Re: Shakin' Fake Flashlights

"Ancient_Hacker" (grg2@xxxxxxxxxxx) writes:
Paul E. Schoen wrote:
I bought a motion-powered flashlight from a Chinese vendor at a flea market
in Harpers Ferry last year. It was only about $2, and it had a fairly
bright blue/white LED that came on when I turned the switch. I could see
that there were two coin cell batteries inside, but there was also a coil
through which a magnet would pass when the light was shaken, and a little
PC board connected to the coil. It appeared that the light got brighter
when I shook it. I used it for a while, and I misplaced it.

Watch out-- I got one of these flashlights for xmas. Very interesting
insides. A quick peek and my dubiousness-meter pinned. The coil had
about 40 turns of wire on it. The PC board had NO components on it.
Opening it up, the moving "magnet" turned out to be non-magnetic.

I guess what happens is if the factory runs out of supercapacitors or
diodes or runs low on coil wire, they switch over to making "fake"
flashlights. Well, they're flashlights all right, but "shake to
charge" in looks only.

If you look closely at the pictures of these flashlights on eBay, a
good 20% of them have no parts on the PC board. Hard to rectify and
store shake energy without rectifiers or capacitors.

I have one of the LED flashlights that has a crank to turn that charges
a battery. It's still doing fine after a year and a half, and it would
be an odd application where I couldn't stop to crank it rather than
simply shake a shaking flashlight. It is more expensive than the
shaking flashlights being talked about. And it's not as bright as
the LED adaptor I bought for my Maglite.

ON the other hand, I once bought an LED flashlight that was in a package
similar to the cheap laser pointers, and when the batteries ran out (the
switch kept activating while in my pocket), I just bought a $1.99 laser
pointer and used the batteries from that. It seemed cheaper than
buying batteries separately (and I have the laser pointer to run from
an external supply if I ever get around it). Actually, the laser pointers
turned out to use the same batteries as a number of items I have around, so
they become a good source of batteries.

Michael


.

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