They did kind of a nice thing at work today (not very often anymore), and were selling some wind-up flashlights (torch in British...) for $2.00, pricing sticker says $14.99 (convience store price), limit 5. So I bought some, mostly for parts. Seem almost too cool to take apart right off, but of course I will shortly... The Leds are pretty damn bright, but I've got some better ones. They have a rechargeable lithium coin cell (was hoping for super-capacitors...), 3.6 volts LIR2032. Hoping I can replace the crank with a propeller or fan blades and make it wind powered for a landscape light. Most likely swap the battery for a NIMH pack, less fire hazzard.

The one I cranked up still hasn't dimmed any, been a good 30 minutes. Definately got to get more monday if they are still selling them. Quite sure there is well over $2 worth of parts in each one.

 

Hi Harvey,

I think I've got a similar one, bought it last year for € 2.
Until now it worked every time I needed it, even without
cranking it up. I started to think there was a miniature
nuclear reactor inside running on nuclear waste.
The second switch locks the crank in to the housing so
that it appears to be a "normal" flashlight.

on1aag.

Attached Images

	Crank 001.JPG (36.3 KB, 16 views)
	Crank 002.JPG (32.5 KB, 13 views)
	Crank 003.JPG (33.7 KB, 12 views)

 

I'll try to get some pictures up later, my camera hasn't been doing so well lately. Just opened one up, and getting ready to replace the Leds. Not much of a circuit, 7 diodes, a zener, transistor, small capacitor, bunch of 1/8 watt resistors. The gears are nice thick nylon. Think the generator was built for the task, not just some cheap hobby motor. Almost no resistance to turn when away from the gear train.

 

I've got a wind up LED torch too!

It's a three LED unit, I can't remember how much it was but it's more expensive than either of the ones you've mentioned but at the time it didn't seem very expensive and it's probably better quality too.

I always wind it regularly so it's never ran flat, I've also noticed that if I wind it whilst it's on it gets a lot brighter which is handy sometimes.

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I've got three of those things. Two of them have dynamo charged batteries. The other is a shake light that's a fraud - it uses a small battery to illumiate the LED and the coil/magnet assembly isn't connected to anything!!! I remember reading about this misrepresented scam by some manufacturer ---- or maybe the company's assembly procedures aren't well understood when translated into Chinese!

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I've got one of the shake lights, too. Mine actually "works", though. There are two 3v Lithium Batteries in a series in it. They power the unit, and i am guessing the coil/magnet assembly recharges the batteries? I know that the coil i connected to something, because if one shakes it fast enough without the batteries in it, it will light the LED shortly.
Could i just put a very large capacitor in the unit (few Farads), and power it from that, after it is charged?

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A super capacitor would work but it won't store anywhere as much energy as a battery.

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yes, those shake torches are really annoying to use. but then the one i had, the battery failed or something so i pulled it apart, and got myself a big heavy magnet, TONS of copper wire and a reed switch. there was so much wire in there i built a small tesla coil

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I have two lights with almost identical packaging and they both appear to be the same. But one has a defective coil with no connection (and the "magnet" isn't a magnet). It has a Li button cell to power the LED. The other has a functional coil (with a lot more turns), a real magnet, and a NiMH battery instead.

As I said, on cursory inspection they are identical. The fake cost me $2.00 and the real one cost $2.50.

We suspect that the fake ones are just a fall-back for when the wire breaks before the coil is finished?

 

HarveyH42,
Could you please post a picture of your wind up LED tourch, I'm interested to see what sort of alternator/dynamo it uses.

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I looked in a friends the other week, it's just a small cheap DC motor - the battery in his had died, he hadn't used it for about a year, when he tried it the battery is completely knackered!.

He's been looking for a replacement battery, but it costs more than the entire torch did!.

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I did think that but it charges when the handle is rotated in both directions.

I thought they could have obviously used a bridge rectifier but would would be the point in that when a single rectifier whould do the job and cost less too.

I have a feeling it uses a cheap and chearful stepper motor but I don't want to open it up as I'll probably never be able to put it back together.

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I didn't look that close, but a bridge sounds a reasonable idea?.

A stepper is a LOT more expensive than a DC motor, and these things are a cheap as they come!. Certainly my friends was very simple to take to pieces and put back together.

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Yeah, you got a good deal. No matter how many times I see it, I still chuckle everytime I see the word "torch" used instead of "light."

Umm, torches have a flame..

 

Yeah, I like the 'torch' thing too, medieval(sp?)... Anyway, took some pictures, camera didn't complain too much, think I'm loosing my last 8 meg Smartmedia card, time for a new camera I guess.

The big Leds are narrow angle (12 degree?). Only difference in brightness was focus. Didn't take them outside and see what kind of distance they were good for. They were plenty bright for most uses, got a bigger flashlight for blinding...

The generator is a motor, or could be used as one, guess it both could be used either way regarless of origional intent. The shaft spins really free, even small cheap, no torque motors have a little resistance. At 4.8 volts (just a handy battery pack), it spun at a high RPM. Didn't think to try to see if it would turn the gear train.

Never worked with lithium batteries, so left the 10 ohm resistors alone. Don't think they'd effect the brightness much.

Have to do some thinking on how to convert these to wind power. Going to need a much larger rotor, then what I've been using directly on stepper motors. The gearing isn't too bad, just going to take a good gust of wind to get it started turning. I did order some 12 props last week, while getting some replacement blades for the helicopter. Give it try next week sometime.

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	Wind03.jpg (63.5 KB, 6 views)
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