5H30.35 - Rotating Plasma - DC Arc

Code Number:
Demo Title:
Rotating Plasma - DC Arc
Magnetic Fields and Plasmas
Area of Study:
Lorentz Force
Induction Coil, Round Electrodes, Magnet in Stand, 12 Volt Power supply.

Video Credti:  Jonathan M. Sullivan-Wood.

Place the electrodes directly on top of the magnet stand so that centering them is easier.  Clean the electrodes with the 3M cloth before use.

12 volt DC input on the induction coil.  Watch how close the wires are on the high voltage DC output sides.  Also, don’t touch the high voltage wires when the unit is operating.

Alignment of the outer points bar on the induction coil is critical for the operation of this demo.  It may need to be moved up or down slightly for it to operate acceptably.

You may need to flip the reed flapper on the induction coil unit to get it started after you turn on the 12 volt input power supply.

The demo should make a high pitched whine like a nest of angry bees when operating as it should.

The 12 volt input should run at 1 amp or less when it operation.  If it is drawing too many amps, the points alignment is not right and the unit is in danger of burning out.

As shown in the movie, the spark (with its plasma sheath) will reverse rotation direction if you switch the wires on the high voltage DC output terminals.  You could also do this by flipping the magnet over, but in our case, that is tied down so the magnet can’t “get away” from you.

  • James Lincoln, Nick Moore, "Five Fresh Lorentz Force Demos", TPT, Vol. 57, #8, Nov. 2019, p. 572.

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