Author Topic: "LightningStorm" VTTC project (Read 13570 times)

Avenger · « **on:** August 23, 2018, 02:04:56 AM »

Hello all! This is my last VTTC project. This project started 3 years ago, and now finally assemble of generator unit case is started.
The objective of the project - to build a powerful vacuum tube Tesla coil on the basis of soviet metal-glass high-power air-cooled tetrode GU-39B-1. This tube is capable to dissipate at the plate power around 6kW. And its output power is 13kW.
It was made the plate and filament transformers. The filament transformer provides 6,6V and 100A. Plate transformer is wound on the base of the output transformer of the high power tube audio amplifier UPV-1,25 (russian УПВ-1,25) used two GU-81M tube in push-pull output stage. Its core is made up of steel plates of thickness 0.35 mm (core sectional area of 49cm^2). It provides voltage 5kV and 2A peak сurrent (nominally 1,5А)
In the power supply used level shifter with eight 1uF 16KV capacitors and homemade diode pack at 50kV and 3a. All ceramic capacitors in circuit - soviet K15U-1 or K15U-2 type.
The tube installed in a steel cylinder with polyamide insulator at the bottom. Centrifugal fan "bahcivan aorb" (BRDS 180-60, 1200 m³/h) is used to cool the tube. Tube operates in triode.
The secondary winding contains 800 turns of 1mm copper wire on 160x800mm PVC pipe. Epoxy coating. 20x5cm (now is 30x10cm) aluminium toroid is installed.
The primary is a 35 turns of 4mm copper wire on 250x500mm PVC pipe. Taps on each turn, starting with the 28th turn. Winding height is 28cm. MMC capacity is 2nF (4x470pf).
Feedback winding has 14 turns of 1.5mm copper wire (taps of the first 5 turns). Located above the primary winding. Grid leak circuit is 200 Ohm and 14nF.
Tesla Coil working in staccato mode. In the cathode circuit installed triac, which is controlled by circuit in 555 timers (based of the staccato cotroller of Steve Ward).
At this moment VTTC gives streamers up to 1.5m length. The length of the streamers is limited to the power of the plate transformer and power mains capability (mains 230V 50Hz, current consumption up to 80A).

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TDAF · « **Reply #1 on:** August 23, 2018, 02:32:31 AM »

EXQUISITE
kudos for the great construction
Love the Qcw comparable sparks

Hydron · « **Reply #2 on:** August 23, 2018, 11:16:06 AM »

Looks amazing, and thanks for all the pictures!

Quote from: TDAF on August 23, 2018, 02:32:31 AM

EXQUISITE
kudos for the great construction
Love the Qcw comparable sparks

I believe that Steve's QCW work came from wanting to replicate a VTTC type look (please correct me if I'm wrong here!)

TDAF · « **Reply #3 on:** August 23, 2018, 01:50:02 PM »

Ya you're completely correct

Avenger · « **Reply #4 on:** August 23, 2018, 01:57:13 PM »

The principle of the QCW and the VTTC is the same. Historically, the VTTC is the first QCW. In the tube coil, the width of the radio pulse is determined by the frequency of the AC mains and is 20ms (for 50hz). In the transistor coil, we can set the pulse width ourselves.

Uspring · « **Reply #5 on:** August 23, 2018, 04:57:39 PM »

Powerful coil

. Did you also try to grow straight arcs utilising the mains waveform? Or is perhaps the frequency too low?

Avenger · « **Reply #6 on:** August 23, 2018, 06:23:31 PM »

The form of the discharges in my case depends on the resonance frequency of the secondary. In my secondary it is 250kHz, which causes the discharge like SGTС or DRSSTC. Sword-like discharges need over 400khz (better 600 and over).

Teravolt · « **Reply #7 on:** August 23, 2018, 08:45:58 PM »

Hi avenger nice work thanks for mooving your thread, do you plan to make your secondary to a higher frequency and was it hard to tune? Does your primary and secondary have the same resonant frequency

Avenger · « **Reply #8 on:** August 24, 2018, 08:00:05 PM »

Quote

do you plan to make your secondary to a higher frequency and was it hard to tune? Does your primary and secondary have the same resonant frequency

No, I'm satisfied with the resonant frequency of the secondary and the shape of the discharges. The frequencies of the primary and secondary windings are of course the same.
New video:

Mads Barnkob · « **Reply #9 on:** August 25, 2018, 08:29:40 AM »

Wow that is an absolutely record breaking spark length for a VTTC, I think only Dr. Spark and RogerInOhio has been near those lengths for a VTTC.

Is the GU-39B tube really easy to drive since you can do with just 5 windings on the feedback coil, or is it because the power output is so great that you are well below the normal 15-20 turns?

How are the temperatures on the secondary/primary/feedback coils and the tube? I guess all the good study Russian capacitors are stone cold

Avenger · « **Reply #10 on:** August 25, 2018, 04:17:44 PM »

Quote

Wow that is an absolutely record breaking spark length for a VTTC, I think only Dr. Spark and RogerInOhio has been near those lengths for a VTTC.

Thank you! My coil will be one of the few, brought to the state of the finished product. Ahead of the manufacture of the power supply (it's also a control panel)

Quote

Is the GU-39B tube really easy to drive since you can do with just 5 windings on the feedback coil, or is it because the power output is so great that you are well below the normal 15-20 turns?

In the first post I wrote that the whole winding of 14 turns, taps from the last five. In fact, the entire winding is used, all 14 turns. The tube is quite difficult to drive, so the resistor in the gridleak is only 200 ohms.

Quote

How are the temperatures on the secondary/primary/feedback coils and the tube? I guess all the good study Russian capacitors are stone cold

Temperatures of most structural elements are small. Nothing is very hot. The temperature of the secondary and primary windings does not differ from the air temperature. Maybe a little warmer.

oneKone · « **Reply #11 on:** August 28, 2018, 04:45:34 AM »

Welcome to the HVF @Avenger. Your build is simply awesome!

Avenger · « **Reply #12 on:** August 29, 2018, 09:25:51 PM »

Quote from: oneKone on August 28, 2018, 04:45:34 AM

Welcome to the HVF @Avenger. Your build is simply awesome!

Thank you!
And yes, more experiments with feedback coil

MRMILSTAR · « **Reply #13 on:** June 15, 2019, 05:38:30 PM »

Great coil. I wouldn't have the courage to operate it in my house as you appear to be. I settled for my single 833A VTTC which only puts out 20 inch streamers.

Avenger · « **Reply #14 on:** June 24, 2019, 01:28:59 AM »

New primary cap (2200pf 30kv) is installed. Installed a ceramic (walkthroughs) insulators in to a front panel. The project is continues.

Mads Barnkob · « **Reply #15 on:** June 25, 2019, 11:40:18 AM »

Looks very good, but how is the creepage distance on the inside of that feed-through? The outer part looks to be fairly long and will be fine for 30kV, this is your tank capacitor rating, but not likely your circulating tank voltage, however it does look like its much smaller distance from the copper band to the mounting screws on the inside.

Avenger · « **Reply #16 on:** June 25, 2019, 03:18:07 PM »

The distance here does not matter. Insulators are located on a fiberglass plate. The distance between the copper conductors and the bolts is sufficient. Yes, I was wrong. 20kV capacitor voltage.

Mads Barnkob · « **Reply #17 on:** June 25, 2019, 08:51:37 PM »

You are right, with a fibreglass plate it does not matter at all, I just thought it was a painted metal sheet

So with your new tank capacitor, you are going to have 15% more capacitance, do you expect much different results or was it just a needed upgrade due to temperature problems?

Are the feed-throughs brass or is it really steel bolts as it looks like?

Avenger · « **Reply #18 on:** July 09, 2019, 07:31:37 PM »

The capacity of the tank capacitor is exactly the same as it was before.

Bolts in insulators is steel, I have not yet found brass bolts.

Bambinz · « **Reply #19 on:** August 08, 2019, 01:15:11 PM »

1.5m of spark with an VTTC? It is Amazing!
The most powerfull VTTC that I have ever seen!

Congratulation!

High Voltage Forum · « **Reply #19 on:** August 08, 2019, 01:15:11 PM »

Author Topic: "LightningStorm" VTTC project (Read 13570 times)

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