Spark Gap Tesla Coil on ZVS Driver

This Instructable will walk you through building a medium sized Tesla coil powered by Zero Volts Switching driver.

in this build I used regular pre-built zvs driver, but you can build your own. For HV capacitors I used 4*15 CBB81 2kv 22nF, spark gap is adjustable(0-28mm), 60 10MJ resistors on each capacitor, primary is 8,5 turns of 6x4mm copper tube, secondary is 1500 turns of 0.12 copper wire 30x5cm. Topload is handmade 16x4.55 cm at approximately 20 pF.

Even medium-sized spark gap Tesla coils (SGTCs) can be dangerous. The main risks are not the visible sparks, but the spark gap and the high-voltage capacitors. Spark gaps operate with very high currents and can produce explosive discharges, hot metal particles, strong electromagnetic interference, and toxic gases such as ozone. High-voltage capacitors store large amounts of energy and can remain charged after power is turned off, making accidental contact potentially lethal. Because SGTCs have no precise control or fast protection, failures can be sudden and unpredictable.

Just like I said before, we need 60 CBB81 2kv 22nF, 4 series of 15 each, with one 10MJ resistor on each capacitor. Unfortunately I received capacitors of different sizes, so I got 2 lines with length of 45 cm and 2 lines of 50 cm. As a result i had to shrink the longer ones, and use longer wires on shorter ones for good connection and to minimize difference in flow of electricity each line can take(lines MUST be equal, so flow of electrons is equal, otherwise it can cause overheating and decreased efficiency). So total volt and nF that gives us our capacitor bank is 30kv and 26.7nf. But for ideal resonant, it is better to keep nf in range of 28-30.

I used 5 6x4mm copper tube for primary, using which I got 8.5 turns, so I had to increase amount of capacitors, due to lack of nF for optimal resonance. Secondary is 30x5 cm, 1500 turns of 0.12 cm copper wire. In your own coil you can increase amount of primary and decrease amount of capacitors for better results(10 turns primary, 3x15 capacitors).

I made my toroid using cupboard, some tape and alluminium foil, which is not so god, because it is incredibly uneven, so I reccomend you to just make it out of ventilation alluminium foil hose tube. Mine is 16x4.55cm, with capacitance of 20pF, toroid works as a capacitor, that charges and discharges at breaking point, if its uneven then sparks will be everywhere else but not at breaking point(toroid also changes frequency of the whole tesla coil, so be careful and take it into consideration). As a breaking point I just used 0.2cm copper wire.

It is very easy to make spark gap, but very important to make it adjustable so you can control frequency of your coil, because when you increase voltage, then capacitors charge and discharge faster, that lead to insane ozone production and too many arcs per second, what makes them smaller, so it is very important to adjust spark gap properly for each voltage and current change.

I used box out of lab power supply, but you can use any box you want, or better option is a wooden box, or even plastic. It is important to make ground, otherwise sparks will be smaller, and primary can shoot at secondary. I used alluminium foil, and connected it to copper wire at the bottom of secondary.

Congrats! Your tesla coil is finished, and it can make arcs 8+cm

Main problem of my tesla coil is uneven toroid, so as soon as I get materials, I'll change it to something better, and update this work with new results. I also plan to make Solid State Tesla Coil, but as for now, it is the end, good luck building your own tesla coil!

Just like I said, I used hose ventilation tube to create new toroid, it is 6cm in diameter and a little bit bigger than previous version, and works much better. The main problem was that I had to figure out how to assemble it on tesla coil, so i just used wheel from my little brother's car which suits perfectly, and has hole in the center for copper wire. As I expected sparks are no longer everywhere, only on breaking point.

some cool videos with experiments:)