be fun.

I doubt it.

--
Andrew Gabriel
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