Mini Spark Gap Tesla Coil

Step 2 Flyback Driver

Earlier I told you I got done building a plasma speaker, well I had some spare parts left over so I decided to use the them. In NO way I am taking credit for the design of this circuit a boy by the name of Plasmana designed it! I will give the schematic and the link to his page

http://www.instructables.com/id/Build_A_Plasma_Speaker/

Hook everything up like it says, to test and see if the tl494 is oscillating put a speaker where the fly back is and change the voltage to 12V, you should hear a loud screech, if nothing play with the pots or look over your circuit. One other reason I wanted to use the Tl494 as a driver is because I thought it would also produce music from the arc. I was soon let down when the sound was coming out of the fly back and the arc from the tesla coil was the sound of the spark gap. If anyone knows how to audio mod this I would love to know! The flybacks secondary from the plasma speaker schematic is the HV DC from the tesla coil schematic.

The cam didnt pick up the screeching you can barly hear it

Also there is another driver that works well to but im not going to go into it. ill give the schematic its called ZVS driver.

Comments

[highvoltageguy]

could u use an ignition coil?

[volthead]

If you want if to sing try replacing the spark gap with some xenon flash tubes from camera flash circuits. Hope it works

[Xellers]

How would that work? Modulation is only possible on solid state and vacuum tube Tesla Coils.

[volthead]

You would need to have a bps of 20000 and vary the current with IGBTs. Also I have learned a lot more since I posted that comment. And some (like me) have a low budget so MOTs are the only option. MOTs can be ballasted resistively with a 150W light.

[Xellers]

www.instructables.com/id/Audio-Modulated-Solid-State-Tesla-Coil/

[Xellers]

Changing the BPS rate does change the frequency that you hear coming from the sparks, but the reason that it is not done with SGTCs is that as you increase the BPS, the energy stored in the tank capacitor in each cycle is lower and lower, and the capacitor is usually matched to the frequency of the transformer and its voltage and current, so on some cycles, the transformer will charge the capacitor and then reverse polarity, and discharge it. It might work, but at each frequency, the sparks would take a different appearance, even though the total energy in the circuit would remain the same. Also, IGBTs are not practical with a SGTC due to the VERY high voltages and currents involved. You might be able to try this with an OLTC, but I wouldn't expect good results. Also, MOTs are usually better ballasted using an inductive ballast, such as another MOT with shorted secondary windings.

[Somersetcommunitycollege]

Im trying to put together another circuit for this. I ordered the parts for it a couple days ago so it should be coming in soon, Im going to make a solid state and improve the spark gap, I have a couple of microwave transformers around here somewhere, Know anything that i can do with them???

[Xellers]

Don't use microwave oven transformers, yet. You should only do this when you are very confident in your constructions skills (verify this by building a few smaller neon sign transformer or OBIT powered Tesla Coils first), when you fully understand the physics of the circuit (be comfortable with LC circuits and using calculators, understand quenching and damping effects within the circuit, and be able to understand the current flow within the circuit), and when you have a large, clean area to work in. Even a ballasted microwave oven transformer is lethal. Also, you should collect more transformers, at least 3 for a ballasted antiparallel setup that should provide 4kV. You may also consider using a voltage multiplier, to make the voltages easier to work with. A Tesla Coil built using microwave oven transformers is a big commitment, and will take a lots of time and effort. I recommend that you set those transformers aside for the time being.

[Somersetcommunitycollege]

well ill just work with what i got now. ill put what I got together and throw it on here and see what you all think! just gotta find the time with school and all.....

[volthead]

You are doing better than me. I keep meaning to make an instructable but I have not made anything cool yet. Good luck.

[pyrorower]

Before I build this and attempt to also modify it to "sing", there is one thing I am unsure of... After modifying the coil to sing, would the current be higher than in the unmodified version?

[Xellers]

First of all, you won't be able to modulate any sort of spark gap Tesla Coil, so don't expect to. Also, modulation does increase the current in the coil. It only varies it, to expand or contract the plasma generated by the coil to oscillate air. We perceive these oscillations as sound.

[Somersetcommunitycollege]

I dont know I didnt test it with a meter, I really dont think you can make it sing unless you get rid of the spark gap and make it a solid state. I tryed the spark gap and you can only hear the music inside the flyback, Im trying a new circuit and got the parts in today so im gonna try it out.

[pyrorower]

Wait, Xellers, I was not referring to making something like plasmana's plasma speaker If that's what your talking about... I meant something like this: http://www.youtube.com/watch?v=BiUlqecQKUo&feature=related

[Xellers]

You cannot achieve that sort of modulation using this sort of topology; you will need a full solid state coil as opposed to a SGTC with a solid state driver. As a sidenote, here is what I built: www.instructables.com/id/Audio-Modulated-Solid-State-Tesla-Coil/.