I was away from Tesla coils for a couple months because I was focusing on some mechanical engineering, but I'm back now. I was studying one of my past boards, one that drives a QCW coil by ramping in sync with mains AC. A problem I had with that board was the limited on time, and I think I asked a question on here about that. Some solutions suggested were variable frequency drives, driving the board from a bldc generator, and gearbox generators. I just thought of a new idea though and want to see if it is practical. The exact board that I'm working on is this one from Labcoatz, there are some slight modifications I have made but none are relevant to the on time. I've attached the unmodified schematic. From my understanding, the signal for the ramp is being derived from the 12vac input, and following the traces on the board confirms that. So the area I was thinking about changing is the input to the 1n4148 diode. My questions are- Since the two AC inputs on the original board are in phase with each other, is there a way to generate a signal that is compatible with the 60hz ramps but has longer ramp times, for example a 30hz signal in phase with the 60hz at the other input? To generate this signal, I would likely need the signal generator to be deriving its signal or at least reading mains frequency so that it can be in phase. Would a simple circuit such as a counter, which counts each zero crossing of the mains signal and then switches an inverter once every 2 crossings be feasible? Lastly, at this point should I just make a vfd? The main problems I'm expecting will come from the high voltage side still being driven by mains, but I'm still looking for a solution that I can keep that and just modify the drive signal. Thank you!

Just found this cool paper when I was researching sic mosfets, a collaboration of CERN, ISEL, and EPS. Interesting read.
https://indico.cern.ch/event/656491/contributions/2947267/attachments/1628338/2600446/Barnes_FCC_Marx_generators_InjectionKckers.pdf
11/04/2018 pub.

Made this when I was really tired, it’s haunting.
https://drive.google.com/file/d/1KFuSQHe6NAkv2K4VGPLQxamGtGrDAKpe/view?usp=drivesdk

Hi, I will keep this one short because I feel like I saw a topic on this somewhere on here though I couldn't find it. I enjoy testing lots of different breakout points of various composition and dimension, and I also love doing mathematical analysis. I was wondering if anyone felt like collaborating on some research to find the ideal breakout point form for a given set of inputs? Something along the lines of CAD and field analysis, hopefully with the end result being an equation that takes coil parameters as an input and outputs the optimal position and size of the breakout point, along with material recommendations. Longer term if the model proves useful we could maybe add it to JAVA TC, as there's nothing for breakout points on there yet. I'm flexible on how we do the research, whether it be more physical modeling or theoretical. I have a lot of time on my hands and this seems like a cool topic. Let me know!
-dru

Hello. I've been working on audio modulation in my DRSSTC and I've run into an interesting challenge. My control circuit is only capable of outputting 1 bit music, so the best I've been able to do is play songs note by note. I don't know if I explained that right, what I'm trying to say is the control signal is either on or off, there is no in between state and I can only play one frequency at a time. I am curious if anyone has had any success in producing chords with this type of controller. I've tried playing notes in succession with little delay to achieve that smooth sound, but I still have the problem of the notes either being on or off so the chord sounds choppy. There are two things I'm aware of that may solve this problem, but I'm not sure about them. I could either 1. modify my driver and the secondary coil so that instead of producing notes by interruption, I inject the audio as a digital signal that rides the carrier waves of my main circuit or 2. I could try fiddling with the frequency and waveform of the driver input to produce varying amplitude waves, and check my work with a fast Fourier transform. I'm sure there are documented waveforms for chords already somewhere out there, I will have to figure out how to play those through the Arduino though. I know I could also send it through optical cables directly from my computer, I worry about proper isolation though.

Hello, I finally decided to join this forum after visiting it frequently for the past few years. I am 20 years old from east coast USA. Please call me out if I am posting something that's already been addressed or if I'm posting in the wrong topic area, I know there are a lot of posts about QCWDRSSTCs but I haven't been able to find a solid thread for this specific question. For the last couple of months I have been working on a QCW DRSSTC with a half bridge topology that utilizes the voltage ramps of my US mains 120vac 60hz to achieve the QCW effect. When I first started working on it, I was designing my circuit based on one I found online from Labcoatz, but I was having a lot of trouble with dying IGBTs and faulty control circuitry. In general I tend to have a lot more success when I design the circuits from scratch, as I find it very challenging to trust the calculations of others without making them myself and running simulations so I can optimize it on my own time. I think Labcoatz design was great, but it was missing a few things that would require me to completely redesign the PCB and control circuitry. Anyways that's a lot of text sorry, my question is if anyone has any good recommendations for development boards from reliable manufacturers that are good for precision PWM control, durable in intense EM fields (or at least easy to put in a faraday cage), and preferably use C++? I'd be flexible on the programming language, I really only know python, c++ and then branches like Sagemath and Matlab. I have a lot of free time to work on circuits right now because I'm taking a year off from school. I have been using random boards that I got from someone on Ebay along with a lot of scrap electronics, so they are a little outdated but are useable. My current focus is on programming the voltage ramps, modulating audio through off-time (though I'm curious about the possibility of carrier waves but not sure that's feasible here), and designing the external control circuit. I'm also open to any advice on general design, tuning, feedback methods, or links to papers so I can better understand the governing dynamics of QCW coils. I included a 10 second exposure photo from the last time the coil was operational. Thank you and apologies for the length of this!