Tesla Coil Build Thread

[Fiddy]

I know streamers add capacitance and tuned it accordingly.
Just need to know the questions I asked.

 

[Sigurthr]

In my sleep deprived state I started to type out a response on how to track the current waveforms to determine the cap charging status and then the obvious dawned on me; you're now resonating at 400KHz instead of 300KHz.

Spark length is inversely proportional to resonant frequency. The higher the frequency the lower the capacitive reactance of the toroid-air-earth system is so the streamers don't have to grow as large to deliver the same current per cycle.

A quick check would be to monitor input current waveform with the old tuning and compare it to the new tuning. Unless input power is drastically different, you're just seeing the effect of a higher f0.

Btw, I'm ready for the files to send to OSHpark now!

 

[The Lightning Stalker]

Pastebin.com - #1 paste tool since 2002!

Still anxious to see the BOM/schematic. :thanks:

 

[Atomicrox]

Sig, I might be interested in trying your board on my SSTC to see if it behaves better.
Are you willing to sell the board with the components (no need to solder them all)? It'd be a *lot* easier for us outside the US. These coils seem to be pretty sensitive about brands/models of the components.

 

[Seoul_lasers]

I rewound my primary with silicon insulation 12AWG wire, its blue!

On a tunning note, im in the process of tunning my Microbrute now i have a scope and signal generator.

The secondary is resonating at 410kHz and the primary was ~300khz so i changed the tank cap to a smaller size and got it real close to the secondary resonance, but now i get shorter arcs.

Is this because the tank cap cant charge up as quick at ~400kHz compared to ~300kHz?

and/or

The tank cap being a smaller capacitance doesn't hold as much energy and energy in the capacitor is proportional to spark length?

Some expertise on this would be grand, im looking at you Sigurthr!

Try changing the top load ( go up a few sizes). You'll need to experiment a little to drop the resonant frequency. Do this instead of lowering the capacitance of the primary circuit which effects the spark length.

 

[Fiddy]

Try changing the top load ( go up a few sizes). You'll need to experiment a little to drop the resonant frequency. Do this instead of lowering the capacitance of the primary circuit which effects the spark length.

You read my mind! im adding a 6" toroid to lower the secondary resonant frequency!

 

[Fiddy]

Yay just hit 15" arcs with a 10 second tune and the OCD doesn't come on

 

[Seoul_lasers]

You read my mind! im adding a 6" toroid to lower the secondary resonant frequency!

Nice coil!!! :beer::beer::beer:
Nice clean build!!

Going to be my next project!

 

[Fiddy]

hehe thanks man

Im planning a small scale SGTC this holiday season!

 

[Sigurthr]

Sig, I might be interested in trying your board on my SSTC to see if it behaves better.
Are you willing to sell the board with the components (no need to solder them all)? It'd be a *lot* easier for us outside the US. These coils seem to be pretty sensitive about brands/models of the components.

I certainly am considering offering a "kit" form (board + board components, and maybe a detailed drawing of proper bridge design), the main issue is investment capitol, and lack there of. I can certainly do it on a one-off basis where the buyer pre-pays for the digi/mouser order + intermediary shipping, it's not like I'm not a Vet, and the BOM total isn't exactly a large sum, heh.

Once my test board passes scrutiny I'll feel a whole lot more confident, and I'd like to write up a nice .PDF instruction booklet for it. While the board population and hookup is simple, layout of wires, proximity of sub-assemblies, and general TC do's and don't's aren't in the common knowledge of most people.

UPDATED:
USSTCC BOM & Schematic: See Post:
http://laserpointerforums.com/f60/tesla-coil-build-thread-73702-26.html#post1262287

 

[Fiddy]

I certainly am considering offering a "kit" form (board + board components, and maybe a detailed drawing of proper bridge design), the main issue is investment capitol, and lack there of. I can certainly do it on a one-off basis where the buyer pre-pays for the digi/mouser order + intermediary shipping, it's not like I'm not a Vet, and the BOM total isn't exactly a large sum, heh.

Once my test board passes scrutiny I'll feel a whole lot more confident, and I'd like to write up a nice .PDF instruction booklet for it. While the board population and hookup is simple, layout of wires, proximity of sub-assemblies, and general TC do's and don't's aren't in the common knowledge of most people.

USSTCC BOM & Schematic:
BOM: https://app.box.com/s/nzjw7w6gdrzqtl0iwk6x
Schematic: https://app.box.com/s/2ciuyhbub2wzredkyseo

Nice man!

Should definitely order enough for 10 kits!

ive got parts for at-least 8x Plasma Speaker kit parts and 10x Nano SSTC waiting to be made, pitty i have this whine in the plasma speaker. I need your assistance with the plasma speaker can i send you the BOM, schematic & board layout


Here's my tuned coil running!
(cant see arcs good in day time but if you look closely one arc is up higher than the handle of the door in back ground)

 

[Sigurthr]

Haha, sure, send the files over and I'll nitpick it for you. I can't guarantee a fix without a board infront of me to scope and scrutinize (not that I'm asking for one), but I can certainly do my best to itemize issues and potential faults.

I wish I could order a 10x parts lot, but there's no way I can afford it, at least not yet.

Glad you got the DR running good! Those EVR coils are solid, no reason to have to settle for poor performance with them.

 

[Fiddy]

If you get real keen, i can send you a whole kit for nit picking.

thanks! yeah man, this thing is super tough, with the OCD it cannot be killed by over current.

 

[DashApple]

Nice PCB design .

I really need to find 220 package gate drivers with enables so I can control the duty on my coil at full power other than pure CW . might try the IXYS series 30A gate drive ICs ( over kill I know ) but the Non inverting driver is the only one to have a enable pin .

 

[Sigurthr]

@ Twirly: use two non-inverting chips and just run the signal to the second gate drive IC through a single pass of the Schmitt Trigger Inverter to make it inverting. Why do you need TO-220's anyway? I've never had any heating issues with the 8-dip ones.

I've decided to revise the BOM and Schematic image to include in a proper "universal" GDT core. I haven't tested it on a CM300 or CM600 but it should hold up for anything the UCCs can handle anyway. One less item for clients to have to figure out. I'll update the files accordingly.

Also, I think I can get the capitol to offer complete board kits (board + all board mounted components + GDT core).

Initial Pricing Projection:
Board ONLY: $25 + S&H
Board Kit: $45 + S&H

I'm also working on a Half-Bridge Guide for those interested. There will be a schematic and BOM at very minimum. It certainly isn't required for the controller board, but this is my recommended setup for use with the controller board. This way a total newcomer can see what all is suggested and isn't left floundering wondering what they need. It is a good way to get a feel for the whole SSTC. I would like to include a detailed write up with pictures of proper bridge layout and design.

 

[Speedy78]

Sounds interesting! Definitely would need some guidance on the bridge.