I just spent a few hours going over all the info I could find on this thing.
What Steorn has done is to intercede two magnetic fields in a helix configuration. The toroidal coils do indeed have an exterior magnetic field, but
it is a closed field (as opposed to an open field which has an area that is easily interacted with by other objects, like a horseshoe magnet). When
the toroids approach the pairs of magnets mounted on the wheel, they are switched on. This allows the toroidal magnetic field to interact with the NIB
magnets on the wheel, giving a tug of attraction and spinning the motor.
Since the toroidal field is closed and the NIB magnets are set (apparently) in opposing directions, the attraction exists regardless of the direction
of the toroid field. The only difference in the magnetic forces would be a torque trying to twist the toroids around, which is countered by the
mounting. Reversing the polarity of the applied current only reverses this torque, not the attraction.
The motor direction is set by the optical encoder used for timing the pulses. Adjust that and the motor will change its direction.
As to back EMF: Back EMF is created by a collapsing magnetic field perpendicular to the wires. The arrangement of the toroids means that there is no
collapsing field at right angles tot he conductors, thus no back EMF. In that regard, this is an ingenuous design. The closed field of the toroids as
well as their orientation relative to the wheel keeps any change in magnetic field away from the loops of wire.
That was Steorn's rig; as to the JNL rig:
In this case the toroids are turned with respect to the wheel, with their centerlines facing the wheel instead of parallel to the axis. Also, single
NIB magnets are used instead of pairs. Thus, this is not an exact duplication of the Steorn design, but rather an adaptation. Still, the fact that it
works so well indicates the flexibility of using toroidal coil design.
The lack of back EMF is for the same reason as in the Steorn design. In both cases, the toroidal field and positioning insulates the wire loops
forming the coils from perpendicular interaction with the NIB magnets.
Also, JNL uses a Hall effect sensor instead of an optical encoder. there is really no difference in the final operation of the two different
approaches; both simply turn the toroids on and off at the appropriate time. The optical encoder is much simpler and easier to build, but the optical
switches can be pricey. I would assume that cost is the reason JNL went the Hall effect route. If anyone tries to use a Hall effect sensor, remember
that the position of the sensor is critical and will need to be adjusted to get the best efficiency out of the motor. Notice JNL uses tape to secure
the sensors... there is a reason for this.
The electronics used to control the coil current is very simple, and yes, it can be built at home if anyone wants to try it. A quick tip on working
with MOSFETs: the gate terminal is very sensitive to electrostatic fields! Make sure you are grounded when working with any type of CMOS or MOSFET
devices! A discharge too small to see or feel will blow the MOSFET in a microsecond. I have installed strictly only incandescent lights in my shop
(florescents give off electrostatic fields) and I am touching a grounded piece of metal every few seconds to make sure any static build-up in my body
is dissipated. Also avoid working in carpeted areas, as carpet tends to create electrostatic fields as well. And lastly, make sure your soldering iron
has a grounded tip. If it only has two prongs where it plugs in, the tip is not
If anyone has ever built computers from boards,it is the same principle why you continually touch the case while assembling, just more sensitive since
the components are not pre-mounted on boards.
I'll put in a shameless plug for the place where I get my magnets: KJ Magnetics
. They have been very reliable
and have a good selection of smaller NIB magnets as well as decent prices.
Now, as to whether or not this is over-unity... no, it is not. At least, no more so than any electric motor. It is simply efficient, probably due to
the lack of back EMF. The power is being supplied by an external source, not by the device itself. I do believe that there is an inherent property in
permanent magnets that appears to defy the laws Conservation of Energy, but to date no one has been able to develop this in a useful form. The same
goes for gravity. In both cases, the problem is that we are not able to switch either ferro-magnetism or gravity on and off to create usable
And neither has Steorn or JNL at this time, in my 'expert' opinion.
Oh,and there is a financial consideration here as well: the Steorn Knowledge Database (SKDB)
fee of €419.00 (about $600 at present exchange rates) annually. The License Agreement can be found
for those interested. I personally would not waste my resources at this
I will not degrade Steorn for offering this license at this price. Should I have technology that appeared to be a good investment for others, I would
probably do the same. However, I would personally want more information (such as what is shown on
) before investing,and would certainly not invest
merely on the basis of YouTube videos.
It's a very interesting and very efficient electric motor, and would make for an excellent science project or learning tool. But it is still just an
electric motor. Nikola Tesla would be proud.