building a 'shake 20 sec and have light for 20 minutes' torch?

[dinges]

G'day everyone,

I was wondering if anyone on this board ever tried building one of those 'shake 20 seconds and have 20 minutes of light' torches. They seem simple enough to build, just a coil, neodymium magnet, goldcap and a led (plus some current limiting resistor to the led). Only variable seems to be the amount of turns for the coil.

Anyone tried to build one of these, and if so, with what outcome? Think I'll try building one myself soon, in one of those spare hours with nothing to do.

Peter,

The Netherlands.

[TomW]

Peter;

I never built one but I often thought the voicecoil from any largish speaker would be a fine ready made coil for one. Thought of that dismantling speakers for the magnet rings and out comes this beautifully wound cylindrical coil. Would need the proper round magnet and the ones I took apart looked about right for those "cow magnets" they feed to cows to collect iron items they might ingest.

Cheers.

TomW

[ghurd]

Been there, done that. Sort of.

Used a no battery pumper flashlight to start with.

Worked much better than the factory shake lights, meaning more light longer.

The generator had a low peak voltage, so the caps could not get very charged.

The only trouble was size. It was the size of a shoe box!

And the gears in the genny were plastic. It would wear out fast.

The factory made lights are not as good as they say. There is light, but not usable light very long. You must look into the LED to tell if it is still on.

It was fun!

G-

[Arno]

Peter,

How do you find one of those spare hours you talked about?

arno

[stevesteve]

Never heard of 'Cow Magnets'... may be a wind-up but it made me grin anyway!

Job for the lowest worker in the pecking order: finding and collecting the used cow magnets ;-)

[Nando]

To those interested in building pumped charger.

I have designed and built some, several years ago.

A business I could not sell around 20 years ago. AND DO NOT LAUGH !!

You need a minimum of 3 NIMH batteries in series ( 4.6 volts) or a capacitor 5 volts and 10 to 20 FARADS.

The coil needs to be around 5 Henries, not more than 10 OHMS resistance value, the coil leads feeding a full bridge diode rectifier (4 each 1N4454 or 1N4148 diodes OK ) (coil leads to the AC inputs) and the + and - leads of the rectifier going to the + and - of the storage device.

The magnet, the strongest available and if round best, the coil is going to take around 1.5 inches in length and the inside of the coil not less that 0.5 inches in diameter, of course if you have a rectangular magnet you could make the coil with a internal rectangular magnet, ALSO I suggest that the inside wall is covered with TEFLON tape to reduce the friction of the magnet movement.

As well, I built some that have a small DC brush motor with a small handle to charge the storage device -- This works better with stronger charging capability and easier to make.

IF there is enough interest I can calculate the coil again, though I recommend a DC motor, ( a 12 or 24 volts motor ideal ).

Presently, I have one that uses a motor from a Cigarette package "PROPAGANDA" Display with gear reduction that was run using 6 volts NIMH battery, in addition it has a micro-size PWM MPPT charge controller regulator, 30 seconds FAST charging time feeds a 0.5 Amp that feeds a 0.5 watts WHITE LED with a controller that regulates the intensity and/or the current usage.

Regards

Nando

[ghurd]

Cow Magnets are real.

Cows are real stupid (wood is smarter). They eat metal. The cow magnet holds the metal were it will not kill them, the owners hope.

There is even a dohicky to push a magnet down their throat. Big Fun!

They stay put for quite a while (for ever?). Not expensive (meaning the magnets, the cows ARE expensive).

The magnets are quite weak. OK, very weak, but cheap. Availiable locally anywhere you can see Holstiens.

The N# is probably too low to do any good.

They are round. Sort of like a hotdog.

I wonder who gets them out?  lol

G-

[TomW]

Steve;

No joke. Very common item here in farm country.

http://www.magnetsource.com/Solutions_Pages/cowmags.html

[ghurd]

Notice it says "Ceramic 5".

"Solid Steel Connector Rod".   wow.   o boy.

"Power Enhancing Pole pieces"!!! Why didn't we (as in somebody here) think of that!

Oooo... I mean 'Moooo'

But yep, real stuff.

[nothing to lose]

Hmmm, perhaps you now know why cows get mad!!

First ram the magnet down the throat.

Magnet and metal bouncing around one of the stomaches.

Someone taking the magnet back out.

Hmmm, I would be kinda mad  to if it were me!!

[ghurd]

Big Fun!

HELLO! This is OHIO!

We were happy to watch the last snow melt! Again! Yesterday! 18".

"Look! Brown sludge under the white stuff! Now we know summer is here!"

The children were all so excited.

Now we can make mud angels.

What I wouln't give to see the mud of spring.

Day before yesterday, neighbor cut his grass.

Yesterday was 5" of snow.

I cut mine today.

G-

[jimjjnn]

Common here in Colorado too. Cows ingest anything in the grass including metal. As long as it doesn't get into the intestine, all is ok. Cow magnets keep iron particles in one of the stomachs untill it is dissolved and then it can go through the intestines. Mostly nails that theyswallow.

Crazy subject for the board and slightly "Gross" but that's the way it goes. HEHE

[jimjjnn]

THe cow mags stay in place since they are below the stomach outlet to the next stomach. I believe if memory serves me, cows have 3 stomachs. The doohicky that places them in the stomach is a hollow tube with a plunger. Lots of farmers just use a piece of pipe with a stick to push the mag into the stomach. Cows don't seem to mind as they are always getting something shoved down their throats. Big pills especially. It's the other end of the cow I hate. Ever have to pull a calf that is stuck or backwards during birthing? Gross and MESSY.

[Aelric]

I believe Wondermagnet has some NdFeB sphere's up for sale up to 1 inch in size.  They also have some NdFeB cylinder's.  Both would probably be excellent for this project.  If anybody does do this I would love to see pictures, drawings and ratings (ie 10 shakes = 1 minute etc.) Very interesting idea, especially with the caps because then there is never a danger of the batteries leaking or going bad just when you need them hehehehe.  Seems to be the way it always is with me, no lights and flashlight batteries are all bad LOL.  Anyway I think this is a neat project and would like to hear more.

[nothing to lose]

Oh great and I missed it

We had like about 3" once this year I think, maybe it was 6" .

Actually not this year, I think that was Christmas.

Way too mild winter here last/this year!

[nothing to lose]

Well not really, but I am sure it's much worse than a goat! Biggest animal I've had, pigs are alot smaller and eggs aren't a problem.

Not pigs eggs! I meant the ducks, chickens, turkies silly

[nothing to lose]

So would a shake light or crank light be best?

Remember those survival radios, crank the handle a few cranks and they play for awhile.

[Nando]

The crank light is best, also you may get one of those lights that you could squeeze to produce electricity and add a set of NIMH batteries and a diode to charge then for longer lighting.

Some of the better "Squezzable" lights may have internal space for the batteries, the diode and a small switch for ON/OFF since they do not come with switches.

South Africa was the country that started utilizing a rolled spring to maintain the battery charge for a Rural radio and later they added a light, now is world wide common.

Regards

Nando

[Chiron]

The guy at the slaughterhouse that gets to deal with the stomache.

My ex father inlaw worked at one for 30+ years and used to bring them home by the bucketfull for his brother inlaw who had a dairy farm.

You don't want to know where a lot of the innards wound up, or just exactly what "all beef franks" really means

[ghurd]

I think I would agree.

The Russian pump or squeeze lights have cast Al gears, but I still do not believe they will hold up long under real use. The Chinese pumpers are all plastic and I bet they will not last long enough to charge 2000mah batteries even once.

The Russian volts peaked at 3.5 or 4v and used a 2.4V bulb, if I recall correctly.

The 3.5 or 4v was after a diode.

I read somewhere one of them could make about 1/2 amp. (Not bad IMHO)

The problem with the one I made was all the caps. Could not get them really charged up voltage wise. So there were a lot of them. Every big cap we could find, even a couple from motors.  Batteries would have been a better choice, but that took out the 'no battery needed' fun.

I think a pumper would be pretty decent with an LED bulb and one decent cap.

Would not stay on long, but it may be long enough to change hands or something, and it would not be such pulsing light.

G-

[dinges]

Thanks for the comments, everyone.

Arno, you have a Dutch sounding name; are you in NL?

I expected these lights not to be very good, with the LED barely glowing at best after 30+ seconds, which I think will be the case. But, since they seem so easy/simple to make (few components, all of which I have) I'll give it a try & keep you informed. The voice-coil from speakers is a good idea, will see what I can find. I wasn't planning to wind such a coil myself. Too many windings of very thin wire.

BTW, just today I got my other wire (1.3mm+insulation) for my 'bike generator'. Coil winder is ready, so I know how I'll spend this weekend :-(  The only thing I hate about building generators is making the coils. Not difficult, just boring.

The shape of the cow magnets reminds me of something else, and the story that this doctor on TV told yesterday about the sound of a vibrator he heard from someones belly. Apparently, it got stuck (in rear reverse ?? :-) ). Shape also reminds me of suppositories and stories of my brother (pharmacist) about them :-| Dirty mind, trying to turn it of, but doesn't work. And anytime I see a UPS car or man, I wonder whether that UPS-girl with the solar-panels works in my area... Know who I mean ?

Anyway,

had heard about the cow magnets but still made me laugh. Whoever thought of this application for magnets must have a sick mind too.

Nando, thanks for the information! Seems you've got quite some experience with one of those. Very to the point, thanks. Anyone ever try to reverse engineer (read: dismantle) one of those shake lights?

We used to own one of those 'squeeze lights' too (until the bulb went out & replacement couldn't be found). If I find one again, I'll modify it to LED & supercad. BTW, over here those squeeze lights are called 'knijpkat' (lit. 'pinch cat'). This has some innuendo, since the proverb 'hij knijpt de katjes in het donker' (lit. he squeezes the little cats in the dark') means something like 'he gets his nookie in the dark'. All this innuendo for such an innocent squeeze light....

BTW, I always got my skin stuck under the squeeze handle; hurt a lot and it happened often. Never liked those lamps. Prefer my Surefires (2 on my body, plus 2 photons; paranoid or what ? )...

That's why I'd like to give the shake light a try; sounds simple, have all the parts, plus it has a huge gadgety attractiveness (and buying them is out of the question; ridiculous prices, 57 E (70$) or around...

Thanks for all the replies so far.

Peter,

The Netherlands.

[dinges]

Oops,

I did a patent search (US patent office website) on the nrs. 5,795,714 and 6,220,719 and it basically gave all the information I wanted or needed... from size of magnets to nr. of turns for the coil and wire size and pitfalls.

Peter.

[judyofthewoods]

There is some really good info on building a shake-light on this site

http://www.creative-science.org.uk/main.html

The pages are in a frameset without individual URLs, so here the path for convenience:

THINGS TO MAKE (in left frame) >Sheake-a-gen  and also  >Shake-a-gen storage device

A free source of large F capacitors (but watch the Voltage, some might not be high enough for white LEDs)is electronic repair shops. Often they have unrepairable circuitboards to throw away, and video recorders or anything with a clock is likely to have a large memory capacitor.

For a tongue-in-cheek adult version check this page

http://www.judyofthewoods.com/lustlight.html

[ghurd]

Mine was more like this, just much more cap storage.

http://www.c-realevents.demon.co.uk/comprecyc/dynotorch.jpg

G-

[ElSenator]

Could I attach a piece of steel pipe around the handle of one of these and make it more effective? Kinda like you would use behind a coil on a windgen.

[judyofthewoods]

My new website is www.judyofthewoods.net and the lustlight link is now www.judyofthewoods.net/lustlight.html