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.
Registered Member #1361
Joined: Thu Feb 28 2008, 10:57AM
Location: Cairns, Australia
Posts: 305
Hey guys
I am about to start building some rolled caps, but i need a powerful DC supply to test them with. So my best bet would be rectifying my NST. I dont have money to go out and buy super fast HV switching diodes, so i am trying to se stuff i can get down the road. Could i use a bunch of 2N4007's (i think thats what they are)?
Registered Member #1361
Joined: Thu Feb 28 2008, 10:57AM
Location: Cairns, Australia
Posts: 305
Sorry for the double post, thought i'd ask while i was at it. below is a pic of my NST. GND is mains ground, HV is HV and line is mains. There is a spare screw terminal next to the mains ground with a weird looking e on it. I'm thinking this may be a centre tap, can anyone confirm?
Registered Member #30
Joined: Fri Feb 03 2006, 10:52AM
Location: Glasgow, Scotland
Posts: 6706
Apologizing for double posts doesn't make it right. You should have posted the picture in the attachments board, and then edited your original post to include it.
Registered Member #690
Joined: Tue May 08 2007, 03:47AM
Location: New Jersey, USA
Posts: 616
1N4007 are very commonly used as rectifiers at 50/60Hz, so you don't have to worry about speed at all. They are, however, only rated for 1kV. You will need a bunch in series for each leg of the rectifier.
Registered Member #72
Joined: Thu Feb 09 2006, 08:29AM
Location: UK St. Albans
Posts: 1659
Make it 30. As they are neither avalanche rated nor intended to be seriesed (specified reverse recovery time, charge storage and junction capacitiance), you can assume they won't share nice.
<edit>
whoa! 15kV rms is 20oddkV peak, and you need to withstand the peak volts. Make it 45.
It doesn't matter whether you run diodes from just one 7.5kV leg or from both, you'll get the same DC voltage. Rectifying both legs will give you less ripple and more current output capability, however neither is necessary for testing caps.
Given the large number of diodes you need, I'd build just two strings of 45, and use one leg to give both +10kv and -10kV outputs, for 20kV balanced.
Registered Member #1340
Joined: Thu Feb 21 2008, 12:47AM
Location:
Posts: 23
could mot rectifiers work or are they diffrent. asuming you could find them. i used to have alot of them but, i don't think i had enoth to rectify a nst.
Hmm.. DC caps those cap allways bit me when i worked with them be careful I was and still, they would suprise me snap!!!
Registered Member #1361
Joined: Thu Feb 28 2008, 10:57AM
Location: Cairns, Australia
Posts: 305
lol it's $8 a packet for 100, so i dont care if i blow a few along the way. Is there a limit as to how many you can wire in series? If not, then i could make strings of 50 , 1 for each leg.
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.
Rectifying my NST?
