Hi

I just finished my DRSSTC III and I wanted to share it with you.
All electronics fit in a small 29x29x17cm box.

SPECS :

• secondary : 125mm x 410mm (125kHz)
• Toroid : 480mm x 125mm
• primary :  6.35mm dia. copper tube
• MMC : 5s15p of 0.039nF 2Kv (R75UN239050H3J) (forced air cooling)
• IGBTs: 2x SKM150GB128D
• Bus cap : 350v 6800µF
• Driver : UD2.7
• OCD : 375A 400A

Photos of the build : https://photos.app.goo.gl/C4tJ3HKW8YK31F247



I set the OCD at 375A and the results are quite good, approximately 1 meter of arc at 150Vac and 120µs :

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The OCD did not trigger, I still have to test it with more voltage, I think set the OCD at 400A.

I haven't seen any DRSSTC with SKM150s, has anyone ever done a DRSSTC with SKM150s ?

Hi,

Something very strange happened on my drsstc, fortunately I had a camera that filmed.
I have never seen this before and this is the first time it has happened to me.

But before, some news about my drsstc :

I lowered the OCD to 300a for more "reliability" and I am very satisfied with the results with the small IGBT I use.
I also made a smooth toroid and the result is quite nice !

Let's come back now to this strange phenomenon, rather than trying to explain it here is the video (It happens at the end):

(a simple MIDI reading at 100µs, 8% max Duty, 150Vac and 300a OCD)

Hello everyone,

I'm starting to think about doing a DRSSTC with a 160mm secondary, I read Mads' page on secondary coils and I saw that for a 160mm secondary, 0.4mm - 0.45mm wire is fine, and that below 0.35mm the impedance was getting too big.



On the Kaizer DRSSTC I, the secondary coil (160mm) is made with 0.25mm wire, why did he make this choice ?



I have a 0.25mm wire spool but I don't know if it's too small for a 160mm secondary coil.

I'm thinking of making a 160mm x 650mm secondary with 0.4mm wire, I wanted to know your opinion, for this secondary size, if 0.4mm wire is a good choice.

Hello, I will present to you a tesla coil that I made a few years ago, I think it may interest you.

I started making a spark gap tesla coil about 4-5 years ago when I was 14, I started building the primary circuit, without the capacitors , and the secondary circuit. It was only after 2-3 years that I bought the capacitors.
The primary power supply is composed of four MOTs (by testing the power supply, it draws 60a on 230v by making electric arcs! In normal operation the tesla coil draws about 10-12a), the capacitors are 940c 150nf 2000v well known of the coilers.

The secondary coil was an adventure, it's the first time I've wound such a big coil, when winding, everything went well but when putting on the varnish, the coil completely expanded, which failed.
After a few months, I decided to try again to make another secondary coil and it was a success, the coil is pretty well done !
The rotary spark gap was also an adventure, I had to do 5 or 6 different versions before the final version.

summary of specifications :

• Triple MOTs
• 75nf 16kv MMC with 940c 150nf 2000v cap
• Rotary spark gap
• Secondary coil on a 125mm by 58cm PVC tube with 0.4mm copper wire
• consumption: 10-12a on 150Vac (not measured and not really tested at full power)
• around 180cm of streamers
• Primary supply: 6.6kv for about 600-800ma
• 120 cm total height

Here are some pics of the coil :

overview:


Power Supply :



Spark Gap :



MMC : (4 groups in parallel of 8 capacitors in series, with 10Mohm 1w balancing resistors)



Control Box :



Some pictures :



bad photo when a lightning strikes the power cord of a neon lamp :



And a double exposure :



Some videos :

Test at "low" power, Approximately 180Vac on larger arcs and approximately 100Vac on smaller ones
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And in this video the input voltage is about 150Vac
https://www.youtube.com/shorts/feoHkGc6uiU

Hello,
First of all sorry for my bad english, I am French
My name is Mathieu I'm 18 and I make my first drsstc, i wish i could tune my tesla coil better
and I have some questions.

First the setup:
     -controller : UD 2.7 rev c
     -IGBT : HGTG30N60A4D
     -OCD : 350 A (can I set it higher ?) 300 A
     -MMC : 10kv 60nf
     -CT : n87 (400:1 with two 20:1)
     -Secondary frequency : 210khz (10x30cm ; 0,25mm wire)
     -Primary frequency : 204khz 190khz
     -interrupter : up to 450hz and up to 100us (I ordered and am waiting for the famous Midistick!)


Here are some pictures :








During my first lightning test I obtained 50-60 cm of lightning (primary at 213 khz and secondary at 210.3khz) but the ocd at 350a was triggered at 100 Vac
I lower the frequency of the primary to 204 khz and I get 60-70cm of lightning and the ocd is now triggered at 150Vac.
I also noticed that the tesla coil draw less power at the input.
Do I have to lower the frequency of the primary much more? Are there any factors to consider?


In the next part the bus voltage is 30v which comes from a lab power supply because I don't have a differential probe

I tried to adjust phase lead as best as I can (7m3 153 inductor), here is the signal, in yellow the output of the bridge and purple the primary current:


What bothers me is that we can see that the beginning of the signal is quite good but towards the end there is a huge spike,
here is another screenshot:



And finally, here is a photo of the wires that go from the gdt to the igbt (around 20-30cm), are they a little too long?