Tesla Coil Build Thread

[Sigurthr]

Ohh on the interrupter. Lol. For the bridge test I just ran it CW. But on the interrupter itself the slow clock is why it maxes out at 1.8Hz - 418Hz instead of 2 - 512Hz. It isn't fixed but the Digispark footprint doesn't have room for additional circuitry, the interconnects used up the entire protoshield (13 wires for my interrupter). If I was going to use a bigger footprint I'd have slapped a 20MHz xtal on there per your suggestion.

 

[The Lightning Stalker]

I have just discovered that the Attinies default to 1MHz from the factory and that I don't like Atmel's
datasheets. You have to "burn" the flash "fuses" to get it to use an external clock. I'm going to refer you
to the datasheet on the exact value you'll need. Then it's something like avrdude -U lfuse:w:0x??:m to put
the smoke in.

 

[DashApple]

ion: Are those isolated tab FETs? I don't see anything between the FETs and the H/S.

The Fets are normal TO-247 package , but for testing there is a 220 size thermal pad with thermal paste squished between it on each mosfet , Crude but it works for testing .

 

[Fiddy]

Re-wound and re-tuned my primary to suite a smaller capacitance as Sigurthr advised.

Ive tripled the spark length now

any thanks to Sigurthr

 

[The Lightning Stalker]

Ahhah, I knew you must have been hiding something under there! You are a sneaky one, ion.

Sig: Have we lost you inside the datasheets? The Atmels are slightly different from the PICs I'm used
to. The config word(s) on the PIC is programmed at the same time along with program memory. Not so
the Atmel. Programming the lock and fuse areas are separate steps. This should disable the clock
prescaler and give you the full 8MHz leaving everything else default.

avrdude -p t85 -c usbtiny -U lfuse:w:0xe2:m

If the chip on there is the 20MHz version, you can even go to 16MHz by switching to the PLL clock. I'll let you
figure that one out if you want to do that.

 

[Sigurthr]

Ahhah, I knew you must have been hiding something under there! You are a sneaky one, ion.

Sig: Have we lost you inside the datasheets? The Atmels are slightly different from the PICs I'm used
to. The config word(s) on the PIC is programmed at the same time along with program memory. Not so
the Atmel. Programming the lock and fuse areas are separate steps. This should disable the clock
prescaler and give you the full 8MHz leaving everything else default.

avrdude -p t85 -c usbtiny -U lfuse:w:0xe2:m

If the chip on there is the 20MHz version, you can even go to 16MHz by switching to the PLL clock. I'll let you
figure that one out if you want to do that.

I think you're running a different IDE than I am for these Amtel chips. That syntax and parameters don't work in the environment I'm using.

Trying to fix the clock issue on the digispark is moot anyway as apparently trying to do any higher level reprogramming just bricks the platform. So I'll not be trying it. When I get my UNO in the mail and make my own ATTiny ISP shield I'll look into getting 20MHz xtals and getting the full speed out of these 85's. I have a LOT of projects which could benefit from using ATTiny85's in place of things like complex strings of comparators. I love analog work and it is often less buggy, but making complex if > then conditionals with tons of pots, comparators, resistor networks, inverters, etc. is way more of a hassle then slapping an ATTiny85 in there with a handful of lines of code.

@Fiddy Now, THAT is more like what I was expecting out of that coil! Glad I could help.

 

[Sigurthr]

Double post rules be damned. This is my thread anyway >.> !

I built my test board and just finished a rigorous testing schedule of said test board. After many hours of blood, sweat, and painstaking concentration I am happy to announce the USSTCC is a COMPLETE SUCCESS!

I ran the gamut on this board 100KHz to 1MHz, antenna and CT feedback, floating board ground and tied to RF ground, 14Vac to 24Vac input, ground strikes, sustained ground arcing, you name it. She's a real beauty.

Pics and Videos to follow:

Stress Testing my Testing-Half-Bridge and my MCU Interrupter.

https://www.youtube.com/watch?v=SSEqXllg8Zc

Alpha Testing the board:

https://www.youtube.com/watch?v=ki0I2u0teaQ

Long Duration testing the board:
200W CW 666KHz
30min warm up before filming began.

https://www.youtube.com/watch?v=QFoIBfOGhrU

 

[Fiddy]

Wow thats awesome man! love how the boards turned out

 

[Speedy78]

BGS (Big Green Secondary)

 

[Fiddy]

Good news, i found a guy selling some new NST's he has 4 of them, he listed the like this.

1x 5kV, 30mA
2x 6kV, 30mA
1x 8kV, 30mA

Anyway i asked for photos of each one and found something interesting.

I found on the 5kV NST it said "5000-E-5000" meaning there is 2 windings 5kV each!
Also found one of 6kV NST's was "3000-E-3000" and the other was"6000-E-6000" so 12kV all up on that one.
The 8kV NST was "4000-E-4000" so not too good their.

Also put together the flexibrute MIDI Modulator for the micrbrute, which was only just a bare PCB board, ive put it in a box and cut out and engraved a traffolyte face plate for it turned out well.

 

[Speedy78]

Im still looking for a 15KV 60mA but having no such luck. That interupter is sweet

 

[Sigurthr]

Very nice! How much did they want for the 6k-0-6k NST? That's a sweet find. Strange that the EVR modulator was just a pcb, I thought they encased everything with their logo. How did you engrave the panel so nicely!?

I have sad news to report; my 3kW coil was forced into leave of absence. I was doing a run last night at high power and noticed corona on the top turns of my primary. This coil has super tight coupling, with PP sheeting between the secondary and primary windings for insulation. The corona started to melt the PP sheeting. I have not removed it yet to see if there is any damage to the varnish, but it is still electrically sound so I know there is no damage to the enamel on the windings. I'll have to make and install a brand new primary to get this guy running again, and I don't have the time or money for it now. I'm glad I caught it when I did because 3kW + pri/sec failure = FIRE.

Meanwhile I put my medium sized secondary and higher impedance primary on my main bridge. Since my 3kW coil was PLL driven I'm now using my Universal Logic Controller board to drive my main bridge and the medium resonator. It's working rather nicely!


https://www.youtube.com/watch?v=TPmcE1j1aas

 

[Fiddy]

Im still looking for a 15KV 60mA but having no such luck. That interupter is sweet

15kV 60mA is the big boy isnt it? Cheers!

Very nice! How much did they want for the 6k-0-6k NST? That's a sweet find. Strange that the EVR modulator was just a pcb, I thought they encased everything with their logo. How did you engrave the panel so nicely!?

I have sad news to report; my 3kW coil was forced into leave of absence. I was doing a run last night at high power and noticed corona on the top turns of my primary. This coil has super tight coupling, with PP sheeting between the secondary and primary windings for insulation. The corona started to melt the PP sheeting. I have not removed it yet to see if there is any damage to the varnish, but it is still electrically sound so I know there is no damage to the enamel on the windings. I'll have to make and install a brand new primary to get this guy running again, and I don't have the time or money for it now. I'm glad I caught it when I did because 3kW + pri/sec failure = FIRE.

Meanwhile I put my medium sized secondary and higher impedance primary on my main bridge. Since my 3kW coil was PLL driven I'm now using my Universal Logic Controller board to drive my main bridge and the medium resonator. It's working rather nicely!


https://www.youtube.com/watch?v=TPmcE1j1aas

They want $100AUD each for the NST's.

Yeah i dont know why they didnt put this one in a case either.

At work we have a Traffolyte engraver, its like a mini CNC:

Wow thats a nice vid! love the CW and interupted feature

 

[Speedy78]

Got the new variac in the mail today!

 

[Fiddy]

haha nice speedy! how many VA is it? ive got a little 500VA one atm.

in other news im heading down the bipolar coil way,

heres a mini i intend to use on the plasma speaker driver

 

[Speedy78]

2KVA

Nice! I want to see that thing running! When do you think you will have it throwing sparks?