Tesla Coil Build Thread

[Sigurthr]

Lolololol. I love your builds. Nice results btw!


Was reading 4HV today and this was relevant to the conversation here:

A synchronous gap will only give a performance improvement if your tank capacitor is big enough to fully load the power supply at a low break rate, like 100 or 120bps.

If you have a smaller tank capacitor, then a higher break rate will give best performance, and beyond about 240bps, the difference between sync and async is hardly worth worrying about.

TLDR: It's actually the big tank capacitor that improves performance, the sync gap is just required to charge a big capacitor at a low break rate in a consistent way without massive voltage surges.

 

[Speedy78]

Did some work on the primary today. Still conical but less pronounced and lower. Also added two more turns to give me more tuning options with the big toroid. Strike rail is back on as well.



Also added a brass breakout. Figured with longer arcs possible I want a little more control of them.

.

Next step is to fix the MOT box issues that S_L pointed out and begin planning the ARSG. Also the base needs to be rewired because I'm removing a fan and the power source is no longer on the base but I still want my switch to activate the MOTS and have my VARIAC switch on the SG.

 

[Seoul_lasers]

Nice looking setup there!!

^^

Can't wait to see what the final product will look like! :beer:

 

[Speedy78]

PP 12x12x.25 sheet
Phenolic sheet sane diameter
Angle grinder 11000 rpm
3/4 PE tubing
1/4 PE tubing
15 ceramic HV not looking insulators
all in the mail

Still need to figure out what to buy for the electrodes on the rotor. Can't seem to find anything that can screw on or something. I have tungsten for the stationary electrodes but no idea how to do the 4 on the rotor. How big of a diameter do i need to cut for the rotor?

 

[The Lightning Stalker]

Well, I had an interesting day. Assuming they still work, what can I do with a couple CM75DU-12F and a
CVM55BB160?

 

[Seoul_lasers]

PP 12x12x.25 sheet
Phenolic sheet sane diameter
Angle grinder 11000 rpm
3/4 PE tubing
1/4 PE tubing
15 ceramic HV not looking insulators
all in the mail

Still need to figure out what to buy for the electrodes on the rotor. Can't seem to find anything that can screw on or something. I have tungsten for the stationary electrodes but no idea how to do the 4 on the rotor. How big of a diameter do i need to cut for the rotor?

¾" copper bolts will work fine as the rotating electrodes. You'll want 4.

 

[Sigurthr]

Well, I had an interesting day. Assuming they still work, what can I do with a couple CM75DU-12F and a
CVM55BB160?

The 45V 15mF caps are good for stereos and other low voltage high current work, but not much use for TCs unless you want to do something like Staci Elaan where you make a handheld DRSSTC that runs off of a boost converter powered by LiPos.

The 450V caps are great, I have several. They're excellent for DC bus caps for half/full bridges.

 

[Speedy78]

MOT box has been fixed. All vinyl tubing and two porcelain HV terminals.


Brass screws are just here to hold the terminals before I had the appropriate hardware.


Terminals sit on a section of PP plastic to isolate them from the wooden frame.


The wire running from these to my ARSG will also be covered in tubing and I plan to make caps (sort of like the red rubber cap on the battery of a car on the positive terminal) out of vinyl and hot glue to isolate them as much as possible.


Grinder is in and phenolic sheet. How big of a diameter rotor am I making for this spark gap? Grinder is 11000 RPM and I plan to have 4 electrodes.

 

[Sigurthr]

Very nice work!!

Going to be a sweet coil for sure!

 

[Speedy78]

Used leftover PP sheet and made these primary dividers to help tame so much copper and keep the turns separate.


Vinyl tubing everywhere! This is the tap wire for the primary.


Other side of the primary. Will fill that gap in the corner with hot glue.


I didn't unsolder the caps but a made this sleeve out of vinyl tubing with a slit down one side to snap over all of this.


Sadly this is the only location for my spark gap due to the length of that 4ga piece. Which means I either offset the base to face 45 degrees or so away from me or, and this is my plan, weld up a 1/4 inch plate steel bullet proof scatter shield and ground it. This will also block the spark gap arcing from direct view.

 

[Sigurthr]

Any progress on the solid state coil?

 

[Speedy78]

No. Haven't had time to sit down and work on it. I still can't find heat sinks I like. That and I need some thick lean for the top. Just using wood for the bottom part.

 

[Sigurthr]

PVC end caps work well too for a top piece. You could mill down a large one for the flat pvc round needed.

 

[DashApple]

Lolololol. I love your builds. Nice results btw!

Thanks ,

I've started to make a full bridge mini SSTC using the 2" x 2.8" secondary , with a topload I get a Frez of 800Khz but I plan to have a small MMC inside the secondary coil to try and bring the Frez down abit .

Record for the coil was 9" with a half bridge so I hope full bridge is better

 

[Sigurthr]

I put a lot of work in on the big coil rebuild the last two nights.

Today I worked on the H bridge. In total there are 21 silicon devices in this bridge, if you count the full wave rectifier as one device anyway. If you don't then there are 24 devices.

4x FDL100N50F MOSFETs
8x MUR1560 600V 15A Schottky Diodes
8x 15V 5W Zeners
1x 600V 30A Bridge Rectifier
1x CDE 940series 600V 680nF DC-Block Primary Capacitor
1x CDE 942series 2000V 47nF Snubber Capacitor
4x 5W 5Ohm Non-Inductive 3kV rated Gate Resistors
Arctic Alumina compound and 5kV rated Silpads for isolation and thermal junctioning.

10ga copper interconnects.

Tomorrow I plan on doing the pentafilliar GDT, but the rest has to wait as I am quite busy all week.

 

[ped]

I hate winding GDTs , that thing looks gnarly.