Re: DRSSTC Tuning and Split Frequencies of Dual coupled system

["Tesla list" <tesla@xxxxxxxxxx>]

Original poster: "Qndre Qndre" <qndre_encrypt@xxxxxxxxxxx>

Richie Burnett has done really impressive work concerning the 
analysis of the resonant modes of resonators used in solid state 
coils and the kind of load they present to the driver circuit when 
fed from their bases. It is published on his "Driver circuit theory" 
page. http://www.richieburnett.co.uk/sstate2.html

He has also done much research concerning frequency splitting in 
coils driven in a disruptive mode which should come pretty close to 
what's happening inside a DRSSTC since both coils, spark gap and 
DRSSTC are using two resonant circuits and inductive coupling. It's 
also published on his website. 
http://www.richieburnett.co.uk/operatn2.html#splitting

I don't know which frequency a solid state driver will use to drive 
the circuit. All the peaks seem to be more or less equivalent.

Regards, Q.

----Original Message Follows----
From: "Tesla list" <tesla@xxxxxxxxxx>
To: tesla@xxxxxxxxxx
Subject: Re: DRSSTC Tuning and Split Frequencies of Dual coupled system
Date: Sat, 15 Apr 2006 11:58:33 -0600

Original poster: "Bob (R.A.) Jones" <a1accounting@xxxxxxxxxxxxx>

Hi Q,

Ignoring high order modes and assuming a series connected primary.
Below their resonance frequencies the primary and secondary have a
capacitive impedance (looks like C).
Above their resonance frequency their impedance is inductive  (looks like
L).
The impedance of the secondary referred to the primary is an impedance in
series with the primary L as (Lm*s)^2/Zsecondary (Lm is the mutual
inductance, s is the Laplace complex variable) i.e. the L goes to C and C
goes to L

Assuming the primary and secondary have the same resonance when independent.
At a lower frequency than the primary resonance the primary looks like C and
the impedance of the secondary looks like C which when referred to the
primary looks like L.
At a frequency that the primary inductive impedance equals the referred
capacitive impedance of the secondary the system resonates i.e. the lower
pole.

At a frequency above the primary resonance the primary looks like L and the
secondary looks like L which when referred to the primary looks like C.
At a frequency that the primary inductive impedance equals the referred
capacitive impedance of the secondary the system resonates i.e. the upper
pole.

The above works even if the primary and secondary are resonant at different
frequencies but its more tricky to explain in particular the movement of the
poles.
Essential as you separated the primary and secondary frequencies of the
poles asymptotically approach the frequencies of the primary and secondary.
The above assumed a series connected primary but a parallel connected
primary is similar.
I have a Mathcad 2000 files that shows the effect along with the input
impedance and transfer function if any one wants a copy of it.

Robert (R. A.) Jones
A1 Accounting, Inc., Fl
407 649 6400
----- Original Message -----
From: "Tesla list" <tesla@xxxxxxxxxx>
To: <tesla@xxxxxxxxxx>
Sent: Thursday, April 13, 2006 4:12 PM
Subject: RE: DRSSTC Tuning and Split Frequencies of Dual coupled system


> Original poster: "Qndre Qndre" <qndre_encrypt@xxxxxxxxxxx>
>
> Hi Dan,
>
> as far as I remember the capacitance of the resonator is translated
> into the driver circuit using the coupling coefficient. If so, then
> the resonant frequency of the coupled coils system is derived from
> that coupled system so that...
>
> C_total = C_primary + (C_secondary * coupling)
>
> And since: f_res = 1 / (2 * Pi * sqrt(L * C))
>
> This results in: f_res = 1 / (2 * Pi * sqrt(L_primary * (C_primary +
> (C_secondary * coupling))))
>
> Regards, Q.
>
> ----Original Message Follows----
> From: "Tesla list" <tesla@xxxxxxxxxx>
> To: tesla@xxxxxxxxxx
> Subject: DRSSTC Tuning and Split Frequencies of Dual coupled system
> Date: Thu, 13 Apr 2006 12:40:26 -0600
>
> Original poster: "Mccauley, Daniel H" <daniel.h.mccauley@xxxxxxxx>
>
>
> Just a question regarding frequency splitting within a two coil coupled
> system.
>
> With two coupled coils, there is a frequency split which occurs that is
> depending on the coupling factor.  The higher the coupling, the greater
> the frequency split.  That we know.  Now, with DRSSTCs, it has been
> stated that tuning the primary circuit to the lower frequency pole of
> the frequency split is beneficial for DRSSTC systems.
>
> The question is, and its not as easy or straightforward a question as it
> sounds, is what exactly is occuring when you "tune" the primary to the
> lower pole of the split frequency.  Firstly, as you decrease the natural
> resonant frequency of the primary circuit, the lower pole frequency will
> move as well, so you will never match the natural primary frequency with
> the lower pole frequency.
>
> Does tuning the primary circuit lower in frequency (closer to the lower
> frequency pole) force the feedback to operate the DRSSTC at the lower
> pole frequency?  To basically kind of fall in place?
>
> What are your thoughts?
>
> Dan
>
>
>