Complete newbie needs some basic guides/information/tutorials

Hi Guys,

I've only very recently gotten interested in making custom lights (I got into it trying to make myself a night riding light for my bike!).

Although I have made a reasonable light myself by just using a pair of MR16 LED replacement bulbs and a 12V battery, I realized that to make something a bit better I would probably need to delve into deeper territory.

What I am specifically interested in is information about how to actually power an LED emitter, for example a SSC P7 C-Bin LED Emitter.

The tech specs indicate that it runs on 3.6-3.7v, and draws 2.8A of current. This is where my knowledge of electronics runs pretty dry. I assume I need to find a constant current driver (?) which will provide exactly 2.8A of current to the emitter (at 3.7v). Or can I just hook it up to a 3.7v battery (or a couple in parallel) and be done with it? If I can't find a driver to give the exact voltage and current I need, is it possible to have them in parallel, for example have 3 * 1A drivers in parallel giving 3A of current?

I also have read that high power LED's need a heat sink or they overheat, anyone able to shed a bit more light (no pun intended) as to what size/shape/etc heatsink I would need, and how to attach it?

Ideally if there is a tutorial somewhere showing exactly how to (for example) convert an old flashlight into one that uses a SSC P7 emitter, showing step by step what needs to be done, and an explanation, that would be ideal.

Thanks!

Moved to Homemade & Modified Flashlight Discussion.
Norm

I'm also very new here so take everything I say with a grain of salt. www.dealextreme.com is your friend.

http://www.dealextreme.com/p/regula...ree-mc-e-ssc-p7-emitters-8-4v-max-input-20330

I'm still waiting on a tonne of gear I ordered from DX so my actual practical experience is zero. However if you hook a few batteries up to obtain the right voltage for an LED, and connect it all the LED will light up - but I only do this to make sure it's working and never for longer than a few seconds. Also don't look at the bloody thing when you do it lol! My brother and I learnt the hard way.

No idea about heat dissipation yet, but I am building a flood light with Cree XM-L T6 LEDs at the moment (common drivers get here already!!!!) and a few pro's on these forums have kindly informed me that an old AMD CPU cooler, with the fan still attached as active cooling "should" be enough to keep 2 of them cool. This is at their max 3A rating that is.

Again - grain of salt etc. I'm sure someone infinitely more knowledgeable than me will round soon.

Good luck!

"The search bar is your friend, bla bla bla bla bla"

Although I prefer google searching "LED STUFF:candlepowerforums.com" because it has no 30 second timer and it always seems to find more relevant results.
Short answer for your broad questions...

Driving directly from battery is called, well "Direct Drive" and it is very possible, often with a low value resistor that is 1-2 watts strong. Problem with direct drive is that as your batteries sag, so does your LED current
http://www.candlepowerforums.com/vb/showthread.php?227077-Direct-Drive-P7-M-g-Experience

Drivers can be stacked in parralel, although there are several that have the correct params for a P7.
http://www.shiningbeam.com/servlet/the-132/3-dsh-Mode-Regulated-Circuit-Board/Detail

Heatsinks? Yes
Material? Aluminum
Size? How long do you want it to run? Anywhere from a half dollar disk that thermally connects to the body to a 3" diameter 2"+ long slug
Shape? The LED doesn't care, whatever shape fits in your host.
Attached? Thermal epoxy or thermal past and some sort of mechanical attachment IE screws or bracket.

Search "tutorial" "step by step" or "whatever"
http://www.candlepowerforums.com/vb...o-Mod-a-Maglite-P7-38-PICS&highlight=tutorial
Direct Drive P7^^^

FYI DealExtreme is great if you don't mind waiting three weeks for shipping. For a few dollars more you can source elsewhere and get it next week at the latest.

-B&C