For an art project, I need to generate a bright, noisy arc about 1/2" long. In the past I've successfully done this with with this: https://www.sparkf un.com/products/11218 but that isn't working in the new installation; the d evices get hot and fail after a few minutes of use. I'm looking for someone with expertise in this area to suggest a design I can build.
The requirements are:
Able to be run off a small 12v lead acid battery. Extra points if it can ru n off 5v and 3A, which is what the sparkfun device uses.
Portable - I'll be carrying the circuit in a backpack. Large Marx generator s need not apply. Neither do designs that require twenty pounds of copper t ubing.
Stable and Safe - I'll be carrying the circuit in a backpack and long term stability is a concern. It will be heavily insulated but I am still very un interested in sudden failures, magic smoke, fires, internal arcing, and oth er surprise effects. I need long-term reliability.
A bright, fat, noisy, snarling, visually continuous arcing spark - which pr obably means I need an output frequency somewhere between 40Hz and 200Hz. I don't have specs on the sparkfun device, but it does "loud" and "bright" v ery well.
Capable of more or less any duty cycle; the design calls for about 10 secon ds on and a few seconds off, repeating, but I want it to be able to run con tinuously.
Able to survive any sort of spark gap from "too big to actually arc" to "br ief short circuit", but the typical gap is 3/8ths inch to 3/4ths inch.
Repeatability - I need to be able to build several and I want repeatability , so "scavenge a flyback from a CRT" is much less interesting than a mouser or digikey part number.
And - crucially - able to handle a capacitive load. The high voltage travel s through two longish (several feet) parallel wires, though a small brass t ube and into a chunk of aluminum that showcases the spark, but it all adds to the capacitance, and I think that's why the sparkfun devices are dying.
I'll say it now - yes, I know a spark that can bridge 3/4" and be "fat", br ight and noisy requires tens of thousands of volts and several mA. I know t hat misuse of that kind of power leads to pain and possible death. Since I' ll be carrying the device and the high voltage wires will be running down m y arm I will be paying a lot of attention to insulation and safety concerns . Extra points if the voltage and current can be minimized to limit risk, b ut no matter what I will consider any design as potentially fatal and treat it accordingly. I know about the one hand rule, and "heavily insulated" is my favorite phrase.
I just built a Mazilli ZVS circuit
I'll accept any help, but I'm less interested in "well, you could try this" than "here is what is known to work." I've been researching things I could try for days, but mostly I've fried components and lost time. If you have expertise and don't mind drawing a schematic I will be very grateful. TIA!