>
>Certain analogue filters will also give sine _and_ cosine output, which
>could be put to good use generating a nice rotating magnetic field:
>two coils angled at 90 deg to each other.  Stick a permanent magnet
>inside this and voila - a synchronous motor.
>
Interesting suggestion, let me clarify by saying the motor I'm using is a
Globe model with 3 coils at 120 Deg. apart.