
Oxford Electric Bell - okket
https://en.wikipedia.org/wiki/Oxford_Electric_Bell
======
okket
Previous discussions:

2014:
[https://news.ycombinator.com/item?id=7833010](https://news.ycombinator.com/item?id=7833010)
(60 comments)

2013:
[https://news.ycombinator.com/item?id=5995422](https://news.ycombinator.com/item?id=5995422)
(13 comments)

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jhallenworld
It's fun to make one of these: use two metal coffee cans, suspend a washer
between them using string tied on a plastic comb or something. There should be
only a small gap between the washer and each can. Charge one of the cans- rub
styrofoam on fabric then touch it to one of the cans. The washer will swing
back and forth, transferring the charge from the can you touched to the other
one. It makes quite a racket.

You can make a chain of these.

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LeoPanthera
I used to work at the Clarendon Lab and made this video about the bell while I
did:

[https://youtu.be/1Dx1-f8xQio](https://youtu.be/1Dx1-f8xQio)

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mrfusion
How many joules or watt hours has these used?

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zaarn
Some quick, back-of-the-envelope-math, suggests the total energy used amounts
to about 1'389 mAh (roughly 5 Coulombs, based on an article saying it
transfers about 1 nanoampere of current per ring and rung about 10 billion
times since it was completed).

Watthours and Joules is difficult to know without measuring the voltage on the
device, which would also have to involve the change in voltage over time to
get a more accurate number. I'm probably wide off once you account for the
reduced power over time.

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tim333
You'd think a battery like that lasting decades could be quite handy for
internet of things devices. You could maybe use a capacitor to accumulate
power as the output seems to be in nano amps and low current processors seem
to need about 1 uA upwards. Not sure if anyone is working on that stuff?

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hnarn
> You'd think a battery like that lasting decades could be quite handy for
> internet of things devices

We probably have to invent a standard that lasts one decade first.

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lb1lf
The humble AA/R6 battery has been around since before WW1.

Obviously, the capacity has improved vastly, but the size, terminals and
voltage has been with us since your great grandfather wore diapers.

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phinnaeus
I think GP was referring to a software or service standard for the IoT device
to interact with rather than a hardware standard.

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mrfusion
I firmly believe there’s an ocean of undisovered applications for
electrostatics.

