If we alter the definition of a 'Perpetual Motion Machine/Device', ignoring the initial force needed to get it started, if that force, however large or small, was not taken into account, have you and can you think of a 'device' which would need no extra power of any kind, that would work?
It need not be of use, just continue to work. This in itself might suggest uses?
For discussion purposes, Supercooled Magnets are allowed, but do not have to be used. No other continuous power supply of carbon based sources, or Electricity. You can use anything derived from carbon to build it and 'power it', but no fuel of any kind.
All and any ideas are welcome.