[time-nuts] A different timenuts interest

Kasper Pedersen time-nuts at kasperkp.dk
Thu Jul 22 08:06:23 UTC 2010


On 07/22/2010 02:13 AM, Morris Odell wrote:
>
> The pendulum requires a sustaining system to compensate for the inevitable
> energy loss with each swing. The system is located in the building and
> therefore rotates relative to the pendulum. It needs to provide an impulse
> which does not affect the plane of oscillation of the pendulum. I was
> thinking of an electromagnet located below the centre of the swing which
> would be pulsed appropriately as the bob passes over it.
>

As a kid, I did a self sustaining pendulum with no moving parts and no 
magnets:

The bob was suspended by two parallel wires, lacquered together, and 
shorted at the bob end. As the bob passed over the center, a one-shot 
sent a good-sized current pulse through the wire, heating it, making it 
slightly longer, and then shrink again as it cooled at the outside of 
the swing.

For a heavy pendulum, and thick wire, the time constant in the cooling 
phase will likely make this infeasible.

/Kasper Pedersen




More information about the Time-nuts_lists.febo.com mailing list