Permanent Magnet Devices

First experiment. July 2000
This is what I used when I first experienced the mind-altering effect from exposure to low frequency magnetic fields. The NeFeB magnet is diametrically magnetized. I assumed, incorrectly, that the effect was caused by induced electrical currents in the brain. See story on the 'About this Site' page.
November 2000
Next, I designed a professional product and made a small production run. A free-spinning ball bearing rotor containing a large NeFeB magnet is spun to an initial speed of 20-30Hz by dragging the small rubber spindle over a finger or a long stick. The rotor coasts to a stop in about a minute. In use, the device was typically held close to the top of the head, and produced a mild feeling of euphoria. The effect was subtle, and only about 2/3 of those who tried it felt anything.

When spun to higher speeds of 35-55 Hz and stroked over the legs for a few minutes, the device completely relieves RLS symptoms for several hours.

Counter-rotating magnets. November 2003
Counter-rotating opposed magnets are driven by a 470 rpm induction motor, resulting in a 7.83Hz oscillating dipole field. This was equivalent to a wire-wound solenoid driven by an AC current. The purpose was to look for evidence that the effects on the mind are mediated by magnetic particles in the head that are physically moved by the field, as opposed to eddy currents generated by the changing field. To do this, the dipole was aligned with the Earth's field and effect strength at 20 feet was compared with other orientations. Although there was no effect when aligned with the geomagnetic field, the effect at other orientations was weak and I considered the experiment inconclusive.
Computer-controlled magnet. March 2004
Computer controlled 1 x 2 x 0.5 inch NeFeB magnet. A Quatech digital frequency synthesizer adapter for the IBM PC could be set at arbitrary frequencies with 8 digit resolution to drive the magnet from 2-15 Hz.  Ramps and frequency hopping were also possible. Used to investigate anecdotal reports of unusual sensitivity to special frequencies, such as the Schumann resonance at 7.83 Hz. None were found, however reports of 6 Hz causing an unpleasant feeling seemed to have merit. Also, above 10 Hz the response tapered off to near zero at 15 Hz. Surprisingly, the maximum range was about 10 feet, where the field strength was only 0.2% of the Earth's geomagnetic field.
August 2009
This was my first experiment that did not use permanent magnets. Three orthogonal Helmholtz coils were used to find out if a rotating magnetic field exactly equivalent to the Earth's geomagnetic field would produce a mind altering effect. Much to my surprise, a test at 0.5 Hz produced an effect stronger than any of the previous devices. This rotation rate was well within the normal turning rates that humans experience in everyday life.
Counter-rotating Mind Orbit November 2009
Taut-band device with 2 counter-rotating opposed 1 cubic inch magnets for rhythmically changing the amplitude, but not the direction, of a dipole field. In operation, the device is held at waist level parallel to the ground, beneath the head, and the cylinders are rotated 90 inward and outward. In the mid-latitude northern hemisphere, the sum of the varying field plus the Earth's field will rock back and forth up to 60, causing a powerful effect on the mind.

If the device is used upside-down, such that the dipole field is not in opposition to the geomagnetic field, it will not work. This is compelling evidence that the effect is mediated by magnetic particles that respond to magnetic torque, as opposed to eddy currents that would be unaffected by the Earth's background field.

Wrist ball Mind Orbit January 2011
This device uses a commercial gyroscopic wrist exerciser ball to rotate a 0.28 cubic inch N42 neodymium magnet at speeds of 1-2 rev/sec. Despite the smaller magnet, it is quite effective, perhaps due to the varying orientation of the magnetic field spin axis. However, about 10 minutes of use is required to produce a moderately strong effect.

May 2013
The rotor on this apparatus contains 30 Br 3850 ceramic magnets, each weighing 4 lbs, for a total magnet weight of 120 lbs. The rotation speed is 1 rev/sec. The inner frame can be swiveled to change the rotation axis from vertical to horizontal. At a close range of 10-20 feet it is intensely powerful; a 30 second exposure can cause a stoned feeling that lasts for hours. Maximum effective range is about 100 feet when the exposure time is 15 minutes. At this distance the magnetic field is less than 0.1% of the Earth's geomagnetic field. The machine has been tested on many people, and clearly demonstrates that humans can experience a strong mind-altering effect when exposed to sinusoidally varying 1 Hz magnetic fields, even at strengths orders of magnitude weaker than the Earth's geomagnetic field.
Plot of magnetic field strength