An interesting idea occured to me today while at work. If we were to use
the same principle used in the acoustic compressor, and using an
electromechanical oscillator, we could create a standing wave in a
suitable size of magnet. I was thinking that this action by creating the
various compressions and rarefactions associated with sound (or in this
case mechanical) waves, the flux of the magnetic field would vary in
response. If, for example, our magnet's resonant mechanical (acoustic)
frequency was 50KHz (too high?), and we pinged a rather powerful 25KHz
wave into it, it would create a 25KHz standing wave. If the oscillator
being used to induce this standing wave were a VCO (voltage-controlled
oscillator), then hooking a microphone up to the Voltage Control side of
the circuit, we could Frequency Modulate say a human voice onto this
system and transmit via a purely magnetic signal.
BillP