Looking for a way to use lipo in Aspherilux

[B@rt]

So I have this Docter Aspherilux, a light I like a lot, but since it is the rechargeable version it is underdriven at 4.8V.

The non-rechargeable version uses 4 alks, so 6V should be safe to drive the bulb (specs: 5.2V/0.5A ). :thinking: :shrug:

I'm looking for a circuit that will accomplish this and will cutoff when the 7.4V lipo pack reaches 6V. Obviously it will have to be able to withstand being powered up with no load attached (in case of bulb failure).

This should be doable (I think :green: ), but since I'm blessfully ignorant about anything beyond recognizing symbols in a diagram or butcher poor components with a hot iron when it comes to electronics, any help is appreciated.

 

[B@rt]

:bump:
Since this is a dream so far, any chance of incorporating momentary on if pressed longer than 0.3 seconds, otherwise on/off?

 

[VidPro]

well not really.
rechargable or alkaline it is probably running ABOUT the same power, as alkalines run at about the 1.2V per cell under load. check out silverfoxes charts on it.

if it was my light i would do 1 of 2 things. tear it apart, and put in better rechargable cells, like enloops if Shelf time was an issue, or high-cap ni-mhys if the runtime was more important than having to recharge it more often.
Most (but not all) rechargable consumer stuff has a pretty sick little set of cells in it, and just replacing with modern quality cells that meet the needs of the user increase runtime, and have a adequite output for the whole runtime.

OR
i would check positivly all the specs, and losses of resistance through the light, and put it on the power supply, and see what the actual exact optimal running specs on it are. then if its something like say 500ma 750ma or 1000ma, a person could just as easily use a 3.6-9v LED type driver the same they would use it for the led.
then use 2X li-ion either Flat packs li-poly (fit well in 4xAA slots)
or 2 series 2 parellel 14500s (4 total) and either put protection on, or use protected cells.

per cell protection is more valuable than having a cutoff on the unit itself, although BOTH is also good.

i would be far less likly to alter a 4XAA or 4XAAA light to a li-ion when its already rechargable, and already expecting voltages that are not consistant with a 3X1.2V of the 3.6v li-ion cells.


because not a lot of people have a Docter Aspherilux , whatever the heck that is, you should provide more specs, it sounds like a Led light, but for all we know its incadescent.

 

[B@rt]

because not a lot of people have a Docter Aspherilux , whatever the heck that is, you should provide more specs, it sounds like a Led light, but for all we know its incadescent.

Hmm, a 5.2V/0.5A bulb usually means it is incandescent.

I know voltage will sag under load, I used it to indicate that IMHO the bulb could take 6V. I'd like to drive it a little harder for a better color rendition, so nimh etc is not going to work.

Since I won't be able to use the charger that came with it after modding anyway, I'd like to use Lipo's, because I have those lying around. And, they give me room for a converter/regulator.
The light has 3 contacts, so I can use those for balanced charging.

 

[VidPro]

well, IF there was enough room, and money available for it, i would use this curcuit.
http://www.taskled.com/leds/nflexuib2_v1.00.pdf
its very well done, or even overdone, the interface is very simple, it can go on/off quick and jump to a low Quick, but it wont do the momentary thing you want :-(.
the one thing i can think of that does the momentary the way you want it a Nite-ize(sp) switch, but the nite eyes switch just has a bit of resistance, not a regulation, and is designed for the back of a tactical type of tube light.

that nflex, will change in current (deep in the UI menu), so if you got tired of it actually Working at 500ma, you could crank it up to 750ma and have fun blowing the bulb out instead.

it has different ways of setting a cutoff.
it sounds horribly complex, but it isnt at all, 4 wires to connect like anything, locations well marked and easy to get a wire on to.
the interface also sounds complex , it is complex to set the (one time) current rating, but after that even a 4 year old could operate it.

then of course 2 cheap chargers or a multitap charger , wiring up the li-polys to the charger jack, and wiring 2 chargers or a multitap charger to the plugs.
adding protection to each li-poly is about $2 and very small, or buying preprotected cellphone or pda/ipod packs would be prewired ready to go.

i would say "piece of cake" but nothing ever is, its just very possible.

the problem with that nflex curcuit, is it wants a momentary switch , not your usual click on/off type of thing. and there is a tiny drain that will drain the batteries in about 1 whole month.
the "parasitic" drain of it waiting for your click, can be solved by having a disconnect switch.
For example, in a mag mod, you use the MAIN switch to disconnect the whole thing, on and off it comes back to the posisition it was last on.
then you ADD in a tiny momentary that will do the adjusting.

soo in a light like what you showed (very little of) use your main switch as the disconnect, just like before, and find a location for a tiny momentary switch, a membrain switch like from an old stereo, or the smallest momentray at radio shack will surface mount easily. when you use the normal switch it will go on and off as before, when you push the Other switch it will change in levels, and you can acess the current control.

all of that might be WAY beyond your needs, as changing levels was not mentioned at all. but it sort of "finishes" it in one move, changes can be made through the software UI interface, to adapt to your desires at the time.

another route would be to just toss in one of them cheap small china curcuits that is used in the leds, get a 500ma one that works with the (up to) 9V.
the key reason to use an nflex would be to change current drives at will, a valuable assett.

Adding : the Bflex Also does about the same thing as the nflex, and is in a smaller package, both can have a cute little led now for a battery light

 

[B@rt]

Cool, I'll check it out.