Author Topic: GU5B VTTC Flashover  (Read 1449 times)

Offline SalinsLV

  • High Voltage Enthusiast
  • *
  • Posts: 31
  • Karma: +2/-0
  • Electronics experience starting from 2015.
    • View Profile
GU5B VTTC Flashover
« on: January 24, 2021, 03:01:46 PM »
Hello!

I was experimenting with my newest build and while i was increasing power a flashover happened (i attached some photos in the attachments).
I am thinking of adding PVA glue (i currently can't get proper varnish because of the virus) on top of where the flashover happened, to isolate the burned area better. I also plan to decrease the number of turns on the feedback coil. Currently the feedback coil has 19 turns of 1mm wire and i have a tap point at 13 turn.

I also posted a video on how it happened:
/>
Before i turn on the coil is there anything i should check so that the flashover doesn't happen again?
K. Salins

Offline Mads Barnkob

  • Administrator
  • High Voltage Expert
  • *****
  • Posts: 1876
  • Karma: +50/-0
  • Denmark
    • View Profile
    • Kaizer Power Electronics
Re: GU5B VTTC Flashover
« Reply #1 on: January 25, 2021, 09:02:35 AM »
Looks like too high coupling between the secondary circuit and the feedback coil. Not so much the height of the coil but the diameters of the secondary coil, primary coil and feedback coil seems very close.

You could use a high voltage rated wire for the feedback coil instead of kinked varnished copper wire, it could be some cracks in the insulation that gives you problems. I had had problems with arcing between turns of my feedback coil in a dual 811A VTTC and I could only fix that with more spacing or another type of better insulated wire. The voltage per turn ratio on the feedback coil just seems too high for enameled copper wire.
https://kaizerpowerelectronics.dk - Tesla coils, high voltage, pulse power, audio and general electronics
https://www.youtube.com/KaizerPowerElectronicsDk60/join - Please consider supporting the forum, websites and youtube channel!

Offline MRMILSTAR

  • High Voltage Engineer
  • ****
  • Posts: 372
  • Karma: +12/-0
  • Cedar Rapids, Iowa
    • View Profile
Re: GU5B VTTC Flashover
« Reply #2 on: January 25, 2021, 04:42:52 PM »
You could try rewinding the feedback coil onto a larger diameter plastic ring that will fit over your existing primary coil tube. This will put more distance between the feedback coil and the secondary coil. Done properly, it could also provide a means of raising and lowering the feedback coil to adjust the coupling. This is how I implemented the feedback coil on my 833C VTTC.
« Last Edit: February 22, 2021, 08:50:22 PM by MRMILSTAR »
Steve White
Cedar Rapids, Iowa
Retired electrical engineer

Offline SalinsLV

  • High Voltage Enthusiast
  • *
  • Posts: 31
  • Karma: +2/-0
  • Electronics experience starting from 2015.
    • View Profile
Re: GU5B VTTC Flashover
« Reply #3 on: January 25, 2021, 04:48:02 PM »
Thanks for the replies! :) 

I will replace the feedback coil and report the results afterwards.
K. Salins

Offline SalinsLV

  • High Voltage Enthusiast
  • *
  • Posts: 31
  • Karma: +2/-0
  • Electronics experience starting from 2015.
    • View Profile
Re: GU5B VTTC Flashover
« Reply #4 on: February 02, 2021, 09:35:42 PM »
I made a ring that increases the distance between the secondary and the feedback coil. Now i have no problems with flashovers. The sparks aren't that big. I'm using only one MOT at 90% power and the coil is partly tuned. I'm having a hard time with calculating the required capacitance for the tank circuit. That's why I'm experimenting with the capacitors that i have and looking for which makes the longest sparks at the lowest voltage.
Here are some specs if anyone is interested:

Secondary coil
Diameter: 13 cm
Lenght: 45cm
Wire diameter: 0,3mm
Turns: ~1500
Resistance: 126 ohm (measured with basic multimeter)
Secondary Fres: 197 406 Hz (with topload)

VTTC [primary coil]
diameter: 20cm
turns: 31
wire diameter: 0.1mm
height of primary: 7.1cm
inductance: 0,19mH +/- 0,18mH
resistance: 0.2 ohm (multimeter) but cheap LCR says 0,6ohm +/- 0,7ohm

Inductive reactance: 223.261 Ohms @ 197 406 Hz (secondary coil Fres)
Primary inductance: 0.18mH (measured with cheap LCR from ebay)
=
Currently used tank capacitor value: 3.6nF
Recommended capacitor: ????
K. Salins

Offline MRMILSTAR

  • High Voltage Engineer
  • ****
  • Posts: 372
  • Karma: +12/-0
  • Cedar Rapids, Iowa
    • View Profile
Re: GU5B VTTC Flashover
« Reply #5 on: February 03, 2021, 05:38:09 AM »
Do you have selectable tap points on your primary coil? Its hard to determine from your pictures. If not, then you need to add them in order to tune this coil.

You can use JAVATC to give you a good idea of the tap point with your capacitor.
Steve White
Cedar Rapids, Iowa
Retired electrical engineer

Offline SalinsLV

  • High Voltage Enthusiast
  • *
  • Posts: 31
  • Karma: +2/-0
  • Electronics experience starting from 2015.
    • View Profile
Re: GU5B VTTC Flashover
« Reply #6 on: February 22, 2021, 08:15:40 PM »
Currently i have no tap points. The way i tried to tune this coil was by changing the capacitor values to match with the primary coil inductance to oscillate at the secondary coil resonant frequency. The coil works and if i bring my hands closer, the sparks also get louder and bigger.

I am now upgrading the coil with another MOT and extra filter capacitors for higher power. I will also add tap points on the primary as previously suggested.
K. Salins

Offline SalinsLV

  • High Voltage Enthusiast
  • *
  • Posts: 31
  • Karma: +2/-0
  • Electronics experience starting from 2015.
    • View Profile
Re: GU5B VTTC Flashover
« Reply #7 on: February 24, 2021, 09:30:40 PM »
 Should i also add tap points to the feedback coil?
K. Salins

Offline MRMILSTAR

  • High Voltage Engineer
  • ****
  • Posts: 372
  • Karma: +12/-0
  • Cedar Rapids, Iowa
    • View Profile
Re: GU5B VTTC Flashover
« Reply #8 on: February 24, 2021, 10:14:02 PM »
Some people do add tap points to the feedback coil. I didn't.
Steve White
Cedar Rapids, Iowa
Retired electrical engineer

Offline SalinsLV

  • High Voltage Enthusiast
  • *
  • Posts: 31
  • Karma: +2/-0
  • Electronics experience starting from 2015.
    • View Profile
Re: GU5B VTTC Flashover
« Reply #9 on: March 13, 2021, 11:04:14 AM »
The coil is working and it even plays music:
/>
I will design a new secondary coil because this one has a resonant frequency of 210KHz. At 3Kw the spark length is about 30cm.
« Last Edit: January 16, 2022, 02:56:36 PM by SalinsLV »
K. Salins

High Voltage Forum

Re: GU5B VTTC Flashover
« Reply #9 on: March 13, 2021, 11:04:14 AM »

 


* Recent Topics and Posts

post Re: Hi! 811 A tesa coil
[Vacuum Tube Tesla Coils (VTTC)]
jpvvv123
Today at 04:13:06 AM
post Re: Self Starting Coil (Not)
[Solid State Tesla Coils (SSTC)]
davekni
Today at 03:34:15 AM
post Self Starting Coil (Not)
[Solid State Tesla Coils (SSTC)]
alan sailer
January 23, 2022, 10:45:46 PM
post Re: GDT Slow Rise/Fall times even with resistor shorted
[Dual Resonant Solid State Tesla coils (DRSSTC)]
davekni
January 23, 2022, 09:06:49 PM
post GDT Slow Rise/Fall times even with resistor shorted
[Dual Resonant Solid State Tesla coils (DRSSTC)]
SalinsLV
January 23, 2022, 07:18:56 PM
post Re: Hi! 811 A tesa coil
[Vacuum Tube Tesla Coils (VTTC)]
304er
January 23, 2022, 06:18:13 PM
post Re: 120VAC Mains Ramped Builds
[Solid State Tesla Coils (SSTC)]
Magneticitist
January 22, 2022, 11:20:55 AM
post Re: 120VAC Mains Ramped Builds
[Solid State Tesla Coils (SSTC)]
ZakW
January 22, 2022, 07:07:09 AM
post Re: GDT Testing
[Solid State Tesla Coils (SSTC)]
johnf
January 22, 2022, 05:27:37 AM
post Re: Help on my "first" SSTC (LabCoatz SSTC 2.0)- Popping transistors
[Solid State Tesla Coils (SSTC)]
davekni
January 22, 2022, 04:27:38 AM
post Re: Hi! 811 A tesa coil
[Vacuum Tube Tesla Coils (VTTC)]
jpvvv123
January 22, 2022, 12:53:04 AM
post Re: 120VAC Mains Ramped Builds
[Solid State Tesla Coils (SSTC)]
Magneticitist
January 21, 2022, 07:36:07 PM
post Re: Muon Decay
[Detection, Counting and Measurements]
Uspring
January 21, 2022, 07:27:23 PM
post Re: Etching PCBs with a SLA 3d printer
[Printed Circuit Board]
TMaxElectronics
January 21, 2022, 02:05:52 PM
post Re: 120VAC Mains Ramped Builds
[Solid State Tesla Coils (SSTC)]
ZakW
January 21, 2022, 09:08:18 AM
post Re: Muon Decay
[Detection, Counting and Measurements]
Da_Stier
January 21, 2022, 08:42:54 AM
post 120VAC Mains Ramped Builds
[Solid State Tesla Coils (SSTC)]
Magneticitist
January 21, 2022, 03:00:04 AM
post Re: Muon Decay
[Detection, Counting and Measurements]
alan sailer
January 21, 2022, 02:16:57 AM
post Re: Help on my "first" SSTC (LabCoatz SSTC 2.0)- Popping transistors
[Solid State Tesla Coils (SSTC)]
TiagoBS
January 20, 2022, 06:56:35 PM
post Re: Muon Decay
[Detection, Counting and Measurements]
Da_Stier
January 20, 2022, 05:19:26 PM
post Re: Muon Decay
[Detection, Counting and Measurements]
alan sailer
January 20, 2022, 03:53:54 PM
post Re: Muon Decay
[Detection, Counting and Measurements]
Uspring
January 20, 2022, 01:20:19 PM
post Re: Muon Decay
[Detection, Counting and Measurements]
Da_Stier
January 20, 2022, 10:11:21 AM
post Re: Muon Decay
[Detection, Counting and Measurements]
alan sailer
January 19, 2022, 08:22:49 PM
post Re: Muon Decay
[Detection, Counting and Measurements]
Mads Barnkob
January 19, 2022, 06:49:36 PM
post Re: Etching PCBs with a SLA 3d printer
[Printed Circuit Board]
hardboiled99
January 19, 2022, 07:37:27 AM
post Primary Coil Winding Technique
[Solid State Tesla Coils (SSTC)]
alan sailer
January 18, 2022, 10:34:48 PM
post Re: Muon Decay
[Detection, Counting and Measurements]
alan sailer
January 18, 2022, 08:46:53 PM
post Re: Muon Decay
[Detection, Counting and Measurements]
Mads Barnkob
January 18, 2022, 08:08:53 PM
post Re: GDT Testing
[Solid State Tesla Coils (SSTC)]
ZakW
January 18, 2022, 07:15:22 PM
post Muon Decay
[Detection, Counting and Measurements]
alan sailer
January 18, 2022, 06:49:48 PM
post Re: Strange reading for grid feedback coil voltage
[Vacuum Tube Tesla Coils (VTTC)]
304er
January 18, 2022, 08:47:53 AM
post Re: QO-100 / EShail 2 Uplink amplifier development adventures
[Radio Frequency]
Da_Stier
January 17, 2022, 09:13:32 PM
post Re: QO-100 / EShail 2 Uplink amplifier development adventures
[Radio Frequency]
Da_Stier
January 17, 2022, 09:05:56 PM
post Re: Help on my "first" SSTC (LabCoatz SSTC 2.0)- Popping transistors
[Solid State Tesla Coils (SSTC)]
Mads Barnkob
January 17, 2022, 07:45:48 PM
post Re: General Questions
[Dual Resonant Solid State Tesla coils (DRSSTC)]
Mads Barnkob
January 17, 2022, 07:41:34 PM
post Re: Strange reading for grid feedback coil voltage
[Vacuum Tube Tesla Coils (VTTC)]
Mads Barnkob
January 17, 2022, 07:38:25 PM
post Re: SSTC with push-pull configuration
[Solid State Tesla Coils (SSTC)]
Mads Barnkob
January 17, 2022, 07:31:03 PM
post Re: GDT Testing
[Solid State Tesla Coils (SSTC)]
Mads Barnkob
January 17, 2022, 07:28:02 PM
post Re: Induction heater Driver for Flyback?
[Voltage Multipliers]
MRMILSTAR
January 16, 2022, 09:00:02 PM
post Induction heater Driver for Flyback?
[Voltage Multipliers]
abstruse1
January 16, 2022, 07:35:26 PM
post Re: SSTC with push-pull configuration
[Solid State Tesla Coils (SSTC)]
Bambinz
January 16, 2022, 12:21:40 PM
post Re: SSTC with push-pull configuration
[Solid State Tesla Coils (SSTC)]
davekni
January 15, 2022, 07:10:03 PM
post Re: SSTC with push-pull configuration
[Solid State Tesla Coils (SSTC)]
Bambinz
January 15, 2022, 06:31:33 PM
post Re: SSTC with push-pull configuration
[Solid State Tesla Coils (SSTC)]
Magneticitist
January 14, 2022, 08:47:43 PM
post Re: SSTC with push-pull configuration
[Solid State Tesla Coils (SSTC)]
davekni
January 14, 2022, 08:39:07 PM
post Re: Unusual Youtube channel activity
[General Chat]
davekni
January 14, 2022, 08:14:17 PM
post Re: Unusual Youtube channel activity
[General Chat]
Mads Barnkob
January 14, 2022, 08:12:13 PM
post Unusual Youtube channel activity
[General Chat]
MRMILSTAR
January 14, 2022, 05:51:52 PM
post Re: Strange reading for grid feedback coil voltage
[Vacuum Tube Tesla Coils (VTTC)]
304er
January 14, 2022, 08:51:57 AM
post Re: SSTC with push-pull configuration
[Solid State Tesla Coils (SSTC)]
Bambinz
January 13, 2022, 08:20:02 PM
post Re: Help with SSTC feedback circuits with 4046 IC and Schmitt Triggers
[Solid State Tesla Coils (SSTC)]
davekni
January 13, 2022, 05:27:40 AM
post Re: General Questions
[Dual Resonant Solid State Tesla coils (DRSSTC)]
thedoc298
January 13, 2022, 03:10:32 AM
post Re: Strange reading for grid feedback coil voltage
[Vacuum Tube Tesla Coils (VTTC)]
304er
January 12, 2022, 06:18:15 PM
post Re: Single mosfet bifiliar gdt
[Solid State Tesla Coils (SSTC)]
alan sailer
January 12, 2022, 05:45:26 PM
post Re: Strange reading for grid feedback coil voltage
[Vacuum Tube Tesla Coils (VTTC)]
MRMILSTAR
January 12, 2022, 03:29:04 PM
post Re: Help with SSTC feedback circuits with 4046 IC and Schmitt Triggers
[Solid State Tesla Coils (SSTC)]
AFreshLad
January 12, 2022, 01:30:38 PM
post Re: Strange reading for grid feedback coil voltage
[Vacuum Tube Tesla Coils (VTTC)]
304er
January 12, 2022, 09:09:13 AM
post Re: Strange reading for grid feedback coil voltage
[Vacuum Tube Tesla Coils (VTTC)]
MRMILSTAR
January 11, 2022, 08:05:27 PM
post Re: Nokia Siemens 3G Flexi 2100MHz 50W Amplifier Teardown
[Radio Frequency]
Mads Barnkob
January 11, 2022, 07:42:12 PM
post Re: Strange reading for grid feedback coil voltage
[Vacuum Tube Tesla Coils (VTTC)]
Duane B
January 11, 2022, 07:33:15 PM
post Re: 8x MOT transformer, weird power draw
[Transformer (Iron Core)]
AstRii
January 11, 2022, 06:19:49 PM
post Re: Strange reading for grid feedback coil voltage
[Vacuum Tube Tesla Coils (VTTC)]
304er
January 11, 2022, 05:19:46 PM
post Re: Strange reading for grid feedback coil voltage
[Vacuum Tube Tesla Coils (VTTC)]
MRMILSTAR
January 11, 2022, 04:31:28 PM
post Re: 8x MOT transformer, weird power draw
[Transformer (Iron Core)]
AstRii
January 11, 2022, 03:21:37 PM
post Re: GDT Testing
[Solid State Tesla Coils (SSTC)]
davekni
January 11, 2022, 06:50:49 AM
post Re: Strange reading for grid feedback coil voltage
[Vacuum Tube Tesla Coils (VTTC)]
Duane B
January 11, 2022, 06:34:20 AM
post Re: Help on my "first" SSTC (LabCoatz SSTC 2.0)- Popping transistors
[Solid State Tesla Coils (SSTC)]
davekni
January 11, 2022, 06:24:13 AM
post Re: Strange reading for grid feedback coil voltage
[Vacuum Tube Tesla Coils (VTTC)]
davekni
January 11, 2022, 06:15:08 AM
post Re: Strange reading for grid feedback coil voltage
[Vacuum Tube Tesla Coils (VTTC)]
MRMILSTAR
January 11, 2022, 05:25:31 AM
post Re: Strange reading for grid feedback coil voltage
[Vacuum Tube Tesla Coils (VTTC)]
Duane B
January 11, 2022, 12:07:22 AM
post Strange reading for grid feedback coil voltage
[Vacuum Tube Tesla Coils (VTTC)]
MRMILSTAR
January 10, 2022, 10:56:48 PM
post Re: Hi! 811 A tesa coil
[Vacuum Tube Tesla Coils (VTTC)]
Duane B
January 10, 2022, 09:38:53 PM
post Re: Help on my "first" SSTC (LabCoatz SSTC 2.0)- Popping transistors
[Solid State Tesla Coils (SSTC)]
ZakW
January 10, 2022, 07:50:13 PM
post Re: GDT Testing
[Solid State Tesla Coils (SSTC)]
ZakW
January 10, 2022, 07:19:17 PM
post Re: Help on my "first" SSTC (LabCoatz SSTC 2.0)- Popping transistors
[Solid State Tesla Coils (SSTC)]
TiagoBS
January 10, 2022, 03:13:08 PM
post Re: GDT Testing
[Solid State Tesla Coils (SSTC)]
davekni
January 10, 2022, 04:21:46 AM
post Re: Hi! 811 A tesa coil
[Vacuum Tube Tesla Coils (VTTC)]
304er
January 10, 2022, 03:59:09 AM
post Re: 8x MOT transformer, weird power draw
[Transformer (Iron Core)]
davekni
January 10, 2022, 03:54:59 AM
post Re: GDT Testing
[Solid State Tesla Coils (SSTC)]
ZakW
January 09, 2022, 11:45:09 PM
post Re: Hi! 811 A tesa coil
[Vacuum Tube Tesla Coils (VTTC)]
jpvvv123
January 09, 2022, 11:04:25 PM
post 8x MOT transformer, weird power draw
[Transformer (Iron Core)]
AstRii
January 09, 2022, 04:22:11 PM
post Re: Hi! 811 A tesa coil
[Vacuum Tube Tesla Coils (VTTC)]
Duane B
January 09, 2022, 05:52:11 AM
post Re: GDT Testing
[Solid State Tesla Coils (SSTC)]
davekni
January 09, 2022, 05:10:50 AM
post Re: Performance issues regarding phase angle in SSTCs
[Solid State Tesla Coils (SSTC)]
davekni
January 09, 2022, 01:20:40 AM
post GDT Testing
[Solid State Tesla Coils (SSTC)]
ZakW
January 09, 2022, 12:38:28 AM
post Re: General Questions
[Dual Resonant Solid State Tesla coils (DRSSTC)]
flyingperson23
January 08, 2022, 06:36:28 PM
post Performance issues regarding phase angle in SSTCs
[Solid State Tesla Coils (SSTC)]
Max Seiringer
January 08, 2022, 03:21:31 PM
post Re: Hi! 811 A tesa coil
[Vacuum Tube Tesla Coils (VTTC)]
304er
January 08, 2022, 09:05:41 AM
post Re: Hi! 811 A tesa coil
[Vacuum Tube Tesla Coils (VTTC)]
jpvvv123
January 07, 2022, 10:20:10 PM
post Re: Hi! 811 A tesa coil
[Vacuum Tube Tesla Coils (VTTC)]
304er
January 07, 2022, 05:56:28 PM
post Re: First SSTC based on profdc9 PCB Pack
[Solid State Tesla Coils (SSTC)]
davekni
January 07, 2022, 05:15:38 AM
post Re: DRSSTC tuning
[Dual Resonant Solid State Tesla coils (DRSSTC)]
davekni
January 07, 2022, 05:01:21 AM
post Re: How to prevent secondary to secondary to primary arcs?
[Dual Resonant Solid State Tesla coils (DRSSTC)]
davekni
January 07, 2022, 04:59:59 AM
post Tophat QCW 1
[Dual Resonant Solid State Tesla coils (DRSSTC)]
dbach
January 07, 2022, 02:27:35 AM
post How to prevent secondary to secondary to primary arcs?
[Dual Resonant Solid State Tesla coils (DRSSTC)]
dbach
January 07, 2022, 02:19:40 AM
post Re: General Questions
[Dual Resonant Solid State Tesla coils (DRSSTC)]
Mads Barnkob
January 06, 2022, 09:33:06 PM
post Re: First SSTC based on profdc9 PCB Pack
[Solid State Tesla Coils (SSTC)]
alan sailer
January 06, 2022, 06:09:39 PM
post Re: DRSSTC tuning
[Dual Resonant Solid State Tesla coils (DRSSTC)]
kubajed
January 06, 2022, 04:48:22 PM
post Re: First SSTC based on profdc9 PCB Pack
[Solid State Tesla Coils (SSTC)]
SK1701
January 06, 2022, 03:05:55 PM

Sitemap 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 
SimplePortal 2.3.6 © 2008-2014, SimplePortal