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.
I am working on the construction of a high current capacitor charging curcit and was wondering if an IGBT or mosfet would be better for a theoretical waveform like the one attached, the switching voltage rises from 12V up to 44 volts max when charging a cap to 600V, but the current spikes in the beginning at 110A there for I thought an IGBT would be better, also because of the pulse style operation of the DC-DC convector. but because of its lower voltage operation, I was thinking mosfets would be better, although a super high current mosfet here would be overkill, I think I can find a 100A 70V mosfet, but I like to have more lee way.
do you think a 110A 60V mosfet would be sufficient?
or should I look for a method of soft start? how difficult would this be to start the switching at a higher frequency and as the voltage increases the frequency decreases allowing for less current to be drawn in the beginning. What do you think,
Thanks for the help in advanced.
Danielle
for a printable PCB ready for toner transfer click here: (warning: 3.2MB) PCB.pdf (3.2 MB)
A mosfet with not such a big current capacity would just give not so much current in the beginning of the charging cycle, right? That might as well work as your current limiter or soft-starter :) The cap will drive big currents out of the power device in the beginning, but I dont think this will burst it into flames in just under 0.5millisec...
Registered Member #1497
Joined: Thu May 22 2008, 05:24AM
Location: Toronto, Ontario, Canada
Posts: 801
A 60V mosfet might simply blow when subjected to starting charge, current isn't the largest deal since the most current it will encounter will be based on the inductor trying to avalanche through your MOSFET, whereas voltage won't spike so easily (at least in my recent experience of building a boost converter).
Another problem I'm spotting is that your MOSFET drain and source are too close. What voltage are you planning to charge this up to? Can you post a schematic?
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.
Quick question about a Capacitor Charger
