Author Topic: Marx Generator misfiring  (Read 508 times)

Offline Andy Kay

  • High Voltage Enthusiast
  • *
  • Posts: 15
  • Karma: +0/-0
    • View Profile
Marx Generator misfiring
« on: May 15, 2018, 10:47:24 PM »
Hi guys, I've been busy building my first ever Cockcroft-Walton voltage multiplier and my first ever Marx Generator. I don't know if it's permitted to supply video links here but if so then I can show provide a link to a YouTube video that shows the setup. My question concerns misfiring. I'd like to understand what is happening in the Marx Generator when it occasionally misfires, with the minor spark gaps showing weak sparks (or maybe they are just plasma paths). I can't see any obvious shorting pathways, so I'm wondering where all the energy is going on the misfires. Thanks for reading.

Offline Mads Barnkob

  • Administrator
  • High Voltage Senior
  • *****
  • Posts: 825
  • Karma: +6/-0
  • Denmark
    • View Profile
    • Kaizer Power Electronics
Re: Marx Generator misfiring
« Reply #1 on: May 16, 2018, 12:19:51 PM »
Please do post the video, if you put in a youtube link, it is automatically embedded so you can play the video directly here in the post.

Misfiring is often due to imbalance in charging resistors/inductors, but lets get a look at your setup before troubleshooting more :)
http://www.kaizerpowerelectronics.dk - Tesla coils, high voltage, pulse power, audio and general electronics

Offline Andy Kay

  • High Voltage Enthusiast
  • *
  • Posts: 15
  • Karma: +0/-0
    • View Profile
Re: Marx Generator misfiring
« Reply #2 on: May 16, 2018, 05:11:54 PM »
Please do post the video, if you put in a youtube link, it is automatically embedded so you can play the video directly here in the post.

Misfiring is often due to imbalance in charging resistors/inductors, but lets get a look at your setup before troubleshooting more :)
Thank you Mads.
The setup consists of a car battery at 13V driving a two-port CCFL inverter. One port of the inverter is driving a T5 fluorescent lamp in cold cathode mode, the other is driving a 13-stage CW voltage multiplier. I have tapped off the CW at the fifth stage to supply an 11-stage Marx generator. The gap is something like 90mm, but when I set it at 100mm the misfiring begins in earnest.

Here is the link:

/>

Offline Andy Kay

  • High Voltage Enthusiast
  • *
  • Posts: 15
  • Karma: +0/-0
    • View Profile
Re: Marx Generator misfiring
« Reply #3 on: May 19, 2018, 07:30:29 AM »
Misfiring is often due to imbalance in charging resistors/inductors,
The resistors are all 1W 1M 1% metal film. I guess I'm really asking about the mechanism of failure when the main gap gets too large. I would have expected all the capacitors to become fully energized just as before, and so the energy should be finding some easier path than the main gap, but I don't see any evidence of that. Perhaps the capacitors aren't getting to full charge, but I don't see how that would follow from just increasing the main gap. Still perplexed.

Offline Michael_DA

  • High Voltage Enthusiast
  • *
  • Posts: 12
  • Karma: +0/-0
    • View Profile
Re: Marx Generator misfiring
« Reply #4 on: September 22, 2018, 01:59:16 PM »
Hello Andy,
how does the schematic of your Marx generator look like? To my knowledge, the most common is this one, but in principle there are several variations of it, so thats why I ask.



Normally, the output voltage of a Marx generator is the measurable voltage across the load capacitance (in the circuit diagram named C_b) This has the following shape (without a flashover of your main gap. With a flashover, the voltage collapses very quickly.):



This results from the fact that the surge capacitance (C_s) is discharged into the smaller capacitance C_b via the resistor R_d, resulting in the rapid increase of the voltage. The time of the rise can be increased or decreased by the variation of R_d. If the voltage is not large enough to produce a flashover in your main gap, the load capacitance (C_b) will discharge via the resistors R_d and R_e, causing the slower, falling voltage waveform. The drop in voltage (without flashover) is significantly slower, since the discharge resistance R_e is usually chosen to be greater than the resistance R_d.

For a better understanding, I have painted here the two possible paths. The red path is the case if your main gap does not flashover. And the blue path when your main gap rolls over. (Unfortunately, I am not a very good draftsman, but I hope it is obvious  :D).



I hope I could help you.

Kind regards,
Michael
« Last Edit: September 22, 2018, 02:07:20 PM by Michael_DA »

High Voltage Forum

Re: Marx Generator misfiring
« Reply #4 on: September 22, 2018, 01:59:16 PM »

 


* Recent Topics and Posts

post Re: My First DRSSTC
[Dual Resonant Solid State Tesla coils]
sjsimmo
Today at 12:19:32 AM
post Re: TO-247 IGBT Comparison for High Frequency & Paralleled Operation
[Dual Resonant Solid State Tesla coils]
Laci
December 18, 2018, 10:30:34 PM
post Re: TO-247 IGBT Comparison for High Frequency & Paralleled Operation
[Dual Resonant Solid State Tesla coils]
Mads Barnkob
December 18, 2018, 09:42:25 PM
post Re: TO-247 IGBT Comparison for High Frequency & Paralleled Operation
[Dual Resonant Solid State Tesla coils]
Laci
December 18, 2018, 09:25:26 PM
post Re: My First DRSSTC
[Dual Resonant Solid State Tesla coils]
Mads Barnkob
December 18, 2018, 12:50:45 PM
post Re: My First DRSSTC
[Dual Resonant Solid State Tesla coils]
sjsimmo
December 18, 2018, 10:45:01 AM
post Re: My First DRSSTC
[Dual Resonant Solid State Tesla coils]
Mads Barnkob
December 18, 2018, 09:47:51 AM
post Re: TO-247 IGBT Comparison for High Frequency & Paralleled Operation
[Dual Resonant Solid State Tesla coils]
sjsimmo
December 18, 2018, 03:18:05 AM
post Re: My First DRSSTC
[Dual Resonant Solid State Tesla coils]
sjsimmo
December 18, 2018, 02:08:57 AM
post Re: TO-247 IGBT Comparison for High Frequency & Paralleled Operation
[Dual Resonant Solid State Tesla coils]
Fumeaux
December 17, 2018, 10:22:31 PM
post TO-247 IGBT Comparison for High Frequency & Paralleled Operation
[Dual Resonant Solid State Tesla coils]
Laci
December 17, 2018, 09:36:03 PM
post Re: spectral analysis of Tesla coils
[Spark gap Tesla coils]
Mads Barnkob
December 17, 2018, 02:20:01 PM
post Re: DRSSTC design guide - progress report
[Dual Resonant Solid State Tesla coils]
Mads Barnkob
December 17, 2018, 01:13:34 PM
post Re: spectral analysis of Tesla coils
[Spark gap Tesla coils]
Uspring
December 17, 2018, 01:02:35 PM
post Re: DRSSTC design guide - progress report
[Dual Resonant Solid State Tesla coils]
Uspring
December 17, 2018, 12:33:07 PM
post Re: My First DRSSTC
[Dual Resonant Solid State Tesla coils]
Mads Barnkob
December 17, 2018, 12:26:08 PM
post Re: Building of my first tesla coil
[Dual Resonant Solid State Tesla coils]
Mads Barnkob
December 17, 2018, 10:42:17 AM
post Re: My First DRSSTC
[Dual Resonant Solid State Tesla coils]
sjsimmo
December 17, 2018, 06:49:52 AM
post Re: Building of my first tesla coil
[Dual Resonant Solid State Tesla coils]
Skylex86
December 16, 2018, 09:09:13 PM
post Re: Welcome new members, come say hello and tell a little about yourself :)
[General chatting]
Mads Barnkob
December 16, 2018, 07:48:55 PM
post Re: Welcome new members, come say hello and tell a little about yourself :)
[General chatting]
NordicGaben
December 16, 2018, 06:13:54 PM
post spectral analysis of Tesla coils
[Spark gap Tesla coils]
Physikfan
December 15, 2018, 02:24:20 PM
post Re: Welcome new members, come say hello and tell a little about yourself :)
[General chatting]
DashApple
December 14, 2018, 10:21:25 PM
post Re: DRSSTC design guide - progress report
[Dual Resonant Solid State Tesla coils]
Mads Barnkob
December 14, 2018, 08:38:52 PM
post Re: DRSSTC design guide - progress report
[Dual Resonant Solid State Tesla coils]
Uspring
December 13, 2018, 12:23:30 PM
post Re: My First DRSSTC
[Dual Resonant Solid State Tesla coils]
sjsimmo
December 12, 2018, 11:57:02 PM
post Re: My First DRSSTC
[Dual Resonant Solid State Tesla coils]
Mads Barnkob
December 12, 2018, 01:15:30 PM
post Re: DRSSTC design guide - progress report
[Dual Resonant Solid State Tesla coils]
Mads Barnkob
December 12, 2018, 01:00:34 PM
post Re: My First DRSSTC
[Dual Resonant Solid State Tesla coils]
sjsimmo
December 12, 2018, 11:45:08 AM
post Re: My First DRSSTC
[Dual Resonant Solid State Tesla coils]
Mads Barnkob
December 11, 2018, 09:13:49 AM
post Re: My First DRSSTC
[Dual Resonant Solid State Tesla coils]
sjsimmo
December 11, 2018, 12:03:54 AM
post Re: My First DRSSTC
[Dual Resonant Solid State Tesla coils]
Mads Barnkob
December 10, 2018, 12:25:15 PM
post Re: My First DRSSTC
[Dual Resonant Solid State Tesla coils]
sjsimmo
December 10, 2018, 11:13:38 AM
post Re: My First DRSSTC
[Dual Resonant Solid State Tesla coils]
Mads Barnkob
December 10, 2018, 09:18:24 AM
post Re: First SSTC build, need help troubleshooting
[Solid state Tesla coils]
Mads Barnkob
December 10, 2018, 09:13:37 AM
post Re: My First DRSSTC
[Dual Resonant Solid State Tesla coils]
sjsimmo
December 10, 2018, 02:18:59 AM
post Re: First SSTC build, need help troubleshooting
[Solid state Tesla coils]
sjsimmo
December 09, 2018, 11:09:34 PM
post Re: First SSTC build, need help troubleshooting
[Solid state Tesla coils]
Fumeaux
December 09, 2018, 10:23:38 AM
post Re: My First DRSSTC
[Dual Resonant Solid State Tesla coils]
sjsimmo
December 09, 2018, 06:05:02 AM
post Re: First SSTC build, need help troubleshooting
[Solid state Tesla coils]
Jesjes
December 09, 2018, 04:50:56 AM
post Re: My First DRSSTC
[Dual Resonant Solid State Tesla coils]
Laci
December 08, 2018, 12:52:41 PM
post Re: My First DRSSTC
[Dual Resonant Solid State Tesla coils]
sjsimmo
December 08, 2018, 09:51:47 AM
post Huawei RRU3928 1800MHz radio base station teardown (part 1 of 2)
[Radio frequency]
Mads Barnkob
December 06, 2018, 07:49:06 PM
post Re: First SSTC build, need help troubleshooting
[Solid state Tesla coils]
Fumeaux
December 03, 2018, 10:35:13 AM
post Re: First SSTC build, need help troubleshooting
[Solid state Tesla coils]
sjsimmo
December 03, 2018, 08:40:43 AM
post Re: First SSTC build, need help troubleshooting
[Solid state Tesla coils]
Jesjes
December 03, 2018, 05:31:29 AM
post Re: Hacking the IKEA 2000 Watt induction stove (5 parts)
[Electronic circuits]
chjarup
December 02, 2018, 11:44:14 PM
post SSTC-Driver PCB 1.3
[Printed Circuit Board]
Fumeaux
December 02, 2018, 10:25:23 PM
post Re: Hacking the IKEA 2000 Watt induction stove (5 parts)
[Electronic circuits]
Mads Barnkob
December 02, 2018, 04:23:16 PM
post Re: Hacking the IKEA 2000 Watt induction stove (5 parts)
[Electronic circuits]
chjarup
December 02, 2018, 12:12:57 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