5H25.15 - Rotating Magnetic Field
To demonstrate what happens to a perminant magnet that is suspended in a rotating magnetic field.
Connect one set of coils to channel 1 output of the amplifier. Connect the other set of coils to the channel 2 output of the amplifier. 2 sodium bulbs are connected in series with the coils to limit the current and provide enough impedance for the amplifier. The 2 inputs are connected to 2 different function generators to allow each coil to be controlled separately. Set up a camera on the hanging magnet so the audience can view what is going on inside the coil assembly.
Set each function generator to the same value of about 3.1 Hz. Turn on the amplifer and ramp up the amplitude until both sides illuminate the first yellow bar of the power indicator. To get the magnet to begin to spin, the function generators must be adjusted slightly to one another until the phase is correct. Once that occurs, the magnet will begin to spin. Sometimes it spins continuously and sometimes it will pulse as it is rotating.