Help???

[yondermeister88]

So I am new here but thought I would give it a try before I do anything too stupid.

I have 3 of these: (See Linked Thread) - http://www.candlepowerforums.com/vb/showthread.php?t=199344

I got them on super clearance at Target :huh:

I would like to run a 3 Series LED system but I have no Idea what the Circuit board inside this thing is??? Can I use one or wire up a system of them to drive my 3xLED light, or are they too under-built for that?

I plan on using some Li-poly batteries that I have from my R/C stuff, if that makes a difference.

 

[Al Combs]

:welcome:

If I understand correctly, you want to put 3 LED's in the same light? To quote from the thread you linked to, "Since heat sinking is poor, I would not use it at maximum output for a long time." And he was just talking about 1 LED only driven to about half power (500 ma). Plastic doesn't make a very good host where there is heat build up. Also what would you use for optics?

OTOH, the light is so inexpensive it isn't risking much if it doesn't turn out the way you expect. Here's an inexpensive regulator that would probably work well with a LiPo cell. You'd need a reverse clicky switch for mode change. At full power it would be almost twice as bright on your existing LED. Again the heat build up would be a serious problem. You could only expect to get momentarily use on high power (1 amp). Then the 2 lower setting could be used continuously. I take it by 35% DX means 350 ma output. Which is less than the 500 ma the stock board delivers.

Good luck & happy modding :wave:

 

[yondermeister88]

Thanks For the Reply!


Don't worry about the heat, I have machined my own housing from billet aluminum with plenty of surface area. I also plan on using a thermal grease when mounting the LED's.

I have some leftover optics as well, that will work perfectly.

All I want to know is what those boards are and do? I have already used a "bread" Proto-Board and wired it all up using one of the "scroll" boards and a 3-cell 11.1v battery. It all worked fine.

I am just curious if anyone knows knows more about the boards than I already do? Will one be OK for extended use? If I do fry the board do I run the risk of damaging my LED's.

I am just experimenting and thought I would try using what I have before Buying anything else.

Thanks Again for any Help!

 

[Al Combs]

Sounds good.

The type of board typically used to drive LED's is called a constant current regulator. When you drive multiple LED's from one driver you want them in series. Since current is everywhere the same in a series circuit, that will protect the LED with the lowest forward voltage from being over-powered. The regulators you have won't be very useful. Even if you could fit all three board assemblies in whatever light you are building, it would still only be 500 ma output. A Cree XR-E at full power requires ≈ 1 amp. It is OK to parallel regulator inputs assuming you have a battery hefty enough to drive them all. Here is the driver board list you'll find very helpful. Three XR-E's in series draw ≈ 11.1 volts @ 1 amp. If your battery has higher voltage than that, you need a buck regulator. If less than 11.1 volts, you need a boost regulator. The Shark or the MaxFlex (see driver board list) are two excellent boost regulators.

The linear regulator I previously linked to will be no good in this case. There was however an excellent thread by CPF member Download you might want to look at. Only linear regulators work in this setup since their input and output current is almost identical. The $3.60 AMC7135 16 mode driver I linked to would work fine here. The idea is it's the regulator's input side that gets wired in series with the other two LED's. That way the regulator is only driving one LED and not all three.

 

[Al Combs]

If I do fry the board do I run the risk of damaging my LED's.

I forgot about you other question. I'm not really sure what happens when your regulator blows. I suppose it would depend on the design of the board. My guess is an open circuit instead of a short. So the LED's would be fine.