Driver for one P4 off 3xAA Alk

Hey guys...

What drive board would work best for a lone P4 off of 3xAA batteries?

I'm looking for a simple on/off driver board, no fancy three-way level settings.

Thanks!

all info here is based solely on the specific configuration mentioned, none of this information i put here, applies to less or more voltage of battery.


i donno, how about a fatman?
http://www.taskled.com/fatman.html
BOOST, wants battery to be lower than voltage of led.

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then this
https://www.kaidomain.com/WEBUI/ProductDetail.aspx?TranID=3150
boost
RammerJammer

but ya know for 3XAA alkaline or lithium, almost EVERY one of these drivers listed at being able to handle 4+ volts on the battery side are RammerJammer curcuits.
https://www.candlepowerforums.com/threads/179551
see my dafynition of RammerJammer in this thread scroll to the pics.

http://www.dealextreme.com/details.dx/sku.6190
this same thing with PWM levels, rated to 4.5 probably still a rammerjammer
boost
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then there is http://www.dealextreme.com/details.dx/sku.1886
which is a hedgetrimmer, if you have enough input voltage
this would never cause an overdrive situation, but you will still end up with a dwindler because it cant BOTH buck and boost.
This would be OK with enough voltage, so need to know what kind of 3AA Lithium???

current trimmer, voltage wacker

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http://www.dealextreme.com/details.dx/sku.7425
this , high voltage curcuit, falls out of regulation at around 4v, wants 4 not 3 cells.
http://www.dealextreme.com/details.dx/sku.3256
this too

almost every one of these type of drivers falls out of regulation when the voltage on your 3X AA battery goes lower
these make good Dwindlers

Buck style
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http://www.dealextreme.com/details.dx/sku.4735
buck boost, that sags more than a battery
ifrom the data the users provide it looks like Boost only

limpey or rammerjammer, depending on who reviewed it, or wired it? or which item was sent
they got it into a hard overdrive with high voltages.

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http://www.taskled.com/d2dim.html
IF all the curcuits are going to be falling out, or direct driving at some point anyways
then for a single led, might as well put control on your DIRECT DRIVE
this would work with 3xAA alkaline or ni-mhy but not lithium and one led

PWM control only max 3amp

would be RammerJammerDwindler untill you add a bit of resistance, then a dwindler

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its gotta be something from Dat2zip, or the sandwitch shop, they probably have something.
http://home.comcast.net/~theledguy/cpf_store/converters/converters.htm

http://theledguy.chainreactionweb.com/product_info.php?&products_id=327
Mad max
boost from 2x AA (not 3)
in your configuration this would be a Mad RammerJammer

the wizzard, if i remember right would bend both ways.
http://theledguy.chainreactionweb.com/product_info.php?cPath=48_49_61&products_id=920
wizzard replacement GD500 Buck/Boost Converter




http://theledguy.chainreactionweb.com/product_info.php?cPath=48_49_61&products_id=1004
the SOB
""Will operate in DD mode when Vin is less than Vout (Vf).""
Dwindler, would be ok falls out of regulation

http://theledguy.chainreactionweb.com/product_info.php?cPath=48_49_61&products_id=721
SHARK
boost (or step-up)
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the only reason i am pointing this stuff out, is because your input and output voltage match sorta needs a Boost&Buck curcuit to do its FULL range of voltages, any one of these things would "work" and work ok. but a good Direct drive (resistered) matchup would work and have less loss going into some chip. and it would treat the batteries better.
that is all i am saying, i am not trying to knock anything, just trying to understand it.

Thanks VidPro - so you're saying, the long and the short of it is... it'd just be better to user resistors?

yes , but i did find you one that would stay most regulated, it just took more seeking.
the one in bold, the wizzard was really popular before too, because you could mod it around a bit. and because it did handle this configuration.
i have NOT used it myself.

and that clipper from DX is reasonably priced "glorified resister", it would only have a .12V drop acording to Torch boy.
once i learned more about it, i realised it doesnt loose that much. it will clip the too high voltage off only when its to high.
it just wont keep full drive going when battery sag.

you did not tell what kind of AAs you would be using, because:
Alkaline AAs will sag all over the place, no mater what driver you put in, if you try and pull higher current when the voltage is down, they will just sag down more. so a device that maintained fully regulated current control, the alkalines would still choke, low runtime. they can regulate themselves from battery weakness some.

Ni-MHY AAs would maintain under the load, and keep thier voltage up, and would have far less voltage droop occuring

Lithium AAs would have much high voltage, maintain 4.5 volts for much longer and less droop, lithium AA in one of them low voltage drivers could stay in overdrive very long.
lithium AA will have a battery voltage well over the led voltage for a longer time, Buck or clip works there as long as the buck doesnt have huge losses.

its all about Where did you want to go today to some runtime is very important, to others they insist on harsh regualtion, to others the huge overdrives are like WOW, course sombody forgot to tell them 1.6-2AMPs is why
some dont want to fork over $2 for a dang battery, and some would rather "invest" in power and use rechargables.

Post deleted
nevermind, that was right, , to many numbers.

Haha, well for AA I have a few choices - I have standard Alks and some 2500 mAh NiMH batteries. I suppose I should start using the NiMH batteries for my light applications, yeah? Also, I'm trying to figure out if running direct drive on the 3xAA Alk killed one of my Seoul P4s...

probably
the problem with the Seoul is, if you had to "isolate" the dang base, the tiny thin layers of psudo heat transfer .

over TIME the Vf of an led can go down, that must be put into the DD equasion, and so the setup initially should be close to spec, then when the voltage drops over time, it will go into overdrive without help.

and heat is a biggey, if you can keep the heat off, you can drive hard, if you cant you cant even drive spec.
i smoked a in-air star in an amasingly short period of time, and water dunked a led for huge overdrive that it didnt bother it.
after those tests, i figured heat is more of a major factor than i thought. before.

even 3 alkaline Dcells had a hard time burning up the old luxIII x3, the modamag direct drive compatability chart showed all that stuff, but that is sooo old news, once drivers became a 'dime a dozen' the DD usage went down, it wasnt fasionable still with some really great alklines, and the right temps and all, it could do it.

on the other hand if you looked at some of them reviews on the drivers i posted , 2-3AMPS going to the led, when they thought it Was regulated

i think with the seouls special isolation needs, that a driver might be survival. and the right driver will actually keep out of overdrive.

another correction in bold.