DIY led chip ringlight battery powered

[TomStoff]

Hi!
Recently I was watching how to make portable (hot shoe mounted or camera bolt) ringlight battery powered. So without thinking i Bought on amazon 20 pcs of 10W LED chips and 10 aa battery case. Is it built quite easily a ringlight which can be AA battery powered? My electrician friend says - that the current is to high and the batteries will fry - the same as chips - beacuse they don't have cooling system. What i wanted to do - is to attached the LED chips to plywood and make a plug for battery case and mains powered. Any ideas?

Thank You
Tom

 

[Canon Bob]

Without any form of switching or control then you're going to be drawing about 16 amps from your supply......about 8-10x the normal, continuous limit for typical AA cells.

Bob

 

[TheBigYin]

I used to make DIY mountain bike lights from the cree LED Emitters a few years ago (before the chinese started knocking them out for £30 including a battery pack...) and the big problems with using multiple emitters was handling the current regulation and providing adequate heatsinking. IIRC they require something like 3.7v at up to 1amp - a 10xAA case will be chucking out between 17v (with fresh Duracells) and 12v (with cells around a hour old...) Normally, you'd use a voltage/current regulating circuit to drive the led's - i'm a little out of touch with whats available these days, but basically these circuits take a DC voltage of between 8 - 20v, and output a regulated level of current/voltage suitable to drive the emitters... They often also provide different levels of (iirc) current output (by switching the current on/off really quickly) to "dim" the emitters from "full on brightness"...

What kind of emitters have you bought ?? Not that I'm likely to be able to come up with any suitable circuitry BTW, but without knowing the type of emitters you're using, it's difficult to even point you in the right direction...

personally, I think you may be as well asking your question on one of the DIY LED light forums - the only one that I can remember off the top of my head was http://www.candlepowerforums.com/

 

[TheBigYin]

one of my "fugly" bike lights... in pre-assembly test...

Another Bike Light by The Big Yin, on Flickr

each emitter had a chunk of aluminium as a primary heatsink, which was thermal epoxy bonded to the case (also ally) as a secondary heatsink... if the case didn't start to get warm as the ligh was switched on, there was something wrong and it was a case of "quick, switch off the power NOW". Notice that the emitters had different lenses - one clear which had a longer narrower throw to the beam. and the other a hexagonal patterned diffusion grid on the front, which gave quite a nice spread to the overall beam...

directly after the emitter, via the red/black cables were the current regulator disks - in this case I used a seperate regulator for each emitter because they were fairly low current versions designed for use in flashlights... the cables then go from the regulators, back into the "breadboard" where a switch and status led were mounted (the breadboard was eventually made smaller to fit inside the rear cap of the case... from the switching circuit, the wires came out - in this case direct to a 4xAA rechargeable pack - 6V, though the lamp would work at anything between 3v and 9v - the regulators basically just drawing more current on the lower voltages - so it made sense to have as large a voltage battery as the regulators would cope with...

Assembled - rear plate...

Wall-E by The Big Yin, on Flickr

And from the Front...

Easy DIY Bike Light by The Big Yin, on Flickr

god-awful photo's I know - this was before I got back into photography again, and they were really just record shots...