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Self charging cell phone battery


William Sommerwerck

Jan 1, 1970
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.

William Sommerwerck

Jan 1, 1970
I'm surprised nobody has made a wind-up cell phone. Besides not
requiring a battery or charger (uses a super-capacitor), it will keep
the chronic talkers in line. Not exactly energy scavenging, but (in
my opinion) just as good.

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.
Oh, well.

As the drive would have to be connected to computer that could power it, and
the wind-up mechanism + interface would be more complex than a motor -- what
would be the point?

William Sommerwerck

Jan 1, 1970
Incidentally, I designed, prototyped, but never produced a
This was the early 1970's. What's a computah?

You said '80s for the floppy-disk drive, which is what I was referring to..

The original pager was Motorola H04ANC (all germanium).

Really? Perhaps for the RF transistors, but not the rest of the device.


Jan 1, 1970
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 don't like hand exercises. Maybe you could connect it straight to
my jaw, so it would charge when I talked.

William Sommerwerck

Jan 1, 1970
I suppose you don't want to hear about my gasoline engine-
powered hard disk drive?

Does it meet EPA specs?

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
the HT200.

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
was UHF.)

Is there really such a thing as a rechargeable mercury battery?

I still have one or two tube type walkie talkies from that era.
Pencil tubes are fun.

One of my uncles had an earphone-only "very-large-pocket" radio that used
two of these.

William Sommerwerck

Jan 1, 1970
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.