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 #1643
Joined: Mon Aug 18 2008, 06:10PM
Location:
Posts: 1039
Well...Just make sure he understands the dangers of electricity...Not to be sticking stuff in it like paper etc...I'm sure you are well aware with how dangerous HV is. But as mention above, it would be best to keep some time of cage/fence to at least keep those who are not educated in HV, away from any harm. A simple large chicken wire cage (like the 5mm space grid kind) would obviously make a good cage (given you keep it away from the HV and the peak of the arc as it rises and breaks at the top) But you'd want it grounded. Of course it will take away that 'cool simple' look, but at least it will prevent risk of shock and safety of others.
I did this as a Demo using dual-stack MOTs before. But this was with people age 18, so the most I had to do was say "Stand at least 10ft back" No worries someone would just run up to it...Everyone was far away, and my self had a 4ft PVC pipe with a 15" rod at the end. But young students will be different.
Registered Member #1451
Joined: Wed Apr 23 2008, 03:48AM
Location: Boulder, Co
Posts: 661
Speaking from experience science fair rules are really anal about safety. It would absolutely need to have a Faraday cage and remote operation or you could get in trouble with the judges. You might also want to have someone with some sort of qualifications go over the device before you turn it on. I know that you have more knowledge about safety and this sort of stuff than most of the people you could get a hold of, but the judges don't care at all. Just get someone with a fancy title to sign off that it's safe.
Go with the project for sure; it will be a big hit. More advanced than most the other projects kids his age will be doing.
Registered Member #1643
Joined: Mon Aug 18 2008, 06:10PM
Location:
Posts: 1039
My school stops doing science fairs after like 5th grade. So I would have done a ladder, but they don't do it in highschool. It will defiantly stand out in a science fair for his grade :)
Banned on 1/22/2011 for repeated rule violations after multiple warnings. Registered Member #3299
Joined: Sat Oct 09 2010, 08:11PM
Location: Bantown, USA
Posts: 220
I realise they are very anal about safety, my sgtc got qualifiedly for safety reason, then i had to explain to the priciple what a tesla coil is.
but... hes seen my projects and what i do with hv, and he wanted to do something similar, so i said i'd help and supervise him, the obit i'm gonna use is only 10,000 volts at 21ma, it will REALLY wake you up, but it won't kill you.
Registered Member #1408
Joined: Fri Mar 21 2008, 03:49PM
Location: Oracle, AZ
Posts: 679
I helped someone make a little project for school (I pretty much gave him all the materials) but when it came down to finding some safety shielding; this was a great place to find clear tubing in larger sizes - polymers in general - for shielding. Good prices.
Registered Member #1643
Joined: Mon Aug 18 2008, 06:10PM
Location:
Posts: 1039
ubuntupokemoninc wrote ...
I realise they are very anal about safety, my sgtc got qualifiedly for safety reason, then i had to explain to the priciple what a tesla coil is.
but... hes seen my projects and what i do with hv, and he wanted to do something similar, so i said i'd help and supervise him, the obit i'm gonna use is only 10,000 volts at 21ma, it will REALLY wake you up, but it won't kill you.
This is true but it can be a different story if it is grabbed by two hands. We had a kid in our class stupidly grab onto both terminals of a 12KV 30mA NST, he is lucky enough he didnt have to go to the hospitable or worst. Muscles contracted so it made him grab and he couldnt let go..Once unplugged, the NST fell onto the floor and broke the terminal off. Wasn't there to witness, Just what my teacher said, when someone asked "Why is this insulator broken?"
Any plans on how big of a ladder? Going for a mini 12-20"? or are you going to make it climb high like 6ft, slowly getting wider and wider.
Registered Member #1408
Joined: Fri Mar 21 2008, 03:49PM
Location: Oracle, AZ
Posts: 679
From what I had read from a safety equipment mfg (which sold high quality gloves, etc); although the fibrillation current on AVERAGE is approx 35ma, there really is no absolute in this, as many variables exist (contact area, pre-existing medical condition, resistance of contact point, AC/DC, grounding, sourcing contact size. etc). The point of both hands contacting (making a "cross-chest" conduction possible) is an extremely serious one and even current as low as 5ma has been known to have fatal results. How many young people have collapsed on a Basketball court with a heart attack? There may be a undiagnosed problem and some situations (AC especially) can have tragic results.
Simply from raising children I can attest that some of them notoriously experiment w/ their lives but think they are invulnerable. My strongest recommendation is simply design the thing so that either an accident OR a volitional contact simply can't take place. An acrylic tube is cheap insurance and because it channels the warm air upward will give better results. This also could be achieved by two planes of transparent sheets which totally enclose the ladder, yet allow for movement - there may be slight movement of the tynes as the arc climbs -
One of the greatest problems of a high energy hobby is the possibility of injury as it harms the hobby. The "big-picture" of safety is one of general importance as it has repercussions further in time.
Registered Member #3395
Joined: Thu Nov 04 2010, 08:42AM
Location: Christchurch, New Zealand
Posts: 193
quicksilver wrote ...
From what I had read from a safety equipment mfg (which sold high quality gloves, etc); although the fibrillation current on AVERAGE is approx 35ma, there really is no absolute in this, as many variables exist (contact area, pre-existing medical condition, resistance of contact point, AC/DC, grounding, sourcing contact size. etc). The point of both hands contacting (making a "cross-chest" conduction possible) is an extremely serious one and even current as low as 5ma has been known to have fatal results. How many young people have collapsed on a Basketball court with a heart attack? There may be a undiagnosed problem and some situations (AC especially) can have tragic results.
Simply from raising children I can attest that some of them notoriously experiment w/ their lives but think they are invulnerable. My strongest recommendation is simply design the thing so that either an accident OR a volitional contact simply can't take place. An acrylic tube is cheap insurance and because it channels the warm air upward will give better results. This also could be achieved by two planes of transparent sheets which totally enclose the ladder, yet allow for movement - there may be slight movement of the tynes as the arc climbs -
One of the greatest problems of a high energy hobby is the possibility of injury as it harms the hobby. The "big-picture" of safety is one of general importance as it has repercussions further in time.
I agree with quicksilver. It's a really good idea to make a HV display as safe as possible by eliminating the risks that could happen. You could put everything in a perspex box screwed together with holes at the top with a fan to ventilate the heated air out. The power supply should be in a hidden wooden box that they also can't get their curious poking around into.
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.
jacobs ladder in science fair?
