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Killa-X's first SSTC (mni sstc)

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LAN_403

Killa-X

Sat Nov 07 2009, 04:30AM

Registered Member #1643 Joined: Mon Aug 18 2008, 06:10PM
Location:
Posts: 1039

Hello everyone! I decided it should be about time i posted a project thread about my tesla coil. Seeing how it works, and still has many things to be fixed. Some..Specs

**Secondary
-Roughly: 900 turns (Hand coiled, didnt count :( )
-Roughly: 350khz (Will update later when i have my tesla tuner fixed)
-Wire size: 30awg - Made from those 'shake-flashlights' with the magnets
-Form Height: 9 7/8"
-Form Width: 4.5" PVC
-Ground source: Mains.

**Primary
Lets not fill this out. Planning on getting some materials tomorrow, to make a new primary...all my current ones suck and corona.

**Power Supply
For now, Stereo transformer, guessing 2-3A rated, using at 78V. Made a multiplier today to run 158V at a limited amperage...Works

**Interupter
Controllable Duty cycle and frequency, Thanks to Arcstarter for his schematics, and his design of it.

**Results - So far, I get roughly 6 inches from this, after being on a 400V 470uf capacitor 2X multiplier, for 78VAC input, and some 150 output. All has been going decent so far, only done short runs, so even 10 secs of 150V maybe 1A, my IRFP260s stay cool with no heatsinks. The coil however, did have a flash over, from one of my spool connection points (middle coil) to maybe 10 coils up. I cut the wire, added a little hot glue, and it no longer arcs.

Warning! Large pictures are posted after the text below, may be slow for some users, and i posted it at MY site for the sake of the 400pixel limit for saving 4HV.orgs space. Thanks!

1. Chip power board, 12V 5V regulator

2. Half-bridge of IRFP260s

3. My longish'wired GDT (4 turns)

1. Chip board Power supply - 18V, 3A

2. GDT driver

3. GDT waveform, scope FETS pin 1 and 3

Result 1

Result 2

To do list:
1. Make new Primary (tomorrow by all hopes of getting pipe from godwin
2. Finally case my interrupter
3. Make GDT wires a lot shorter
4. actually make a thing worth showing

As you see, its a big, clutter mess, many wires 1ft long. This is what I call "Debug mode" Now that it works, and getting better, I'm going to start ripping all wires out, making it all neat looking, and case it up. I just need to mess with some more GDT stuff and wavesforms first.

brtaman

Mon Nov 09 2009, 01:40PM

Registered Member #2161 Joined: Fri Jun 05 2009, 03:36PM
Location:
Posts: 247

Nice coil Killa-X, it is really coming along! Check 4 of your list, it is already well worth showing.

Only thing I would suggest if you want to square up the GDT waveform as much as possible, is to perhaps add a turn or two to the GDT, it will get rid of the sloping. Though it shouldn't make too much of a difference though as the sloping is pretty minimal based on what I can see.

Best Regards,
brtaman

GeordieBoy

Mon Nov 09 2009, 03:27PM

Registered Member #1232 Joined: Wed Jan 16 2008, 10:53PM
Location: Doon tha Toon!
Posts: 881

Congratulations on getting it up and running.

I'd add heatsinks to the "to do list." Running power MOSFETs with no heatsinking is exceedingly risky even for short runs!!! You are practically begging them to overheat

The metal backplate of the device itself has very little thermal mass so will quickly overheat if you dissipate more than a watt or two of power. After the device pops, it will then quickly cool down to room temperature again before you have chance to turn the power off and stick a finger on it to check for heating. Very misleading for fault finding!

I'd recommend fitting at least some clip on heatsinks before doing long runs or increasing the power.

-Richie,

Killa-X

Mon Nov 09 2009, 10:22PM

Registered Member #1643 Joined: Mon Aug 18 2008, 06:10PM
Location:
Posts: 1039

Yeah, I moved my other fets to the board now, since they were heatsink mounted...2X2X2" heatsinks, 24 fins, they are called MOSFET / CPU heatsinks :D

About checking 4 off, isnt what i ment by showing off. The fact that i have my whole desk in wires due to my tesla coil is the issue. I plan to take all wires out, make boards closer together, make things look neater, and make it portable. Right now, it's just a huuuuge mess! Yes, Those are fans. I got them long ago for these heatsinks, so I'm using them! Blows air in, air comes out vents on top.

Killa-X

Sat Nov 21 2009, 05:47AM

Registered Member #1643 Joined: Mon Aug 18 2008, 06:10PM
Location:
Posts: 1039

Just thought I'd shout out an update. I only had one test so far, and it did work, but some tuning / changes on primary are needed...But as far as that goes, I nearly have my new casing finished. I need to still install the wood backplate for the heatsinks, and add switches, indicators, and other things. But so far, it works. No test on a variac (0-140, 7.5A) but will eventually.

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