Main Menu
bullet Home
bullet Forum
bullet Members
bullet Member Map
bullet HvWiki
bullet Chat Room
bullet Submit News
bullet Site Rules
bullet Archives
bullet Visits
bullet Forum
Welcome
Username or Email:

Password:


Missing Code




[ ]
[ ]
Online
  • Guests: 27
  • Members: 0
  • Newest Member: omjtest
  • Most ever online: 396
    Guests: 396, Members: 0 on 12 Jan : 12:51
Members Birthdays:
One birthday today, congrats!
MicroTesla (34)


Next birthdays
07/09 Avi (41)
07/09 Jannick Hagen (15)
07/10 Sparcz (69)
Contact
If you need assistance, please send an email to forum at 4hv dot org. To ensure your email is not marked as spam, please include the phrase "4hv help" in the subject line. You can also find assistance via IRC, at irc.shadowworld.net, room #hvcomm.
Support 4hv.org!
Donate:
4hv.org is hosted on a dedicated server. Unfortunately, this server costs and we rely on the help of site members to keep 4hv.org running. Please consider donating. We will place your name on the thanks list and you'll be helping to keep 4hv.org alive and free for everyone. Members whose names appear in red bold have donated recently. Green bold denotes those who have recently donated to keep the server carbon neutral.


Special Thanks To:
  • Aaron Holmes
  • Aaron Wheeler
  • Adam Horden
  • Alan Scrimgeour
  • Andre
  • Andrew Haynes
  • Anonymous000
  • asabase
  • Austin Weil
  • barney
  • Barry
  • Bert Hickman
  • Bill Kukowski
  • Blitzorn
  • Brandon Paradelas
  • Bruce Bowling
  • BubeeMike
  • Byong Park
  • Cesiumsponge
  • Chris F.
  • Chris Hooper
  • Corey Worthington
  • Derek Woodroffe
  • Dalus
  • Dan Strother
  • Daniel Davis
  • Daniel Uhrenholt
  • datasheetarchive
  • Dave Billington
  • Dave Marshall
  • David F.
  • Dennis Rogers
  • drelectrix
  • Dr. John Gudenas
  • Dr. Spark
  • E.TexasTesla
  • eastvoltresearch
  • Eirik Taylor
  • Erik Dyakov
  • Erlend^SE
  • Finn Hammer
  • Firebug24k
  • GalliumMan
  • Gary Peterson
  • George Slade
  • GhostNull
  • Gordon Mcknight
  • Graham Armitage
  • Grant
  • GreySoul
  • Henry H
  • IamSmooth
  • In memory of Leo Powning
  • Jacob Cash
  • James Howells
  • James Pawson
  • Jeff Greenfield
  • Jeff Thomas
  • Jesse Frost
  • Jim Mitchell
  • jlr134
  • Joe Mastroianni
  • John Forcina
  • John Oberg
  • John Willcutt
  • Jon Newcomb
  • klugesmith
  • Leslie Wright
  • Lutz Hoffman
  • Mads Barnkob
  • Martin King
  • Mats Karlsson
  • Matt Gibson
  • Matthew Guidry
  • mbd
  • Michael D'Angelo
  • Mikkel
  • mileswaldron
  • mister_rf
  • Neil Foster
  • Nick de Smith
  • Nick Soroka
  • nicklenorp
  • Nik
  • Norman Stanley
  • Patrick Coleman
  • Paul Brodie
  • Paul Jordan
  • Paul Montgomery
  • Ped
  • Peter Krogen
  • Peter Terren
  • PhilGood
  • Richard Feldman
  • Robert Bush
  • Royce Bailey
  • Scott Fusare
  • Scott Newman
  • smiffy
  • Stella
  • Steven Busic
  • Steve Conner
  • Steve Jones
  • Steve Ward
  • Sulaiman
  • Thomas Coyle
  • Thomas A. Wallace
  • Thomas W
  • Timo
  • Torch
  • Ulf Jonsson
  • vasil
  • Vaxian
  • vladi mazzilli
  • wastehl
  • Weston
  • William Kim
  • William N.
  • William Stehl
  • Wesley Venis
The aforementioned have contributed financially to the continuing triumph of 4hv.org. They are deserving of my most heartfelt thanks.
Forums
4hv.org :: Forums :: High Voltage
« Previous topic | Next topic »   

Prototype small CW
Move Thread LAN_403
GrantX
Mon Sept 12 2011, 04:40AM Print
GrantX Registered Member #4074 Joined: Mon Aug 29 2011, 06:58AM
Location: Australia
Posts: 335
 		Hey everyone,

I'm building a mini full wave CW as a prototype before investing in more expensive parts for a larger one.

I ordered 6 Russian vacuum capacitors each at 200pF 25kV on impulse a few days ago, and I already have 10 30kV 20mA diodes sitting here.

So, if I understand it correctly, a 2 stage multiplier fed with my 6kV/30mA NST will give me:
(3x3000)x2x(square root 2) = 25455.8 V

I only have a 4.4 Mega ohm resistor to use on the ouput, with will limit current to about 570uA. Which is regrettably low, but I don't want to spend much cash on this project as it's only a prototype.

I'm hoping the small cap size will limit current enough to protect the 20mA diodes from the 30mA NST, am I correct in this assumption? Or will I need some kind of input impedance?
Back to top
Ash Small
Mon Sept 12 2011, 05:00AM
Ash Small Registered Member #3414 Joined: Sun Nov 14 2010, 05:05PM
Location: UK
Posts: 4245
 		I understand a lot of people place resistors in series with each diode.

I understand this can have several advantages, especially when drawing arcs.

Don't take my word for it though, I've not tried it yet myself.

(Apparently this eliminates the need for one big resistor on the output, and protects the diodes.)
Back to top
jpsmith123
Mon Sept 12 2011, 01:21PM
jpsmith123 Registered Member #1321 Joined: Sat Feb 16 2008, 03:22AM
Location:
Posts: 843
 		Your 200 pF capacitors are rather small for a multiplier...especially one being driven from a 60 hz source (i.e., your neon sign transformer).

I recommend that you d/l a spice simulator from somewhere and study the behavior of some virtual multipliers before you start assembling any hardware.
Back to top
GrantX
Tue Sept 13 2011, 01:42AM
GrantX Registered Member #4074 Joined: Mon Aug 29 2011, 06:58AM
Location: Australia
Posts: 335
 		Yes, as its a prototype, I'm just using small cheap caps which I know will limit output to a few micro amps.

As I understand it, the small caps will have enough impedance that the full wave multiplier will charge at a low current, so my 20mA diodes will be safe, even though the power source is a 30mA NST? I don't have any other diodes to use, so if this won't work, then I can't build my multiplier, so I really need help with this point.
Back to top
Adam Munich
Tue Sept 13 2011, 01:32PM
Adam Munich Registered Member #2893 Joined: Tue Jun 01 2010, 09:25PM
Location: Cali-forn. i. a.
Posts: 2242
 		If you just want to draw arcs, sure put in the resistors. You'll have to remove them if you'd like to power an x-ray tube though.
Back to top

Moderator(s): Chris Russell, Noelle, Alex, Tesladownunder, Dave Marshall, Dave Billington, Bjørn, Steve Conner, Wolfram, Kizmo, Mads Barnkob

Go to:

Powered by e107 Forum System
 
Legal Information
This site is powered by e107, which is released under the GNU GPL License. All work on this site, except where otherwise noted, is licensed under a Creative Commons Attribution-ShareAlike 2.5 License. By submitting any information to this site, you agree that anything submitted will be so licensed. Please read our Disclaimer and Policies page for information on your rights and responsibilities regarding this site.