Re: slow-wave helical resonator

["Tesla list" <tesla-at-pupman-dot-com>]

Original poster: "Antonio Carlos M. de Queiroz by way of Terry Fritz <twftesla-at-qwest-dot-net>" <acmq-at-compuland-dot-com.br>

Tesla list wrote:

> Original poster: "Malcolm Watts by way of Terry Fritz
<twftesla-at-qwest-dot-net>" <m.j.watts-at-massey.ac.nz>

> It took about five minutes with an oscilloscope to find out that this
> recipe doesn't work for anything. In treating the pri-sec system as a
> master oscillator, the assumption is made that the primary is driven
> by a voltage source and that the pri-sec behaves like a voltage
> source. Unfortunately, neither is true. The primary is driven by a
> charged capacitor which runs down as energy is transferred, and
> coupling constant between primary and secondary of less than 1 or
> close to it also causes the system to deviate from the properties of
> a voltage source.

In my interpretation of the magnifier circuit, the transformer is
optional. The essential circuit is directly coupled:

 o---+--C1--+--L2--+--L3--+
     |      |      |      | 
PWR gap     L1     C2     C3 (distributed)
     |      |      |      |
 o---+------+------+------+--o ground

An ideal transformer can be inserted between L1 and L2, and L1 and L2
can be combined with it to form a real transformer. This doesn't change
anything in the behavior of the circuit, but just adds an extra degree
of freedom, turning possible to scale up or down the impedance level
at both sides of the transformer, and so control the voltage gain
(sqrt(C1/C3)) independently of the number of cycles required for
complete energy transfer.

                n:1
 o---+--C1--+---+ +--L2--+--L3--+
     |      |   ) (      |      | 
PWR gap     L1  ) (      C2     C3 (distributed)
     |      |   ) (      |      |
 o---+------+---+-+------+------+--o ground

The voltage vaweforms over the primary and secondary windings of
the transformer are scaled copies of the voltages over L1 and C2
in the original circuit. In a capacitor-discharge system they
really don't look at all as what would be expected in an ideal 
transformer.

Observe are that C2 is necessary, otherwise the circuit
is just a conventional Tesla coil built in a variant way, because
L2 and L3 can be treated as a single inductor L2+L3.

With C2, the directly coupled circuit is quite attractive, as with
fixed C1 and C3 it is possible to obtain faster energy transfer
than is possible with a directly coupled system with just 2 coils.
For example, the circuit that I describe in:
http://www.coe.ufrj.br/~acmq/tesla/mres4.html
transfers energy in 5 cycles, or 16.7 us.
Using the same C1 and the same resonator, it's possible to
adjust the system (to mode 3-4-5) and transfer in 2 cycles, or
8.2 us only. The element values are:
C3: 15.0816 pF
L3: 28200.0000 µH
C2: 122.5676 pF
L2: 3463.1579 µH
C1: 1000.0000 pF
L1: 484.8421 µH

More details about these designs:
http://www.coe.ufrj.br/~acmq/tesla/magnifier.html
and the references there.

Antonio Carlos M. de Queiroz