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 #3926
Joined: Fri Jun 03 2011, 08:32PM
Location: UK.
Posts: 525
If my coilgun uses an SCR, will I need a protective diode (Only ones I got is RU4Z,Y, can I put them in series? for more voltage) to obviously protect the circuit and all that?
SCR = BTW30-1000
Also I'm using rectified mains to charge it, 320v, yet caps are 420v 1510uF, will the coilgun be powerful.
My coil is a bunch of thick wire on a plastic spool taken from a Ferrite core of a 12v 32A PSU, it does not have many turns, does this matter?
Thanks. When I get the info I need I'm going to build it inside a shoebox ^^
I also have another coil, it has a bucket load of turns I used all of the windings off a CRT deflection coil, not very think wire, but who care.
Registered Member #3943
Joined: Sun Jun 12 2011, 05:24PM
Location: The Shire, UK
Posts: 552
Platinum wrote ...
Just tested one of my coils without SCR, and it is terrible, the coil acts as a inductive resistor. ¬¬
If you are in the UK, which I see you are then get to maplins and ask for a spool of 24 SWG magnet wire. I did not take any wire off of the spool but just inserted a PVC pipe into the middle of the spool and I then discharged my capacitor bank into the two ends of the spool. It has quite a bit of force behind it!
Registered Member #1525
Joined: Mon Jun 09 2008, 12:16AM
Location: America
Posts: 294
Platinum wrote ...
If my coilgun uses an SCR, will I need a protective diode (Only ones I got is RU4Z,Y, can I put them in series? for more voltage) to obviously protect the circuit and all that?
If your coil is underdamped, you will need a protective diode (also known as a commutation diode). In order to determine if your coilgun is underdamped, enter your coil properties here and simulate your circuit here. If the capacitor voltage ever becomes negative, your coil is underdamped.
wrote ...
SCR = BTW30-1000
This data sheet contains all of the information for your SCR, and was found with Google.
wrote ...
Also I'm using rectified mains to charge it, 320v, yet caps are 420v 1510uF, will the coilgun be powerful.
The formula for energy (in Joules) stored in the capacitors is E = 0.5*C*V^2, where C = Capacitance and V = Voltage. Calculate that and compare to other coilguns with similar energy to find out what results you can expect.
wrote ...
My coil is a bunch of thick wire on a plastic spool taken from a Ferrite core of a 12v 32A PSU, it does not have many turns, does this matter?
Magnetic force is proportional to coil turns and coil current, so you will need a significant number of turns. I made a simple guide to designing a coil here.
Registered Member #4237
Joined: Tue Nov 29 2011, 02:49PM
Location:
Posts: 117
That could be because you surpassed the maximum surge current of your SCR. It was fairly low (210A), and since you told us your coil did not have many turns, I suspect the current shot through the roof. You'll need more turns, giving the coil higher inductance and resistance. This will slow down the discharge, producing less current. It will also give a nice, long and steady magnetic field, that'll give you higher efficiency than a short high-powered pulse.
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.
Coilgun question.
