Thread: low voltage light dimmers.

Now I feel like I'm back at work, someone has just started talking all dirty about sine waves and thyristor trigger points.......
I'm gunna go and find some nice friendly splinters to play with

I changed out the 12V downlights when we moved into our house. Four in the bedroom, four in the kitchen, all had 50 watt globes.......changed them all to 240V GU10 downlights (exactly the same size as the 12V). They look like this


Used four warm white 7 watt Megaman compact flurescent downlight globes in the bedroom. Slowish to come to full brightness but fine for this room - saved about 220 watts I reckon.
They look like this


In the kitchen, we are using two 11watt Megaman CF lights and two 35 watt halogen globes that have the same output as a 50watt. The halogens go over the critical work areas while the CF's are more general because they are slower to light and have a much wider light beam. Although you can get reflectors (different light fitting) that help focus that broad CFL beam down tight to 50 degrees (same as the halogen).

And there are dimmable CFL downlights these days. However, they are expensive and the dimming action is step-wise. I think there are four steps between zero and flat out.

If I were building/renovating (which I am) then I'd switch to the PL/PLC form of compact fluro light in the work areas http://www.cromptonlighting.com/cat/...?subcat=6&id=1# the fitting are more expensive but the light is good (just like normal fluro) and the globes are cheap.

Yep ... depends on if you use the old style transformers or the new mini switchmode tx's.

Hi SBD thanks for all the info, those 240V GU10's what wattage are they?

Typically, the 240V halogens can be had in 35W and 50W.....there are typically two versions of the 50W - one which has the same light output as the 35W and another with high light output. http://www.cromptonlighting.com/catb...=6&page=2&id=#

The Megaman CFLs can be had in 7W, 9W and 11W, each with three different colour temperatures (coolwhite, daylight and warmwhite)....no idea what the lumen output is!

So all the new gear is 240v? You'd need new fittings as well then, obviously not just a matter of switching globes. 12v Halogens are about $20 ea. with the transformer. How does that compare to what you put in?

Originally Posted by silentC

So all the new gear is 240v? You'd need new fittings as well then, obviously not just a matter of switching globes. 12v Halogens are about $20 ea. with the transformer. How does that compare to what you put in?

$9 for the 240V fitting http://www.neco.com.au/product.asp?pID=94&cID=10, $23 for the Megaman GU10 CFL globe http://www.neco.com.au/product.asp?pID=168&cID=47 or $4 for the GU10 halogen globe http://lightingpro.com.au/catalog/pr...7cec3432f97d4d

There is a really good article about this very topic in the latest Jul-Sep 2007 issue of ReNew Magazine pp20-23 www.ata.org.au

Thanks. Looks like you can just buy the adapter as well, it will probably work with the existing housing that I've got. http://www.neco.com.au/product.asp?pID=139

Might get a couple and try them out.

I've heard that Halogen lamps don't like running at less than full brightness. This bloke offers a fairly good explanation as to why.
http://members.misty.com/don/bulb1.html

Another way to get the "mood" right could be to use a couple of floor standing "up" lights. Just the basic model without an inbuilt dimmer, chuck in a 5w warm white CFL's and you're done (works for me anyway).

Originally Posted by silentC

Thanks. Looks like you can just buy the adapter as well, it will probably work with the existing housing that I've got. http://www.neco.com.au/product.asp?pID=139

Might get a couple and try them out.

Yeah you can.....but the adapter costs more than the entire fitting. And it is the same thing that's in the new fitting So you're better off buying the entire fitting, removing the wiring bit and tossing the alloy in the recycling if all you want is the wiring

The 12V and the 240V fittings themselves are EXACTLY the same. The alloy bits I mean.

And your local lighting shop will have them so you don't have to buy over the internet if don't want to.

If you have a fixed 12V downlight then just grab a fixed 240V downlight, same goes for the gimbal version.

Just make sure you don't have a gimbal version and try and replace it with a fixed version. The holes in your ceiling will be a different size. I know this from experience.. ...however, I managed to make a series of bastard versions (based on old and new) that looks just fine

They show the prices as $8.95 for the whole thing and $7.95 for the adaptor, unless I'm missing something.

But for $1 difference, I might as well buy the whole thing and sell the 12v ones with the transformers at a garage sale.

Originally Posted by silentC

But for $1 difference, I might as well buy the whole thing and sell the 12v ones with the transformers at a garage sale.

I'll give you 50c each for the lot.

Yeah OK but there's a 4000% buyer's premium attached to this sale