Self charging cell phone battery

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 battery.

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.

y,

Quite similar to the self winding mechanical wrist watches.

Certainly nothing new !

It's called "energy scavenging". It's a big thing in portable product design. If it reduces battery size, or eliminates the battery, it's a winner. I'm finding such ideas in watches, shoes, automobile shock absorbers, PDA's, etc. It will take a while for them to come to market but I expect them to be commonplace fairly soon.

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.

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.

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.

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?

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 phone.

This was the early 1970's. What's a computah? The original pager was Motorola H04ANC (all germanium). I later hot wired it to a Pageboy I and a much nicer Pageboy II. This was all before the introduction of LCD displays on pagers. You either got a blast of tone (tone only pager), or you a blast of tone followed by a blast of unintelligible noise (tone and voice). LED displays were around, but between the logic and the LEDs, sucked far too much power. My wind up mechanism printed a permanent record of the message on a 1/4" wide strip of paper. The mechanism was similar to a stock ticker, but much smaller. The drive was mechanical, but the printing pins were solenoid driven. The solenoid drivers, idler/capstan ratchet, tone decoder, and timing, were the major electronics, which ran off 2ea AA batteries. If I had to include a battery to power the tape motion mechanics, my guess would be about 6ea AA batteries. While not a totally mechanical replacement, it wasn't all that horrible for the 1970's technology.

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

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

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

Watch out for exploding cells, though. ;-)

Sorry. I thought you meant the paper tape pager printer. I never built the wind up floppy disk drive. You're correct that the drive would require power to run the electronics. The plan was to power it from a small generator connected to the clockwork spring mechanism. I built a non-functional prototype to impress the investors. It didn't work because I couldn't keep the 300 rpm rotation speed sufficiently constant for reliable operation. The head actuator was run by a stepper motor, but I had some ideas to make it mechanically driven. When I saw the first 3.5" floppy disk drive in about 1984, I gave up.

I suppose you don't want to hear about my gasoline engine powered hard disk drive?

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 manual.

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

Does it meet EPA specs?

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?

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

Nope. It was a Seagate ST225 20MB disk drive. (That's megabyte, not gigabyte). It had a large flywheel spinning at the bottom. I attached a rubber pully and model airplane engine to the drive. The problem was that the laptops of the day had trouble making it through a typical airplane flight. This would extend the operating time of the laptop. Smoke and noise was not considered a problem on commercial airplane flights at the time as this was before smoking was banned on commercial flights.

I need to dig through a few file cabinet drawers to find the manuals. Give me a day or so. I'm fairly sure these were all germanium.

I'm not sure. There were plenty of logic devices using 2N404 xsistors well into the late 1970's. Also germanium audio output and power supply switchers used in 2way radios. While everything I designed in the 1970's used silicon, many of the radios I worked on during the late 1960's and early 1970's were a conglomeration of tubes, germanium, and silicon. For example, the Motorola Motrac series had one model with a silicon receiver, germanium audio and HV PS switcher, and tubes in the driver and RF power output stage.

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.

Nope. I think the author got confused as the Pageboy I would take either battery, but only the NiCad version was rechargeable.

More later.

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.

My Moto Advisor alphanumeric pager ran on a single AA. Lasted as much as 3 weeks. Most anything using 1.5 vdc needs a multivib.

Seiko makes "Kinetic" quartz watches now:

I wonder if the "tiny technological marvel" mentioned as the energy storage device is a supercap or a rechargable battery?

Jeff

Only if it was fully blown, and could back up a floppy in under two nanoseconds. :)