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 #2148
Joined: Tue Jun 02 2009, 02:22AM
Location:
Posts: 62
Hazmatt_(The Underdog) wrote ...
No part of the secondary should be inside your former because you will have a racing arc down the inside of the tube. You can't see it when it happens, which makes things difficult. You may hear a cracking sound inside the tube, but that's about it.
Metal should be avoided because it can act as a breakout point, or HV stress point. A large potential can build up and cause a burn on the plastic, which causes carbon tracking and eventually a large spreading conductive burn. That's worst case, but should still be avoided.
For the top try a T type plug or an end cap. Many people use this so they don't need fasteners.
Hi Okay then, i will remove all metals in the former for the better and make remedies to attach what i have to attach! Thank you, my laziness gone! Btw what is a t~type?end cap?sorry for my innocence but Can you provide pictures?
Registered Member #480
Joined: Thu Jul 06 2006, 07:08PM
Location: North America
Posts: 644
eniyuki -
A "baffle" is just a sealed partition (a wall) inside the secondary that provides an insulating barrier between the top end and the bottom end of the secondary so arcs cannot occur inside.
Like this:
Your "sucker-gap" should work well if you remove the sharp edges at the ends of the metal fittings that you are using as electrodes. My question is, how will you attach your primary wiring to these fittings to obtain a good, low-resistance electrical connection?
At this point, I would just add an internal baffle to your secondary, and not make any other changes until you get the coil running. Other changes may not be necessary.
If you have not already done this, you may also want to determine your primary-secondary coupling coefficient (K-factor) using one of the Tesla coil design programs (JAVATC, MAND-K, etc) BEFORE you first run your coil. It's better to start with a lower K-factor, and gradually increase it, than to start with an excessively high coupling factor. If the K-factor is too high, it can cause arcing on the surface of the secondary ("racing arcs") that can seriously damage or even destroy it. Typical K values for medium-sized spark-gap Tesla coil are between 0.1 and 0.18. Coupling can be adjusted by changing the height of the primary coil, relative to the secondary coil (or vice-versa).
Regarding spark gap electrode materials, there won't be any significant difference in performance between 3/8" dia copper tube, and 10mm brass tube. If these are your only choices, i'd use the copper. I think if you keep looking you can find 15mm or 20mm or 25mm copper tubing or copper pipe. It is very commonly used in industrial applications all over the world.
Examples of typical PVC "slip caps" can be seen at: However, seeing as your secondary is essentially completed, I'd just test it as-is, after installing a baffle.
Registered Member #2148
Joined: Tue Jun 02 2009, 02:22AM
Location:
Posts: 62
i see, i used javatc to determine the coupling coefficient of my coil based on what i've measured, its 0.13 to 0.14 but i will do it again with fine measurements.
My big problem now is i dont know how to attach the primary lead to the electrodes. Maybe i will wrap the hexagon shape with fabricated copper and make it really tight then i attach wires to it, What do you think?. and actually it is not really that sharp, about 1.5 mm. thick but maybe i will make it to 3-4mm
Registered Member #30
Joined: Fri Feb 03 2006, 10:52AM
Location: Glasgow, Scotland
Posts: 6706
Last chance to resize those images before I delete them, also please stop double and triple posting (read the forum rules again: 48 hours since last post AND you have new information)
Edit: thanks for removing the oversized pics. hint: if you upload them using the forum's own attachment facility, you can upload any size pics and it will thumbnail them for you. You can only do this when creating a post though, not when you come back to edit it.
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.
My SGTC (design and recommendation)
