You need at least 100 VDC on the bus, to not get fooled by switching spikes from the voltage dependant capacitances of the IGBT. The output capacitance Coes will result in virtually the same amplitude switching spikes, but they look very big against 60 VDC compared to 300-600 VDC.

Maybe your spikes are not that big afterall, but circumstances of the measurements make them look big

2) Receive Bluetooth data from another Esp32 to adjust interrupter frequency and duty cycle. (No Optical modules needed which brings down cost even further).

Bluetooth seems like a nice idea.  I've been surprised how well wireless microphones work around TCs and even my Marx generator.  No direct experience with Bluetooth, but I'd guess it will work in spite of TC arcs nearby.  Please post your results with Bluetooth when operational.

I have also added the ability to switch between SSTC and DRSSTC operation with the help of few jumpers.

Are any of the jumpers actually needed?  No harm in registering enable with SSTC, especially with a self-oscillating feedback path making clock continuously available.  In particular, J5 if open leaves a CMOS input floating, not recommended.

Ramped or CW DRSSTCs can be fine without OCD.  Primary current is consistent enough to be limited by design and testing.  For conventional pulsed DRSSTC with primary current feedback, some form of OCD is strongly recommended.  Perhaps could be simple (but not precise) using spare 74HC14 to monitor current.  A fixed resistor of say 10 ohms on bottom side of RV2 can provide current sense without requiring a separate OCD CT.

Line ZCD looks good, once delay is added by the processor as you mention.  Of course, could use bit-cheaper diodes such as 1N4148, but then wouldn't be common parts with other parts of your circuit.

Probably cheaper than UCC2732X parts but a bit more ECB area:  Logic-level-drive FETs can be driven directly with 5V logic outputs, especially logic with high drive current such as 74AHC00.  I'll be testing this for my next coil, a CW DRSSTC plasma speaker, using logic level FETs BSS306N and DMP3165L driven by 74AHCxx logic.
This discrete FET option has performance advantages too.  GDT drive voltage can be much higher than your existing 12V (or up to 15V for UCC2732X).  Using 12V requires non-1:1 GDT ratios with their associated much higher leakage inductance.  UCC drivers have high current at Miller plateau, but don't clamp nearly as hard to supply rails.  This can be problematic if GDT inductance is on the low side.  And discrete FET solution removes need for output clamp diodes.
I'll post a schematic in a day or two.  My schematic uses 74ACT14 to allow drive from 3.3V PLD outputs.  Would be easy to change to 74AHC00, two parallel for each output.  NAND gates provide enable gating.  One inverter is needed, such as your spare 74AC14, on one input side of NAND gates.

Hope your design all goes well!

Quote

Can somebody explain how can i suppress that ringing ? GDT is 8 turns 1:1:1:1:1 EPCOS B64290L0618X035 5400nH , gate resistors 5.1Ohm / 2W.

Vge ringing is caused by a combination of GDT leakage (parasitic) inductance with Cge (gate capacitance).  Gate resistor is to damp that ringing.  5.1 ohms is too low for your GDT/IGBT combination.
Rather than just increasing resistor values alone, I'd reduce GDT leakage inductance too.  Less inductance will allow smaller resistors so keep switching fast.  Below are links to my GDT tutorial and then Mads' recent one with video:
    https://highvoltageforum.net/index.php?topic=1854.msg13949#msg13949
    https://highvoltageforum.net/index.php?topic=3167.msg22464#msg22464
Your existing ringing is marginal.  Only real issue is first negative half-cycle after rising edges, enough to partially turn IGBT back off again.  Falling edge ring is not an issue.  Vge is below zero, and not enough negative to damage gate oxide.  Vge waveform with bus voltage applied will change too.  Was likely just good enough before.
Without diodes across gate resistors, your dead time may be marginal too.

Impressive what you accomplished before getting an oscilloscope!  You'll learn much more now being able to measure things.

I did some tests, and here are the results: I added 5.6 Ohm resistor to the output of the driver, and it seems like that the spikes disappeared.



I connected the primary, and used a dummy load. Vbus was set to 60 VDC,  and the waveforms looked like this:


IGBT C_E


I tried to adjust phase lead too, but i got way bigger spikes with phase lead on than without the inductor .... strange ?!?



But at least the coil works.

Teardown of Cisco / Atlanta Scientific Cable TV combining amplifier. These small amplifiers are used in receiver stations with combining amplifiers to send out the different channels on a single cable.

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Scientific Atlanta HG Combiner  Amplifier model 9954H 1 GHz. This model can use primary and backup 28 VDC  power supply and takes two input signals at 1GHz to combine them into a single output.

The schematic on the side of the amplifier shows signal paths for input 1 and input 2. PAD is the orange attenuator pads, signal conditioning for correct signal strength. EQ is the equalizer, for compensating cables losses ahead. Gain block is the ACA2402R IC / power amplifier. The output 2-way combiner is a passive circuit.



The power supply is marked as Scientific Atlanta P2-PS-M-A-W, manufactured february 2008. It is however a OEM product from Tectrol Total Power Solution with product number TC53S-1469A. Input voltage 100-240 VAC and max output power 250 W. Made in Canada. No mentions of output voltages, but from the amplifier a good guess would be dual 28 VDC.

Hi  everyone,
I have designed this circuit with focus on moving from SSTC to DRSSTC operation and bringing the cost down.

I am using ESP32 which serves few purposes.
1) Adjust timing received from ZCD circuit (uses only vanilla components) to enable UCC drivers at right moment of zero crossing of AC mains. (No bulky transformer needed).
2) Receive Bluetooth data from another Esp32 to adjust interrupter frequency and duty cycle. (No Optical modules needed which brings down cost even further).

Other features.
I have also added the ability to switch between SSTC and DRSSTC operation with the help of few jumpers.

I know it doesn't have advanced features of ud2.9 (I have also designed my own board for that also in KiCAD 7, although I haven't tested it yet).
I am just trying to dip my toes in DRSSTC world and understand it more before I test ud2.9.
The idea is to enclose everything in a custom 3d printed enclosure box for and wrap the box in aluminum foil tape and then ground it.

I have implemented all of the knowledge I received from this forum in this design.
I would really appreciate some feedback on some design improvement and maybe even some additional functionality because Canada-Post is on strike and I want to make sure I got everything right before I order boards.

Edit: I have tested the ZCD detection circuit and ESP32 operation on perfboard. Tesla coil works as expected with over 10" arcs.
Edit2: I know 24V is usually used for DRSSTC operation for IGBTs. I will adjust for that in next iteration.