Double barrel AAA conversion

What if I used a 6AA double barrel which would be at 4.5v with the alkalines or 3.75v with rechargeables(would that be safer?). Would this work, or will it burn out the led as well?
I would rather prefer this configuration, so that this way if I wanted to used the incandescent bulb I would still be able to.

<BLOCKQUOTE><font size="1" face="Verdana, Arial">quote:</font><HR>Originally posted by J. Ma:
What if I used a 6AA double barrel which would be at 4.5v with the alkalines or 3.75v with rechargeables(would that be safer?). Would this work, or will it burn out the led as well?<HR></BLOCKQUOTE>

If you use rechargeables, then don't even bother with a resistor - it isn't needed.
Unless something's changed in the last two or three weeks, the LED(s) will be perfectly safe.

Yes a 6-cell double barrell would be fine. With alkalines you`d be best to use a current limiting resistor like telephony said above, but rechargeables with their lower voltage would probably be fine without a resistor.
Modern Nichia white leds are surprisingly robust I have found, and will usually show their displeasure at being seriously overloaded long before burning out. Watch for overheating, dimming of the light and turning a strong blue tint. You should be OK though especially with a current limiting resistor. If you have a multimeter to measure current, try not to exceed 50mA maximum LED current, but up to about 30mA is safer but not so bright.

Craig- you`re too fast for me!

J. Ma- just a thought, but if you want a simple quick fuss free LED conversion for the 6-cell d.b. then why not try a (3-cell) LEDcorp replacement bulb? It has the same PR base of the incandescent bulb (I`m right in thinking d.b`s use PR base bulbs aren`t I?) and just pops right in there in its place. Whats more it should make use of the reflector to give a bright focussed beam of pure white with no blue rings or hotspots. Though they are designed for focussable MAG-lights, I`ve had good luck with mine in a couple of smaller fixed focus lights here.

see- http://ledcorp.com . They also have 2-led bulbs that are brighter but have a wider beam and don`t make such use of the reflector. Depends on what sort of beam pattern you want from your light. And http://theledlight.com have 3-led bulbs for 4.5v/3 cell lights that are brighter still, so I`ve ben lead to believe.

<BLOCKQUOTE><font size="1" face="Verdana, Arial">quote:</font><HR>Originally posted by Chris Millinship:
J. Ma- just a thought, but if you want a simple quick fuss free LED conversion for the 6-cell d.b. then why not try a (3-cell) LEDcorp replacement bulb? It has the same PR base of the incandescent bulb (I`m right in thinking d.b`s use PR base bulbs aren`t I?) and just pops right in there in its place. <HR></BLOCKQUOTE>

Chris,
The AA DB's use a special bi-pin bulb like this. I assume the AAA's are similar.



The inside of the head looks like this:



Hope this helps...

Does anybody here know what the
series/parallel batt. configuration on the 8AA version of the double barrel is?
(Just don't always have enough time to check on these things)
-too many kazillion other lights
to fool with...

Thanks Gadget I didn`t know what they were like before. I never had one and from what I hear about them being discontinued, probably never will

So, J. Ma- for the led conversion I`d reccomend a 6-cell d.b. and just stick a white 5600mcd led in place of the bi-pin bulb. You`ll need to trim the leads to the same length as the bulb, and probably file/cut down the wider spacer portions of them too so it can sit all the way down. Watch the polarity- if you have a multimeter, first check the polarity (long led lead/smallest shape on the end inside resin case is +) otherwise briefly flash it to test and you should be OK. If it doesn`t light swap the led round and test again. Older white leds were often damaged by reverse polarity but the newer ones should survive it a little better.

Does anybody here know what the
series/parallel batt. configuration on the 8AA version of the double barrel is?


Sure. Going by the setup of the other double-barrell lights it would be 2 sets of 4 series cells giving 6 volts total (with 1.5v alkaline cells). And like the other d.b.`s it will work fine on just one barrell of 4 cells but with half the runtime.

Thanx Chris,
BTW-you might get those little
reflectors (and surprise), a lot
sooner than u might think...
I just got from "Nectarine Ltd" (in Cardiff) the Traser/tritium
glow columns I ordered only
5 days ago

Hey guys, anyone here know if I can use one white photon led in the double barrel 4AAA flashlight??? I really want to convert it to led, but I'm afraid of burning out the LED. But my guess is that since the photon needs 6v, it should be fine in the double barrel???
BTW, I have also seen that some of you guys are interested in getting the 8AA double barrel flashlight. I have them here localy, let me know if I help anyone on the board here.

Yes you can use a white led just fine, but it won`t be at all bright. A white led needs about 3.6 volts to burn brightly though in many lights it is overdriven at higher levels. Your 4AAA double barrell light will only give 3v at best.
I have read elsewhere on the boards that it`s possible to rewire the light and convert the series-paralell arrangement into all-series, ie 6 volts (you would need all 4 batteries, it wouldn`t work with just 2 like before), then you can connect a white led with limiting resistor in series, and have it at a nice high brightness.
I havn`t seen a 4AAA double-barrell myself so can`t say how or if the re-wiring can be done, sorry.

<BLOCKQUOTE><font size="1" face="Verdana, Arial">quote:</font><HR>Originally posted by J. Ma:
Hey guys, anyone here know if I can use one white photon led in the double barrel 4AAA flashlight??? I really want to convert it to led, but I'm afraid of burning out the LED. But my guess is that since the photon needs 6v, it should be fine in the double barrel???<HR></BLOCKQUOTE>

The LED in the Photon doesn't *need* 6 volts, it's ruthlessly forced down its throat. The LED only *needs* about 3.6 volts to function well, and around 3.8 volts to mildly but safely overdrive.

Up around 4.5 volts, you're flirting with disaster, but still the LEDs won't normally go out with a bang. Most of the seriously overpowered flashlights pump 4.5 volts directly to the LED and get away with it.

It's all in the batteries. Even at a normally fatal 6 volts, the CR2016 lithium coin cells just can't produce enough current (amperage) to deliver the fatal blow to the LED, the voltage drops to well under 5 volts (probably 4.5 to 4.6), and that's why it works so well.

Now, with a 4 AA double barrel, your choice in LED colors will be limited. Because the batteries are in a series/parallel arrangement, only 3 volts goes to whatever lamp is in the socket, be it LED or incandescent. White LEDs need 3.6 volts.

You will therefore either have to put an inverter circuit in there or graduate to a 6-cell double barrel, and at that point you may want to stick a 33 ohm resistor in series with your LED to prolong both it and the battery life.