Shaker LED flashlight

Have you tried removing the batteries and NOT shorting the holder? They may be using the batteries as storage devices.

Nope, they're nearly always lithium coin cells, which are primary cells (i.e. not rechargeable). It's a gimmick to attract the ignorant. The coil doesn't even slow down the weight as it goes by, so how is it going to extract any energy from it?

Try dropping a rare-earth magnet down a copper tube, if you want to see what a shake-type generator ought to look like.

Cheers,

Phil Hobbs

I have a shakey light. It has a clear case, you can see all the circuitry. No batteries.

But the OPs light may still work without the batteries if the remainder of the circuit is properly designed.

Since my post I drew out the schematic and yes, by shorting the battery holder I was shorting the storage capacitor. The LED does light, but very dimly. Also I noted the capacitor was not soldered to the board, it just had the leads bent. Interesting also is that the 5.5v capacitor has 6v of batteries across it. Mike

amdx has a rip-off--those use coin cells. The original, authentic shake light used coil+magnet.

Best, James Arthur

I don't mean it can't be done. But all the ones I've seen had coin cells.

Cheers,

Phil Hobbs

Well, the good news is, you now know of a cheap source of CR2032 batteries (which can be expensive elsewhere)...

Michael

Actually, there are cheaper sources. I got some of them for a penny each, after throwing away the ASIC and 100 SMD LEDs. I need a few thousands of them, but it wouldn't justify the gas cost. CR2032s are approximately 25 cents each in volume.

plates

Correction, digikey has them for 14 cents each in QTY 4000.

plates

Where'd you get the ASIC and LEDs?

I've got to stop shopping at Wal-Mart...

flux

plates

Try the yellow one next to it.

"amdx" wrote in news:85a60$47850f6e$45013935$ snipped-for-privacy@KNOLOGY.NET:

mine had a CR2032 and a CR2025,NO CAP,coil not connected,the "magnet" was an unmagnetized soft iron slug.

Phil Hobbs wrote in news: snipped-for-privacy@SpamMeSenseless.pergamos.net:

who says the "magnet" really IS a magnet? Mine wasn't. just a soft iron slug.

On the fakes, I'm sure it is. That's why it doesn't interact with the coil. No dB/dt, no induced voltage, no opposing magnetization, no drag on the weight--rattle rattle.

Terminal velocity for a 5/16 inch NdFeB magnet dropped down a 1/2 inch copper pipe is about 1 foot per second. You can easily see the difference between copper, aluminum, and brass tubes due to their conductivity. It's pretty interesting to watch.

Cheers,

Phil Hobbs

Yup lots of fakes, or so I've heard. Mine has no batteries, and the illumination is proportional to the # of shakes, up to a point where additional shakes make no change. And it has a magnet, of course. Damn thing can almost support the flashlight's weight when held against the 'fridge.

Ed

I was going to post, at least I got two cr2032 batteries inexpensively, but then I decided they are probably worth what I paid for them. Mike

And only $4.99 at Radio Shack! Mike