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 #2591
Joined: Fri Jan 01 2010, 11:58AM
Location: netherlands
Posts: 76
Dr. Kilovolt wrote ...
The cap and the primary winding form a parallel resonant circuit and the driver starts to operate in "pseudo class E" mode, not exact Class E switching, but it improves performance greatly and decreases transistor heating (mainly because it has more time to turn off - Toff switching losses are minimised).
is this paralel resonance? the primary and cap are in serie.
I think it is serie resonance or do I understand something wrong?
Registered Member #152
Joined: Sun Feb 12 2006, 03:36PM
Location: Czech Rep.
Posts: 3384
yes its the same, just I'd rather put the cap across the transistor because of wiring inductances which might result in some ringing (but probably of no significance).
Registered Member #152
Joined: Sun Feb 12 2006, 03:36PM
Location: Czech Rep.
Posts: 3384
tritium wrote ...
@dr kilovolt, how did you calculate the resistor values
The bottom resistor sets the turn-off current (via the transistor's Hfe) and in turn output power. The upper resistor just needs to provide above 0.7V on the divider output, so the transistor doesn't stay turned off.
Ps. This circuit is a little outdated, now I would maybe do it a bit different, but have no time for testing the circuits right now.
Registered Member #1408
Joined: Fri Mar 21 2008, 03:49PM
Location: Oracle, AZ
Posts: 679
I've tweaked this circuit many times and that's what I've come to understand (the bottom resistor is turn-off current) However even 5w is a touch light in certain circumstances: do not go to anything lower than 5w; in fact it appears to preform w/ less stress on a TO-220 package if yo raise that to 10w. Using a MJ13009 x-sistor I got some fair performance with anything from a 18-24ohm.
I happen to like it because it's so "flexible". I beefed up all components and it handled quite a bit of power. I have compared differing caps and gotten great results with higher (than 4700uf) capacitance (& voltage). It's a far cry from a ZVS but for it's potential size; it's a lot of fun.
I HAVE tried putting a cap across the x-sister & I like it better. The fact that you can make it SO small that the only real room is taken by the heat-sink makes it fun to put in a small box w/ the flyback.
Registered Member #3943
Joined: Sun Jun 12 2011, 05:24PM
Location: The Shire, UK
Posts: 552
I am going to give this a try but have one question, is the 4700uF cap across the power supply essential as I am using a 12 7AH lead acid battery for my supply (which works fine for the regular 2n3055 version, giving 1 1/2 inch arcs from one of my flybacks!). Or is it only needed when using a power supply where ripple current might be an issue?
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.