Re: Proposed capacitive transformer TC?

["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: "Jolyon Vater Cox by way of Terry Fritz
<twftesla-at-qwest-dot-net>" <jolyon-at-vatercox.freeserve.co.uk>
> 
> Point taken- there is a mistake in my diagram and the spark gap SG1 should
> be in parallel with the PSU so that when SG1 fires, current flowing out of
> C1 is conducted by L1 back to the gap starting the resonant effect.

Ok. This works. I have just made some low-power tests of this system,
using low-impedance square wave generator in place of the power supply
and the gap (this produces a scaled down version of the waveforms).
In this way I can observe everything with an oscilloscope safely.

I found why my system with an antenna besides the main terminal worked,
but produced relatively low output: The coupling in that configuration
is low, and the system operates with many cycles required for the
energy transfer (13 to 27 for 15 to 30 cm of distance between the 
antennas). This increases losses, and also turns the tuning very
critical.

I tried then the system with a plane around L2, but using a loop 
of wire around L2, at about 10 cm from the coil. I obtained a tighter
coupling in this way, with the energy transfer taking from 9 to 15
cycles for a distance of the plane below the terminal varying between 
13 and 25 cm. Tuning is less critical, and losses are smaller. This 
system would work well at high power (I will try soon).

This is the waveform observed at the induction plane with the system
adequately tuned (by adjusting the antenna at the terminal):

http://www.coe.ufrj.br/~acmq/tesla/vc1ct.jpg

The beats indicate that all the energy is oscillating back and forth
between the primary and the secondary circuits, with ~9 cycles
being required for the total energy transfer. As the capacitances
were not significantly changed from the ones used in my directly
coupled coil, the voltage gain is expected to be a bit below 9.5.
(9.5 times the primary voltage that would exist over C1 at the time 
of the first notch ir it were not present, or about 3/4 of the 
starting voltage, as can be interpolated from the image).

Antonio Carlos M. de Queiroz