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 #14
Joined: Thu Feb 02 2006, 01:04PM
Location: Prato/italy
Posts: 383
I tried the royer way to charge by coilgun banks. I selected 2 60V 4.5mOhms 70A d2pak ultrafets, 2 1n6822 shottky diodes, 1 (x2) MUR4060 15+15A common cathode diode (ultrafast) and a small non-gapped E shaped transformer core with small cross section (i suppose good for 40-50Watts. As charge switching i used a 15A relay driven from the control board.
This relatively small circuit charges a 260J @ 300V bank in 5 seconds drawing 5A from the battery (SLA first time i have blown the fuse). No heating at all just a concern about battery voltage drawn down by the high current requirement of the charger (the same battery powers the halfbridge electronics, I'm worring to not toast my IGBTS by incorrect driving), but this is solved turning off the charger during the firing.
Anyway since the royer cannot be pulse modulated i have been forced to use a relay, that isn't the optimal choice. I have thought an alternative: drawing the both Mosfet gates to ground to turn the circuit off, but a problems arise: i need to introduce histeresys in the control loop to avoid continuous turning on and off the charger (due to the leakages), leading to overheating.
Any better ideas on how to control it? Please share.
Apart from this misadvantage royer charger for coilguns has many vantages: 1) It is higly efficient, saving battery and producing little heating 2) no heating means that smaller heatsinks (or no heatsink at all) is needed 3) Space saving (small transformer, few components, no heatsink) 4) the power can be tuned changing the turns of the input filter inductor to allow the batteries to work in their SOA. 5) Voltages can be chosen arbitrarily taking into account the transformer ratio law.
I have the Eagle circuit board if someone is interested but the layout depends mainly on the transformer pinout so use it carefully
Registered Member #191
Joined: Fri Feb 17 2006, 02:01AM
Location: Esbjerg Denmark
Posts: 720
I don't even use a board for ZVS. This is a full spec ZVS using IRFP250s, UF4007, 12V zeners. only change is the gate resistor. I'm using a pair of 1K 1/4W in parallel for each gate. since im only driving mine at 12 or 24 v they never even get warm.
Registered Member #30
Joined: Fri Feb 03 2006, 10:52AM
Location: Glasgow, Scotland
Posts: 6706
What took you guys so long!
In this thread in the archives I suggested controlling it by using a transistor to cut off the supply to the MOSFET gate pullups. That transistor could be driven by a comparator with hysteresis, looking at the capacitor voltage.
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.
Compact dc-dc converter for charging a coilgun.
