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 #2566
Joined: Wed Dec 23 2009, 05:52PM
Location:
Posts: 147
Demonstration involving electrostatic generator and high school kids . Scroll to 12:25 and watch. Isn't that dangeorous since they are not in a Faraday cage any more?
All I can say is that I wish my high school was that awesome. I asked my Physics teacher if he had a tesla coil. He does... a really teeny tiny one, apparently.
Registered Member #3900
Joined: Thu May 19 2011, 08:28PM
Location:
Posts: 600
As long as they dont jump down they'll be fine. yes they are charged, but there is no current flowing through them(unless the guy put the discharge rod up to them). the only current flow they ever saw was the discharge of the energy stored in the capacitance of their bodies flowing though their feet when the sphere was grounded. hence the jumping from foot to foot.
Registered Member #834
Joined: Tue Jun 12 2007, 10:57PM
Location: Brazil
Posts: 644
They have an impressive demonstration of electricity at the Palais de la Decouverte (this site). I once took part of this demonstration, and managed to draw large sparks to my hand by reaching for the grounded rail in front while charged, scaring the presenter...
Registered Member #2566
Joined: Wed Dec 23 2009, 05:52PM
Location:
Posts: 147
ben123324 wrote ...
the only current flow they ever saw was the discharge of the energy stored in the capacitance of their bodies flowing though their feet when the sphere was grounded. hence the jumping from foot to foot.
And that's exactly the point! ESD shock in feet and hands when the body is discharged from 200 kV DC to zero potential... Looks like there's practically no shock and there should be (a serious one).Why? One more example to watch
Antonio wrote ...
They have an impressive demonstration of electricity at the Palais de la Decouverte (this site).
Registered Member #2901
Joined: Thu Jun 03 2010, 01:25PM
Location:
Posts: 837
I don't think he pain sensation in your feet can compare to the one in your fingers, which is the one we are all familiar with where it concerns static charge.
Registered Member #3900
Joined: Thu May 19 2011, 08:28PM
Location:
Posts: 600
dex wrote ...
ben123324 wrote ...
the only current flow they ever saw was the discharge of the energy stored in the capacitance of their bodies flowing though their feet when the sphere was grounded. hence the jumping from foot to foot.
And that's exactly the point! ESD shock in feet and hands when the body is discharged from 200 kV DC to zero potential... Looks like there's practically no shock and there should be (a serious one).Why?
because the bulk of the energy is stored in the torroid they stand on. yes they have plenty of potential, but its only the capacitance of their bodies at the v potential that flows through them.
imagine that you are charged with static charge the same way you do when you give someone a shock. except instead of touching someone, the charge flows out of your feet into the ground. no danger whatsoever. but you now know how they feel standing like that.
those huge sparks were generated using the capacitance of the torroid. if THAT energy flowed through them, then they'd be in trouble. notice how they never allow that?
Registered Member #4074
Joined: Mon Aug 29 2011, 06:58AM
Location: Australia
Posts: 335
What sort of HV supply are they using to charge the toroid? I know it says electrostatic, but I didn't think I conventional van de graaf (even a large one) would discharge and recharge that rapidly. Is it perhaps just a current limited voltage multiplier that continually trickles current into the toroid?
Registered Member #2566
Joined: Wed Dec 23 2009, 05:52PM
Location:
Posts: 147
ben123324 wrote ...
because the bulk of the energy is stored in the torroid they stand on. yes they have plenty of potential, but its only the capacitance of their bodies at the v potential that flows through them.
imagine that you are charged with static charge the same way you do when you give someone a shock. except instead of touching someone, the charge flows out of your feet into the ground. no danger whatsoever. but you now know how they feel standing like that.
those huge sparks were generated using the capacitance of the torroid. if THAT energy flowed through them, then they'd be in trouble. notice how they never allow that?
So you think if they wore thick rubber boots while holding onto the fence they would feel strong shocks in hands?I think there's more capacitance in that fence and the vertical pole than in the toroid.
Registered Member #834
Joined: Tue Jun 12 2007, 10:57PM
Location: Brazil
Posts: 644
XravenorX wrote ...
What sort of HV supply are they using to charge the toroid? I know it says electrostatic, but I didn't think I conventional van de graaf (even a large one) would discharge and recharge that rapidly. Is it perhaps just a current limited voltage multiplier that continually trickles current into the toroid?
I have seen this demonstration twice. In 2010 they were using an electronic power supply. In 2001 they had a more powerful mechanical generator enclosed in a compressed gas chamber. Probably a Van de Graaff.
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.
Danger?
