hi, when sizing the tank capacitor, the impedance of the NST transformer is calculated which must be equal to the impedance of the tank capacitor: why? Thank you

Hi, how can I know a chain of Villard multipliers, how much current can it deliver? it just depends on the capacitors? how can i calculate it?
thank you

I detected this signal with a probe, what does it make you understand?  What are those peaks on each ridge?  It is not seen well but at the beginning of the oscillations there is a signal of 17mhz while the resonance frequency is about 400khz

do you know if there is a circuit in LTSpice that can simulate a sparkgap well? it would be very useful ...

Thanks friends for your advice ... I looked better at my circuit and saw that, since I had already burned many, I had put 2 40kv capacitors in series, thus obtaining a total value of 80kv 5nf ... So the  problem I don't think it is the sizing of the capacitor ... Keep in mind that during the discharge a discharge bang occurs so strong that at 1m away the ears hurt ... therefore it may be that this kind of condenser is not suitable for these  discharged or is it another problem? I add that the device must be kept on for at least 20 minutes, ... For a short time it is good for over 20 minutes it is not reliable

If this is the schematic for a spark gap coil, you need to swap the position of the capacitor and spark gap. I don't think this is causing your capacitor problem but it could cause problems for your transformer. As Mads stated, it sounds like you are exceeding the voltage rating of your capacitor. You want at least a 2x and preferably a 3x voltage rating for your capacitor.

no, the position of the sparkgap and coil are exact. This circuit is not to make a tesla coil but a therapy device with pulsed magnetic fields (as in the picture)... and then I don't use a transformer as a power supply but a 30-40.000v direct current generator.
then for the voltage of the capacitor maybe you are right but I used doorknob which told me that they are not really suitable for fast impulses while I should take the polypropylene ones, but apart from this problem, would you have other tips to avoid damage?

I stand with Steve about it being easier on the transformer to drive across spark gap instead of across capacitor. Maybe not a lot easier, because of the 10M resistor.

As Mads said, there's more to learn about how you are abusing the capacitors, or if the capacitors are over-rated fakes (?).

What is the RF current in each spark, the tank circuit energy, and the average power?

Power input is partitioned somehow between losses in L, C, and spark.
Do L or C get hot when you operate the circuit at power below the destructive level?

the power is less than 10J, but before the capacitor broke, I saw a flash of lightning go through it ...

in tesla coils, a so-called "terry filter" is often used but there is an alternating transformer and it is used to avoid RF or that could damage it, instead mine is a DC circuit....

Help!
Hi everyone, I need to use this circuit, but after a while the capacitor burns out!
the power supply comes from a voltage multiplier, and the capacitor is 50kv 10nF, the coil 10uH
what can I do to protect it? thank you.