This general idea is hardly new. There have been patents for gadgets you
attach to your leg, and body movements generate electricity to charge a
The problem with this patent is that it uses a piezo device. Unfortunately,
they don't generate very much energy. You'd certainly be able to "top off"
the battery, but I don't think you'd be able to bring it back from a heavy
discharge very quickly. Maybe the former is all they care about.
I have a hand-crank radio/flashlight/charger that can charge cell phones.
The problem with building it into the phone iteself is that it's "too big"
for such a small device.
Incidentally, I designed, prototyped, but never produced a paper tape
printing pager in the early 1970's. The pager ran on batteries, but
the 1/4" paper tape transport and printing was all wind-up mechanical.
I also proposed a wind-up portable floppy disk drive in the 1980's,
which was summarily rejected by literally everyone as a lousy idea.
I've seen small pancake PM motors that are made to be wound up with a
pull string. They're flat, small, and fairly powerful. Most of the
space in the flashlight contraption is in the gears to gear up the
speed. It can be done.
Think of it as a form of hand exercise while yacking on the cell
I'm fairly sure the H03ANC pager was all germanium xsistors. I don't
have a manual for it to check. I think (not sure) that the next
model, the Pageboy I, was all germanium, but I'll have to check the
I know the associated walkie talkie, the HT200, was all germanium,
because I worked on enough of them. I should also have a manual for
I could be wrong, but my memory is that germanium transistors were "dead and
gone" by the early 70s. Certainly they'd disappeared in audio equipment.
Germanium devices had higher carrier mobility, so at that time (I believe)
they offered better performance at VHF and higher frequencies. (This pager
Is there really such a thing as a rechargeable mercury battery?
The big advantage of germanium for portable equipment
was that it would operate at a lower voltage than silicon.
For switching power supplies (i.e. free running multivibrator
with no regulation or protection), the lower saturation voltage
of germanium meant less loss and less heating.
Didn't some of those pagers run on a single AA cell? You're right -- even
with a switching supply, that would have been difficult with silicon
devices. At least, if you wanted to get reasonable battery life.