550 mA from (actually, into) a Dorcey AAA !?!?

[zapper]

Let me give you something to chew on till the morning. /ubbthreads/images/graemlins/thinking.gif I hooked up a TWOH LS III to the circuit from a Dorcey 1AAA with two AA batteries supplying the power. Now, I've read the other test reports on this circuit (~220 mA) but I went ahead anyway to see just how bright it would look in person. /ubbthreads/images/graemlins/naughty.gif Well, with the leads hooked up and ready to go I measured 550 mA ! /ubbthreads/images/graemlins/faint.gif /ubbthreads/images/graemlins/drool.gif I'll talk to you guys later in the morning and repeat the test. /ubbthreads/images/graemlins/smoker5.gif Maybe I did something wrong! /ubbthreads/images/graemlins/twakfl.gif /ubbthreads/images/graemlins/whoopin.gif

 

[Doug S]

Re: 550 mA from a Dorcey AAA !?!?

Sounds like you meant to say 550mA *into* a Dorcy AAA. /ubbthreads/images/graemlins/grin.gif

Your measurements sound reasonable to me. With this circuit driving a low Vf lux I have measured inputs of 461mA at Vin=2.75 and 493 mA at 3.00V. Under these conditions the current is largely determined by the current limit value of the switcher IC and this is a parameter that typically can have a large variation from chip to chip.

 

[zapper]

Re: 550 mA from a Dorcey AAA !?!?

Well, ofcourse, you are correct sir !! /ubbthreads/images/graemlins/twakfl.gif /ubbthreads/images/graemlins/whoopin.gif From people I respect, such as yourself, I accept your information as ~95 - 99% true and accurate. (I always like to see for myself though when I get a chance!!) Anyway, the current reading was a gozinto, not a gozouta. /ubbthreads/images/graemlins/jpshakehead.gif The actual gozouta (If) was 310 mA! Still not too shabby for a $6 dollar circuit with an LED and battery holder!! (~60% eff, ~4hrs runtime 2AA guesstimated, not too bad) /ubbthreads/images/graemlins/naughty.gif I think I'll start using these little gems (or other semiprecious stone) for applications I have in mind /ubbthreads/images/graemlins/wink.gif /ubbthreads/images/graemlins/thinking.gif You wouldn't happen to know of a replacement chip for higher possible current would you !?

 

[Doug S]

Re: 550 mA from a Dorcey AAA !?!?

Zapper, I'm with you. For $6 I would rate it as a "BEST BUY" for experimenters. Sorry, I don't know of any drop in replacement for that IC to up the current. If you find one, you will probably need to change out the inductor to avoid saturation issues.

 

[gadget_lover]

Re: 550 mA from a Dorcey AAA !?!?

I was working on adding a lux to a 2aa angle light for a family friend. I find that if I cut the extra tabs and springs off the Dorcy AAA board I end up with a rectangle that is small enough to hide in lots of spots.


Daniel

 

[zapper]

Re: 550 mA from a Dorcey AAA !?!?

YUP, it even fits in a Minimag when trimmed just a bit!

 

[milkyspit]

Re: 550 mA from a Dorcey AAA !?!?

That reading sounds about right to me. I think I've actually measured in the low 600mA range coming from 2AA cells in my mods with that little board. /ubbthreads/images/graemlins/ooo.gif

My Milkbone 2AA mod is driven by the Dorcy AAA circuit, and performs well with 2AA alkalines, and REALLY nicely on 2AA NiMH or even a single 123 cell! /ubbthreads/images/graemlins/cool.gif

Recently I even built one into a Mag 2C that I converted to LED for my stepfather, and given that he's an aging NON-flashaholic, I wanted to leave the light running off 2C alkalines. Worked great!
/ubbthreads/images/graemlins/thumbsup.gif

Okay, I'm getting more and more off topic. Sorry! /ubbthreads/images/graemlins/icon15.gif

 

[rdshores]

Re: 550 mA from a Dorcey AAA !?!?

Does anyone have the circuit diagram for the Dorcy AAA booster board?

 

[zapper]

Re: 550 mA from a Dorcey AAA !?!?

I thought Doug S had one or at least figured out what it was by reverse engineering.

 

[TrueBlue]

Re: 550 mA from a Dorcey AAA !?!?

I'd sure like to know what electronics and how they work in the Dorcy light. You can bet the electronics are cheap, easy to get parts that are not exotic. And the electronics would not be hard to put together.

 

[milkyspit]

Re: 550 mA from a Dorcey AAA !?!?

I believe the electronics are some sort of Zetex-based boost circuit, but could be wrong about that... but the Dorcy 1AAA 1 LED flashlights cost $5.94 at WalMart and the circuit is already built for you. They're easy to pull out of the light to use in whatever you want. Why build it yourself? By the time you bought the parts and spent the time soldering them together, and possibly even spent more cash making your own circuit boards, you might actually be losing money (accounting for the labor) or at best saving a dollar or two for a lot more effort. Just my two cents, of course.
/ubbthreads/images/graemlins/icon3.gif

 

[ViReN]

Re: 550 mA from a Dorcey AAA !?!?

Could it be a simple SMT Transistor based boost circuit ?... with an added sence resistor & a transistor.. for some regulation ???

ViReN

 

[Doug S]

Re: 550 mA from a Dorcey AAA !?!?

It is not a Zetex based design. That IC is a simple stepup switcher IC with a fixed 5V output. It of course can never reach 5V with an LED attached so it operates out of regulation. If you give it enough input voltage, it will peak current limit at around 0.7A IIRC. I was unable to ID the make and model of the IC from it's markings.

 

[milkyspit]

Re: 550 mA from a Dorcey AAA !?!?

Thanks Doug. (Been saying that a lot lately.) /ubbthreads/images/graemlins/grin.gif You're kinda the Dorcy 1AAA circuit expert around here, so thanks for chiming in with your observations.

I've been running this board off 3V source voltage to drive a Q2H Luxeon on the output side at something in the 350mA-400mA range, speaking in very rough terms. Are you saying that I could perhaps be running 3AA alkalines or even 3AA NiMH into this circuit, then drive a Lux III in the vicinity of 700mA on the output side?

I'd assume that 4AA NiMH would be risky since the cells come off the charger at 1.3-1.4V each... or could I simply install a rectifier diode in series with 4AA NiMH to drop input voltage by maybe half a volt and thereby take care of that potential risk?

 

[WildRice]

Re: 550 mA from a Dorcey AAA !?!?

going by the same kind of circuit, I have been using the 1AA version. It uses the same chip just a different inductor. I am using a 3.6v AA sized Li-ION driving several LUX III's(swappable heads) in the range of 700mA. I have also modded a AAA with 2x 1/3AAA NiMH and a LUX I with ground down NX-05 optics. With the dorcy AAA board and 2.4v I was getting 240mA. Right now I am trying to get 1A from the AA circuit, but it sounds like it clamps at 700mA.
Jeff

 

[Doug S]

Re: 550 mA from a Dorcey AAA !?!?

[ QUOTE ]
milkyspit said:
Thanks Doug. (Been saying that a lot lately.) /ubbthreads/images/graemlins/grin.gif You're kinda the Dorcy 1AAA circuit expert around here, so thanks for chiming in with your observations.

I've been running this board off 3V source voltage to drive a Q2H Luxeon on the output side at something in the 350mA-400mA range, speaking in very rough terms. Are you saying that I could perhaps be running 3AA alkalines or even 3AA NiMH into this circuit, then drive a Lux III in the vicinity of 700mA on the output side?

I'd assume that 4AA NiMH would be risky since the cells come off the charger at 1.3-1.4V each... or could I simply install a rectifier diode in series with 4AA NiMH to drop input voltage by maybe half a volt and thereby take care of that potential risk?

[/ QUOTE ]

Are you saying that I could perhaps be running 3AA alkalines or even 3AA NiMH into this circuit, then drive a Lux III in the vicinity of 700mA on the output side?

No.

I'd assume that 4AA NiMH would be risky since the cells come off the charger at 1.3-1.4V each... or could I simply install a rectifier diode in series with 4AA NiMH to drop input voltage by maybe half a volt and thereby take care of that potential risk?

Not a good idea. Even if it didn't smoke, it would use the energy from 4AA NiMh less efficiently that a simple resistive ballast. If you really want to use 4AA NiMh, just use a resistor to limit current.