Tiny driver?

Looking for as small of a driver as possible that can provide 3a of current for a XML emitter. Any help would be great.

What would be the supply voltage to the driver?

That could be flexible but I would say 1-3 lithiums more than likely depending on the need of the driver.

You need to give more details to get an answer. "small" ? How small? Dimensions in mm?

how about no driver (direct drive)?

hanachan said:

how about no driver (direct drive)?

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:devil:

Hearing "tiny" and "3A" in the same sentence makes me cringe.
I hope he's trying to jury rig an XM-L into something with lots of mass, otherwise

Ok the details..... I am trying to mod a penlight like a 2xAA or 2xAAA size that you would slip in your shirt pocket with a pencil or something. It will get very limited usage and is only ever really turned on for a few seconds at a time to inspect something. I really just want a tiny light that cranks out a ton of light to get some reactions from my coworkers. They have already seen my maglite mods that go 1000 lumen and I want to condense that same idea into the smallest possible package. I would thermal bond the driver directly to the inside of the housing and with only running it in short burst it will not get hot. The criteria on size is really just as small as I can find and I will then find the smallest housing that will accommodate that driver as it is going to be the largest piece of the puzzle more than likely. I can find cells to fit pretty much any application.

I do not know enough about direct drive right now to try and tackle that. I get the concept but that's about it.

some math: xm-l at 3 amps is around 3.35 volts. for a total of 10.05 watts. under heavy load lets assume 1.1 volts per battery so 10watts/2.2volts = 4.5 amps drawn from teh batteries. but lets go back a second and assume the driver is 83% efficient (easy number to work with). that means 12watts input and thus 5.5 amps input. good AAs can do this (but it is hard on them) and AAAs can't come anywhere close, they might do 1-2 amps.

smallest driver i have seen* is 14 and 15 mm (fits inside a 2xAA minimag) but those are only rated for 0.75 amp or 1.5amps at most. you'd have to get a few of them (2-4) in parallel and that adds a lot of volume to this supposedly small light, bringing it from teh size of a 2 AA light to a 3xAA light.

you might be best to get 3xAAAs and direct drive an XM-L (although this coudl harm/kill the LED, i havnt tried it)

have you tried inspecting such and item with your 1000lumens light? do you really want/need that much light? i'd expect it woudl be way to much if the object of inspection was close to you. if it is close up inspection, have you considered a 1xAAA light? they are pretty good for stuff thats 5 feet or less away from you.

*apperently DX has a few 12mm drivers, but as discussed AAAs wont be able to put out the power needed.

Well your standard AA or AAA might not provide the punch needed but their lithium counterparts will. Especially the AW cells.

how much current can AW AAA lithiums cells provide? maybe just run one of those direct driven? (maybe thats a bad idea, i don't know lithiums too well)

I suppose if you don't need modes you could stack a bunch of AMC7135s up (4 or 5) for each of 2 batteries (in parrallel).

if you havnt yet, you coudl take a look at the driver database and see what you cna find
http://www.videofoundry.co.nz/ianman/laboratory/research/driverlist.php

yazovyet said:

how much current can AW AAA lithiums cells provide? maybe just run one of those direct driven? (maybe thats a bad idea, i don't know lithiums too well)

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They're lithium-ion, not lithium, but yes, that's probably a bad idea. It might be viable for short bursts only, but any sort of continuous use (10s of seconds at a time) would be dramatically overloading the cell. Could theoretically be as bad as venting-with-flame, but in practice 10440s abused like that probably just die peacefully after only three or four cycles. .

If you want a AAA-ish sized Li-ion cell that can handle high current, look into the 8mm round li-poly cells used in e-cigarettes; I know hobbyking has bare cells available, rated at 15C discharge.

For 38mm long (smaller than AAA), it's 180mAh, so you could run up to 2.5A; some single AAA lights might be adapted to take a 8x52mm cell, which gets you up to 270mAh, or 4A continuous; and 2xAAA lights could take either two 8x38 (in series or parallel), or one 350mAh 8x75mm cell -- either way handily exceeding the power requirements of a single XM-L and letting you get runtimes over 4 minutes...

An advanced configuration for a 2xAAA would be 1 8x38 and 1 8x52 in parallel (not series -- that's how you make a bomb) to get 450mAh, but I wouldn't recommend it -- you're probably better using the extra space for an AMC7135 driver and a quick-connector so you can easily remove the battery and charge it.

Have you tried setting up a three XML cluster and ran it at the current your specifying? The intensity is so excessive that it is unpractical for anything except search & rescue or area flood light, both of which could be better implemented with better battery/driver combinations.