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 #3429
Joined: Sun Nov 21 2010, 02:04AM
Location: Minnesota, USA
Posts: 288
I built a similar project back in 1975. The idea goes back to the days of Nikola Tesla, and therefore it is nothing new. Some companies that make portable electronic gagets (such as cell phones and cordless toothbrushes) are just now starting to utilize this scheme for recharging their devices without using an electrical contact of any kind.
Registered Member #1938
Joined: Sun Jan 25 2009, 12:44PM
Location: Romania
Posts: 701
yes, tesla did this using spark gap oscillators, like in the early radio transmitters. I never said it was something new, but since I completed another project I thought it was a good idea to share it with the community. Bet tesla's design wasn't this compact :)
Registered Member #2063
Joined: Sat Apr 04 2009, 03:16PM
Location: Toronto
Posts: 352
the only problem with this technology is that the reciver have to very close to the transmitter. the recived power prabably follows the inverse square law.
Registered Member #3429
Joined: Sun Nov 21 2010, 02:04AM
Location: Minnesota, USA
Posts: 288
radhoo wrote ...
yes, tesla did this using spark gap oscillators, like in the early radio transmitters. I never said it was something new, but since I completed another project I thought it was a good idea to share it with the community. Bet tesla's design wasn't this compact :)
I agree, this is a great project for electronic hobbyists, and you have given a good example of how it can be constructed. You did a nice job, and it looks professionally assembled.
Many years ago, I wanted to make a wireless headphone that would allow me to walk around my house while listening to an audio source that originated in my basement. I first tried the transformer technique by winding a VERY large primary coil around the entire perimeter of my basement ceiling, and the headphones were connected to a secondary coil that I carried on my belt. The unit was a little clumsy because of its size but it did work. But some time later I used the tuned circuit technique like you did in your project, and it was much smaller than my first attempt, and the secondary coil was also much smaller and easier to lug around. The circuitry was more complex than the simple transformer technique of coupling, but overall it was much better. In my case, I wasn't transmitting power to light a bulb or charge a battery, but I was transmitting modulated power, not unlike a standard AM radio transmitter. I used a carrier frequency of around 500KHz.
Registered Member #1938
Joined: Sun Jan 25 2009, 12:44PM
Location: Romania
Posts: 701
Thanks for the feedback, guys, I was about to think you're all away on some exotic holidays, drinking cocktails and having fun
@haxor5354: all electromagnetic waves (radio, light, X-rays, etc.) obey the inverse-square law. so yes, distance can be a problem. @Inducktion: I believe that would increase the power density. I can change the capacitor to increase the frequency. @Xray: actually there is an easy way around that, probably you've all seen self-powered little radios using just a few components. would love to see your project, but since it was long ago, you probably don't have any pics. @Patrick: I used ExpressSCH . It comes in a bundle with ExpressPCB
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.