Re: The PING Test

["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: "John H. Couture by way of Terry Fritz
<twftesla-at-qwest-dot-net>" <couturejh-at-mgte-dot-com>
> 
> Antonio -
> 
> I agree with what you say about the continuous-wave, sinusoidal
> steady-state, conditions regarding the Q factor. However, the Q factor is a
> pure number derived from a dimensionless ratio (wL/R) that can also be
> applied to any TC secondary coil. John Freau says tests have shown that when
> the secondary coil turns are increased the sec voltage increases without any
> other changes in the TC system except to retune by changing the pri coil
> taps. 

The maximum voltage gain in a correctly tuned system is sqrt(L2/L1),
or sqrt(C1/C2) (I inverted this in a previous message). With greater
L2, the maximum gain is higher. If the capacitances are the same,
retuning L1 would result in the same maximum gain. But as the
inductance increases faster than the resistance as the number of
turns is increased, the Q of the coils increase and the losses
decrease. The result is that the actual voltage gain gets closer
to the maximum. I am not sure about what happens with losses in the
spark gap. I know that John says that they also decrease.

> John, can you give us more details? This indicates the Q factor has
> been increased. The two equations involved are
> 
>     Q = 6.283 F L/R
>     Vs = Q Vp Eff

The second equation doesn't apply in the case. Even the first is
only an approximation, because there are -two- oscillations in the
system during the energy transfer, each one with its own Q.
 
> The tests indicate that according to the first equation the (F L) has
> increased more than the R has increased giving a larger Q factor. The tests
> also indicate that according to the second equation the secondary voltage
> has increased because the Q factor increased or because the Eff increased or
> both. 

First affirmation: ok. Second: not for this reason.

> It is interesting that the TC sec voltage and spark length are being
> increased without changing the input wattage or the pri capacitor. This can
> only mean an increase of energy in the sec coil and an increase in the
> overall efficiency of the TC system.

Correct.

Antonio Carlos M. de Queiroz