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FrozenGate by Avery

Tesla Coil Build Thread






Pretty cool. Can't see clearly from the pictures but the strike ring should have a considerable gap (1-2 cm) to avoid losses.
 
The strike ring shouldn't be a whole circle, else induction will cause eddy currents in it and waste part of your coil's power as heat. Just cut out 1 or 2 cm of copper and leave the circle incomplete.
 
Yep, otherwise the ring appears as a shorted turn. Just make sure to leave no sharp edges where you cut it.
 
Did you measure your resonance frequency's Speedy?

I had to order a small uF tank cap to raise my primary to meet the secondary resonance.

I tuned my EVR microbrute by ear, but now i have a scope and function generator, i measured i was 70kHz off the mark! Ordered new tank caps for that also.

Also bought some alumina oxide isolation pads for the IGBT's on the onetesla too.
 
Its whatever I want it to be now :). Per build instructions it came out to 245/333. 5 Turn primary was 307/333. With the bare copper horizontal primary I'm sitting around 311/333 but still messing around with it.
 
good stuff! yeah mine was similar at 267/334.

im planning a small spark gap coil for the holidays.

Reckon this will work?

Diagram.png
 
hahaa yeah, im not sure if the igntion coil puts out ac or dc, i seen a few diagrams with a HV diode in their so im thinking ac.

my coil puts out ~30-40kV too so not sure if its too high for the spark gap.

someone will chime in with more advice i hope :D
 
Fiddy said:
good stuff! yeah mine was similar at 267/334.

im planning a small spark gap coil for the holidays.

Reckon this will work?

Diagram.png
Click to expand...

You need something between the diode and capacitor or else the RF energies will kill the
diode. Either a HV resistor or possibly an air coil. I don't know for sure weather the coil
would work as I've never tried it. If you don't have a HV resistor, you can make one by putting
lots of regular ones in series. They can be hard to find. A ballast resistor from a HeNe might
work. Regular resistors are only rated like 1kV, so you would have to put a lot in series.

Ignition coils are always AC.
 
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I don't know why exactly, but any time you have a diode charging a low ESR HV capacitor that goes
into a spark gap unprotected like that it will die.
 
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so would i go for a high ohms or relatively low ohms resistor bank? im going to get a RC charging circuit there of the capacitor with this too.
 
*cough* Ahem. Hello gentlemen! I believe I am needed here...

Hey Fiddy, remove the diode and swap the position of the spark gap and the tank capacitor. The gap will essentially short the LF side while the HF side is ringing, which prevents RF feedback into the LF stuff. SGTCs will operate fine on AC or DC, no need to introduce a lossy (and capacitive at TC frequencies) rectifier in there. DC resonant coils do exist but gain no improvement over AC coils until you reach the 10kW or so level.

TLS the reason the diode will die is because it appears as a capacitor at TC frequencies because the NP junction can't populate/depopulate fast enough, thus it no longer conducts in one direction above a certain frequency. Also, resonant rise in the tank circuit quickly exceeds the Vbr causing the diode to be overvolted.

Oh, btw, 30kV is a lot easier to set up a SG for than 3kV, tell you that much!

Edit: NO lossy resister bank. NO. haha.
 
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