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24" SGTC - 12/60 NST

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LAN_403

Killa-X

Tue Oct 19 2010, 08:25PM

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

I'm a bit amazed I never made a project thread for this coil yet. Before I go into details....

I started this coil ... Over a 2 years ago. It got put off MANY times because of parts. The resistors on the terry filter, a good friend of mine purchased, and couldn't mail them until nearly 6 months later. Then,kept putting it off to the side, and working on other projects, like my SSTC. So...Now, that coil is aside, and I'm working (and hopefully finishing) My SGTC.

Details:
Secondary Former - 24" tall -- 4.5" diameter PVC pipe
Primary -- Flat construction. 1/4" copper tubing. ID = 8" OD = 28" Spacing of tubes, 7mm.
Power Supply -- 12KV 60mA NST
Filtering - Terry filter
Tank capacitor - 7500VAC 30KVDC at 20nF (942C20P15K-F) 2X (15 series) in parallel.
Resonating frequency, 350khz.
Sparkgap -- Suction (possibly RSG)

First, I know this bank is under the voltage we need. I've made a post LONG ago about this, and I was told It's ok...Everyone over volts them, they just wont last for years. I have done past tests with this bank shorting to a sparkgap, and it was very loud (even with plugs)

I have a possible motor I can use. The problem is, It's not a ASYNC. It runs 3598RPM, and when placed on a table, it makes a phase-in phase-out hum. From 20VAC to 120VAC, it's 3580-3698RPM. I wanted to use this for a RSG, with 4 pegs because it's not sync. Using 2 pegs would be stupid due to that reason. I'm not fully sure if a terry fitler will be able to block the spikes during the off time though. Ideas?

Pictures of current work:

The bottom side of my Primary base, you will see 4 squares. These are 1CM high intensity (i think 200,000MCD+) blue LEDS that point up to the topload. You can find an old picture, here. (Taken February 13, 2009)

Any questions, Ask....This is just current "What I have" Things are to be done!

ScotchTapeLord

Tue Oct 19 2010, 09:22PM

Registered Member #1875 Joined: Sun Dec 21 2008, 06:36PM
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Posts: 635

Looks good but does that one picture show that the wire goes through the inside of the secondary?

Killa-X

Tue Oct 19 2010, 10:15PM

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

ScotchTapeLord wrote ...

Looks good but does that one picture show that the wire goes through the inside of the secondary?

Yup, its how I do all of my coils. Middle-plugged coils. My SSTC does the same thing, and it did 28" streamers. Goes inside, then cuts out to the side by a tiny hole. This was done so the end caps could fit.

The wire in the middle then connects to the topload.

ScotchTapeLord

Tue Oct 19 2010, 11:17PM

Registered Member #1875 Joined: Sun Dec 21 2008, 06:36PM
Location:
Posts: 635

People usually warn about keeping metal outside of the coilform. I think it's a valid argument, as there could be internal secondary strikes that you wouldn't know about until it's far too late...

It personally would make me worry...

Killa-X

Wed Oct 20 2010, 02:17AM

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

Well Wednesday I plan to do some small low power tests if I get the time. I'll just have all the things layed out side by side...If it works, I'll consider ramping it higher. Then I'll start designing a case before doing a true full power test.

I havnt decided if I'll paint anything, probably will leave it natural wood. The green secondary was actually made for my DRSSTC, 100khz coil...My real SGTC god temporary placed into my SSTC.

Killa-X

Wed Mar 16 2011, 12:29AM

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

Well its been 2 years since i started this project and i decided today to do a low power, 40-60VAC test. I had the sparkgap set for 4mm, 4000V on a 12KV system. Estimated sparks by eye was 15-24 inches. Video shows smaller, but I'll show the results. I was basically tuning it.

Herr Zapp

Wed Mar 16 2011, 05:14AM

Registered Member #480 Joined: Thu Jul 06 2006, 07:08PM
Location: North America
Posts: 644

KX -

In your fourth photo (close-up of bleeder resistor across cap), it's not clear that the capacitor leads are soldered together. The resistor leads are soldered to the bent-back cap leads, but the cap leads themselves look like they are just looped around each other and not soldered.

Is this your intent??

Herr Zapp

Killa-X

Wed Mar 16 2011, 11:17PM

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

My new MMC has all the capacitors soldered together now. So this has been fixed.

was my latest test run, added more topload capacitance which increased the spark output a bit.

Killa-X

Thu Mar 24 2011, 03:10PM

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

Well the last test I did was weird. My sparkgap was no blower. But after a minute of running it went from static to constant bps and made smooth flowing streamers. Getting ready to do a full power test this week...all 12KV

I have a Terry filter, should I use this or am I fine with a simple HV-GND-HV spark gap?

Arcstarter

Thu Mar 24 2011, 11:31PM

Registered Member #1225 Joined: Sat Jan 12 2008, 01:24AM
Location: Beaumont, Texas, USA
Posts: 2253

Killa-X wrote ...

Well the last test I did was weird. My sparkgap was no blower. But after a minute of running it went from static to constant bps and made smooth flowing streamers. Getting ready to do a full power test this week...all 12KV

I have a Terry filter, should I use this or am I fine with a simple HV-GND-HV spark gap?

Well of course you should use a filter. Don't be like me and think your NST will last as long as you don't run it often, i got maybe 10 minutes run time in Tesla coil duty in all before i smoked it.

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