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 #2922
Joined: Sun Jun 13 2010, 12:08AM
Location:
Posts: 226
Ward, are you using the same ground of secondary or a separated ground? Here I made the same and I'm using separated grounds like you told me in a email. I'm using EMI filter in the driver before de rectifier with the Y caps to the same ground.
Registered Member #146
Joined: Sun Feb 12 2006, 04:21AM
Location: Austin Tx
Posts: 1055
Ward, are you using the same ground of secondary or a separated ground? Here I made the same and I'm using separated grounds like you told me in a email. I'm using EMI filter in the driver before de rectifier with the Y caps to the same ground.
I do hook up mains ground to my tesla coil base along the secondary ground and my EMI filtering ground. I fear that if i do not tie mains ground to RF ground, there could be a very high RF voltage there when the tesla coil arcs to RF ground, dumping large charges back and forth at high frequency. Since my power cable is shielded for strike protection, its shield gets tied to the RF ground too. Its very likely that my power cables are a source of radiated EMI, id like to see if i can reduce that with big ferrite beads on the cable.
I also use a couple of EMI filters. There is one on my DC bus as i mentioned, i think this is mainly for protection of the power circuit from high voltage transients during strikes, but probably cant control the EMI going out over my power cable. I use a DC power supply that is remote from the tesla coil, so the DC has an EMI filter at both the tesla coil, and the power supply output. I use another EMI filter on our 3 phase AC power feed, which also has some filtering of the ground wire, to hopefully stop sending common mode noise down the AC power, which would make the whole building's power potentially noisy with common mode RF.
As a side story, Ive had one of my DC PFC power supplies literally explode because of RF ground noise not being coupled with the power electronics bus. The voltage was enough to break down the isolation between the heatsink (at wild RF ground potentials) and mains voltage (which was not coupled in any way, as an EMI filter would have provided with Y-caps from line to ground). So the IGBT insulation failed causing the input rectifiers to explode and catch fire, with 3 phase 100A available to feed the arc. After adding my DC bus "EMI" filters, this problem is no more, because if the RF ground bounces, the power electronics bus will have to bounce too, so its all common mode and doesnt matter hopefully.
Registered Member #1875
Joined: Sun Dec 21 2008, 06:36PM
Location:
Posts: 635
Steve Ward wrote ...
As a side story, Ive had one of my DC PFC power supplies literally explode because of RF ground noise not being coupled with the power electronics bus. The voltage was enough to break down the isolation between the heatsink (at wild RF ground potentials) and mains voltage (which was not coupled in any way, as an EMI filter would have provided with Y-caps from line to ground). So the IGBT insulation failed causing the input rectifiers to explode and catch fire, with 3 phase 100A available to feed the arc. After adding my DC bus "EMI" filters, this problem is no more, because if the RF ground bounces, the power electronics bus will have to bounce too, so its all common mode and doesnt matter hopefully.
I hope you have something equally spectacular planned for the next NY Maker Faire!
Registered Member #2922
Joined: Sun Jun 13 2010, 12:08AM
Location:
Posts: 226
I have one EMI filter at my tesla coil DC input that is grounded with a separated gorund. The secondary have a rf ground and the filter another. I have anoter EMI filter at the driver AC input to the same filter ground. I'm using one remote DC supply too, I will put one filter at its output. I will try to use the same ground for all the filters and the secondary but I'm afraid that with the same ground the EMI filter will no help to prevent igbt destruction over primary strike condition. Or it's will help even more than now?
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.
drsstc primary strike protection
