# Re: [TCML] VTTC-tuning. John got me started ;-)

```Hi Dex,

```
Moderators are not going to change an equation. They may later reply and correct it with a reply, but they don't need to be messing with a persons equation (what is obvious is subjective to how much attention is being paid to the equation). Their looking for more of content as it relates to the TCML and not necessarily every calculation detail.
```
```
DC's equation as you state is a standard energy equation that has been around forever. What DC is doing is showing are losses with the efficiency factor of 0.7. The same equation is derived with the capacitances as well. Your equation is dependent on di/dt. Have you measured this yet? If yes, what was the change in current and over what time frame (0 to peak). May as well state L also. This equation requires measurement to verify, so I can't go any further without some data if you have it.
```
Take care,
Bart

Dex Dexter wrote:
```
```I see that Vp is missing in the formula I typed below.
It should be obviously :

V=0.7*Vp*SQRT(Ls/Lp)

Note for Moderators:
If You see obvious mistakes of similar kind in the future,feel free to correct it!

Dex

--- dexterlabs@xxxxxxxxxxx wrote:

From: "Dex Dexter" <dexterlabs@xxxxxxxxxxx>
To: "Tesla Coil Mailing List" <tesla@xxxxxxxxxx>
Cc:
Subject: Re: [TCML] VTTC-tuning. John got me started ;-)
Date: Tue, 7 Apr 2009 01:44:40 -0700

Very interesting paper.
But what do you think of formula:

0.5*L*di/dt < V < L*di/dt

Note that this gives good agreement with Dr. Resonance's  max voltage formula of a typical coil:

V=0.7*SQRT(Ls/Lp)

The factor 0.7 is somewhere between 0.5 and 1 so we have:

V=0.7*L*di/dt

Dex

```
--- bartb@xxxxxxxxxxxxxxxx wrote:
```
From: bartb <bartb@xxxxxxxxxxxxxxxx>
To: Tesla Coil Mailing List <tesla@xxxxxxxxxx>
Cc:
Subject: Re: [TCML] VTTC-tuning. John got me started ;-)
Date: Mon, 06 Apr 2009 18:14:33 -0700

Hi Dex,

```
Let me point you to Paul Nicholson's TSSP site. There have been numerous measurements made regarding current distribution, base current measurements, etc. There is a link on the front page to pn2511. Read through this document (it's right down your path of interest). This may give you a better understanding of what is happening in the background of Javatc which is accounting for the distribution along the secondary.
```http://abelian.org/tssp/

Take care,
Bart

Dex Dexter wrote:
```
```Yes ,you understand me now.
The problem with this can be that current distribution prior and after spark breakout across secondary isn't the same.
That will affect more tesla coils with small toroids but big sparks.
We can measure bottom current and make the estimation  only.

Dex
```
```--- bartb@xxxxxxxxxxxxxxxx wrote:

From: bartb@xxxxxxxxxxxxxxxx
To: "Tesla Coil Mailing List" <tesla@xxxxxxxxxx>
Cc:
Subject: Re: [TCML] VTTC-tuning. John got me started ;-)
Date: Fri, 3 Apr 2009 18:59:48 -0700 (PDT)

Hi Dex,

(hope you get this ok. My server has a problem and I'm using a backup web
mail thing to write this).

Are you talking about capturing base current waveforms and looking at the
data just before breakout? If that is the case, then yes, I agree with
you. This will eliminate everything after breakout.

Excellent! I think I understand where you are going with this. As long as
you store the data and differentiate the time at which breakout occurs
(ignoring anything after breakout), then yes, you will get a good look at
top volts in a one-shot mode of operation. Continuous operation will prove
difficult of course.

Take care,
Bart

```
```Hi Bart,
No I don't think so.
It doesn't depend on the temperature of the day,humidity,radius of
curvature etc.
If you consider it more it is not the formula for the prediction.
It is formula for calculation if you know secondary base current (or given
the current).
That's the voltage developed across inductor.
The only unknown thing is "L" which varies from design to design and size

Dex
```
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