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 #1403
Joined: Tue Mar 18 2008, 06:05PM
Location: Denmark, Odense C
Posts: 1968
I made a spring loaded switch that charges the capacitor when pulled backwards and when you let it go it disconnects from the charger and shorts the capacitor through the larger wires connected to the load.
This way I do not have to worry about damaging the charger circuit from reverse voltage spikes.
Registered Member #2566
Joined: Wed Dec 23 2009, 05:52PM
Location:
Posts: 147
29 kA is a lightning like current. Ok, this is only 1.8 kV but still >1 kV and counts as high voltage. Nice measuring system as well. Last time I checked hf current probes, they were expensive like hell
Registered Member #1403
Joined: Tue Mar 18 2008, 06:05PM
Location: Denmark, Odense C
Posts: 1968
dex wrote ...
29 kA is a lightning like current. Ok, this is only 1.8 kV but still >1 kV and counts as high voltage. Nice measuring system as well. Last time I checked hf current probes, they were expensive like hell
Once in a while you can find a cheap Pearson current monitor on ebay, by cheap I mean around 100-200 USD for a 5kA and up to 100kA models. Connected through a 1:10 probe its easy to measure to the monitors maximum current on a regular 300V max input oscilloscope.
Registered Member #54278
Joined: Sat Jan 17 2015, 04:42AM
Location: Amite, La.
Posts: 367
CHARGING LARGE CAPACITOR BANKS: I have several homemade high voltage capacitor chargers. One in particular is made from a neon sign transformer (NST). I charge the very large heavy Maxwell type caps for explosive discharges. I got tired of having to disconnect the charger before discharging the caps (...somewhat dangerous too). One thing I did, recently, was connect the charger directly to the caps through the extremely high inductance of secondarys of automotive ignition coils. I have two ignition coils on the charger--one on each line going to the cap bank (one will do). The wire in these automotive coils is EXTREMELY thin (less than 40AWG??). Well, it charges fine--in fact, the coils don't noticeably affect the charging rate, and so far the monstrous discharges have not harmed the charging circuit--which includes a sensitive voltmeter.
MEASURING LARGE DISCHARGE CURRENTS: In the 80's I started using thin short lengths of steel as current shunts for measuring 10's of amps. Then, I was asked to look into an electrical problem at a large steel plant. I needed to measure large current spikes on three phase lines. The simple sensors I ended up using were 1/4 inch steel bolts (all thread eventually). They could handle 100's of amps and, obviously, simple to adjust. If I recall correctly, it required just a few inches to make a 0.001 ohm (1 milliohm) resistor. This gave *1* volt across per *1000* amps through. I now use an 800 amp brass current shunt (cheap from ebay) to tune laser flashlamp inductors to critical damping by capturing the current waveform (as well as calibrated amplitude) on a storage scope. BTW, I see no reason that larger all-thread wouldn't be good for 10's of thousand amps.
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.
4kj capacitor bank
