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Driver for 1 X NiMH AA to put out 400 - 500 mA for BDR-205 diode? re-post

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Greetings fellow forum members,

I posted this inquiry in the driver section: http://laserpointerforums.com/f67/d...00-500-ma-bdr-205-diode-53582.html#post752885
but haven't gotten a response so I am thinking that I might have misdirected the post and this Bluray section would be more suited.


Being an RC Helicopter pilot I currently have a decent collection of quality NiMH AA cells that I use for my radios.

I am interested in using this resource to power a 12X BDR-205 build. I would prefer a smallish host and so I am hoping to learn of a driver that can give 400 to 500 mA current to the diode using a single AA NiMH battery.

Is there anything currently available premade that is up to this task?

I searched this forum for 'AA' and came up empty.

Anyone have any suggestions?

Thanks,

-Scott
 





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Boost converter that would boost from 1.2 to 5.5V with half amp current...
Damn, it'll be pulling A LOT of current from that poor battery.
Your best bet is to use two or three of those in series and use a regular Boost Drive or Flex Drive.

There are drivers for green lasers which work on 1x AAA , but I don't think they can boost up to 5 V even, and certanly can't give that amount of current.

Sorryz, but constructing something like that would not be simple...
 
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Jul 27, 2010
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1x AA is tougher. 2x AA and there's a bunch of parts out there.
I'm going to be doing a 200ma constant current switcher in the not too distant future,
but 3V input will be my lower limit.
 
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Thank you Eudaimonium, Markus Unread, and LazyBeam for the responses! Putting this post in this forum was the trick! ;)

Why not use a protected 14500 Lithium Ion?
Same dimensions as a AA and puts out 3.6V with good current output.
While it's $7, you can recharge it hundres of times. Totally worth it.

Protected UltraFire 14500 AA sized 3.6V Li-Ion Rechargeable Battery 900 mAh CR14500 Lithium Ion

Yes, this appears to be the standard move relative to trying to put together an AA sized host. My primary desire was mainly to be able to tap into the resources I already have (mainly a boatload of 2600 mAH AA NiMH batteries).
I am going to read up some more and will make a decision.

Thanks again for the responses! :thanks:

-Scott
 
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If you really want a 1.5V AA and NiMh can't output the needed current, don;t forget to try NiCad.
They have more current output at the expense of lower capacity.
 
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Or simply go with lithium ions like we all do :D

18650 can power a 12x at current of 400mA with boost driver for aproximately 4 hours (more or less, give or take an hour ).

Recharges in like 2 hours, unlike 12 or even 24 like NiMHs.
Can give up to 5 A with good life.
 
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Or simply go with lithium ions like we all do :D

18650 can power a 12x at current of 400mA with boost driver for aproximately 4 hours (more or less, give or take an hour ).

Recharges in like 2 hours, unlike 12 or even 24 like NiMHs.
Can give up to 5 A with good life.

Actually modern NiMH AA cells can be charged in 15 minutes with the right thermal-control type chargers.

I'll probably end up going with a 14500 option.
icon14.gif


-Scott
 
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Actually modern NiMH AA cells can be charged in 15 minutes with the right thermal-control type chargers.

I'll probably end up going with a 14500 option.
icon14.gif


-Scott
Charger for NiMH I have right here, for AAA, AA, and 9V bricks, has a selector switch for 12 - 24 - 48 hours charge. I hate it.

Didn't know you can charge them fast but general rule is , slower you charge them the longer they last...

Did I mention that you do not need to strickly obey the cycle of lithium ion batteries? You can charge them and discharge they however you want, no need to drain them dry to put them in charger. That's what I love about them.
 
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The rule with new the lithium ions is drain 20% (its always stated 80% total capacity) you can use it and charge it for 5 years. Drain 50% it will last 2. Drain it 80% and it will last a few months to a year.

Same goes with phones and laptops. This is why people are always killing them and wondering why it won't hold a charge.
 
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Charger for NiMH I have right here, for AAA, AA, and 9V bricks, has a selector switch for 12 - 24 - 48 hours charge. I hate it.

Didn't know you can charge them fast but general rule is , slower you charge them the longer they last...

This really is somewhat of an urban myth. What is required is a charger that properly senses termination. In fact, at lower rates, most all but the best chargers do miss termination and cook the battery. Alternatively, a simpler method is a timed charge at 1/10C for ~14 hours, which is probably what leads people to believe it is best to charge them slow.

If possible, check the white papers for your particular cell, but normally it is no problem to charge at 1C, oft time better than that. Especially with a quality charger such as Maha C9000.

2 excellent sights to educate yourself on proper care and feeding of batteries are How to charge Nickel Metal Hydride Batteries. and Welcome to Battery University

I would especially suggest reading the safety concerns regarding li-co cells such as the 14500 linked above. I most certainly do not suggest not strictly following protocol there. Too high a discharge rate, missed termination and too fast a charge rating, reverse charging (in the case of multi-cell applications) improper storage can all lead to explosive venting with flames. There is a significant amount of energy stored in these batteries and deserve respect. I have seen many pics and vids, though luckily no first hand experience with such. I did have a short that I managed to curb very quickly and the metals were hot enough to instantly blister my fingers and char a small spot of skin.

The protection circuits included on the cells that many of us are using are there to insulate us from those dangers, but remember they are quite cheaply made, and also pretty sensitive to shock, crushing etc. So, while a protected cell is better than non-protected, a wise consumer never counts on it to save them without following proper precautions.

Please take a few moments to peruse some threads here if you will:
Smoke and Fire, Hot Cells and Close Calls - The dangerous side of batteries - CandlePowerForums
Now, FYI I have used and sold literally hundreds and hundreds of these cells with no catastrophic failures to date, but I always attempt to educate on the potential dangers.
 
Joined
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Boost converter that would boost from 1.2 to 5.5V with half amp current...
Damn, it'll be pulling A LOT of current from that poor battery.

Quite a bit, but certainly possible for a quality cell. I built a flashlight called the mag85 that uses a welsh allyn 1185 projector bulb What is a Mag85? - CandlePowerForums
As I am sure you probably know, after recharging nimh batteries, they will read a pretty high voltage, surface charge. In my case about 1.44 volts per cell. Nominal voltage for a nimh is 1.2V. Under the heavy load of that bulb, ~3.3 amps I expected the voltage to sag enough to allow usage. The quality of the Sanyo Eneloops cells impressed me because rather than sagging under the load they simply insta-flashed the bulb. I documented the case here if anyone cares to read it first hand: Mag85 instaflash, switch to 8 cells? - CandlePowerForums If you do, go easy on any mistakes I may have made, that was
nearly 2 years ago :)

Here are some discharge graphs of many different nimh AA batteries tested as high as 8 amps on the consumer cells.
CandlePowerForums - View Single Post - NiMh Battery Shoot Out

Cells aimed specifically towards high discharge such as used in remote control hobbies routinely deliver 20 amps. Look at the Elite 1700 AA found here: CHEAP BATTERY PACKS (CheapBatteryPacks.com) Wholesale Battery pack source product.asp(76620DD738) "capable of 25 amps with no problem and even higher burst rates"

As to a possible driver, the DX sku 7882 will easily deliver the voltage and current requited, I can't guarentee the output is stable enough for a laser diode, but I have used it many times with light emitting diode. Warning, it is a voltage regualtor, not a true current regulator. If using it, I would suggest setting it at ~200mA with a test load before wiring to laser diode, then creap up on it from there.
 
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Quite a bit, but certainly possible for a quality cell. I built a flashlight called the mag85 that uses a welsh allyn 1185 projector bulb What is a Mag85? - CandlePowerForums
As I am sure you probably know, after recharging nimh batteries, they will read a pretty high voltage, surface charge. In my case about 1.44 volts per cell. Nominal voltage for a nimh is 1.2V. Under the heavy load of that bulb, ~3.3 amps I expected the voltage to sag enough to allow usage. The quality of the Sanyo Eneloops cells impressed me because rather than sagging under the load they simply insta-flashed the bulb. I documented the case here if anyone cares to read it first hand: Mag85 instaflash, switch to 8 cells? - CandlePowerForums If you do, go easy on any mistakes I may have made, that was
nearly 2 years ago :)

Here are some discharge graphs of many different nimh AA batteries tested as high as 8 amps on the consumer cells.
CandlePowerForums - View Single Post - NiMh Battery Shoot Out

Cells aimed specifically towards high discharge such as used in remote control hobbies routinely deliver 20 amps. Look at the Elite 1700 AA found here: CHEAP BATTERY PACKS (CheapBatteryPacks.com) Wholesale Battery pack source product.asp(76620DD738) "capable of 25 amps with no problem and even higher burst rates"

As to a possible driver, the DX sku 7882 will easily deliver the voltage and current requited, I can't guarentee the output is stable enough for a laser diode, but I have used it many times with light emitting diode. Warning, it is a voltage regualtor, not a true current regulator. If using it, I would suggest setting it at ~200mA with a test load before wiring to laser diode, then creap up on it from there.

Yes, it seemed possible to me that with quality NiMH AA batteries it should be possible but in the mean time I have just decided to go with a 14500 build.
I am sure I will revisit this again and refer to your post here. Thanks vegasf6.

-Scott
 
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Same goes with phones and laptops. This is why people are always killing them and wondering why it won't hold a charge.
:drool:
:gun::banned:
 




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