Re: magnifer coil and extra coil. What are they for?

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

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

Tesla list wrote:

 > Original poster: "Dr.Resonance by way of Terry Fritz 
<teslalist-at-qwest-dot-net>" <resonance-at-jvlnet-dot-com>
 >
 > In a nutshell, they multiply the output of a conventional pri/sec system by
 > increasing the output potential times the operating Q factor of the system.
 > Typically coeff. of coupling in the pri/sec system is very tight with
 > increased insulation (to prevent breakdown) and the break rate goes from the
 > typical 400 pps to around 800-1000 pps.

The multiplication is by the turns ratio of the transformer. But the
overall voltage gain continues to be limited by the square root of the
ratio between primary and terminal/resonator capacitances.

To interpret the driver of a magnifier as an ideal transformer is an
approximation, that works to some extent.

A better interpretation is to use a simple equivalence to a
regular transformer:

       k               k'=k((L2/(L2+L3))^0.5)
o---+    +--L3--o      o---+     +---o
     |    |                 |     |
     L1   L2        =       L1  L2+L3
     |    |                 |     |
o---+    +------o      o---+     +---o

A magnifier designed in this way is just a Tesla coil with the
secondary split in two parts, and tight coupling in the driver.
No advantages, except for more freedom on the placing of the
resonator, and maybe slightly smaller terminal capacitance
and so higher output voltage.

An even better approach is to consider that there is significant
capacitance across L2, that if not included in the design will
trap energy and reduce the efficiency of the system. This increases
the speed of the energy transfer and reduces the power dissipated
at the gap, turning easier the operation with first notch
quenching, and allowing the operation with very high break rates.
Design formulas for the 6th-order system including this capacitance
can be found at:
http://www.coe.ufrj.br/~acmq/acmq/tesla/magnifier.html
See also my transformerless magnifier:
http://www.coe.ufrj.br/~acmq/acmq/tesla/mres6.html
(The site appears to be down now.)

Antonio Carlos M. de Queiroz