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 #1025
Joined: Sun Sept 23 2007, 07:53PM
Location: Czech Rep.
Posts: 566
jmartis wrote ...
I heard that dc arcs pull longer than ac ones. Is this true? For example if I rectify the output of my MOT will I get bigger arcs?
DC arcs should be much more stable but you need a good choke in series (not a parallel cap!) to see a real difference. The point is tha DC arc generates much higher temperature inside the track and thus you get much longer conductive path...
Registered Member #27
Joined: Fri Feb 03 2006, 02:20AM
Location: Hyperborea
Posts: 2058
The capacitor goes in parallel to smooth out the ripple of the rectified AC, that way you get DC with low ripple.
If you read the specifications for switches you will see that the DC voltage rating is usually a lot less than the AC rating because of the arcing problem.
Registered Member #152
Joined: Sun Feb 12 2006, 03:36PM
Location: Czech Rep.
Posts: 3384
I would try it but I would need at least 80 3A 1KV diodes to make 20KV bridge rectifier (the output from my dual MOT bank peaks up to 15kV).. not exactly cheap well maybe I can try with just 1 MOT
Registered Member #162
Joined: Mon Feb 13 2006, 10:25AM
Location: United Kingdom
Posts: 3140
If you rectify the output of your mot with a capacitor across the dc when you try to pull an arc you will be rewarded with a VERY loud BANG as the capacitor discharges almost completely in an instant for a stable dc arc you will need resistance in series, which will make the arc very weak. You could have diodes and an inductor which would be better but the inductor required would be very large to get sufficient inductance that doesn't saturate = not practical.
Registered Member #1025
Joined: Sun Sept 23 2007, 07:53PM
Location: Czech Rep.
Posts: 566
jmartis wrote ...
I would try it but I would need at least 80 3A 1KV diodes to make 20KV bridge rectifier (the output from my dual MOT bank peaks up to 15kV).. not exactly cheap well maybe I can try with just 1 MOT
I recommend using IN5408 diodes for this purpose and use small (1nf/1000V) ceramic cap with 1,2Mohm resistor parallel to each of the diode. Use twice the voltage ratting of diodes than is the expected voltage you going to rectify. I have an experience with this setup for MOT rectifying and it works well... I think that with bridge setup you should see already some improvement, but the choke made of another MOT is a good idea, however I'm not sure if it survives...
Registered Member #1025
Joined: Sun Sept 23 2007, 07:53PM
Location: Czech Rep.
Posts: 566
Bjørn Bæverfjord wrote ...
If you read the specifications for switches you will see that the DC voltage rating is usually a lot less than the AC rating because of the arcing problem.
We are disccusing plasma pulling and not arcing which can be aslo the problem of the switches. Otherwise I do not agree , according to my experience the AC sparks for greater distances...
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.
Do dc arcs pull longer?
well maybe I can try with just 1 MOT
