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 #96
Joined: Thu Feb 09 2006, 05:37PM
Location: CI, Earth
Posts: 4059
Heh, has anyone tried to build this yet?
I was toying with the idea of making one of these with wall mounted extender coils to remotely charge my electric bike's battery at say 250mA from 20 feet away through an upper window.
The idea of using blue LEDs in reverse bias to keep the coils in tune would probably work.. ?
Registered Member #96
Joined: Thu Feb 09 2006, 05:37PM
Location: CI, Earth
Posts: 4059
Might try my hand at DIY metamaterials. Seems that bismuth is diamagnetic, and so is pyrolytic graphite. So... Combine the two in alternating layers, and form them into grids like a PCB. You can grow PG in a low pressure argon plasma containing a small amount of methane, needs around 1200C IIRC. The methane acts as the carbon source and deposits onto whatever is in the chamber.
So have bismuth plated onto the graphite squares coated on glass, put this between the transmitter and receiver and see what effect it has at moderate frequencies with various sizes of grids.
Plating Bi is a total PITA but can be done with nonaqueous electrolytes and pulsed HVDC.
Registered Member #3900
Joined: Thu May 19 2011, 08:28PM
Location:
Posts: 600
i have never seen someone try to scale one of these things up to compensate for distance. maybe a 320v halfbridge pumping +2kw over long distances? you might be able to get 250mA from over 50 ft away.
Someone on the IRC told me that was an SSTC driver. hm, but anyways @ conundrum I doubt anyone has the means of heating or growing elements in their house. i wonder if this would work for cars.
Registered Member #1316
Joined: Thu Feb 14 2008, 03:35AM
Location: Cambridge, MA
Posts: 365
Resonant wireless power transfer systems are rather efficient when well optimized. Nothing decent at close to 20 feet though. You would need quite large coils.
A third identically tuned coil between the transmitter and receiver will passively increase the range.
There is research being done on wirelessly charging electric vehicles. I have personally seen a prototype system capable of a few KW. Coil separation was on the order of one foot and I recall correctly, the total system efficiency was over 70%.
Registered Member #96
Joined: Thu Feb 09 2006, 05:37PM
Location: CI, Earth
Posts: 4059
OK guys, can someone point me towards ideas for making 10.250 GHz metamaterials? My Gunnplexer now works again as the fault was a defective tantalum across the diode (facepalm!) It exploded in my face when I turned up the current but luckily it missed anything important.
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.
Wireless power
