Lets' design a compact/cheap direct drive LED light...

KDOG3 · Jul 6, 2008

I'd like to be able to go to the hardware store and get some PVC pipe that a CR123a will fit it in, get a cut-down SMJLED with a reflector. (you can get them from terralux.com - theyre the ones that go with the 2AA mini mag upgrade module). I think it would be better if it was direct-drive for simplicity. Also I think it should be throw oriented for max "apparent" brightness. Waddya think? It would make a great loaner and could be produced by the buckets...

KeyGrip · Jul 6, 2008

I'm down, sounds kinda like a simplified Milky Candle. Throw oriented is good since it can always be modified for flood with a diffuser.

paulr · Jul 6, 2008

I don't see much point to this. You've lost the simplicity as soon as you rely on an exotic battery like a CR123A. The simplest direct drive light is probably the 9v snap cap type (Pak-lite and others). If you want a compact light produced by the buckets, it should run on one AA, which means no direct drive, but uses the most common batteries in the world. You can get plenty of those on the usual Chinese sites for under $5 a pop. The idea of trying to out-cheap that with a custom lithium-powered flashaholic light using a specialty led that someone has had to turn down in a lathe, just seems unworkable.

If you want to make simple cheap lights, the 9v snap cap design should be doable for under 1 buck including a cheapo zn-c battery, or a couple bucks with an alkaline. It would be just a 9v snap connector, two LEDS and a resistor soldered on. If you want to get fancy, add an on-off switch. For the non-fancy version you'd just unsnap it from the battery to turn it off.

Calina · Jul 6, 2008

paulr said:
If you want to make simple cheap lights, the 9v snap cap design should be doable for under 1 buck including a cheapo zn-c battery, or a couple bucks with an alkaline. It would be just a 9v snap connector, two LEDS and a resistor soldered on. If you want to get fancy, add an on-off switch. For the non-fancy version you'd just unsnap it from the battery to turn it off.

This is one light I've been wanting to build for over a year now except that I want it to have two light levels, hence two resistors and a three positions switch. The only reason it is not built yet is that I can't find a suitable switch that won't turn itself on unintentionally too easily. The switch, resistors and snap connector will fit nicely into the tip of an oval toothbrush holder. Any help in finding a suitable switch would be greatly appreciated :grin2:

.

Thanks.

KeyGrip · Jul 6, 2008

paulr said:
You've lost the simplicity as soon as you rely on an exotic battery like a CR123A.

I want this so I can dry up single used cr123 cells that are too dead for other lights.

Meduza · Jul 6, 2008

Calina said:
This is one light I've been wanting to build for over a year now except that I want it to have two light levels, hence two resistors and a three positions switch. The only reason it is not built yet is that I can't find a suitable switch that won't turn itself on unintentionally too easily. The switch, resistors and snap connector will fit nicely into the tip of an oval toothbrush holder. Any help in finding a suitable switch would be greatly appreciated .

Thanks.

http://www.9voltlight.com/inc/sdetail/5414 ?

Calina · Jul 6, 2008

Medusa, thank you for your help but I already knew about the Pak-Lite . For one thing I find their price hard to swallow for what they are and frankly it would just be plain fun to build my own.

sed6 · Jul 6, 2008

paulr said:
I don't see much point to this. You've lost the simplicity as soon as you rely on an exotic battery like a CR123A. The simplest direct drive light is probably the 9v snap cap type (Pak-lite and others). If you want a compact light produced by the buckets, it should run on one AA, which means no direct drive, but uses the most common batteries in the world. You can get plenty of those on the usual Chinese sites for under $5 a pop. The idea of trying to out-cheap that with a custom lithium-powered flashaholic light using a specialty led that someone has had to turn down in a lathe, just seems unworkable.

If you want to make simple cheap lights, the 9v snap cap design should be doable for under 1 buck including a cheapo zn-c battery, or a couple bucks with an alkaline. It would be just a 9v snap connector, two LEDS and a resistor soldered on. If you want to get fancy, add an on-off switch. For the non-fancy version you'd just unsnap it from the battery to turn it off.

The most polite, and utterly complete, shoot-down of an idea I've read in a long time. :crackup:

paulr · Jul 7, 2008

KeyGrip said:
I want this so I can dry up single used cr123 cells that are too dead for other lights.

In this case you're going to want a boost converter.

paulr · Jul 7, 2008

Calina said:
This is one light I've been wanting to build for over a year now except that I want it to have two light levels, hence two resistors and a three positions switch. The only reason it is not built yet is that I can't find a suitable switch that won't turn itself on unintentionally too easily. The switch, resistors and snap connector will fit nicely into the tip of an oval toothbrush holder. Any help in finding a suitable switch would be greatly appreciated .

Thanks.

It used to be easy to scrounge switches from old radios etc. that you could get out of junk bins. These days you might have to go to a parts store (RS even) and pay money for one, but a few bucks should be enough.

KeyGrip · Jul 7, 2008

paulr said:
In this case you're going to want a boost converter.

I've read that using a circuit to do this could damage the battery? True?

SemiMan · Jul 9, 2008

Bought a package of 3, 40-50 lumenish LED flashlights from Costco complete with 9AAA Duracells (3 per light)...total cost $15.00. Direct drive, pretty good throw. I am not sure how you could ever build anything yourself any where near that price.

I build lights myself, but generally cause I want something I can not get off the shelf. Parts wise, they probably cost more than off the shelf, and time wise, waaaaaayyyyyy more expensive. That said, go for it. From experience, AA batteries fit very nicely into 1/2 copper tubing. If you go with plastic tube, you need a wire from the back of the tube up to the light.

Semiman

Scattergun · Jul 10, 2008

Isn´t this what DX and KD are doing all the time?? Hard to beat the price of a chinese direct drive flashlight...

lctorana · Jul 10, 2008

Scattergun said:
Isn´t this what DX and KD are doing all the time?? Hard to beat the price of a chinese direct drive flashlight...

I agree, but I am also of the opinion that DX/KD lights are not cheap enough.

I am far more interested in the market segment below this - cheap, direct-drive, and plastic bodied.

Think of the cheap 2D and 2AA lights in your local supermarket, in the $2 - $5 range, and now think about puttting Luxeon or Cree drivers in this standard of torch.

Right now, the LED component of this market segment is solely composed of 7 or 9 5mm LEDs, so the general public doesn't get a fair idea of what LEDs are capable of.

Until now, Luxeons et al have been too dear to go mainstream, but I feel that might be ready to change.

I am fully aware that many CPFers hold cheap torches in utter contempt, but I do not.

spencer · Jul 11, 2008

The problem with the cheap $2 - $5 light with an XR-E or SSC P4 is that the LED costs $5ish dollars on it's own. If your going to be spending that much on an LED then you may as well just spend a little bit more on the light body and get a better light.

lctorana · Jul 11, 2008

Yes, and that's why they are not in cheap torches yet!

Right now, you won't see any change out of $20 for any sort of torch with a Luxeon, and that is way, way, way too dear for most people.

But, I repeat, that may be about to change.

Lets' design a compact/cheap direct drive LED light...

KDOG3

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KeyGrip

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paulr

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Calina

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KeyGrip

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Meduza

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Calina

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sed6

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paulr

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paulr

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KeyGrip

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SemiMan

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Scattergun

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lctorana

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spencer

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lctorana

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