Powering 3 x Cree Q5 from 12V

[MrNaz]

I am trying to make a MR16 replacement. I am looking for a driver for the device, and was thinking of using this to power 3 x Q5 LEDs hooked up in series:
http://www.dealextreme.com/details.dx/sku.13557

Apparently it can drive about 540mA through the LEDs at 12V. I am about to buy some and I would like to get the opinions of people on this forum before I go ahead. My plan is to thermally bond three of these
http://www.dealextreme.com/details.dx/sku.11023

To a 50mm metal disc, and then bond a heat sink on the back, such as this one:
http://www.cutter.com.au/proddetail.php?prod=cut765

Does this sound like a reasonable plan, or are there problems with this that I just don't see?

 

[Greg G]

I would buy the WG tint instead. DX has them. WC is a very *cool* color temp.

I'm leery of cheap drivers. Since you're in Australia I'd get a TaskLED Nflex from Cutter. Top of the line driver. More expensive, yes, but you get what you pay for. If you buy the driver from Cutter, might as well get some R2 bin Cree's too. WG, WH etc. tint.

 

[LukeA]

I am trying to make a MR16 replacement. I am looking for a driver for the device, and was thinking of using this to power 3 x Q5 LEDs hooked up in series:
http://www.dealextreme.com/details.dx/sku.13557

Apparently it can drive about 540mA through the LEDs at 12V. I am about to buy some and I would like to get the opinions of people on this forum before I go ahead. My plan is to thermally bond three of these
http://www.dealextreme.com/details.dx/sku.11023

To a 50mm metal disc, and then bond a heat sink on the back, such as this one:
http://www.cutter.com.au/proddetail.php?prod=cut765

Does this sound like a reasonable plan, or are there problems with this that I just don't see?

In still air I don't think that heatsink will be effective by itself.

 

[MrNaz]

I'm also trying to keep cost down, as there are about 100 of these fittings throughout the house. That rules out the use of an expensive driver board. This is also why I would like to use that $3 part from DX, unless there is a good reason not to use it.

Pricing out the items:
3x Q5 emitters = USD20
Driver = USD3
Heat Sink = USD6

My main concern with that was the ability of the assembly to deal with the heat from the 3 emitters.

An alternative idea I had was to use a single MCE warm white emitter from Cutter (about USD18), although I can't think of a sub $3 way of driving that from a 12V source. It would be far easier to deal with the heat of a single emitter though, if I can find a cheap way of driving it. Any ideas?