First DRSSTC (In progress) / Projects / Forums

Forums

4hv.org :: Forums :: Projects

« Previous topic | Next topic »

First DRSSTC (In progress)

Move Thread

LAN_403

Killa-X

Sun Jul 17 2011, 10:28PM

Registered Member #1643 Joined: Mon Aug 18 2008, 06:10PM
Location:
Posts: 1039

After getting a confirmation email from EVR, I was told I am allowed to post pictures/videos as I please of his boards. Obviously I am one of the selected testers of his universal DRSSTC system. This is my first DRSSTC. In the past I have built fullbridge SSTCs that could do 24-28 inch sparks, so I saw this as a challenge to see how far I have come. Got the stuff months and months ago, and slowly worked on it. Being limited to how much i could spend at a time, things got done. Origionally I made a 4.5 x 28" coil for steve wards board. 120Khz resonance. I then found i was selected to beta test, and saw he used the older CM300s. I know its not the best idea to push these to 120khz. So, I was kinda stupid not using a 6" diameter 30awg coil. I figured I want the ability to do power. So I made a 12x48" coil out of 24awg, roughly 48Khz. The coil is massive to me, and I still view it big. It's wrapped on a cardboard tube, which i poly coated the inside and outside of for protection against moisture. I then used the rest of my poly for the coil. As see, the poly coat is rather cruddy, its foggy not glassy. May fix it someday, but wont be fun im sure.

Self explained really, PVC...Partical board...and Black lexan where used for base construction. wheels on the bottom for easy transportation, and i tried to make things look neat and clean by using lexan as a case to hide most wires. I probably spent 4 hours straight at night drilling and working on part placement. my CT wires are a little long, but oh well.

For testing, The most I have done so far is 300VDC to the bridge, running about 600 amps on the primary. I did a 1 minute solid run, made a coffee can smoke, my wires/primary got 100F, some traces on the board (plus and power rails) got 98+ degrees. The rectifier was hot, but besides all that, the system held fine. My CM300 was only at 80F, from a 79F ambient room. the blowing fan was not being powered. So, I'm confident things will be fine. It didnt fail, so obviously my bridge is being driven decently. My variac was pumping its full power ratings, 120VAC 8A. I'm going to do my next test with a 150VAC 30A variac. I bought this variac 3 months ago FOR the DRSSTC.

The topload was bent at a local company that makes awnings. They use a "Home made tube bender" whic was 3 wheels on a flat table. No offense, it sucked. They cant put in measurements, the guy bent the tubes and the smallest radius is what you see, even that i shorted by 3 inches by banging on it with a hammer. Horrible, i think its the worst thing ever. I'm lucky I didnt ask for 8 tubes to be bent! But, it does its job. I may cover it with Screen to add more capacitance that im loosing between the largely spaced rings.

The tank capacitor consists of 32 Avetronic capacitors rated at 1200V 1.200uF, I have it hooked for 4 parallel sets of 8-series. 9600V, 600nF. I did capacitance reactance calculations as well as other math to figure a safe voltage (with a 1000A reference) as well as the amount of capacitance to use.

Things needed to be done:
* Grounding of the driver, Driver case, heatsink
* Adding capacitors of 0.1uF on the bridge, as well to ground for primary strike allowance
* General wire organizing, CT wires bug me, they are all over.
* Maybe lower the base, it stands 7" above the capacitors roughly
* Possibly varnish the particle wood, Does moisture effect this kind of wood?
* More fine tuning of the bridge/waveform
* Test with 150VAC 30A variac, Breakers the limit!
* My wants of a 1000A test of induction heating
* Actual sparking tests

A shout-out to people who have helped me with information, references, as well as general suggestions...ideas...scope work..
* Kizmo - Many thanks, Lots of help as I worked through this, teaching me as well as helping with wave forms, math, and just general DRSSTC work
* Arcstarter -- Also for helping me with general DRSSTC work, board issues, and of course the teaching of SSTC years ago

So, below I have my latest bridge waveforms, as well as the project it self. I shall update as I go. The last picture, I did fix the ringing a bit, I havnt tested this after the ferrite bead on the GDT to prevent common noise issues. yet.

Updates will follow. Questions/Comments are welcomed.

Test of induction running 300VDC at 400A
http://www.youtube.com/watch?v=X4IRud_fAmQ

Killa-X

Wed Jul 20 2011, 06:03PM

Registered Member #1643 Joined: Mon Aug 18 2008, 06:10PM
Location:
Posts: 1039

Hello, Adding a recent update.

Manage a first test to get 25" of sparks to a grounded 24" x 24" chicken-wire grid. Primary was not tune, I just randomly stuck a tap on it and that was it. Power it up, and 60VAC got me what you saw.

Killa-X

Sun Jul 31 2011, 06:50AM

Registered Member #1643 Joined: Mon Aug 18 2008, 06:10PM
Location:
Posts: 1039

Well, I just got to tune it now really, and fix my interupter, as it has an isolated wire that caused issues while running the coil, making it randomly go from 20" to 12" streamers until i dropped the voltage.

Is this the first time someone has actually stuck a camerea in a Tesla coil? The cameras audio sounded like videos people make of microwave cannons, just a loud BZZZZZZZZZZ sound. Just as an obvious side note, this camera has loud lens gears, I care less if it dies. But, it still works fine, and i was able to retrieve the video! I plan to make a better mount, this was just a test. That way when I do larger stuff like 4ft, I can have a topload view, and outside view. What would be nice is a CHEAP camera that has Bluetooth streaming so i can view it on my PC, that way also, if anything dies, I can record off my PC, and have no lost video due to an unfinished video file.

But, as seen, people told me in the past my topload has horrible capacitance being spaced so far. So i added copper.

Killa-X

Sun Sept 11 2011, 12:12AM

Registered Member #1643 Joined: Mon Aug 18 2008, 06:10PM
Location:
Posts: 1039

For those who are Get-to-the-point skip to 1:34

I did some tuning, i got it over tuned so sparks pull it into resonance. I manage to get 30" sparks now. The limit is my room, i was running at 70V 4-5A, out of 150V. The sparks started to want to touch the ceiling, so i didnt push it anymore. I will save the larger test for outside, not indoors! So for now, enjoy progress!

After all the testing, the system was cool, nothing was over 80F except the rectifier, 100F.

Moderator(s): Chris Russell, Noelle, Alex, Tesladownunder, Dave Marshall, Dave Billington, Bjørn, Steve Conner, Wolfram, Kizmo, Mads Barnkob