S. Gunnar Sandberg
(School of Engineering & Applied Sciences, University of
The objective of this report is to reconstruct the experimental
work carried out between 1946 and 1956 by John R. R. Searl that
concerns the geometry, materials used, and the manufacturing
process of the Sear1-Effect Generator (SEG).
The information given here is based on private communication
between the author and Searl and should be considered
preliminary as further research and development may give reason
to alter and/or update the content.
The SEG consists of a basic drive unit called the Gyro-Cell
(GC) and, depending on the application, is either fitted with
coils for generation of electricity or with a shaft for transfer
of mechanical power. The GC can also be used as a high voltage
source. Another and important quality of the GC 1s its ability
The GC can be considered as an electric motor entirely
consisting of permanent magnets in the shape of cylindrical bars
and annular rings.
Figure 1 shows the basic GC in its simplest form, consisting of
one stationary annular ring-shaped magnet, called the plate, and
a number of moving cylinder-shaped rods called runners.
During operation each runner is spinning about its axis and is
simultaneously orbiting the plate in such a manner that a fixed
point p on the curved runner surface traces out a whole number
of cycloids during one revolution round the plate, as shown by
the dotted lines in Figure 2.
Measurements have revealed that an electric potential
difference is produced in the radial direction between plate and
runners; the plate being positively charged and the runners
negatively charged, as shown in Figure 1.
In principle, no mechanical constraints are needed to keep the
GC together since the runners are electromagnetically coupled to
the plate. However, used as a torque producing device, shaft and
casing must be fitted to transfer the power produced.
Furthermore, in applications where the generator is mounted
inside a framework, the runners should be made shorter than the
height of the plate to prevent the runners from catching the
frame or other parts.
When in operation, gaps are created by electromagnetic
interaction and centrifugal forces preventing mechanical and
galvanic contact between plate and runners and thereby reducing
the friction to negligible values.
The experiments showed that the power output increases as the
number of runners increase and to achieve smooth and even
operation the ratio between external plate diameter Dp and
runner diameter Dr should be a positive integer greater than or
equal to 12. Thus:
(1) P/Dr = N > 12 (N = 12, 13,
The experiments also indicated that the gaps O between adjacent
runners should be one runner diameter D as shown in Figure 1.
More complex Gyro-Cells can be formed by adding further plates
and runners to the basic unit. Figure 3 illustrates a 3-plate GC
consisting of three sections, A, B and C. Each section consists
of one plate with corresponding runners.
The experiments showed that for stable and smooth operation
sections should be of equal weight. Thus:
(2) WA = WB = WC
WA = weight of section A,
WE = weight of section E,
WC = weight of section C.
The Magnetic Field Configuration
Due to a combined DC and AC magnetising process, each magnet
acquires a specific magnetic pole pattern recorded on two tracks
consisting of a number of individual N-poles and S-poles, as
illustrated in Figure 4.
Magnetic measurements have revealed that the poles are
approximately one millimetre across and evenly spaced. It was
also found that the pole density (x) --- defined as the
total number of poles N per track divided by the circumference,
pi D --- must be a constant factor specific for a particular
x = Np / 3.14 Dp = Nr / 3.14
where Np is the total number of poles per track on
plate and N r is the total number of poles per track
Furthermore, the distance dr between the two pole
tracks must be the same for all runners and plates which are
parts of the same GC.
The pole tracks allow automatic commutation to take place and
create a turning moment. Exactly how this is achieved is not
understood and will require further research efforts.
Likewise, the source of energy is at present unknown. Further
research is also needed to establish the exact mathematical
relationship between output power, speed, geometry and material
parameters, such as mass density and electromagnetic properties
of the materials used.
The magnets used in the original experiments were made of a
mixture of two types of ferromagnetic powders imported from the
USA. One of these magnets, still in existence, has been
qualitatively analyzed and was found to contain the following
elements: Aluminum, Silicon, Sulfur, Titanium,
Neodymium, Iron. The spectrogram is illustrated in figure 5.
The Induction Coils
If the SEG is sued as an electrical power plant a number of
induction coils must be fitted to the GC. The coils consist of
C-shaped cores made of soft steel (Swedish steel) or high
u-ferrite (mu-metal). The number of turns and wire gauge used
depends on the application. Figure 6 shows the basic design.
The block diagram in Figure 7 illustrates the main stages in
the manufacturing process.
(1) Selection of Magnetic Materials >> (2) Weighing
>> (3) Mixing >>
(4) Moulding >> (5) Machining >> (6) Inspection >
(7) Magnetization >>
(8) Inspection >> (9) Assembly >> (10) Final
Stage 1: Magnetic Materials & Bonding Agents
It is feasible that future research will reveal other magnetic
raw materials to be cheaper and/or more efficient than the ones
used in the original experiments. It is also possible that other
types of binder may improve the performance.
Stage 2: Weighing
In general, to produce efficient magnets the right amount of
each element contained in the ferromagnetic powder is crucial.
It is therefore reasonable to suggest that when mixing different
types of powders an optimal weight ratio does exist that will
produce a 'best' magnet.
At present, however, this weight ratio is not known for the
powders used by Searl in his past experiments. Together with new
magnetic materials and optimization of generator geometry, this
is an area in which research efforts could be profitable.
In general, the amount of binder used should be as small as
possible to achieve maximum mass density of bonded magnets.
However, the possibility that the binder is taking an active
part in the generation of the Searl-Effect must not be excluded.
For instance, the dielectric properties of the binder may play
an active role in the electromagnetic interactions taking place
in the SEG. If that is the case, then a further amount of
bonding material may be beneficial.
Stage 3: Mixing
The mixing is an important process which will decide the
homogenity and reliability of the finished product. A
homogeneous mixture can be achieved by using turbulent air flow
inside the mixing container The experiments did show that an
improved performance was achieved if all magnets for the same
generator were made from the same batch.
Stage 4: Moulding
During the moulding process the compound- consisting of
ferromagnetic powders. and thermoplastic binder is compressed
and simultaneously cured by heating. Figure 8 illustrates the
tool used for making 'blinds'. A 'blind' is an unmagnetized
runner or plate/part of plate. When manufacturing large plates
(Dp > 30 cm) it may be necessary to make them in
segments rather than in one piece.
The figures given below should be considered as guidelines
only, since correct data are not available regarding the
influence of the moulding process on the Searl-Effect.
1. Pressure: 200-400 bars
2. Temperature: 150 C-200 C
3. Compression time: > 20 minutes.
Before releasing the pressure the mould must be allowed to
Stage 5: Machining
This process can be bypassed if the weighing and moulding
procedures are carried out correctly. However, it may be
necessary to polish the cylindrical surface of runners and
Stage 6: Inspection
Control of dimensions and surface finish.
Stage 7: Magnetization
Runners and plates are individually magnetized in a combined DC
and AC-field during one on-off duty cycle. Figure 9 illustrates
the magnetizing circuit.
The function of the automatic control switch (ACS) is to
simultaneously switch on the DC-current, idc and the
AC current, iac at such a time, t = ton,
that the instantaneous value of the total magnetomotive force
(MMF) is always positive. Thus:
MMF = idcN1 + iacN2> 0
Where N1 is the number of turns in the DC-winding
and N2 is the number of turns in the AC winding.
Figure 10 shows the total MMF as a function of time.
The magnetization coil consists of a DC winding containing
approximately 200 turns of heavy copper wire and an AC winding
containing approximately 10 turns of copper strip wound on top
of the DC winding. Figure 11 shows a cross-section of the coil
and its dimensions.
Recommended parameter values:
DC current, idc = 150 A to 180 A
AC current, iac = 0.1 to 0.2 A
Frequency, f = 1-3 MHz
Stage 8: Inspection
The purpose of this control is to test for the existence of and
the correct spacing of the two pole tracks. The measurements can
be made with a magnetic flux density meter in combination with a
set of control magnets.
Stage 9: Assembling
The assembling procedure depends on the application. Used as a
mechanical drive unit, the magnets must be mounted inside a
framework and fitted to a drive shaft. Used as an electric power
plant, induction coils must be fitted to the framework.