On Sat, 18 Aug 2007 10:40:33 -0700, wrote:

I have understood that switching fluorescent lamps - tubes - on and
off was not a good idea and that they should be switched on and left
on. Unlike filament lamps which do not seem to mind.

Why do you say they don't mind? Haven't you noticed that they almost
always burn out at the moment they are turned on?

That's when they heat up, the filament expands (maybe faster than when
it contracts on turning it off) and stresses on the filament are
greatest.

If you leave a filament bulb on, it will generally last much longer
than if you turn it on and off.

How do the modern CFLs compare/suffer etc etc?? I know that they can
take a minute or two to warm up and maximise their light output.
If they should be switched on and left on, then they begin to defeat
the very purpose of having energy saving CFLs fitted.