A "Large Coil" parametric circuit

by Fred B. Epps

Created on 23 August 97

Date :   20/08/1997 11:56:59    
From:	fepps@halcyon.com (Fred Epps)
Hi Folks!
   In the spirit of others who have built or discussed overunity devices
using large coils, here's mine.  It is a parametric transformer that uses
large coils to create a large change in L in ferrite or metglas cores which
is tapped by a parametric output circuit for power.  According to Stefan
Hartmann's understanding of the Newman motor, this could be called a Newman
transformer, understanding of course that Mr. Newman's explanation for his
motor is totally different. In the attachment you will see three identical
pairs of coils.  (The number of pairs is arbitrary.)  The primary circuit
consists of parallel windings across all six coils in a resonant tank
circuit driven by a low-power oscillator.  These windings have many turns
and are individually high inductance, although because of the parallel
arrangement the L of the primary tank as a whole is relatively low. The
secondary consists of much smaller windings in a series resonant circuit
with the load.  Every other secondary winding is in reverse direction so
that the sum EMF generated by induction is zero.  There is no back EMF
because there is no forward EMF-- the energy transfer is entirely through
the changing inductance.
   The cores consist of manganese zinc ferrite or other magnetic material
with a high variation of mu with applied field.  The entire core assembly
may be biased with an orthogonal permanent magnet field to put the cores at
the knee of their B/H curve, to maximize change of L with changing primary
   How it works:  it is conventional that a large coil generates a large
magnetic field, thus the fields in the primary coils are large for a given
current. Since the core materials are set up so that even a small variation
in field causes a large variation in L, it takes a very small oscillating
current in the primary to cause large changes in the inductance of the
   The energy in a parametric circuit is strictly dependent on the
variation of inductance in that circuit.  This also is conventional,
although not as widely known.  Therefore the current in the resonant output
circuit will be high.  Small current in, large current out...it's as simple
as that.
   Actually it's not as simple as that-- it never is :-)  The large current
flowing through the output circuit does load the primary to a certain
extent by changing the inductance of the cores in opposition to the
primary's effect.  But this effect is minimized by the large difference
between the size of the secondary and primary coils.  And the primary
current is so small that even if it were to double because of the loading
it would still be small compared to the output. (Keep in mind that the
usual voltage/winding equation in transformers does not apply here, since
there is no induction).
   I will be interested in comments, especially critical ones.

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