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 #1025
Joined: Sun Sept 23 2007, 07:53PM
Location: Czech Rep.
Posts: 566
Do you know somebody what defines the shape of the spark from the SSTC coil. When I compare the shapes from VTTC or my own sparks from single transistor vs. half-bridge design , they look pretty different in their shapes and ankle of radiation. Is it the straight line spark a sign of a better resonance than a wavy one?
Registered Member #152
Joined: Sun Feb 12 2006, 03:36PM
Location: Czech Rep.
Posts: 3384
The straight and "wavy" streamers that do not branch much usually occur when the RF envelope is halfwave rectified mains frequency. Branched sparks occur when the RF envelope has sharp "jumps" in it (e.g. interrupter or SG coil). That's how I see it
Banned on 3/17/2009. Registered Member #487
Joined: Sun Jul 09 2006, 01:22AM
Location:
Posts: 617
This question comes up all the time. I agree with Jmartis. I always use bridge rectified mains and I usually get branchy sparks.
I had one coil that got super straight sparks and it used 2 diode full wave rectified mains with very small capacitance. I also suspect there might be a few other things that effect it. Like how much your cap voltage dips each time the coil fires.
Registered Member #56
Joined: Thu Feb 09 2006, 05:02AM
Location: Southern Califorina, USA
Posts: 2445
It has to do with the operating frequiency of the coil (higher frequiencies give moe static, 'flame' looking arcs), the shape of the topload (if there is a nice uniform e-field the sparks are more static), and the modulation in the output power (the more stable the coil is the more static the spark is).
The shape of the spark is usually not an indicator of 'better resonance', but if the driver has some instabilities (like a pll driver that isn't tracking properly) it can give the sparks a more dynamic/brnched appearance. Of course, better tuning = longer sparks.
Banned on 3/17/2009. Registered Member #487
Joined: Sun Jul 09 2006, 01:22AM
Location:
Posts: 617
Yeah that too. My straight spark coil ran at 700KHz. If I decreased the on time the sparks branched more. I had them looking like leafs at one point. Really cool looking. I'll post a video.
I don't thick VTTC's dip the power supply as much. Lower current. Remember on Richies site he got all the different spark shapes by messing with the power supply. Of course the frequency does effect it more.
Although a lower frequency means the switches have to sustain a certain power level longer per cycle, not overall of course. Dips the FET driver power supply more and does the same thing to the FET power supply. Hmm. I think. Or am I over doing 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.
Question about the sparks shapes
