I must've gotten lucky, because I picked up a few years ago cheap and they are 
the real deal. Works great - real magnet, proper coil. I have a question 
though, as I've only peered through the clear plastic at the circuit without 
much detail. I wound a small coil (a few hundred turns) around the flashlight 
at the area of the inner coil and applied (IIRC) an approx 12v 60Hz sine wave 
to it. My idea was to see if I could apply an external field and maybe keep it 
'charged and ready' at full power in a stand or such.

It wasn't an overly scientific or controlled test, but I figured I could get it 
to a little peep of light after some time. Nothing though... Took it out, a 
couple of shakes - light again.

I got involved in more serious things and dropped it, but the discussion 
reminded me. Has anyone here tried this or have any ideas, should one want to 
make such a thing?

Thanks,
Skip


Jonathan Hallameyer wrote:
> Ive seen both, the real shaker flash lights use a supercap to hold 5v @
> 1farad or so, and have a bridge rectifier from the coil etc.. like you would
> expect.
> 
> The knock offs from china contain a coil of magnet wire, just one layer
> typically, which in the one Ive seen both leads were soldered to the same
> pad on the pcb, and there was still 4 diodes, hooked up to nothing, and 2
> 2032 coin cells stacked where the cap would go. The knock off ones are
> cheap, the legit ones are pricy, as you would expect.  (guess that super cap
> and all that copper for the coil adds up...)
> 
-- 
http://www.piclist.com PIC/SX FAQ & list archive
View/change your membership options at
http://mailman.mit.edu/mailman/listinfo/piclist