With the semester almost ending, I’m glad that my second DRSS-Tesla Coil is finally done! DRSSTC 2 began almost a year ago with the goal of making my first tesla coil using brick-style IGBTs.

DRSSTC makes 4 feet of sparks look easy, in MITERS

First Version

The project began when I bought two Toshiba IGBT half-bridge modules on ebay, good for 150A 600V. The original plan was to build a compact and powerful DRSSTC running this full bridge, with about a foot long secondary. The coil also uses a revised version of Steve Ward’s UD2 as the driver. After many months of work, I finally got everything put together. Unfortunately, initial tests were worrying, and I soon found out that one of my IGBTs was half-dead. With the lack of time and money, I wasn’t able to continue with these bricks.

Revision 2

I managed to get hold of a CM200DU-24F 200A 1200V IGBT and decided to make a half-bridge coil instead. The CM200 bricks are larger, so I wasn’t able to fit a fullbridge inside the box I had already made. Finally, this worked perfectly and everything came together.

Specifications:

– CM200 Half Bridge
– 208VAC input (2 leads from 3 Phase, though the coil was designed for 240VAC operation)
– 13″ x 3.5″Secondary, ~2000 turns
– 16″ x 4″ Toroid (I want to get a spun one someday)

For more information, please visit www.loneoceans.com/labs/ – writeup with full details in progress!

Where do you stand?

we cleaned.

a lot. (you can’t tell really tell it now. people, clean up after yourselves!)

we even threw stuff away!

we fixed the “MIT Sloan School phone” that people can use to call MITERS to be let in after daylight hours

(well, as of 1 april 2013 it broke again and is super quiet… if you amplify it up to be audible you also get a lot of buzzing noise. to be fixed)

Mars built new ventilation for our welding area

also there was yurt building

it disassembles into something amazingly small and portable

that’s all. oh, by the way, the future is going to be awesome.

Introducing my first DRSSTC. It’s a small tesla coil made to be portable and to make lightning at home. This coil is based of the amazing oneTesla pcb. I’m still in the process of doing a detailed write up at http://www.loneoceans.com/labs/drsstc1/!

As a learning experience, I wanted to go for something simple and nothing too fancy. I’ve had the fortune of being in the good company of other brilliant coilers (like Bayley, Tyler, Kramnik), and managed to get an older version of the oneTesla driver PCB, which runs this coil! I faced a couple of problems over the past few weeks but I’ve modified some parts and managed to get the coil working very well! See the video of it in action here:

• Max spark length – I don’t know yet, does >22″ sparks to free air and ground with ~100us on-time. More testing to come soon. Right now it’s limited by hitting the floor.
• 222kHz resonant frequency (within 1%)
• 2.4″ Diameter PVC Secondary, ~2000 turns of AWG36 for a 10.25″ length
• 3.5″ Diameter Acrylic Primary, 6 turns of AWG 14 for about 0.8″ length
• Single 0.101uF 2kVDC 942C CDE Primary Capacitor
• 340VDC (120VAC rectified and doubled)
• Roughly 100us on-time (in the photos here)
• 2.2″ x 8″ AmazingOne spun toroid
• Half Bridge of 60N65 IGBTs (seems to be similar to the 60N60 TO247 IGBTs)
• Coupling = 0.22
• Energy Transfer time = 9.87us

Performance has been pretty good. Originally, the coil used a 0.068uF 940C capacitor but that made my primary frequency about 19% too high and I lost a 60N60 half bridge. Increasing the primary to 8 turns of 14AWG (k=0.26) turned out to be a bad idea and I had a lot of racing sparks. After a few more coats of Polyurethane on the secondary, a return to 6 turns of AWG14 and a larger tank cap, the coil is in tune with a performance I’m very happy with.

This coil currently has a tiny built-in 19VDC laptop power supply for the electronics which uses the famed UCCs from TI as gate drivers to a GDT driving the gates of the IGBTs. Here’s a pretty photo of the ground ‘lighting’ strikes of the tesla coil:

Best Wishes!

 -  Guangyan
    23 Feb 2013
    www.loneoceans.com/labs/