Heh heh ... looking again at the mechanical PNP one, well, it wouldn't even work! The cord won't pull up the emitter hatch when the base opens.
I'm working on a water based transformer analogy using propellors that have magnetically coupled gear 'teeth' on the outside. The bigger propellor in one water pipe, equivalent to the transformer primary, then turns say a smaller propellor (the secondary), which spins faster in its water pipe. Faster means more pressure= more voltage but less unit flow= less current.
Are you following all this??
Edit: the only problem with this model is that with steady state 'DC' water flow it would couple...obvs no good..damn