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 #10
Joined: Thu Feb 02 2006, 09:45AM
Location: Bunbury, Australia
Posts: 1424
Was reorganising my web site and looking at magnetic levitation stuff so thought I'd try a few things.
Here is an air cored coil out of a defibrillator output circuit. Don't know number of turns but the inductance is 10mH (I think). It is drawing 6.5 A at 100V AC to get the lift of about 1/2 inch off a 1/4 inch copper plate. It is tethered like a conventional lifter.
I did try levitating a MOT with the E section opened and facing down but really needed a better winding. Hence I tried a non cored coil.
Registered Member #10
Joined: Thu Feb 02 2006, 09:45AM
Location: Bunbury, Australia
Posts: 1424
uzzors wrote ...
Nice. Have you tried lifting anything with it?
Here is the 284g coil lifting a 217g solder reel (total 500g). Current was a bit higher and distance off the base was 1/4 inch compared with 1/2 inch before. There is a world of difference with an electrostatic lifter where the lift is (mostly) independent of the proximity of the ground and is far smaller.
Registered Member #64
Joined: Thu Feb 09 2006, 06:25AM
Location: Southampton, UK
Posts: 68
very nice Peter, I think i got a bit of an understanding why this works... something to do with eddy currents in the base copper plate? what i'm trying to get my head around is the AC, DC thru a coil would make the coil an electromagnet and it would repell off a magnet giving lfit, but AC? Does the base plate have a repelling magnetic force because of eddy currents induced by the coil? if so would a ring shaped base plate (same shape as the coil) give a better lift for less power?
Registered Member #64
Joined: Thu Feb 09 2006, 06:25AM
Location: Southampton, UK
Posts: 68
could be diamagnetism, copper is slightly diamagnetic i've got a kilo of bismuth shot around somewhere (bismuth is 15x more diamagnetic than copper)... something to try tomorrow :)
Registered Member #70
Joined: Thu Feb 09 2006, 08:19AM
Location:
Posts: 43
It not diamagnetism as the most diamagnetic material on Earth (pyrolytic graphite) can only float mere millimeters above grade N50 neodymium super magnets and barely lifts its own weight.
It is eddy current repulsion from AC being feed to the coil.
Care to give more infomation on this TDU? frequency? power? whoops, I read though the posts quickly and missed that part ^^
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.
Levitating a coil
