The Howard Johnson's permanent magnetic motor

created on 03/04/98 - JLN Labs - last update on 01-02-01

The Johnson's permanent magnetic motor uses the principle of a constant imbalance of the magnetic forces between the rotor and the stator. This permanent imbalance of the forces must be always maintained in the same direction during the complete revolution of the rotor (0 to 360 degres). By this way, the only source of energy will be the magnetic energy from the magnets.

I have made a closed loop simulation with the QuickField software, but it is not necessary in this case because, as you can see in the QuickField picture below, the magnetic configuration is periodic. The magnetic configuration is reproduced every 45 degres.
I have noticed in my design that the shape of the little curved magnet (the magnet actuator) is very important and also the gap between the rotor and the stator. In most cases of configuration (shape and gap), the rotation stops, because the magnet actuator blocks on a reversed magnetic field density. I have checked this with the QuickField simulator, and this causes to me some difficulties to find the correct setup. Today, I think that I have understood how to tune the Johnson's motor.

In this picture below, you see the global setup of this permanent magnetic motor.

You will find below an example of the magnetic flux density around the actuator magnet ( the small boomerang). This is the most important thing to understand.

In the magnetic flux density curve you will see two troughs in the curve, the first is the flux density above and the second is flux density under the actuator. You will notice three peaks : the first and the last are the south pole of the magnet and the middle peak is the north pole.
The MOST IMPORTANT THING for obtaining a continuous rotation of the PMM is that the flux density of the north pole MUST BE ALWAYS LOWER than the flux density of the south pole. If this condition is always obtained, for EVERY ANGLE of rotation, the PMM can turn continuously. :-)

If unfortunately, for only one angle, the flux density slope reverses, then the PMM will stop..... :-(
Today I have found the correct setup for obtaining this condition for all the angles....

You see below, the first decisive document about the Johnson PMM, as you can see in the main picture of the motor, the magnet actuator rotates around the magnets ( the reciprocal is possible ). The geometric configuration is repeated every 45 degres, thus this is the period. In my simulation I have included 12 magnets with a step angle of 30 degres. Also the simulation includes the COMPLETE SETUP of the final design because the main problem of all PMM is the closed loop, this is the reason why I have used the complete configutation. You notice that the zero field edge is placed far around the PMM and it is CIRCLE SHAPED for avoiding all interferences with the PMM simulation.

In the graphic below you see three curves, this is the most decisive part.....
- the
PINK curve represents the flux density at the South pole of the magnet actuator,
- the
BLUE curve represents the flux density at the North pole of the magnet actuator,
- the
RED curve represents the resulting flux density between these two poles, this is very important, and you notice that the resultant flux density is ALWAYS POSITIVE, the continuous rotating condition is now obtained with this setup, because the resulting force is always oriented in the same direction, thus the PMM can accelerate.....

The last graphic shows the curves of the magnetic flux density for a complete turn of 360 degres. As I have said before the period is 45 degres and you can see for each 45 degres a "magnetic spike", this is the regauging area.
We have an incremental periodic and asymetric potential (4 bumps), the 4th bump is the regauging bump. This is the most difficult part to tune, because in this area the flux density can be reversed and this would stop the PMM.
If the Johnson is correctly built and finely tuned, we have the possibility to violate the second law of the thermodynamics by the use of the Rachet potentials.
(see the document from Dieter Bauer at: http://www.overunity.de/magmotor/magmotor.htm)

This motor has already been patented : US4151431 : Permanent magnet motor by H.R.Johnson