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Electrostatic pendulum

I have been looking at the Oxford Electric Bell which has been running since 1840 using Zamboni piles*. There are 2 stacks each having a voltage of 2kV. These piles(cells) have a very high impedance and a voltage around one volt, so 4000 piles would be required. I have done some work trying to create these piles from zinc paper, MnO2 and wall paper paste, but so far I have not been too sucessfull! So as proof of concept I created a 4kV / 5uA supply from a Hartley Oscillator and Cockroft Walton multplier * 10 which only uses 5vdc at 10mA .

4kV PSU

The ball of the pendulum is made from masking tape rolled into a ball and covered with aluminium tape, it is suspended from a cotton thread. The 2 contacts/plates are 5cm apart, this was calculated by trial and error… The principle is when the ball hits say the positive plate it picks up the 4kV charge and being of the same charge, it is repelled, the opposite happens at the negative plate.

The proof of concept seems to be good, so I now need to start making the Zamboni piles!

*There is a high probability that they are Zamboni but as yet nobody has opened them up to investigate.