Bucking 14500 down to 3.2-3.5v @350ma. Driver suggestions PLEASE.

Hi folks.
I decided on a host.

Now I need a driver.

I'm not advertising mind you (DM51) and as a matter of fact, I would prefer not to link to these at all, but emitters vary so widely.
I feel that since this isn't some LED that there are a million threads about (which would allow me to just search)
and since the power requirements are outside the range normally detailed.

http://www.dealextreme.com/details.dx/sku.13458
yeah.. it's a DX link

So I'm poor

Do you folks have decent ideas for a buck for a single L-ion?

I would like to run it off a 18650.

I've applied 3.8volts to this led for a couple of seconds with no damage, but would like to stay around 400ma max.

is there a 2 mode that does 400/100 or something?

malkov has a low-low P60 so why not a low-very low straight body 18650 light?


like this
http://www.dealextreme.com/details.dx/sku.15341

I can always recycle that Q2 and driver with a P60 empty module and sell it for $18 or so anyway.

driver? anyone?
[email protected]

and obviously I see the title differs from the subject matter
14500 or 18650 duh....

I was looking at the 18650 light as a way to simplify the driver selection.
I know the small drivers are hard to find.

I'm guessing I'll need a 16mm board to go in there?

anyone?
let me go look around for info on that light.

search... here I come.....:sigh:

So - the lowest cost approach is a 2 ohm resistor. It's cheap, effective, reliable, quiet, doesn't emit RF noise, readily available, and dependent only on you. Less than a buck - how can you go wrong?

It's not perfect, but over the portion of the discharge cycle of the cell you will actually use, it is plenty good. What does that mean? - well - the light output is a heck of a lot more consistent than most any off-the- shelf incan light you buy for less than $ 100.

Make sure you have a good heat path from the LED to the flashlight walls.

Good luck and have fun.

gratewhitehuntr said:

Hi folks.
I decided on a host.

Now I need a driver.

I'm not advertising mind you (DM51) and as a matter of fact, I would prefer not to link to these at all, but emitters vary so widely.
I feel that since this isn't some LED that there are a million threads about (which would allow me to just search)
and since the power requirements are outside the range normally detailed.

http://www.dealextreme.com/details.dx/sku.13458
yeah.. it's a DX link

So I'm poor

Do you folks have decent ideas for a buck for a single L-ion?

I would like to run it off a 18650.

I've applied 3.8volts to this led for a couple of seconds with no damage, but would like to stay around 400ma max.

is there a 2 mode that does 400/100 or something?

malkov has a low-low P60 so why not a low-very low straight body 18650 light?


like this
http://www.dealextreme.com/details.dx/sku.15341

I can always recycle that Q2 and driver with a P60 empty module and sell it for $18 or so anyway.

driver? anyone?
[email protected]

Click to expand...

700mA AMC7135 board with one chip removed will give you 350mA.

The 2-mode KD AMC7135 board with two of its three AMC chips removed will give you 350mA/50mA.

LukeA said:

700mA AMC7135 board with one chip removed will give you 350mA.

The 2-mode KD AMC7135 board with two of its three AMC chips removed will give you 350mA/50mA.

Click to expand...

I got to wondering about that.

I'm wondering if the voltage won't be too high?

or is it close enough?

BTW, my asherical WF500 ROCKS !!!
R2, 7882, 1400ma, single mode, mounts on a scope.

That LED you've linked to at DX isn't going to be anywhere near as good as a Cree XR-E or SSC P4, are you sure you can't stretch to $5 for the emitter? About $5 will buy a 'U' bin SSC P4 bare emitter or on star, it'll also buy a Cree XR-E Q2 on a star.

The one you're looking at is a bare emitter, i.e. no star (which may or may not be a problem depending on your host) and you don't know how its emission pattern is going to work with your host's reflector. If you used a XR-E / P4 you'd be able to use standard drivers too...

I see challenges ahead that you're going to have fun with.

KowShak said:

That LED you've linked to at DX isn't going to be anywhere near as good as a Cree XR-E or SSC P4, are you sure you can't stretch to $5 for the emitter? About $5 will buy a 'U' bin SSC P4 bare emitter or on star, it'll also buy a Cree XR-E Q2 on a star.

The one you're looking at is a bare emitter, i.e. no star (which may or may not be a problem depending on your host) and you don't know how its emission pattern is going to work with your host's reflector. If you used a XR-E / P4 you'd be able to use standard drivers too...

I see challenges ahead that you're going to have fun with.

Click to expand...

yeah Crees are cheap
that's why I have handled a couple hundred between my lights and ones I've built for others

They are also efficient

they are also gettin kinda blah :sigh:


I've installed one in a 1xAA lighta and since I broke a prong off I decided to just direct drive it on a 14500

color is VERY warm

seems to be holding up OK

I soldered the base of the emitter to the pill
I also soldered the negative tab to the pill

I placed a temp probe on the negative tab (soldered to pill)
it never broke 100

I was kinda worried but it didn't feel hot to my hand and was even able to to touch it and it was only warm

same after 10 min run
adjusted D10 to similar brightness to watch for dimmming

no problems so far

maybe DX got the numbers wrong??

sorry, I haven't looked at it with the DMM yet for a better idea on draw, vf and such

wish me luck

did I mention this thing is mega warm?

oh jeez DX

I ordered two emitters from DX

I got two different emitters

the one I tried first liked 3.9v

the other one won't take 3.6

it turns angry blue




ok, so I think I might make a 123 killer

max v on CR123 is just right

Well

I think I may end up building my first "primary" light

wow, this is why I like building stuff

I never would have carried a 1 X CR123 light because the UBER BRIGHT kills them
I can d irect drive with a CR123

gratewhitehuntr said:

oh jeez DX

I ordered two emitters from DX

I got two different emitters

the one I tried first liked 3.9v

the other one won't take 3.6

Click to expand...

Exactly why I only buy LEDs I can spec the Vf bin - like a Luxeon. The small extra you spend on the LED is more than made up for in savings in driver simplicity.

HarryN said:

Exactly why I only buy LEDs I can spec the Vf bin - like a Luxeon. The small extra you spend on the LED is more than made up for in savings in driver simplicity.

Click to expand...

Right.

OK, I se your point.

Here is my current plan.

Direct drive from a cr123.
That will allow me to pirate the emitter and driver from the 1 x cr123 light and use them in a P60 or something else.

I started on this light so I had a better color tint to find blood and brass.

I reload and brass is pricey.

Like $.25 each for my 10mm.

Makes it expensive to lose brass.

direct drive from a cr123 should give 3-4 hours runtime.
or 1 hour as a battery drainer for 123s

Why not use a resistor?

Its the simplest and cheapest solution....