Low energy lamps with dimmer

[Malcolm H]

I am aware that low energy fluorescent lamps cannot be dimmed with a conventional dimmer. However, in order to save energy, I have replaced a tungsten bulb in a dimmer equipped circuit, with a low energy lamp with the intention of leaving the dimmer always set to maximum brightness.

Out of interest I tried the dimmer just to see what would happen. As expected it was quite unsatisfactory and resulted in various modes of flickering. I therefore set the dimmer permanently to max brightness. All was OK for several weeks.

Now, a few weeks later, the low energy bulb has failed and flickers constantly even on max brightness setting.

My question is this: Could I have damaged the bulb by fiddling with the dimmer or is it a random premature failure?

[Andy Burns]

To go off slightly at a tangent, I've tried one of these

is a 230v CFL, with internal dimmer operated from any normal on/off switch, it is fairly good, the colour does change quite a bit as the brighness changes, and there is a little bit of hum when it's at full brigtness, but it's quite good with a pullcord in the bedroom, fitted in an uplighter the colour change is less obvious too.

[John Rumm]

Chances are just running it from a dimmer could have shagged it. Dimmers will often not provide a true sinusoidal output, even at maximum brightness - there will often be some clipping of the waveform near crossover. This can result in the output of a fair amount of harmonic noise, that could end up dumping extra heat from the filter components in the CFL circuitry.

[Colin Wilson]

- thanks for the link !

[Malcolm H]

> Which is a 230v CFL, with internal dimmer operated from any normal on/off

Thank you for that Andy. I have ordered one!

[Malcolm H]

Thank you for the info John. Yes I think it was my fault.

I have now ordered a Digiflux dimmable lamp (see relevant posts in this thread) and have removed my dimmer. As a matter of interest the warranty on the Digiflux is invalidated if used with an external dimmer!

[A.Clews]

Thus spake Malcolm H ( [e-mail]) unto the assembled multitudes:

There is a DigiFlux CFL dimmable from a standard dimmer switch, so no need for you to change your switch:

[Malcolm H]

Yes thank you Andy I had noticed that, but it was cheaper to change the switch.

[The Natural Philosopher]

What I want is low energy lamps with a BRIGHTENER!!!

[Chris Hodges]

Unless your whole house is lit with 100W lamps, just buy the next size up - 4:1 is about right compared to normal pearl, 5:1 is relative to soft tone. Of course if you want it to have warmed up by the time you've taken your hand off the switch that's a different matter.

[Steve Firth]

How the fans of CFLs fool themselves. I've fitted 24W CFLs supposed to be equivalent to 100W incandescent bulbs. The light from them is about the same as I get from a 15W incandescent bulb.

[Malcolm H]

A modicum of hyperbole I suspect!

[The Natural Philosopher]

With some, its not far off.

I run 25 watters here to get about a 40W illumination level

[Owain]

or use more of them.

[Andy Hall]

I've found them to be suitable for exterior use in lanterns, but that's about it - nothing inside. Too dim and the sickly light.....

[meow2222]

Maybe time to try another brand.

NT

[nog]

---------------8><

Measured how?

[The Natural Philosopher]

By my abilty to actually see teh keys on this ketboard.

[A.Clews]

Thus spake Andy Hall ( [e-mail]) unto the assembled multitudes:

Has anyone tried LED lamps? I bought, as a trial, a couple of GU10 LED spotlamps to fit in a five-unit ceiling fitting (the other three units are GU10 CFLs). They give quite a bright output for only 1.2W consumption each (the CFLs are 7W consumption). They are rather more directional than the CFLs (not to mention having a rather 'cold' quality to their light). For me, the jury's still deliberating...

[John Rumm]

That seems to be the general consensus at the moment, cold and directional. OK for feature lighting perhaps. The other point to watch is the LEDs are driven hard in this application, so the life expectancy is not good (especially compared to what you normally expect for a LED). One of our clients has a shop front that used a whole bunch of these for wall washers, where they actually wanted the slightly blue effect to match their other feature lighting. After as little as six months some of the individual LEDs in the lamps were failing.