I played with ways of turning coils on and off a while ago and had one method that I remember was interesting.
I tried to turn it into a motor and a generator but I kept frying my contacts so I shelved the idea for a while.
Any way it goes it started niggling at me again as to whether or not it was working like I thought so I grabbed some coils and wire and a couple of meters and a magnet to test for an electromagnetic field.
So I did a quick test with the coils hooked up like I wanted and fired them up and then used my "switching method" to turn off a coil or 2 depending on how it is configured, I get this done without opening the circuit or shorting a coil. I could use this setup to move the electromagnetic field around without the need to actually physically move the coils.
