Author Topic: Strange? behaviour in a NST  (Read 253 times)

Offline Alberto

  • High Voltage Experimenter
  • **
  • Posts: 67
  • Karma: +0/-0
    • View Profile
Strange? behaviour in a NST
« on: February 03, 2021, 08:52:57 PM »
Hi everyone.

I have bought this cheap NST on a Chinese website. It is supposed to give 10Kv but the arc can start at 6 cm. The other weird thing is if I connectit in when the wires are 6cm or less the arc start and keeps arcing. But if the wires are more than 6 cm they only generate a small spark at the tip and nothing else happens. Even if I get closer. I need to disconnect and reconnect to "restart"

And fortunately, I am very careful and never touch the wires in the plastic. They arc between them! Very good insulation ...

What you think? It is the first time that I have an NST and I do not do it if this is normal.

Thank you

Kind regards

Offline davekni

  • High Voltage Senior
  • *****
  • Posts: 978
  • Karma: +42/-0
  • Physicist, engineer (electronic), and hobbiest
    • View Profile
Re: Strange? behaviour in a NST
« Reply #1 on: February 03, 2021, 09:08:54 PM »
Most NSTs now are inverter circuits feeding a high-frequency (~30kHz) transformer.  They have internal circuits to detect fault conditions and shut down on faults.  One fault is an arc not starting.  I'm surprised that it doesn't also shut down due to low arc voltage - but you did say that it was cheap.  (I expect that the 6cm air arc is lower voltage than a properly-working neon sign tube.)
David Knierim

Offline Alberto

  • High Voltage Experimenter
  • **
  • Posts: 67
  • Karma: +0/-0
    • View Profile
Re: Strange? behaviour in a NST
« Reply #2 on: February 03, 2021, 10:15:55 PM »
Most NSTs now are inverter circuits feeding a high-frequency (~30kHz) transformer.  They have internal circuits to detect fault conditions and shut down on faults.  One fault is an arc not starting.  I'm surprised that it doesn't also shut down due to low arc voltage - but you did say that it was cheap.  (I expect that the 6cm air arc is lower voltage than a properly-working neon sign tube.)

Thank you for your answer.

Ok ok now I understand, but, if is 10kv rated, how can it generate 6cm arc? 6cm must be around 60 kv, isn´t it?

Offline davekni

  • High Voltage Senior
  • *****
  • Posts: 978
  • Karma: +42/-0
  • Physicist, engineer (electronic), and hobbiest
    • View Profile
Re: Strange? behaviour in a NST
« Reply #3 on: February 04, 2021, 01:49:42 AM »
Voltage depends on the shape of the electrodes (wire ends) besides distance.  However, 60kV may be reasonable.  If the 10kV rating is for operating, NSTs generate a higher starting voltage.  60kV sounds high for starting a 10kV neon tube, but I don't have much experience with this.
David Knierim

Offline Alberto

  • High Voltage Experimenter
  • **
  • Posts: 67
  • Karma: +0/-0
    • View Profile
Re: Strange? behaviour in a NST
« Reply #4 on: February 04, 2021, 08:50:28 AM »
Ok ok, thanks, You are very helpful!


Offline Alberto

  • High Voltage Experimenter
  • **
  • Posts: 67
  • Karma: +0/-0
    • View Profile
Re: Strange? behaviour in a NST
« Reply #5 on: February 04, 2021, 08:54:39 PM »
Ok, I have found that from wikipedia

All NSTs are designed to produce a high voltage starting pulse to a tube, then limit the current through the tube when it has started.

High Voltage Forum

Re: Strange? behaviour in a NST
« Reply #5 on: February 04, 2021, 08:54:39 PM »

 


* Recent Topics and Posts

post Re: Large coil experimenting with long on-times.
[Dual Resonant Solid State Tesla coils (DRSSTC)]
fh89
Today at 07:16:23 AM
post Re: DRSSTC Performs only with 1cm Arcs - Troubleshooting
[Dual Resonant Solid State Tesla coils (DRSSTC)]
davekni
Today at 05:08:32 AM
post Re: Project: FreakyDRSSTC MK1
[Dual Resonant Solid State Tesla coils (DRSSTC)]
davekni
Today at 04:47:32 AM
post Re: Baxandall converter strange output
[Transformer (Ferrite Core)]
dreamth
March 03, 2021, 11:20:38 PM
post Re: Next Gen DRSSTC
[Dual Resonant Solid State Tesla coils (DRSSTC)]
AeraCura_
March 03, 2021, 11:15:32 PM
post Re: Baxandall converter strange output
[Transformer (Ferrite Core)]
Twospoons
March 03, 2021, 10:30:40 PM
post Re: Baxandall converter strange output
[Transformer (Ferrite Core)]
dreamth
March 03, 2021, 10:03:26 PM
post Re: Need Help w/Build - Lightning Pulse Generator
[Laboratories, Equipment and Tools]
Mads Barnkob
March 03, 2021, 09:45:28 PM
post Re: Baxandall converter strange output
[Transformer (Ferrite Core)]
Twospoons
March 03, 2021, 09:44:17 PM
post First power on tests
[Dual Resonant Solid State Tesla coils (DRSSTC)]
GrantV
March 03, 2021, 06:26:23 PM
post Re: Search for opinions concerning the use or test of a yunbao / Ebay drsstc skp
[Dual Resonant Solid State Tesla coils (DRSSTC)]
GrantV
March 03, 2021, 05:54:58 PM
post Re: Baxandall converter strange output
[Transformer (Ferrite Core)]
dreamth
March 03, 2021, 03:13:30 PM
post Re: Baxandall converter strange output
[Transformer (Ferrite Core)]
dreamth
March 03, 2021, 01:18:22 PM
post Re: Baxandall converter strange output
[Transformer (Ferrite Core)]
dreamth
March 03, 2021, 12:25:52 PM
post Re: Baxandall converter strange output
[Transformer (Ferrite Core)]
dreamth
March 03, 2021, 12:24:40 PM
post Re: DRSSTC Performs only with 1cm Arcs - Troubleshooting
[Dual Resonant Solid State Tesla coils (DRSSTC)]
ChrisBlis
March 03, 2021, 10:43:20 AM
post Re: Search for opinions concerning the use or test of a yunbao / Ebay drsstc skp
[Dual Resonant Solid State Tesla coils (DRSSTC)]
GrantV
March 03, 2021, 09:05:02 AM
post Re: Help for people buying the "12-48 Volt 1800/2500 Watt ZVS induction Heater"
[Electronic Circuits]
davekni
March 03, 2021, 05:53:33 AM
post Re: Through-hole layout of UD2.7C universal driver
[Dual Resonant Solid State Tesla coils (DRSSTC)]
profdc9
March 03, 2021, 04:22:01 AM
post Re: Help for people buying the "12-48 Volt 1800/2500 Watt ZVS induction Heater"
[Electronic Circuits]
petespaco
March 03, 2021, 04:00:14 AM
post Re: Baxandall converter strange output
[Transformer (Ferrite Core)]
davekni
March 03, 2021, 01:21:15 AM
post Re: Just a noob with some HV concerns...
[Beginners]
AstRii
March 03, 2021, 12:36:05 AM
post Re: Baxandall converter strange output
[Transformer (Ferrite Core)]
dreamth
March 03, 2021, 12:35:57 AM
post Re: Baxandall converter strange output
[Transformer (Ferrite Core)]
davekni
March 02, 2021, 11:40:16 PM
post Re: Baxandall converter strange output
[Transformer (Ferrite Core)]
dreamth
March 02, 2021, 11:29:28 PM
post Re: DRSSTC Performs only with 1cm Arcs - Troubleshooting
[Dual Resonant Solid State Tesla coils (DRSSTC)]
davekni
March 02, 2021, 10:48:04 PM
post Re: Baxandall converter strange output
[Transformer (Ferrite Core)]
davekni
March 02, 2021, 10:33:13 PM
post Re: Baxandall converter strange output
[Transformer (Ferrite Core)]
dreamth
March 02, 2021, 10:20:22 PM
post Re: Help for people buying the "12-48 Volt 1800/2500 Watt ZVS induction Heater"
[Electronic Circuits]
davekni
March 02, 2021, 10:18:05 PM
post Re: Search for opinions concerning the use or test of a yunbao / Ebay drsstc skp
[Dual Resonant Solid State Tesla coils (DRSSTC)]
davekni
March 02, 2021, 09:38:45 PM
post Re: Through-hole layout of UD2.7C universal driver
[Dual Resonant Solid State Tesla coils (DRSSTC)]
Max
March 02, 2021, 08:54:33 PM
post Re: WTS [EU] Vici DM4070 LCR meter with SMD tweezers
[Sell / Buy / Trade]
Da_Stier
March 02, 2021, 08:53:31 PM
post Re: Through-hole layout of UD2.7C universal driver
[Dual Resonant Solid State Tesla coils (DRSSTC)]
profdc9
March 02, 2021, 05:04:44 PM
post Re: Search for opinions concerning the use or test of a yunbao / Ebay drsstc skp
[Dual Resonant Solid State Tesla coils (DRSSTC)]
GrantV
March 02, 2021, 03:16:25 PM
post Re: WTS [EU] Vici DM4070 LCR meter with SMD tweezers
[Sell / Buy / Trade]
AstRii
March 02, 2021, 09:41:31 AM
post Re: DRSSTC Performs only with 1cm Arcs - Troubleshooting
[Dual Resonant Solid State Tesla coils (DRSSTC)]
ChrisBlis
March 02, 2021, 08:26:30 AM
post Re: Help for people buying the "12-48 Volt 1800/2500 Watt ZVS induction Heater"
[Electronic Circuits]
hightemp1
March 02, 2021, 07:05:01 AM
post Re: Help for people buying the "12-48 Volt 1800/2500 Watt ZVS induction Heater"
[Electronic Circuits]
davekni
March 02, 2021, 06:22:52 AM
post Re: Interesting RF air-core transformer construction
[Vacuum Tube Tesla Coils (VTTC)]
MRMILSTAR
March 02, 2021, 05:24:46 AM
post Re: Help for people buying the "12-48 Volt 1800/2500 Watt ZVS induction Heater"
[Electronic Circuits]
hightemp1
March 02, 2021, 05:21:16 AM
post Re: Help for people buying the "12-48 Volt 1800/2500 Watt ZVS induction Heater"
[Electronic Circuits]
petespaco
March 02, 2021, 04:37:50 AM
post Re: Help for people buying the "12-48 Volt 1800/2500 Watt ZVS induction Heater"
[Electronic Circuits]
hightemp1
March 02, 2021, 01:26:36 AM
post Re: DRSSTC Performs only with 1cm Arcs - Troubleshooting
[Dual Resonant Solid State Tesla coils (DRSSTC)]
davekni
March 01, 2021, 11:07:01 PM
post Re: Very old flyback
[Transformer (Ferrite Core)]
Alberto
March 01, 2021, 11:04:06 PM
post Re: Baxandall converter strange output
[Transformer (Ferrite Core)]
dreamth
March 01, 2021, 09:45:59 PM
post Re: Baxandall converter strange output
[Transformer (Ferrite Core)]
davekni
March 01, 2021, 09:30:44 PM
post Re: DRSSTC Performs only with 1cm Arcs - Troubleshooting
[Dual Resonant Solid State Tesla coils (DRSSTC)]
ChrisBlis
March 01, 2021, 09:27:38 PM
post Re: Through-hole layout of UD2.7C universal driver
[Dual Resonant Solid State Tesla coils (DRSSTC)]
Max
March 01, 2021, 09:05:02 PM
post Re: Baxandall converter strange output
[Transformer (Ferrite Core)]
dreamth
March 01, 2021, 08:22:33 PM
post Re: Baxandall converter strange output
[Transformer (Ferrite Core)]
davekni
March 01, 2021, 08:16:46 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