Author Topic: Voltage mulitplier grounding  (Read 244 times)

Offline MRMILSTAR

  • High Voltage Engineer
  • ****
  • Posts: 248
  • Karma: +5/-0
  • Cedar Rapids, Iowa
    • View Profile
Voltage mulitplier grounding
« on: February 21, 2021, 08:56:33 PM »
I am getting close to the completion of my 14-stage CW voltage multiplier. I have one remaining question. Does anyone ground one side of the multiplier stack AC input? Would it serve any purpose? I am primarily going to just be drawing arcs so it will have current-limiting resistors. I plan on drawing arcs through use of a separate discharge tower that I've made. The discharge tower consists only of an aluminum toroid on top of a PVC tube. The discharge tower will be connected to one of the AC input terminals at the bottom of the CW stack.

The power source is two AC flybacks in parallel driven by a ZVS driver. I am concerned about damage to the ZVS driver and possibly to the SMPS DC power supply. It would be most convenient to not ground anything other than the SMPS.
Steve White
Cedar Rapids, Iowa
Retired electrical engineer

Offline davekni

  • High Voltage Senior
  • *****
  • Posts: 993
  • Karma: +45/-0
  • Physicist, engineer (electronic), and hobbiest
    • View Profile
Re: Voltage mulitplier grounding
« Reply #1 on: February 21, 2021, 10:01:10 PM »
I recommend grounding one side of the CW stack.  Even with discharges going to the other tower, there is still capacitance to ground (to space).  Voltage at the bottom of the stack will depend on the ratio of capacitance to space/ground at the top to capacitance to ground at the bottom.  Bottom capacitance will be higher, but you still may get 20-25% of top voltage at the bottom, which might damage flyback insulation.
David Knierim

Offline ElectroXa

  • High Voltage Enthusiast
  • *
  • Posts: 31
  • Karma: +1/-0
    • View Profile
Re: Voltage mulitplier grounding
« Reply #2 on: February 21, 2021, 10:18:07 PM »
Hi !

I would definitely ground the multiplier on one side of the AC input  :)

(I would ground the diode side, to avoid DC pulses in flyback secondary, to "try" reducing back emf)

I would also ground this multiplier through a small 110- 220V transformer primary used as an inductor choke, to block the AC flyback from leaking, but pass the DC, both to ground
indeed, I noticed on my multiplier that most of the AC leaked, leading to bad output.
adding this choke greatly increased the output  :D

cheers

Offline MRMILSTAR

  • High Voltage Engineer
  • ****
  • Posts: 248
  • Karma: +5/-0
  • Cedar Rapids, Iowa
    • View Profile
Re: Voltage mulitplier grounding
« Reply #3 on: February 23, 2021, 10:19:46 PM »
Hi !

I would definitely ground the multiplier on one side of the AC input  :)

(I would ground the diode side, to avoid DC pulses in flyback secondary, to "try" reducing back emf)

I would also ground this multiplier through a small 110- 220V transformer primary used as an inductor choke, to block the AC flyback from leaking, but pass the DC, both to ground
indeed, I noticed on my multiplier that most of the AC leaked, leading to bad output.
adding this choke greatly increased the output  :D

cheers

Does the attached schematic show the placement of the small choke that you describe?
Steve White
Cedar Rapids, Iowa
Retired electrical engineer

Offline ElectroXa

  • High Voltage Enthusiast
  • *
  • Posts: 31
  • Karma: +1/-0
    • View Profile
Re: Voltage mulitplier grounding
« Reply #4 on: February 23, 2021, 11:34:46 PM »
I would rather put this choke to earth, and the discharge tower directly to the bottom of the multiplier, or else the choke will arc over due to voltage peak

I did that, and it works great  ;)

Edit : I left the secondary open circuit
« Last Edit: February 24, 2021, 10:20:30 PM by ElectroXa »

Offline MRMILSTAR

  • High Voltage Engineer
  • ****
  • Posts: 248
  • Karma: +5/-0
  • Cedar Rapids, Iowa
    • View Profile
Re: Voltage mulitplier grounding
« Reply #5 on: February 23, 2021, 11:37:29 PM »
I would rather put this choke to earth, and the discharge tower directly to the bottom of the multiplier, or else the choke will arc over due to voltage peak

I did that, and it works great  ;)

Thanks. I'll try it that way.
Steve White
Cedar Rapids, Iowa
Retired electrical engineer

Offline MRMILSTAR

  • High Voltage Engineer
  • ****
  • Posts: 248
  • Karma: +5/-0
  • Cedar Rapids, Iowa
    • View Profile
Re: Voltage mulitplier grounding
« Reply #6 on: February 24, 2021, 10:12:44 PM »
I would rather put this choke to earth, and the discharge tower directly to the bottom of the multiplier, or else the choke will arc over due to voltage peak

I did that, and it works great  ;)

Did you short the secondary winding of the grounding transformer or leave it open?
Steve White
Cedar Rapids, Iowa
Retired electrical engineer

High Voltage Forum

Re: Voltage mulitplier grounding
« Reply #6 on: February 24, 2021, 10:12:44 PM »

 


* Recent Topics and Posts

post Re: Question about the meaning of "±20V" specification for Vge on IGBT datasheet
[Solid State Tesla Coils (SSTC)]
Mads Barnkob
Today at 07:34:41 PM
post HFSSTC not working well
[Solid State Tesla Coils (SSTC)]
toooldforthis
Today at 07:18:50 PM
post Re: MOT tesla coil: Why put the midpoint to ground ?
[Spark Gap Tesla Coils (SGTC)]
klugesmith
Today at 05:33:59 PM
post Re: MOT tesla coil: Why put the midpoint to ground ?
[Spark Gap Tesla Coils (SGTC)]
paulj
Today at 04:59:39 PM
post Re: Question about the meaning of "±20V" specification for Vge on IGBT datasheet
[Solid State Tesla Coils (SSTC)]
jhorneljohn02
Today at 04:16:38 PM
post Re: Voltage readings on 13.8KV
[Voltage Multipliers]
Phoenix
Today at 10:13:38 AM
post Re: Voltage readings on 13.8KV
[Voltage Multipliers]
Mads Barnkob
March 07, 2021, 08:57:23 PM
post Re: MOT tesla coil: Why put the midpoint to ground ?
[Spark Gap Tesla Coils (SGTC)]
Mads Barnkob
March 07, 2021, 08:53:07 PM
post Re: Identification of capacitors
[General Chat]
Mr_Project
March 07, 2021, 08:26:27 PM
post MOT tesla coil: Why put the midpoint to ground ?
[Spark Gap Tesla Coils (SGTC)]
paulj
March 07, 2021, 05:49:49 PM
post Voltage readings on 13.8KV
[Voltage Multipliers]
lex1969
March 07, 2021, 10:47:55 AM
post Re: Etching PCBs with a SLA 3d printer
[Printed Circuit Board]
klugesmith
March 07, 2021, 02:48:08 AM
post Re: Question about the meaning of "±20V" specification for Vge on IGBT datasheet
[Solid State Tesla Coils (SSTC)]
davekni
March 07, 2021, 02:19:47 AM
post Re: Etching PCBs with a SLA 3d printer
[Printed Circuit Board]
TMaxElectronics
March 07, 2021, 01:49:55 AM
post Re: Etching PCBs with a SLA 3d printer
[Printed Circuit Board]
klugesmith
March 07, 2021, 01:26:52 AM
post Re: Question about the meaning of "±20V" specification for Vge on IGBT datasheet
[Solid State Tesla Coils (SSTC)]
jhorneljohn02
March 07, 2021, 12:30:36 AM
post Re: Coil destroyed at 4ms on-time.
[Dual Resonant Solid State Tesla coils (DRSSTC)]
fh89
March 06, 2021, 11:30:27 PM
post Re: Simplified mutli-stage coilgun idea
[Induction Launchers, Coil Guns and Rails guns]
johnnyzoo
March 06, 2021, 10:13:19 PM
post Re: Coil destroyed at 4ms on-time.
[Dual Resonant Solid State Tesla coils (DRSSTC)]
davekni
March 06, 2021, 09:54:31 PM
post Re: Coil destroyed at 4ms on-time.
[Dual Resonant Solid State Tesla coils (DRSSTC)]
Mads Barnkob
March 06, 2021, 09:48:37 PM
post Re: Etching PCBs with a SLA 3d printer
[Printed Circuit Board]
TMaxElectronics
March 06, 2021, 09:44:20 PM
post Re: Identification of capacitors
[General Chat]
Mads Barnkob
March 06, 2021, 09:33:17 PM
post Re: Coil destroyed at 4ms on-time.
[Dual Resonant Solid State Tesla coils (DRSSTC)]
Hydron
March 06, 2021, 09:21:44 PM
post Re: Coil destroyed at 4ms on-time.
[Dual Resonant Solid State Tesla coils (DRSSTC)]
davekni
March 06, 2021, 09:15:09 PM
post Re: Osciloscope
[Laboratories, Equipment and Tools]
rikkitikkitavi
March 06, 2021, 08:55:52 PM
post Re: Coil destroyed at 4ms on-time.
[Dual Resonant Solid State Tesla coils (DRSSTC)]
Hydron
March 06, 2021, 08:51:06 PM
post Re: Help for people buying the "12-48 Volt 1800/2500 Watt ZVS induction Heater"
[Electronic Circuits]
rikkitikkitavi
March 06, 2021, 08:48:52 PM
post Re: Etching PCBs with a SLA 3d printer
[Printed Circuit Board]
Twospoons
March 06, 2021, 08:44:23 PM
post Re: Question about the meaning of "±20V" specification for Vge on IGBT datasheet
[Solid State Tesla Coils (SSTC)]
davekni
March 06, 2021, 06:26:56 PM
post Re: Coil destroyed at 4ms on-time.
[Dual Resonant Solid State Tesla coils (DRSSTC)]
davekni
March 06, 2021, 06:24:15 PM
post Question about the meaning of "±20V" specification for Vge on IGBT datasheet
[Solid State Tesla Coils (SSTC)]
jhorneljohn02
March 06, 2021, 06:00:21 PM
post Re: Welcome new members, come say hello and tell a little about yourself :)
[General Chat]
jhorneljohn02
March 06, 2021, 05:53:40 PM
post Re: Aliexpress Yunbao pulse skipping Product Guide manual
[Dual Resonant Solid State Tesla coils (DRSSTC)]
GrantV
March 06, 2021, 05:49:48 PM
post Re: Search for opinions concerning the use or test of a yunbao / Ebay drsstc skp
[Dual Resonant Solid State Tesla coils (DRSSTC)]
JCF
March 06, 2021, 05:31:42 PM
post Re: Baxandall converter strange output
[Transformer (Ferrite Core)]
dreamth
March 06, 2021, 05:16:24 PM
post Re: Aliexpress Yunbao pulse skipping Product Guide manual
[Dual Resonant Solid State Tesla coils (DRSSTC)]
JCF
March 06, 2021, 04:35:37 PM
post Identification of capacitors
[General Chat]
Mr_Project
March 06, 2021, 03:43:41 PM
post Re: Etching PCBs with a SLA 3d printer
[Printed Circuit Board]
TMaxElectronics
March 06, 2021, 12:33:22 PM
post Re: Coil destroyed at 4ms on-time.
[Dual Resonant Solid State Tesla coils (DRSSTC)]
fh89
March 06, 2021, 08:27:54 AM
post Re: Coil destroyed at 4ms on-time.
[Dual Resonant Solid State Tesla coils (DRSSTC)]
alexhanyuan
March 06, 2021, 06:49:27 AM
post Re: Coil destroyed at 4ms on-time.
[Dual Resonant Solid State Tesla coils (DRSSTC)]
davekni
March 06, 2021, 06:33:58 AM
post Re: Rocket engine questions
[General Chat]
plasma
March 06, 2021, 06:20:59 AM
post Re: Rocket engine questions
[General Chat]
klugesmith
March 06, 2021, 06:03:40 AM
post Re: Help for people buying the "12-48 Volt 1800/2500 Watt ZVS induction Heater"
[Electronic Circuits]
davekni
March 06, 2021, 05:59:49 AM
post Re: Large coil experimenting with long on-times.
[Dual Resonant Solid State Tesla coils (DRSSTC)]
fh89
March 06, 2021, 05:08:48 AM
post Re: Rocket engine questions
[General Chat]
Twospoons
March 06, 2021, 04:50:01 AM
post Re: Rocket engine questions
[General Chat]
klugesmith
March 06, 2021, 04:24:44 AM
post Re: Help for people buying the "12-48 Volt 1800/2500 Watt ZVS induction Heater"
[Electronic Circuits]
hightemp1
March 06, 2021, 03:41:03 AM
post Re: Etching PCBs with a SLA 3d printer
[Printed Circuit Board]
Twospoons
March 06, 2021, 01:20:13 AM
post Re: Etching PCBs with a SLA 3d printer
[Printed Circuit Board]
TMaxElectronics
March 05, 2021, 11:26:36 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