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 #3964
Joined: Thu Jun 23 2011, 03:23AM
Location: Valenzuela City
Posts: 332
Hi Guangyan,
Just wanted to share, if it will be of any help to others, that your conclusion for spark length somewhat relates to my experiments as well...
1. i.e. 1 cm is roughly 1 Amp so 130cm is 130 Amp
2. Spark length below reaches about 50 inch (4x6" sec coil, with toroid 13.35") with about 125-130 Amps in the Primary. Sec Fres around 360khz (uncoupled) 325 (coupled k=0.4 to Primary) Primary resonates 400 khz (Upper) and drops around 369 khz at the peak of the ramp. (hmmm... Pri fres is low I think?)
3. Found out that the key for very low Pri current is to keep very high Coupling factor. From JAVATC, my QC is set (0.4), ARCING is really a problem here! I put a lot rubbers around the secondary coil haha! :D it looks nasty but it's okay as long as the insulation does its job.
4. Keep Zurge impedance high, mine hits 41.3 ohms.. i.e. 20uH and a 11.75nf pri cap (uncoupled freq is 310khz)
5. Increase Bus Voltage, Instead of Ramp length.. (my current Ramp set up is @ 8ms/with 4ms down)
I think I can even increase the spark length by just increasing the bus voltage. Now, the V peak is at 328volts. My max Voltage is 450v (18mf/450v DC cap) I am using a boost converter to charge this cap to 430v. With the loading, Peak V can be adjusted and reach up to 420 volts. (90v higher than the previous). Problem here is that I am only using a single full-bridge of FGA60N65SMD (Rjc of 0.25 / 650vdc) I think its max duty for QCW operation can be at 220 Amps (IRGP50B60PD1 Rjc of 0.32/600v is at 200 Amps) but I don't want to test this limit :) instead, I'll be using parallel bridge. And probably add another 10mf/450v DC caps so to help with regulation. Will post the result after I change the bridge.
Question: after doing parallel bridge, do I still need to undergo phase lead tuning? arggg! consumes my time a lot! :(
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.
Small QCW
