Herbert Graf wrote:
> On Tue, 2007-01-23 at 17:24 +0000, Michael Rigby-Jones wrote:
>>> All the main lighting in my house has been switched over to CFLs,
>>> and I'm very happy with the result.
>>> 
>> I have CFLs in every location without a dimmer.  However, I still
>> don't like to see them left on unnecessarily and the problem is
>> that turning them on and off frequently causes them to fail
>> prematurely.
> 
> Perhaps the older ones had that problem? I turn mine off and on alot
> in the course of a day and they are still going strong, not a single
> one has failed (granted it hasn't been more then say a year and a
> half, but I know that if they were incandescent I would have had to
> replace several of them by now).
> 

How long a CFL survives frequent switching depends on the quality of the 
lamp and its electronics. For a long life the tube itself must have a 
certain quality level and the filaments must be preheated before the 
lamp is ignited. If the electronic just tries to ignite the lamp while 
the filaments are still cold, this greatly increases wear.
We had some cheap compact fluorescents failing early - filament broken. 
I guess due to insufficient preheating.

Right at the moment I am experimenting with the ballast controller 
IR21592 for a dimmable ballast. When it is done it will be integrated in 
my room lightning (and there are PICs in it!). These controllers are 
usually used in quality ballast electronics for any type of fluorescent. 
In these controllers there is very much attention paid to details as how 
to ensure that a lamp does not ignite during preheating and so on.

Regards,
Florian
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