Thanks for the hints. I found a mistake, I connected the mounting screw of my DC caps to the heatsink, which is grounded. Turns out that that screw is connected to the negative terminal of the cap. I think that was the problem.
Once I cleaned up the wiring a bit I will make a detailed post with lots of pictures.

I have not given much thought to the parts beyond the IGBTs, as the drivers seamed quite generic. I am intending to use something that is already designed and proven to have something less that might go wrong. The UD2.7 looks quite mature and promising. I will look into that.

The CalcTurn Menu in JavaTC shows up, when I click the small blue calculator. Maybe there are multiple versions of JavaTC out there, I was using the first one that showed up on Google (http://www.classictesla.com/java/javatc/javatc.html).
 

So I want the AC Resistance of my secondary to be equal to the resistance of my spark. But the resistance of the spark varies a lot and can't be calculated well, so I should aim for the "magic 50k Ohms". Do I understand that correctly?

Hello Everyone,

after watching too many videos on musical tesla coils I decided to build my own.
I found Mads Barnkob´s website and his guide on designing a DRSSTC was a gread read, lots of useful information in one place.

Currently I am trying to figure how big I want/can make it, I was thinking in the order of Mad´s DRSSTC 1.
I already have 2 SKM300GB123D igbts and 2 4700uF 450V for my primary DC filtering, I would like to build my tesla coil around these if possible.

I had a play around in JavaTC and tried to design a coil that I like.
But its just that, something I just made up based on the physical proportions I like.
I dont really know if it would work or how I would determine if it would be a good design.



A lot of the formulas for calculating the values of components for the primary circuit require me to know the peak primary current.
How do I calculate that? Or is is just something I make up and design my DRSSTC around that made up value?

Greetings Martin.