Realise that when the time for the voltage to rise and fall the current is still trying to catch up, charge the coil. When the voltage pulse ends the this can be a problem a massive high current spike in the opposite direction, so if your diodes are not made for high current spikes they will fail.
With both Dave’s L and Stan’s circuits they do not allow for the BEMF of the coil collapsing, Stan has placed a diode to try and stop this Dave did not, also Dave did not put a diode to protect the switching FET. Well not in these circuits shown.
Also remember that CAP or the cells are all in parallel, so they will add up the Capacitance and decrease the voltage across them, in the cell this bring about the collapse of the electrolyte just like a normal cap failing, so you create the gas.
The idea of the close pulsed bursts is to try and ‘jack up the voltage’ on caps, pump up some times used.
Now the trick part is the L/R time constant of the coils for the current rise, this has to be fast enough to beat the tenancy of the collapsing current.
Now the resonant frequency is harder, you will have to get the total cap value pf most likely, of the cells(caps) and the total uf of the coils, then include the total resistance of the coils and in Stan’s the current limiting or consuming as he calls it. all this to find the resonate F, in Stan’s use the mid position of the tapped coil, this is used to go either way of the resonate Frequency, to keep the circuit in tune. With Dave circuit the added electrolytic Cap to me has always been a problem to see why it was done, just one AC cap or non-polarised cap in series with the lamp would still work. The reason why the lamp was used it can dampen the burst of energy, and the lamp is used like a bleed resistor on a cap. So the end result is to have another cap in parallel with the cells, or capacitance, with a bleed resistor.
I tried other ways but mostly on plate cells.
Another question WHY did they use SS for both tubes?
With plate cells different material for the positive and for the neg plate were found to be the best I did find the best combination in a plate cell.
So how then did Stan’s Cell really work? I still think a lot was left out of the patent or the paten changed it.
Just my thoughts
Brian