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PostPosted: Wed Jun 18, 2014 5:34 pm
by loneoceans
I thought this little project went well enough for me to publish something. Presenting my general purpose SSTC platform. I always liked ATX power supply boxes because they're everywhere, cheap, and standardized. And while the inverter inside is useful for powering computers, they can be a little bit boring after a while..


So I thought, why not keep the box, but replace it with a different inverter that's more fun to play with! I liked how oneTesla put a whole DRSSTC on a single board (but it's too big and required an external power supply etc), so I made a general purpose single PCB SSTC which fits almost all ATX power supply units. I took apart a few of them and confirmed that they had more-or-less the same sized PCBs inside, and designed one to fit the most common one. The board has everything needed to make an SSTC of your choice. This way, I can wake up in the morning, decide that I'll like a new tesla coil, and have one all soldered up before lunch! I have a few more boards left, not sure if anyone is interested?


The board comes with the following fun features such as an integrated logic supply transformer for both 120 and 240V operation, fuses and undervoltage lockout, as well as a laminated bus accepting a half bridge of your favourite IGBTs. :-) This project was designed with the primary purpose of playing with various kinds of SSTC sparks instead of the DRSSTC flavor. However, it also has a flip flop so you can simply add a tank cap and make it into a DRSSTC.


I also decided to add swappable interrupters that you can plug in and out like a graphics card does on a motherboard. It plugs it conveniently via an 8-pin socket at the side of the board. I made a staccato interrupter to make fake-qcw sparks, as well as an ATtiny SSTC interrupter together with a fiber input jack. They all take two standard potentiometers for pulse width and bps control. Then I made a small 2.8" x 5" secondary with a cute toroid I bought on ebay... and assembled quickly with acrylic cutouts and clear PVC pipes.


And this coil structure attaches via magnets to the ATX case. The result is a very portable SSTC I can take apart and throw into my bag and bring anywhere I want to, or simply carry around the box and plug it into whatever coil I have lying around via only 3 screw connections.


A new coil is born! Another goal of the project was to make sword sparks like VTTC or QCW coils, so I didn't install the optional bus capacitor and run it off a staccato interrupter.

More than a foot long with a 5" tall secondary; very different from the usual DRSSTC sparks. It also takes in a variety of inputs, include any general purpose midi interrupter signal for playing music and all.

This was a fun project! For more information, check out my website here: where I have a writeup in progress.


Re: General Purpose SSTC

PostPosted: Thu Jun 19, 2014 2:24 pm
by Frost273
Thank you for sharing.

Right now I process schematic and working on the circuit board.

So I assume that your IGBT favorites are FGH40N60SMD. Why?
I like how you named it RSSTC, why did you return to general purpose SSTC?

Re: General Purpose SSTC

PostPosted: Fri Jun 20, 2014 12:45 am
by Alex
FGH40N60SMD's were chosen as opposed to the FGH60N60SMD/FGA60N65SMD's because there wasn't as much current, and they switch faster. He is switching at 380-420kHz.

Re: General Purpose SSTC

PostPosted: Fri Jun 20, 2014 11:26 am
by loneoceans
>So I assume that your IGBT favorites are FGH40N60SMD. Why?
>I like how you named it RSSTC, why did you return to general purpose SSTC?

Simple - they were cheap online when I was browsing for parts :) Nope they are not my favourite IGBTs but they do seem to be very fast (even faster than the 60nxx igbts) and better suited for my purpose.

For the naming, the main goal of the project was to make sword like sparks emulating a VTTC or a QCW with a staccato controller and appropriate design choices, hence the name RSSTC. This goal was met :mrgreen:, at least in my books!

The second part of the project was - I was going to build a coil anyway, so I thought I might as well spend a bit more effort making a general purpose platform, which was what it turned out to be. I can easily swap out the controller to an optical input and will be able to play music on this coil as well. Works on a variety of coils, inputs, and can be set up for various configurations.