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My First SMALL DRSSTC (Now with 4X Secondary Length Performance)

Phillip Slawinski, Fri Feb 13 2009, 02:27PM

I'm a little over a month into making my first DRSSTC. I'm near completion and plan to take it to the Winter Western Teslathon. I will be taking one unit to the WWT, but the final system will be a twin coil system. I also plan to audio modulate in the future. Thanks go to John Forcijo (TeslaCoolGuy) for helping me through the design process.

Basic Data:
Fo: 236kHz
Secondary 11.5"H x 2.4"D 34AWG (Single-Build) 1643 Turns
Topload 12"x3" Spun Aluminum
Tank Capacitor .15uF
Primary Coil 3.5"D x 2.5"H .1875"D Copper Tubing
Full Bridge of Farichild SGH80N60UFD
Steve Ward's Universal Driver

I still need to complete the Interrupter and the base, as well as various other minor things. By far the most time-consuming part of this project has been getting it laid out and ordering the parts. I don't know of anyone who has used these IGBTs before. They were super-cheap [$~3]. I'll update this thread when I know how well they work.

Maybe someone can help me on this; I want to add a doubler to this and I have 8x 250V 1200uF caps and the diodes. I plan on running each coil somewhere around 350W. My question is, how do I know what kind of capacitance I need to keep the volt drop reasonable? Also how tolerant are these electrolytics of over-volting? I'm thinking they may not take too kindly to 100V over their rated voltage, which is a shame because It's going to be nearly impossible to fit all eight caps into the box I'm designing.

Here are some photos of what I've completed so far.

EDIT: This stuff is all pretty awful. I have updated every component shown here, see page two for more up to date photos.

Steve's Universal Controller

IC Pile

Bridge Output Side

Bridge Input Side

MMC

Secondary Coils

Projected Design

Re: My First SMALL DRSSTC (Now with 4X Secondary Length Performance)
Tom540, Fri Feb 13 2009, 05:19PM

Looks good so far. I like that cute little MMC, hehe.

Re: My First SMALL DRSSTC (Now with 4X Secondary Length Performance)
MRacerxdl, Fri Feb 13 2009, 11:46PM

Very good work! Keep going :D
Hope it works, I want to see sparks from that

Re: My First SMALL DRSSTC (Now with 4X Secondary Length Performance)
Phillip Slawinski, Sat Feb 14 2009, 02:17AM

Finished the primary coil supports.

Primary Coil

Primary Coil

Re: My First SMALL DRSSTC (Now with 4X Secondary Length Performance)
Tom540, Sat Feb 14 2009, 06:08AM

What are your supports made of? Ive been looking for different things to try out for supports.

Re: My First SMALL DRSSTC (Now with 4X Secondary Length Performance)
Phillip Slawinski, Sat Feb 14 2009, 03:09PM

The supports are made of ultra high molecular weight polyethylene.

Re: My First SMALL DRSSTC (Now with 4X Secondary Length Performance)
Arcstarter, Sat Feb 14 2009, 09:01PM

Absolutely beautiful! :')

Just something about small DRSSTC's that i love.

Re: My First SMALL DRSSTC (Now with 4X Secondary Length Performance)
101111, Sat Feb 14 2009, 10:09PM

All this looks wonderful but there is one thing that I think that can be a problem. Because the MMC is enclosed in that box of plexy they might get a little too hot.

Re: My First SMALL DRSSTC (Now with 4X Secondary Length Performance)
Phillip Slawinski, Sun Feb 15 2009, 05:18AM

Worked on the base today, almost done.

Re: My First SMALL DRSSTC (Now with 4X Secondary Length Performance)
Arcstarter, Sun Feb 15 2009, 08:00AM

Phillip Slawinski wrote ...

Worked on the base today, almost done.

Oh my! That is just beautiful! :O

Can't wait for some sparks!

Re: My First SMALL DRSSTC (Now with 4X Secondary Length Performance)
MRacerxdl, Sun Feb 15 2009, 02:01PM

Really beautifull indeed! Very good work!

Re: My First SMALL DRSSTC (Now with 4X Secondary Length Performance)
Austin, Thu Feb 19 2009, 05:43AM

just how mini is this thing? do you have a dollar bill or something to show the scale?

Re: My First SMALL DRSSTC (Now with 4X Secondary Length Performance)
Tom540, Thu Feb 19 2009, 07:12AM

Austin wrote ...

just how mini is this thing? do you have a dollar bill or something to show the scale?

well according to one of the pictures it says the secondaries are 2.4 x 11.5 " Took me awhile to realize it was somewhat small myself.

Re: My First SMALL DRSSTC (Now with 4X Secondary Length Performance)
Phillip Slawinski, Thu Feb 19 2009, 01:53PM

The dimensions of the base (in inches) are 8x8x4. I think that's the only thing I haven't posted so far, all the other dimensions are in my original post.

The inside of the box turned out to be a pretty tight squeeze for all the components, so I had to ditch my nice looking MMC, no matter though as nothing inside the box is visible unless you remove the top.

I'm pretty close to the point where I can test out the interrupter, and driver, and then .... sparks :)

Re: My First SMALL DRSSTC (Now with 4X Secondary Length Performance)
Phillip Slawinski, Sat Feb 21 2009, 05:58AM

Here are the innards. The assembly is 99% finished. Hope to test tomorrow or Sunday.

Re: My First SMALL DRSSTC (Now with 4X Secondary Length Performance)
Phillip Slawinski, Thu Mar 05 2009, 05:04AM

Well, I got first light. It was pretty uneventful, only 1" sparks to a target. Then the bridge blew up, unfortunately I only have three spares. Oh well, guess I'll have to order some more.

Re: My First SMALL DRSSTC (Now with 4X Secondary Length Performance)
Tom540, Thu Mar 05 2009, 06:50PM

Phillip Slawinski wrote ...

Well, I got first light. It was pretty uneventful, only 1" sparks to a target. Then the bridge blew up, unfortunately I only have three spares. Oh well, guess I'll have to order some more.

3 Spare IGBT's? Whenever mine blow its always only two of them and always the same two that blow. Ohm them out.

Re: My First SMALL DRSSTC (Now with 4X Secondary Length Performance)
Dr. Drone, Thu Mar 05 2009, 07:46PM

Re: My First SMALL DRSSTC (Now with 4X Secondary Length Performance)
coillah, Thu Mar 05 2009, 11:15PM

very good looking work man, mad props

Re: My First SMALL DRSSTC (Now with 4X Secondary Length Performance)
Phillip Slawinski, Wed Mar 25 2009, 03:55AM

Tonight I achieved real First Light.

I still have some major problems to work out. For starters it looks like the ground in my apartment may not be good enough for this DRSSTC, I was getting corona on EVERYTHING. Second, I need to get that OCD circuit working. That would have saved me tonight. If you look at the photos you can see my scope in the background the current is reading about 400A

I designed my case way too small for this project, so that's going to have to go too.

Re: My First SMALL DRSSTC (Now with 4X Secondary Length Performance)
Angstrom, Wed Mar 25 2009, 04:27AM

Very nice, great to see the work-in-progress from the teslathon turn into this!

Re: My First SMALL DRSSTC (Now with 4X Secondary Length Performance)
Phillip Slawinski, Wed Mar 25 2009, 04:46AM

Angstrom wrote ...

Very nice, great to see the work-in-progress from the teslathon turn into this!

Thanks! I'd still call this a work in progress. I think the finished product may have little relation to what I brought to the 'thon. Seeing Chris's work really made me want to raise my own standards.

Re: My First SMALL DRSSTC (Now with 4X Secondary Length Performance)
StevenCaton, Thu Mar 26 2009, 01:31AM

I'm glad to see you got it working Phillip. What were the problems you had earlier with it?

Seeing Chris's work really made me want to raise my own standards.

me too

Re: My First SMALL DRSSTC (Now with 4X Secondary Length Performance)
Phillip Slawinski, Tue Mar 31 2009, 10:56PM

SteveC wrote ...

I'm glad to see you got it working Phillip. What were the problems you had earlier with it?

Seeing Chris's work really made me want to raise my own standards.

me too

Most of my problems have been due to the driver not functioning correctly. Once I got the driver functioning I ran into problems with my bridge. I didn't have enough spacing, and there were some serious arc-overs. I think the bridge should be fixed now, but I have to wait until I get the rest of the parts for my new Driver on Friday to really run the coil through it's paces.

Re: My First SMALL DRSSTC (Now with 4X Secondary Length Performance)
Bennem, Wed Apr 01 2009, 05:57AM

Phillip Slawinski wrote ...

SteveC wrote ...

I'm glad to see you got it working Phillip. What were the problems you had earlier with it?

Seeing Chris's work really made me want to raise my own standards.

me too

What driver problems did you have?

Re: My First SMALL DRSSTC (Now with 4X Secondary Length Performance)
Phillip Slawinski, Wed Apr 01 2009, 12:46PM

Bennem wrote ...

What driver problems did you have?

Well, I've had a lot of driver problems. I'm building my third driver now. The previous one which I have an image of above was a piece of junk. Solder bridges, cold solders, broken vias, you name it, that board had it. The second driver was much better [used UV sensitive boards instead of toner transfer], but I could never get the OCD working correctly, and recently the whole board just died on me. So, I ordered some professionally made boards from Steve, which arrived Monday. I've got the boards mostly populated (this time with brand new parts), but there are still a few parts I'm waiting for, that won't come until Friday.

Re: My First SMALL DRSSTC (Now with 4X Secondary Length Performance)
Bennem, Wed Apr 01 2009, 04:10PM

Phillip Slawinski wrote ...

Bennem wrote ...

What driver problems did you have?

I ordered some professionally made boards from Steve, which arrived Monday. I've got the boards mostly populated (this time with brand new parts), but there are still a few parts I'm waiting for, that won't come until Friday.

yeah...i've had two of those boards off Steve too......they are excellent!!

keep us posted!

Mel

Re: My First SMALL DRSSTC (Now with 4X Secondary Length Performance)
Phillip Slawinski, Sat Apr 11 2009, 01:35AM

I finally got all my driver issues sorted out. It ran flawlessly the past couple times I ran the coil. I also fixed the problems i was having with with my bridge. I increased the spacing between components and I have had no more flash overs. I was able to coax 15" sparks out of the coil before there was some breakdown between the secondary and ground ring. I took apart the old primary and hacked together a flat primary for testing purposes. This turned out to be a bad idea. The coupling went up quite a bit, and I let some smoke out of my secondary [high secondary base currents]. At this point I had upped the OCD to allow 400A of primary which proved to be too much for the IGBTs to handle. They didn't explode, but they silently stopped working.

So moving forward I've wound a new secondary #30 14"x3.5" This secondary has nearly half the series resistance of my previous secondary, and double the Q factor. I'm also rebuilding the enclosure. The UHMWPE was somewhat ugly, and certainly not very sturdy so I'll be rebuilding the enclosure out of black acrylic. I'll be reducing the primary capacitance so I can drop my primary current down to acceptable levels.

Here are the last spark photos I took.

Re: My First SMALL DRSSTC (Now with 4X Secondary Length Performance)
Killa-X, Sat Apr 11 2009, 01:44AM

Very nice results on your tesla coil, Phillip. Can't wait to see what your next coil will result, Nice job at the clean setup :)

Re: My First SMALL DRSSTC (Now with 4X Secondary Length Performance)
Phillip Slawinski, Wed Apr 15 2009, 02:10AM

Wound a new secondary, and built a new primary. Working on getting the coil back to a stage where I can test it. Secondary dimensions 3.5x14 1260T Fo = 240kHz Q = 244

Re: My First SMALL DRSSTC (Now with 4X Secondary Length Performance)
StevenCaton, Wed Apr 15 2009, 02:17AM

Coil looks great Phillip

Is that brass weatherstrip on your primary? It makes for a nice tight primary coil, and looks pretty good too.

However, in a drsstc I think you should go with Cu to cut down the primary resistance.

You did say it was only for testing purposes though.

Re: My First SMALL DRSSTC (Now with 4X Secondary Length Performance)
Phillip Slawinski, Wed Apr 15 2009, 02:22AM

It's .7" copper strip. It was old stock, so it's a little tarnished. I'll clean it up for the final product. I have to redo the secondary, as that didn't come out as planned either.

Re: My First SMALL DRSSTC (Now with 4X Secondary Length Performance)
Dr. Drone, Wed Apr 15 2009, 02:57AM

Re: My First SMALL DRSSTC (Now with 4X Secondary Length Performance)
Phillip Slawinski, Wed Apr 15 2009, 03:45AM

Dr. Spark wrote ...

I must add a little comment here, as offered to leave the coil with me at the Thon and would get it working and mail back. Comment back was â€˜Nice offer but would not learn that wayâ€â€¦.. wow, I was impressed!

This is what it is all about, building the coil and finding bugs and improving, always thinking of next coil and what was learned from previous design will be used as a basis in the next design; however, improved.

A flat primary will work; however, concerned about flash over and coupling. Remember that a DRSSTC is a pulse machine, so power transfer from primary can make or break spark length.

Rgs,
Ch

Hi Chris,

I'm glad I did decide to tackle this myself, as I have learned a whole lot from this project. The offer certainly was nice though!

Regarding the primary:

I am a little concerned about flashover, but this is just an experimental setup, so I'll see how it goes. I've got a rail of IGBTs so no worries

My coupling is sitting around .13 right now, which is just about right. I should also address the lack of strike rail. I have put one on since I took this photo, so no worries there.

I've still got a month or two of debugging and polishing left on this coil, but that's okay. I'm getting a lot of mileage on this project. By the way, I decided to give Acrylic a try. I have a 2'x2' sheet of black acrylic I'm going to use for the final base. I'm also looking into moving to a full bridge of MiniBrick IGBTs so I'll have better thermal handling. I want to be able to run this thing hard at high break rates. Hopefully I'll have a real showpiece to bring to the 2010 W.W.T.

By the way, I figured out why my last secondary was smoking, and it is so simple I'm surprised I didn't see it before.

D'oh! Gotta hate those shorted turns.

Re: My First SMALL DRSSTC (Now with 4X Secondary Length Performance)
Angstrom, Wed Apr 15 2009, 03:48AM

Hmm that is rather spectacular...

Re: My First SMALL DRSSTC (Now with 4X Secondary Length Performance)
Phillip Slawinski, Wed Apr 15 2009, 04:20AM

Here's the current bridge design I'm using. I think this is about as good as it's going to get for the TO-247's that I'm using. It turns out that the tab is not isolated, but in fact connected to the collector. I didn't know this before, and this explains why chunks of the board were blown off in previous failures. I also moved the bus caps much closer to the board, which drops stray inductance.

This isn't the final board I'll be using. I overexposed the board a somewhat and I had to use a sharpie to touch up some of those areas. Unfortunately the touch-up was not perfect. Also, I will tin plate the next bridge

**Note** This is an older version of the bridge, spacing is much improved on the new version, see above. Also the mounting of the caps has been improved. The caps are still in the same physical location.

Re: My First SMALL DRSSTC (Now with 4X Secondary Length Performance)
Phillip Slawinski, Wed May 13 2009, 01:38AM

I got the coil working. Need to to some tuning, but all of the major issues are fixed.

A few things have changed since I took the image above. I changed out the LEDs (who cares, but I thought I'd mention it). I also got rid of that stupid coaxial interrupter connection. I made my own optical link and it works beautifully :) Now I can run the coil farther away from me and not get bitten every time I try to adjust pulse width, or frequency. I'm now able to fit everything in the box quite easily. I ended up pulling the MMC featured in my first post back into service. I removed the sides of the box for better cooling (that's a lie, they fell off

)

As it turns out the coil could have been working for the past week or so, I just didn't realize it was out of tune. I've been so caught up fixing other gremlins with the driver board and bridge that I didn't believe it could be something so simple as tuning.

Re: My First SMALL DRSSTC (Now with 4X Secondary Length Performance)
twist2b, Wed May 13 2009, 08:00PM

I LOVE the prettyness :P

The winding always looks gorgeous... how long did it take?

Re: My First SMALL DRSSTC (Now with 4X Secondary Length Performance)
Phillip Slawinski, Wed May 13 2009, 08:23PM

Thanks for the kind words.

The secondary didn't take that long to make, maybe three hours of work. I messed up when I was coating it, I let the epoxy sit for too long before applying it and it wasn't fluid enough to get the bubbles out or leave a smooth finish.. The box is sort of a prototype box that I put together to make sure I could fit everything.

I am going to rewind a new secondary with red enamel coated wire. I am going to rebuild the box out of black acrylic. This should give it a nice appearance :)

I ran the coil again today and I was able to get 18" sparks, and then the bridge died. I think I'm going to have to move to ISOTOP IGBTs.

Re: My First SMALL DRSSTC (Now with 4X Secondary Length Performance)
Phillip Slawinski, Sun May 24 2009, 05:47PM

I've been hard at work redesigning the bridge for my DRSSTC. I just finished building the bridge yesterday. I decided to go with IXGN60N60C2D1 IGBTs, which should allow me to run 500A quite easily. The IGBTs I was using would struggle to do 310A. The new bridge I've constructed is smaller than the old one despite the increased power handling. I also decided to get rid of the voltage doubler, as I believe it was unable to keep up with the current demands of the coil. I increased the size of the RF bypass cap to 10uF, this is double the size of the previous cap. Aesthetically the new bridge looks much better than the previous one, or so I think.

I haven't tested the new bridge yet, as I'm waiting on my new scope to arrive. (TDS-2024B

)

For a size reference the heatsink is 3.75"x2.75".

Re: My First SMALL DRSSTC (Now with 4X Secondary Length Performance)
Dr. H., Sun May 24 2009, 06:00PM

Are those spacers going to take all the current from the caps ? I suggest you to change them with brass ones. Other than that - really sweet desing

Cheers

Re: My First SMALL DRSSTC (Now with 4X Secondary Length Performance)
Herr Zapp, Sun May 24 2009, 06:17PM

Phillip -

That's a nice looking, compact full bridge module.

Just out of curiosity, where does the 500A capability come from? The IXYS datasheet for this IGBT shows a maximum pulse current of 300A for 1ms.

Regards,
Herr Zapp

Re: My First SMALL DRSSTC (Now with 4X Secondary Length Performance)
Phillip Slawinski, Sun May 24 2009, 06:27PM

Herr Zapp wrote ...

Phillip -

That's a nice looking, compact full bridge module.

Just out of curiosity, where does the 500A capability come from? The IXYS datasheet for this IGBT shows a maximum pulse current of 300A for 1ms.

Regards,
Herr Zapp

Steve has tested these to 600A, with no problems (so I'm told). I'm going to run less than that due to the highish Fo of my coil.

@ Dr. H
Yeah, I know I should change those out to something more conductive. I'm already using tin-plated brass screws to connect to the standoff. Finding a brass standoff that is 1/4-20 is going to be tough though. I hoping hysteresis losses will not really be an issue, as most of the RF will be passing through the RF bypass cap.

Re: My First SMALL DRSSTC (Now with 4X Secondary Length Performance)
Phillip Slawinski, Tue May 26 2009, 10:49PM

I assembled the MMC and enclosure, the enclosure is vented to allow the capacitors to cool off. I did a fit check on the main enclosure, and everything fits perfectly. I plan to use well insulated primary wire to prevent flash-overs. I've also decided to put the driver in a shielded box. With the previous bridge there was not enough room to do this.

Re: My First SMALL DRSSTC (Now with 4X Secondary Length Performance)
Killa-X, Wed May 27 2009, 12:38AM

Very nice looking coil, and results. I hope also to start learning how to do PCB, I got one made but I just need to dip it in solution. This way, when I can make a SSTC, I can do the same :)

Keep up with the clean-work. Makes a project look neater and more-time spent. Maybe at the end you can be all fancy and add LEDs!

Out of random, If I had a mini 1X6 inch tesla with >34awg wire, as a first coil, Would you recommend using thick magnet wire, or copper tubing? I noticed our gimmens hardware store has a good selection of coiled, copper tubing with a 2mm or so hole in it. Seeing you use it, I'll keep it in mind when I find the time to do a 4X24 or so tesla.

Re: My First SMALL DRSSTC (Now with 4X Secondary Length Performance)
StevenCaton, Wed May 27 2009, 03:25AM

Phillip, Excellent work. When I look at what you've done now compared to what I saw at the Teslathon all I have to say is,,, What a Difference!!!

Re: My First SMALL DRSSTC (Now with 4X Secondary Length Performance)
Phillip Slawinski, Mon Jun 22 2009, 02:28AM

It's been a little while since my last update, but that's because I've been quite busy. I've tossed out the last secondary, and I've tossed out the last bridge. As it turns out the PCBs, although very nice looking failed miserably when I tried to run them. I didn't notice how thin the traces were and they burnt off, and blew up two 60N60s in the process

I've since remade the bridge using copper plate, there is no way these components are going to burn in half. This new bridge is not so pretty, but hey it works, and since this is all hidden inside an opaque black box it really doesn't matter. I also replaced the capacitor board with solid copper, and put some copper strip over the standoffs that connect to the +/- rails on the bus.

My new secondary is the nicest secondary I've made yet. I fed the wire inside the form to copper discs to reduce the e-field there. There are baffles inside the secondary at the top and bottom, these are sealed air-tight. The secondary windings are 3.5" x 12". I used #34 wire, and the Fo with topload is about 150kHz.

Here's a capture from my new scope (TDS2024B) of the Primary Current, Bridge Output Voltage, and Gate Signals:

This is what the inside of the box looks like. I've decided I'm going to increase the size of the box by about an inch vertically and horizontally.

Okay, finally the most important images, SPARKS! In these images the upper right target is 32" away. The box is somewhat closer, and the sparks will just hit that instead of the target if I move it farther back.

Re: My First SMALL DRSSTC (Now with 4X Secondary Length Performance)
Dalus, Mon Jun 22 2009, 06:42AM

Nice to see you have your room filled with plasma again. One of the nicer small coils I've seen on the forum, also preforms very well. Great build!

Re: My First SMALL DRSSTC (Now with 4X Secondary Length Performance)
Phillip Slawinski, Thu Jul 02 2009, 04:42AM

I recently went to fellow Coiler's home for a visit and we captured some video of the coil in action. Check it out - > video.

Re: My First SMALL DRSSTC (Now with 4X Secondary Length Performance)
Phillip Slawinski, Wed Jul 08 2009, 04:48AM

I've been tweaking the coil and I managed to coax 18" more inches out of it :) I've got this coil pumping out 50" sparks now, which is over four times the secondary length (12"). Don't believe me? Check out the photos below.

Re: My First SMALL DRSSTC (Now with 4X Secondary Length Performance)
StevenCaton, Wed Jul 08 2009, 05:01AM

Ahhhhhh yes, adding toroids. I remember stacking up toroids on a spark gap coil I built once, just watching the sparks grow as I added more. Apparently DRSSTC's just love fat toploads. As far as I know, a spark over four times the secondary length might be a record.

Re: My First SMALL DRSSTC (Now with 4X Secondary Length Performance)
Phillip Slawinski, Wed Jul 08 2009, 05:17AM

SteveC wrote ...

Ahhhhhh yes, adding toroids. I remember stacking up toroids on a spark gap coil I built once, just watching the sparks grow as I added more. Apparently DRSSTC's just love fat toploads. As far as I know, a spark over four times the secondary length might be a record.

Heh, well the small toroid doesn't change the tune point very much at all. It's there for field control only, so I can lift the major toroid farther from the strike rail.

Steve Conner got very close to 5X secondary length with his small coil.

Also Steve Ward has achieved 4X.

Re: My First SMALL DRSSTC (Now with 4X Secondary Length Performance)
StevenCaton, Wed Jul 08 2009, 05:21AM

Heh, well the small toroid doesn't change the tune point very much at all. It's there for field control only, so I can lift the major toroid farther from the strike rail.

So what brought about the major change in spark length. Did you drop the seconday down an inch, or are you just pushing the bridge more?

Re: My First SMALL DRSSTC (Now with 4X Secondary Length Performance)
Phillip Slawinski, Wed Jul 08 2009, 05:33AM

SteveC wrote ...

Heh, well the small toroid doesn't change the tune point very much at all. It's there for field control only, so I can lift the major toroid farther from the strike rail.

So what brought about the major change in spark length. Did you drop the seconday down an inch, or are you just pushing the bridge more?

I have the coil better tuned, I'm running a higher bus voltage (250V DC) and I've upped the primary current limiter.

Re: My First SMALL DRSSTC (Now with 4X Secondary Length Performance)
Coronafix, Wed Jul 08 2009, 09:03AM

Great work Phil, it looks like a real gem.

Re: My First SMALL DRSSTC (Now with 4X Secondary Length Performance)
Steve Conner, Wed Jul 08 2009, 06:00PM

Phillip Slawinski wrote ...

Sweet!

What's the box in the background of the left hand pic, is that the controller?

Re: My First SMALL DRSSTC (Now with 4X Secondary Length Performance)
Phillip Slawinski, Wed Jul 08 2009, 06:08PM

Steve McConner wrote ...

Sweet!

What's the box in the background of the left hand pic, is that the controller?

The box in the corner is my VTTC, it's arcing to the aluminum front panel on it. Hard to keep that kind of thing from happening when the sparks are this long

Re: My First SMALL DRSSTC (Now with 4X Secondary Length Performance)
vasil, Wed Jul 08 2009, 06:42PM

Big results from such little coil! Enjoy it!