Why do CFL's go bad?

[Vortex1]

some info on CFL's and failure modes.

http://creativelightingllc.info/fluorescent_lamp.htm

One thing that many do not appreciate is that flourescent tubes should be operated with a clean sine wave with as little DC unbalance as practical so as to eliminate migration of gaseous atoms towards one electrode. The blackening will show up rather quickly when used in a circuit with some DC present.

Using flyback pulses will thus shorten the life of the tube. That is why common CFL driver circuits switch to a resonant mode after ignition. The Moyer oscillator is used in many backlighting schemes for long tube life. It has a clean sine wave output.

Many who experiment using flyback pulses to ignite the tube never really measure the Lumen output accurately, but if they were able to drive the tubes to the same intensity as a normal driver circuit, they would notice an accelerated blackening and thus a shorter life of the tube.

[turbo]

CFL's are designed to go bad because of economic reasons.
If they would last forever they would not be selling them anymore would they? 
They have been designed to stop working at a pre defined point.
The gas does not wear down and it is possible to build a CFL that would last forever, but the ones you buy in a store do not,it's designed that way.

Marco.

[the_big_m_in_ok]

All of this is rather disturbing, the initial post was what got me to thinking about them - it literally fried itself on the inside.

A short circuit in any part of the circuit might do that.  However, I've never seen one destroy itself the way you describe.

--Lee

[the_big_m_in_ok]

CFL's are designed to go bad because of economic reasons. ...

Very good.  Money has to be made at the cost of commercial efficiency.

--Lee

[Vortex1]

CFL's are designed to go bad because of economic reasons.
If they would last forever they would not be selling them anymore would they? 
They have been designed to stop working at a pre defined point.
The gas does not wear down and it is possible to build a CFL that would last forever, but the ones you buy in a store do not,it's designed that way.

Marco.

Forever is a long time.... Engineers do not speak in terms of forever, but recognizing that all things have a finite life, try to design items that are both affordable and have a reasonable life expectancy. MTBF....is used to evaluate and optimize designs so that these realistic goals are met.

I urge anyone who can outhink/outdo/outperform the engineers who have skilfully developed the current reasonably designed and affordable CFL's to do so....the world will beat a path to your door.