DRSSTC 3

I recently got a bunch of free power electronics from a guy up in Carstairs. I was planning on making a singular maybe 4ft tall Tesla coil, but once I got the free parts, I decided it might be worth it to make a twin system instead. So thats what I did.

Enclosure

I started by making the enclosure. I use some MDF that I had laying around and some 1" dowel for the supports. Overall, they turned out pretty nice

I then laser cut some supports for the primary and strike ring out of black acrylic.

Primary and Secondary Coil

For the primary I used some 1/4" copper tubing. The primary came to about 6 1/2 turns with a 38cm diameter.

The secondary is around 2300 turns of 28 AWG around a 15cm Sonotube. The total length of winding comes out to 69cm. I covered it with 2 layers of epoxy, creating good protection against mechanical stress and minor arcing.

MMC

The original plan for the MMC was to use 32 0.68uF 630VDC film caps. This was then moved to a temporary solution as I decided on 3s 3p 0.44uF 3000VDC Dawncaps. These things are rated for 60A RMS and in this configuration shouldn't heat up too much, if at all.

Top Load

The top load was made with 6" aluminum ducting with a 66cm diameter. It was secured with 2 MDF plates on each side with some pieces of wood inside as a spacer to make sure it can't be over tightened.

Power Electronics

The inverter bridge for these coils consists of a full bridge of CM300DU-24NFH bricks. Across each IGBT was a 2.5uF snubber, 2uF were used for the other bridge since I had them. The bus supply consists of two 450V 3300uF caps in a voltage doubler so I can get around 600V when running from 220VAC/240VAC.

First Test

This test was not first light but instead the day after. First light was rather small at 1cm because of not being tuned. This test garnered 5ft long discharges at 370V bus and 80us pulse width.

First Twin Test

Both coils were running at almost full power with the one on the right set a little lower. 240V, 900A OCD around 80-100uS. Had a some iterferance with the garage door opener at the end of the video.