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 #46264
Joined: Sun May 11 2014, 05:27PM
Location: Tucson, Arizona USA
Posts: 61
This photo shows an interesting bright red surface discharge on a wood block. The bright red color only happened when the discharge occurred over a dark grain in the wood. After doing some research and more observations, I found that the red color is caused by the discharge occurring just below the surface of the wood. Has anyone seen this before? Thanks Russ
Edit: After doing some research and more observations, I found that the red color is caused by the discharge occurring just below the surface of the wood. Russ
[Moderator edit by Mads Barnkob, double posts merged]
Registered Member #46264
Joined: Sun May 11 2014, 05:27PM
Location: Tucson, Arizona USA
Posts: 61
The wood was not burning. These discharges were low energy from a Van de Graaff generator. The only capacitance in the circuit was from the Van de graaff top terminal and a grounded metal cylinder. I estimate the energy of each discharge at about 0.4 Joule ( 20 pF at 200 Kv ) and a power of about 4 uA at 200 Kv or 0.8 watts. The wood block looked exactly the same as it did before the 30 seconds of exposure to the discharges.
Registered Member #72
Joined: Thu Feb 09 2006, 08:29AM
Location: UK St. Albans
Posts: 1659
Cut out a few crumbs of wood from different parts of the block and do a flame test on each. A colleague used to make indoor fireworks, and used strontium nitrate as the oxidiser when he wanted an intense red light. It does sound like there's a different composition in part of the wood. Different ions emit different colours when excited, perhaps your discharge excites them enough to emit without burning the wood. I'm not suggesting that Sr is the only species that emits red. Break out the old chemical analysis textbooks.
Registered Member #1403
Joined: Tue Mar 18 2008, 06:05PM
Location: Denmark, Odense C
Posts: 1968
I am wondering if you could replicate this with a pickle, those that usually are glowing/burning yellow when put across mains, due to the salt content.
Maybe you could excite it in the same manner with high voltage low current.
Registered Member #46264
Joined: Sun May 11 2014, 05:27PM
Location: Tucson, Arizona USA
Posts: 61
Another wood block discharge photo with a different wood block and electrode configuration. The wood block was placed on top of the negatively charged VDG terminal and a grounded cookie sheet was placed above the wood block. These discharges have more energy than the previous setup. The photo is rotated 90 degrees. Towards the top of the photo, a red/orange subsurface discharge is seen to emerge from the wood surface and then go back down below surface again.
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.
Bright red surface discharge on a wood block
