The picture stuck in my mind - I just wanted to see one up close and in person. While on a road trip up the East Coast (early 90's) I saw a sign (it was somewhere either near or in Boston, MA) where they had some big coils that they used for a lightning display. I remember going by the museum to find that the exhibit was closed. Tesla Coils and man made lightning retreated in my mind.
Fast forward about 20 years - While working with my daughter on some basic electronics projects - make a simple electric motor using a magnet, magnet wire, a battery, paper clips and soda straws I thought why not make sparks!!!
I was really thinking about static electricity (I loved being able to shuffle across the carpet so I could reach out my finger to ZAP my brother or sister - they did the same to me of course). So, I thought why not make a Van De Graff Generator.
After building a small one, that did work, just not very well I wanted a more impressive display. A Tesla Coil seemed to be the answer, so I began my research (thinking it would only take a few weeks to build it). Well, it took a bit longer - more like 4 months research, trial and error, failures and finally success.
During my process of building the coil I was showing videos of Tesla Coils (on YouTube.com) to my daughter and we came across Tesla Coils that could play music. That just seemed so amazing, I looked into how people were able to do it. It appeared fairly complicated but I found something I might be able to do - an audio modulated Plasma Arc (or Plasma Speaker). I did try building a basic Solid State Tesla Coil (Steve Wards Mini SSTC), but I just kept blowing MOSFET's and they were expensive and I had to get them by mail order. So, I put the project on hold until I had more knowledge.
Now, I'm finally going for it and I thought exhibiting at the Southland Mini Maker Faire would be great motivation to finish it . I re-built my half H-Bridge driver board (using my CNC to mill the board). I connected everything up and it WORKED.
Well, for a few minutes at least and then a POP and some smoke. The MOSFET's were quite hot and looking at my new board I saw...
I re-made the board on perfboard and added big heat sinks to the MOSFET's and a fan to help keep then cool. No full test yet, ramping power up slower to make sure everything is OK.
|New Half H-Bridge Board|
Cut copper pads from around component connections to minimize arcing.