I'm quite new to the Tesla Coil stuff and I want to build a VTTC form a GU-81 tube. I'm using schematics from this Instructable.
I don't want to make anything I don't understand and although I understand basic Tesla Coil working principles there are some questions left unanswered. After asking on Instructables page and not receiving a response I decided to ask here.
There are some questions about the design I really need to know the answer for.
You need something that limits the amaount of current floating through the tube grid and the feedback coil. It doesn't really matter if you use a high wattage resistor or a light bulb. The most important thing is that the calculations are correct ! All calculations for the GU-81 pentode R= V(Anode voltage)/(4*I(Anode current)) =5900V/(4*0.6A) =2458 Ohm --> Use at least a 2,5kOhm resistor! (at least 130W) W= (V(Grid Voltage)/R)*V(Grid Voltage) = (600V/2458Ohm)*600V = 162W --> Use definitly not more than a 160W light blub (I use 100W)
There is no clear information what bulb shall I use (What voltage should it be for, The bulb in the picture is way too small for a 100W)
- What is the purpose of the 700pF 12.5KV capacitor? Can I use a 1000pF 15KV cap instead ?
3.What is the purpose of the 4.7nF 6KV cap in the filament transformer output? Does it have to do with the fact that the tube is heated directly?
- Should I use a separate grounding rod for the Coil and if yes, to which part of the circuit should I connect it? (I have RCD breakers so any current flowing to ground will trip them)
5.One more thing. Will I die if i touch the sparks (I mean secondary, not the primary circuit. The primary part of the coil would kill me instantly)
I'm sorry if any one of my questions cannot be answered, I just want to be sure before building a device that is so dangerous.