Couple of questions about energy saving bulbs.

Yes, but not in the UK. It seems there is no market.

I used to buy them when I saw them on special offer, but seem to have built up a small stockpile so have stopped doing so for the time being since none of mine have died now for some years (and I'm pretty much all energy saving lamps everywhere for last 15 years or more).

I, too eagerly await 240 volt dimmable CFLs - the only mention of them online appears to be accross the pond.

B and Q seem to be quite competitive for mini spirals at £2.99-ish

Jeremy

I bought a couple of bulbs through SWEB a couple of years ago that would operate on two settings. Turn on and it works normally (18w?). Turn it off-and-on again and it operates on half power. Ideal on the landing where the children demand a light on all night.

Colin

How odd...

Mmm. What's a good price for generic BC 40W and 60W incandescent replacements for candle and standard respectively?

There is a market. What there isn't at the moment is a control IC that can handle the more complex voltage pulses from most dimmers. I believe STMicroelectronics have a 230volt version in development.

There are ways to dim standard cfls, but they dont involve standard dimmers.

Really a switchbank is a much better solution than dimmers though, it might be better to fit one of them.

What do they do? Fit 2 (or more if you want) bulbs in 2 skts, switched by a 2gang switch, and you have 3 light levels. 3 bulbs gives... a lot. Lights should be fitted this way from new: retrofitting means running an extra core, sometims easy, often not.

You can also dim cfls if you open them up, or for the unusually determined, you can use a variac to dim them.

The good news is theyre such low on power that mechanical shading is also an option.

NT

please illuminate us :-)

The 9 watt lamp I just fitted to my pushbike is currently only taking 4 watts on the camping light invertor and I'm trying to understand how to tweak it ....

is there any mileage in over-volting fluorescents ?

Jeremy

You need to change the mark/space ratio of the tube drive. Best bet for this is to get one of the higher end ones (e.g. the ones that turn on slowly or those with a dusk light incorporated) as these often have a common micro inside that can be replaced with your own code.

Probably only a little before burn occurs. Why not just get a slightly bigger one ?

... or maybe change the timing components in the cruder type of ballasts ?

I think what I was getting at is :- do different designs of tube have different impedance characteristics ?

Thinking about it, the T8 linear tube my invertor was driving is quite different in terms of diameter and length.

I will today be ordering a Maplin twin 8 watt camping light in the hope that it will drive one 9 watt mini-spiral correctly.

failing this I will have to deal with my phobia of winding inductors .

Jeremy

then either its not being supplied with the needed v and i, or its faulty. Why not use a 12v cfl?

yes lots, but you cant do it by overvolting, you need to change the ballast. Sci.egngr.lighting will tell you how to put 2x or 4x rated power through fls.

Cfls have less room for boosting, but still some. Note efficiency falls, so 2x power gives say 1.5x output, not 2x.

NT

I only decided to give it a go when I saw how compact mini-spirals were - and even then I've removed the ballast and made it even shorter.

Unfortunately in the usual IR simple 2 power MOSFET design, it will still tend to keep mark/space ratio the same.

Yes. In fact thinking about what you are after one of the r.f. energised tubes may be your best bet.

May be too low a frequency for your light to run optimally

You can buy them already wound. Several good Chinese and Japanese makes.