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 #4052
Joined: Thu Aug 11 2011, 04:43AM
Location: IN ,USA
Posts: 69
I was thinking about building a very small coil (3/4'' diameter secondary) with a synch rotory gap (with brushes of some sort do to the low voltage)
I have a transformer from some sort of battery charger that I recently rewired to run backwards and submerged in oil. the transformer was rated at (120v in at 50mA : 4.8v out at 350mA) I am limiting the current with a 60 watt lightbulb so it now has (120v in at 500Ma) does this mean that it is running at (3,000v and 71mA) ?
also if my math is correct on the transformer, is this even a possible tesla coil design?
Registered Member #2919
Joined: Fri Jun 11 2010, 06:30PM
Location: Cambridge, MA
Posts: 652
I very vaguely remember a post about a brushed SGTC; the verdict was performance was low. At such low powers, you are better off looking into solid state. Also, running 120V into a coil wound for 4.8V on an iron-cored transformer is very likely saturating the core, which causes your output voltage to be far below what the turns ratio would predict.
Registered Member #4052
Joined: Thu Aug 11 2011, 04:43AM
Location: IN ,USA
Posts: 69
thank you,
I was wonering about the core saturation. is there any way to prevent or decrease saturation?
I did look into solid state but truthfuly I am not sure that I understand it well enough, and I do not have any of the equipment to tune it in properly.
also if this transformer can not be modified to work, is there some other type of very small non-solid state transfomer that could be used?
Registered Member #3888
Joined: Sun May 15 2011, 09:50PM
Location: Erie, PA
Posts: 649
You should be able to find plenty of info on here about tiny tesla coils. One of them even uses camera flash transformers. just look through the tesla forum for "tiny." If you can't find anything helpful (unlikely) then I'll look into it for you.
"Now I am become Forty, the destroyer of transistors."
Registered Member #4052
Joined: Thu Aug 11 2011, 04:43AM
Location: IN ,USA
Posts: 69
I was looking through the forum and I had an idea,
could I use a vacuum tube as an arc gap? not a true VTTC, the tube would just replace the gap as a high voltage switch
the rest of the coil's circuit would be the same as a in rotary coil. I would just have to trigger the tube to ''fire'' at the peak of the AC voltage when the capacitors are charged.
if I had a small negative DC current going to the tube's grid (10 volts or so) with another transfomer wired in parallel with it providing AC current (about 10.5 volts), then as the AC voltage risses it will eventualy overcome the DC supply. Thus changing the tube's grid from negative to positive and allowing it to conduct.
the only problem is that it will only fire 60 times a second, but I am not trying to set any spark length records.
has this ever been done before? ....and if so was it succesful
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.
mini rotory spark gap tesla coil
