Re: [TCML] Spark gaps, Solid state switches and diodes

```Bart and fin wrote:
"I get around 600 something turns....... "
```
"Yes, 648 turns at 32 tpi. I would expect Ipeak to range 185A to 1130A (15/30 up to 15/180). The primary details are important as geometry greatly influences Lpri and thus Ipeak. Top loads play a role also since primary resonance is based on an accurate f2 with all components in place. So if the system is listed in some detail, then Ipeak is better guesstimated."
```
```
Sorry Bart, Finn and others I must have been drunk when I wrote those figures,
```The figures I gave you are wrong, but How were the figures above calculated?

```
I meant to say that the Primary is 30 to 100 micro Henries (not microFarads) sorry silly mistake. and the Secondary is 30.25 inches winding length at 32 turns/inch ( again sorry) so 968 turns total
```the former is 6.5inches diamater
```
The top toroid is 6 inch diameter ring and 6 inch diameter inner ring and 18 inch total outside diameter
```eg: (circles represent the toroid) = in courier font it should look ok
OOO           OOO
OOOOO---------OOOOO
```
OOO OOO |<-6->|<--6-->|<-6->|
```|<----18 inches---->|

```
yeah the Primary circuit would have two of my transformers as a minimum (and 6 at a maximum) I fired it up the other night I used 2 transformers rated at 15kV and 30mA each
```so 15,000 volts at 60mA.
12nF is my primary capacitance (but as a maximum I could have 36nF)
```
The primary was tapped at the 10th turn out from the middle. (and as a maximum could be the 4th turn - but its not working properly)
```The primary is 12.5 turns total Turns
```
The dimensions are 13.5 inches inside diameter and 37 inches outside diameter.
```with 1 inch between turns.
as it is at the moment I'm only getting 6 inch sparks at the best tuning!

(but sometimes I would hook up extra capacitance and transformers)
```
each transformer I have is 15,000 @ 30mA so my capacitance for each transformer should be 6nF right?
```
```
The tuning point for the biggest capacitance I can't verify because I think my capacitor died.
```But it should scale up right when I repair the capacitor bank?
```
just like the primary transformers? eg if I use 2 x the capacitance then the peak current should be twice as large?
```
```
Is that enough info for a ball park Ipeak figure so I can work what IGBT's I need for a SISG?
```
Thanks
Stephen

bartb wrote:
```
Yes, 648 turns at 32 tpi. I would expect Ipeak to range 185A to 1130A (15/30 up to 15/180). The primary details are important as geometry greatly influences Lpri and thus Ipeak. Top loads play a role also since primary resonance is based on an accurate f2 with all components in place. So if the system is listed in some detail, then Ipeak is better guesstimated.
```
Regards,
Bart

Finn Hammer wrote:
```
```Stephen Hiscock skrev:
```
```Hello Fin Hammer,
thank you for helping me out!.

I've done some basic Calculations.
Here is the basic config of the coil.
```
6.5'' Diameter, 20.25 winding length and 32 turns/inch so about 968 turns in total.
```wound on PVC former.
```
```
I get around 600 something turns.......
```
```
```
The primary is 12.5 turns 13.5 inside diameter and 37 inches outside diameter. and in inch between turns. giving inductance range of 30 - 100uF fopr tuning
```
```
```I would expect henries here......
```
```the Capacitor is 6.4nF per transformer as they are 15kV at 30mA each.
so giving a range of 6.4nF to 38.4nF depending on how many I hookup.

you sent me this:
Ipeak is a relation to Lpri, Cpri and Vmax.

First calculate Zpri =>sqrt(Lpri/Cpri)
so from this my Impedance is 781 to 125
Then Ipeak => Vmax/Zpri = 21,213 / 125 = 169
or 21,213 / 781 = 27
and Ipeak ranges from 27 to 169 Amps (this seems a bit low)
is this correct?

```
So I'm guessing the standard design will work fine - but just lots in series?
```
Stephen
```
```

```
Could you supply tuning point for the biggest capacitor you use. This means: how many turns do you have engaged when all caps are in the circuit.
```From this we can calculate Lpri needed to calculate Ipeak.

Cheers, Finn Hammer
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