This looks interesting. I don't have any inverters with parallel IGBTs yet but some nasty overshoot during gate-turnoff. Have you run a simulation to get some parameters? I will have a look at it when i am in my workshop next week.

Yep - its even more! 25A Irms and 937A Ipk for the C4ASWB_3680__H_  thats impressive  I really underestimated them.

The MMC should be  1uF, 12kVdc and 150Arms to get high BPS and polyphony at 1500Apk. If i pay less than 200€ i am more than happy.

The inverter will be a double fullbridge with skm400gb125d bricks
The coils are my twinsystem (update with pictures is comming soon)

The cooker caps are really sturdy but a little bit small. I would need 240 of them and i want to reduce the number of parts.

Those arcotronics look very good. I will keep them in mind as they will make a nice MMC for my smaller coil.

I found some neat caps but i am not sure whether to take the risk and just order some. 2uF, 4kVdc and 80Arms sounds pretty good but no datasheet with further information.  2 strings with 4 Caps will get me right there for 180€

https://www.aliexpress.com/item/4000013362753.html?spm=2114.12010614.8148356.11.16a56390OBmQvM

Thanks, i still have the firmware from last year running  . Connection to SID server and replay works fine with acid64. Teslaterm-master runs aswell. 

These are good news indeed  i can't wait to check out the new features and run my system with two of those!

Do you have any plans about selling populated boards?

On paper the thermal impedance looks just fine. R_(th,JC)(single pulse)  for 200us PW is about 0.008 K/W and for continuous mode it is 0.125 K/W which is in the same region as a CM300.
The pulse rating is 1500A and the maximum switching current 430A. With a maximum dutycycle of 0.026 for high current pulses those bricks really shouldn't die at 600A.

thanks for all the suggestions  . I checked the IGBTs again and there was not much thermal paste but enough to cover the whole base surface and make the bricks stick to the heatsink. So i think this should be ok. Maybe i should stop pushing those little buggers so hard  and go for something bigger .
I am still not really happy with the phaselead. When i go for the smallest switching spikes i have a voltage dip to zero right at pulse turnoff when the phase jumps. When i use a CT and try to switch exactly at  zero crossing i have bigger spikes and a huge voltage dip.  If i go for a clean transition at turnoff i get the biggest spikes and the current seems way behind.
Maybe i am overthinking this already and should just move on and make a better layout for the next bridge.

Hi everyone,

the last days have been quite interesting. I have found a new place to set up my coils. It's an old transformer building turned into science education playground. There are a lot of metal structures where i can clamp on but i still have a high impedance to ground.  The solution to the interference problem was to disconnect the controller housing from hf-ground. I really don't like the idea of having a floating potential but it seems to work.

For the first power test i went with a relative low coupling, 100us ontime and 200 BPS. Everything run nice with a steady buzz. I hit 400A with 230Vac. From there i set the OCD to 600A and slowly increased the ontime.  At around 550A there was a bright flash and a flame shooting out of the inverter followed by a couple of small explosions.     

Two IGBTs and their gate circuits got completely blown apart. All other components seem to have survived. The IGBTs are rated for 400A hard switching so i think they didn't just die from overcurrent. I noticed the hv end of the mmc was very close to the GDT who drove both IGBTs .
I changed the setup so that the mmc connects to the outer part of the primary, set the OCD back to 400A and run some midifiles.

Hi Everyone,

i'm a Tesla addict since 3 years now. Most of the things i have learned regarding tesla coils is from you guys so big thanks to all of you.

My latest project is a twinsystem inspired by Gaos Model82. For now it runs on a IXGN400N60 fullbridge but i will upgrade it as soon as i have the money 
Some specs:

MMC           300nF  /  6kV
BusCap      9000uF 450V
Snubber     2x 2uF / 2kV
Secondary 20cm dia  / 1m length
Torus          60cm outer dia  /  20cm inner dia  / 33mm tubing
Controler   UD2.7
F0               70kHz

Some pics from the build. The case and support for the primary  is made from laminated plywood (Siebdruckplatten)


The bridge is not ideal in terms of low inductance. I will change it to a different design with stacked busbars (turning it inside out  ) but for now the ringing is acceptable.



Our first full power test had to be aborted due to bad grounding. We had very weird sounding interferences and huge sparks randomly popping at about 150VDC. At some point we had 2kV on ground potential between the coils  .


Here we are testing the musical setup at 100VDC



As soon as i find a new place to test i will follow it up with some pics in action. If you have any suggestions regarding running two coils at once i would be happy to hear them .

-Cheers