Urgent - What can I build with these?

I need to build a custom flashlight of some sort for my Dad's birthday (he knows about my LED/flashlight obsession and just told me he wants me to build him one), and I'm seeing him in 3 days. So that kind of rules out ordering supplies unless I can get really fast shipping. I have lots of XRE Q5's on stars, a p7 on a star, those amc7135 1050mA drivers from DX, and that's about it right now. I was thinking I could do a 3D mag mod with an xre and the 1050mA driver, but D alkalines can't really handle that kind of current draw, correct? What if I de-solder one of the chips and make it a 700mA driver? Could alkalines handle that? Or should I just put the p7 in there and direct drive it?

It doesn't even have to be a mag mod, just something that I modified. What have you guys done with similar supplies?

Any suggestions welcome.

AMC are 6v max that means 4 alk cells.

1 amp should be just fine in cells that large(c or d)

What about a heat sink? Without that you're stuffed !

UberLumens said:

1 amp should be just fine in cells that large(c or d)

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I agree, ~1.5 amps is about the upper limit for alkaline C's IMO.

1 amp from alkaline D's shouldn't be a problem - some capacity is lost at that high of a drain rate, but it's still reasonable. They can provide ~6-8 Watt-hours at a one amp load, per data in the Alkaline Battery Shoot Out thread by Silverfox - slightly more than good NiMH C's.

If you have a heatsink, I would suggest modding one of the boards to step the current down to 700mA for driving a single XR-E from 3 D cells. The cells could handle the higher current (I have pulled 1.3 Amps from them), but the slight increase in light is not worth the large decrease in run time IMHO. You could also get 4 C cells in a 3D mag, but the D cells will give you more run time by far.

You will want to mist the stock reflector (cut down of course) with clear-cote to get rid of the Cree rings.

:fail: I forgot about the heatsink. I guess I'll have to tell my dad that his present will be belated.

I think I will do a 3D XRE with one amc7135 removed for 700mA.

Thanks guys

You can use a copper pipe endcap as a fairly good heatsink if you want to get this to him in time and don't mind about aesthetics. Since you're only planning to run the XR-E at 700ma it should be good enough for your purposes:

https://www.candlepowerforums.com/threads/293906

That's a great suggestion. You won't even see the 'ugly' parts of it because it will be hidden by the reflector. :thumbsup:

Really?? A copper endcap will fit snuggly into the mag host? I feel like I've tried this before and they were the same diameter. I'll have to try it again.

andersonEE said:

Really?? A copper endcap will fit snuggly into the mag host? I feel like I've tried this before and they were the same diameter. I'll have to try it again.

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There isn't an exact size that will fit (unless you find one that's for 1.125" size pipe instead of 1.25"...) but it doesn't take much work to get it to. The process is explained in the thread I linked to.

mudman cj said:

That's a great suggestion. You won't even see the 'ugly' parts of it because it will be hidden by the reflector. :thumbsup:

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Exactly.