Good driver for MC-E?

[The Rat]

Can anybody recomend a decent driver for an MC-E? I am building a desk-light for my office, and I need a method of powering the MC-E constantly. The ability to dim the brightness would be nice as well. I am a Structural Engineer, but do not have much experence with circuits.

On the same note, what is a good driver for a XR-E, for the same application?

I have a large assortment of DC power adapters that I can use to power the LED Driver module if nessesary.

Thanks!!!

 

[steve6690]

What voltage and current rating is the adaptor you plan on using ?

 

[The Rat]

I have a 12V Radio Shack desktop power supply that can output 200 watts. I think it is regulated. This would be my ideal power source.

 

[Justin Case]

In a flashlight application, I've used an SOB1000 and an SOB1227 to drive an MC-E wired in 2S2P. I've used two battery combinations: 2xLi-ion (nominally, let's say 7.6V) and 4xSF123A (nominally, let's say 10V). The SOB buck board can handle up to 16V, so it should work with your 12V power supply.

At those drive levels, you should make sure that you devise an effective way to draw the heat away from the LED and from the driver board. The LED is demanding about 6.6W to 8W of power and dissipating most of it as heat. The board has to generate more power than that because it isn't 100% efficient. The board may dissipate another 1W-2W of power as heat.

 

[mudman cj]

You could power an MC-E wired 4s (all dies in series) using a Fatman driver with an external potentiometer for dimming control. That is a boost driver, so 12V input would be boosted to about 14V+ needed to drive the serial dies of the LED. The easiest way to wire the LED would be to use solder paste and reflow solder it to a star board set up for 4s connection. Then, just mount the star board to your heatsink with thermal paste and a couple of screws and solder your two circuit leads to the board. This configuration also requires the driver to be heatsinked, but this is not difficult either because the back of the board has a pad that just needs to contact a heatsink.

 

[bretti_kivi]

^^ what he said.
All of it.

Bret

 

[mudman cj]

Unfortunately, the XR-E will require a more expensive driver such as a Shark Buck from the Sandwich Shoppe. The Shark Buck will reduce the 12V input to the level needed to provide the drive current, and it also can be configured to use an external potentiometer for dimming control. You will want the 1A max version.

Of course, there is more than one way to achieve your design goals. You could save money by making a simple circuit comprised of a fixed resistor to limit the maximum current in series with a potentiometer for adding additional resistance to dim the LED. Circuits could be designed for the MC-E and the XR-E cases. In order to accurately predict the current limits we would need to know the Vf of the particular LED(s) you want to use. If you would like to explore this option further I would be happy to assist you in determining which components would be needed.