Stone age? (was: George Morrow died Wed May 7th 2003

From: Tony Duell <ard_at_p850ug1.demon.co.uk>
Date: Sun May 11 18:41:00 2003

> OK, you can get the voltage that you need by wiring your spuds in series,
> and the amperage by multiples in parallel. For anybody who has ever
> ACTUALLY produced electricity with a potato, how many would you need to
> light an incandescent flashlight bulb? and how close to the efficiency of

A _lot_...

A couple of years back, HPCC (UK HP user club) had a Newton-themed issue
in December (Newtonsday == December 25th, of course :-)). As everybody
knows the story of Newton and the apple, I decided to try to run a
calculator off a simple cell made from said fruit.

So I stuck a galvanised nail and a piece of copper into an apple. I think
I got about 0.8V and a short-circuit current of 500uA. This was enough to
run a small 4-function LCD calculator...

But to run a small bulb you'd need 1.5V (so 2 cells in series) and
perhaps 500mA (so 1000 branches in parallel). So around 2000 apples... I
guess potatoes are similar.

> a commercial bulb can you get with a homemade one?

My guess is you'd have to run the filament cooler in the home-made bulb
(lower melting point filament wire, and a poorer vacuum). That would
reduce the efficiency.

-tony
Received on Sun May 11 2003 - 18:41:00 BST