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Here's project of DRSSTC. I believe that this is one of the biggest coil in Poland. Construction is based on DRSSTC1 project by Steve Ward. Biggest difference is: GB100TS6 instead IGBT. Dimensions are also different, because of unit calculations with limited accuracy, and availability materials like pipes and so on.
Principle of working
As the name speaks for itself we have two resonant circuits. First is controlling by IGBT transistors, LC series circuit. Second is a coil of HT circuit and toroid - as in every tesla coil. Those two circuits should work at common frequency. Of course in practice, there always will be some difference. Primal resonant circuit is powered by rectify voltage with low impedance, current at impulse, could have even 1000 A and more. Limit is set by transformers, breakdown voltage and max current for RMS condensers.
Power:
There are two power supply adaptors. One with low power 5 and 15 V for supply control logic. Second is rectifier plus condenser witch filtering connection directly to grid.
IGBT bridge
It’s a classic bridge H type, powered by 300V. His construction should allow to minimalist inductance between filter condenser and transistors.
Driver work thanks to steering transistors by signal from current feedback.
Primary resonant circuit condenser and primary circuit coil. Coil is 12 circumvolutions of copper pipe diameter 6mm, 1mm thin. I used cooler pipe from air condition. Condenser is 12 condensers 942C20P15K production of Cornell Dublier (150nf/2kV) series connect by two and parallel connection folders.
Secondary resonant circuit Very similar to others tesla coil projects.
More information at
https://www.elektroda.pl/rtvforum/topic1444708.html?sid=13cd2ffff38fff81d856fa79a380df58