Some of you on this forum might have built a tinyTesla, which I always thought was a really small cute SSTC. One thing I was especially fond of was the small secondary coil it uses which are pretty hard to make by hand since they are wound with very thin wire. I had one tinyTesa secondary coil, so this motivated me to build a QCW tesla coil with it to see how much spark I could get from this small coil.
Watch on youtube.com
Another goal of the project was to make a very small QCW coil that could easily fit on top of a table, but still have good performance and be 'plug and play' easy to operate. The size restriction was that it needed to fit into a medium size USPS box (!). The result is a very compact coil, yet capable of sparks just over 32" or so despite its small size (more than 13x secondary length!).
Photo of the coil on my messy bench.
And of the coil in action.
Coil runs with a 340VDC bus with 4 TO-247 IGBTs. I'm using a pretty fat bus capacitor though I could probably replace that with a bunch of smaller ones and make the coil even smaller!
Enjoy!