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 #3623
Joined: Sun Jan 16 2011, 10:13PM
Location: Utah, USA
Posts: 11
Ok, I've got another question regarding choice of capacitors. I've seen many internet sites dealing with railguns. I've seen most of these people building up large cap banks to run them. Most seem to have 2-4 kilojoules or so of power. I've noticed they all have very large and bulky cap banks with 12-30 capacitors. In looking around ebay I noticed there are 400v 10mf caps out there http://cgi.ebay.com/1pc-UCC-400V-10000uF-Computer-Grade-Capacitor-NEW-/200406082928?pt=LH_DefaultDomain_0&hash=item2ea9222570
I've not seen anyone using large ones like these for railguns. and I'm curious if there is something I am missing. It seems 4 or 5 of these, at 800 joules each would make for a smaller and more convienient cap bank, yet I've not seen anyone using such. Just wondering what I am missing in my understanding. digikey lists the CDE ones at only 17mOhm on the ESR. so I'm guessing it's not ESR ratings.
Just trying to piece together a thorough understanding of these things, and it doesn't add up to me that the choice on caps seems to be larger sized banks if these were a viable option. Anyone thanks in advance for any information.
Eventually I am planning on building both a coilgun and a railgun, so learning everything I can first to do things the right way the first time.
Registered Member #1451
Joined: Wed Apr 23 2008, 03:48AM
Location: Boulder, Co
Posts: 661
I think a big thing is that often you can find great deals on eBay on groups of the smaller caps. Like getting 10 of them for 20 bucks. I think that's the main driving force.
Of course, the bigger the cap the more heat built up inside when firing multiple times close together.
Registered Member #3623
Joined: Sun Jan 16 2011, 10:13PM
Location: Utah, USA
Posts: 11
Useful to know, so if not used for quick repeat firing fewer large caps would work fine. Thinking of trying a railgun after I make a coilgun. The large sized caps like those ones seem like they would work well for making a smaller capacitor bank. Ultimately if I do eventually make a railgun, I'd be wanting to make one as compact as possible. I've no delusions of making some handheld version or anything like that. I'm thinking portability in the back of a car, taken out on the 4th of july and fire a couple plasma shots. smaller sized capacitor bank would definitely work better for that I think then a larger bulky one.
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.
Capacitor choice questions
