2AAA

[yclo]

Hi all, just wanted to ask if anyone knows of any 2AAA flashlight led mods excluding using the small 12 volt cell for solitaire mod?

I've been looking around and haven't found any. Sure dc/dc converters are nice, but I haven't found anywhere that sells them in Melb, Australia yet.

Thanks, and keep 'em leds shining brightly!

Ying Chee

 

[php_44]

2-AAA cells in series will produce 3V. This can power lower voltage LEDs just fine. The chemistry of a LED determines how much voltage it needs to run. Typically with really bright LEDS, the follwing colors will work for 3V: Red, orange, amber, and some lime green. These LEDs require between 1.8-2.2V to operate. For many of these - you'll need a small resistor (5-20 ohms) in series with the LED to prevent frying it. Of Course LEDs in these colors are cheap so if you want to try it with no resistor go ahead.



Any Blue, white, turquoise, or "true green" LED will typically require 3.2-5V to run. To operate these from 2-AAA you'll need a voltage boost circuit.



I did my first LED conversion around 1985 by putting a green LED in a 2-AA cell penlight with a resistor to use in a darkroom with red sensitive holography film. I still have it. I did red, yellow, and orange ones as well with cheap 2-AA cell penlights. At the time the red one was by far the brightest.



have fun!

 

[yclo]

<BLOCKQUOTE><font size="1" face="Verdana, Arial">quote:</font><HR>Originally posted by php_44:
I did my first LED conversion around 1985...<HR></BLOCKQUOTE>

Wow... I was only 4 years old then.
Thanks a lot for the info, but I was more looking at white or other high brightnest led mods, and I'd also prefer not to use 2/3 AAA rechargable cells.

Ying Chee

 

[Steelwolf]

With a flashlight that takes 2 AAA cells, you could possibly build the "SatCure circuit" and run that with 1 AAA cell with the circuit taking up space for the other cell.

If you don't know what the SatCure circuit is, it is a very simple booster circuit consisting of 1 transistor, 1 home wound inductor coil and 1 resistor. It can be made a little better with the addition of a Schottky diode and a capacitor. It doesn't appear to be able to regulate the output, so the brightness will fall with battery expenditure.

Try a search in this forum. There should be a bunch of schematics and run time data floating around somewhere. Or email me and I can try sending all the relevant files to you.

Or finally, you could just bug Gransee like what the rest of us are doing, asking him to start selling the regulated booster circuit he uses in his Arc-AAA as a hobbyist kit.

 

[php_44]

<BLOCKQUOTE><font size="1" face="Verdana, Arial">quote:</font><HR>Originally posted by yclo:
Wow... I was only 4 years old then.
Thanks a lot for the info, but I was more looking at white or other high brightnest led mods, and I'd also prefer not to use 2/3 AAA rechargable cells.

Ying Chee<HR></BLOCKQUOTE>



Now I feel old! I was only 18 at the time

. You'd be surprized at how nice an ultrabright amber is on 2-AAA.



On the other hand I did modify a nicely made aluminum 2-AA light with a waterproof push on-off switch to use a white LED. I built a booster circuit with a Maxim MAX757 IC. See craftsman 2-AA boosted conversion for details.