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 #15
Joined: Thu Feb 02 2006, 01:11PM
Location:
Posts: 3068
Thanks!
The front panels were made from an outfit called Front Panel Express. They are a German company and do excellent work. The panels themselves are anodized 3mm aluminum and the lettering is engraved and then painted.
Registered Member #15
Joined: Thu Feb 02 2006, 01:11PM
Location:
Posts: 3068
As Hannibal Smith always said, "I love it when a plan comes together . . . " Anyways, first light was a complete success with almost zero hitches. All the time spent planning, simulating, and designing paid off with a DRSSTC that fired up first time to 30+ inches with a supply rail of only 200 volts driving a half-bridge of IGBTs, of course the initial benchtop prototypes didn't hurt either . . .
Everything worked right off the bat. Current limiting worked, although was initially set for only 200A, and the bar graph peak current meter worked very well.
Only problem was primary to secondary arcing due to overcoupling, so i had to raise the secondary 1.5 inches to eliminate this. When I connected the strike rail to earth ground, i had a disastrous arc over to the secondary destroying it instantly. Damn! Anyways, a simple repair was in order, and the secondary was up and running again.
Increased current limit to 500A peak, and reached output arcs of 34 inches.
40 inches!!!! Current limit was still kicking in at about 75% output, so i increased to about 650A peak current. DC supply voltage now at a full 380V (approx) and output arcs of 40 inches to a grounded strike target. Fantastic! Considering a 12" secondary, thats not too shabby.
Didn't get any photos tonite since i forgot to load my camera, but will get some tomorrow, along with a video or two.
Next order of business is to play with the tuning and look at the primary current to see exactly where i'm operating at. Also, probably bring out the spectrum analyzer if i feel up to it. Biggest problem will be determining the proper coupling and geometry of the strike rail, etc... looks like i'll be cutting that to pieces and re-adjusting quite a bit in the coming weeks.
I'm going to try for 48 inches. Not sure if its achievable with this set-up, but if i'm hitting 40 inches on the first light run without even tuning it, it may be possible . . .
Registered Member #56
Joined: Thu Feb 09 2006, 05:02AM
Location: Southern Califorina, USA
Posts: 2445
wow, I think that 3.3x secondary length is the largest spark length/secondary hieght I have ever seen I can't imagine where you could fit 48" of spark 25"? coil...
Registered Member #15
Joined: Thu Feb 02 2006, 01:11PM
Location:
Posts: 3068
Well, destroyed my secondary again. Nice arc from primary to secondary burnt right through the windings. I'll probably have to move the secondary up another 0.5 inch tomorrow. I did get a single 44 inch strike tonite from toroid to the ceiling, but then the circuit breaker tripped, so i called it quits. Tomorrow, i'll get some video and pics . . .
Registered Member #146
Joined: Sun Feb 12 2006, 04:21AM
Location: Austin Tx
Posts: 1055
Cool, my 11" tall coil did 37" max. My 22" coil did 80", so thats like 3.63X the secondary length. I think Steve Conner still has us beat at 4.something X secondary length. 40" from the 12" coil is still really great.
Maybe you should move to epoxy coating of the secondary winding? Its actually considerably easier than many layers of varnish, and seems to stand up to a lot of flash-over abuse. The arcs just spread out across the epoxy surface, rather than breaking a pin sized hole in the insulation and then causing burning and carbonization.
Also, from my experience, you can often get away with the strike rail sitting at the same height as the last primary turn (so long as the arcs are coming from the toroid). Its too bad that you already have 3 of them built up so nicely and now you need to modify the design.
Registered Member #30
Joined: Fri Feb 03 2006, 10:52AM
Location: Glasgow, Scotland
Posts: 6706
60" from a 14" tall coil is my personal best. It took over 3kW of power to do it though.
I used a similar geometry of strike rail and solenoid primary, and had very similar problems. I got serious flashovers from primary to secondary that eventually burnt clean through the secondary windings and stopped the coil working. I took a few turns off the top of the primary, and raised the secondary as far as I could. I guess I should rebuild the primary as a cone, but I couldn't be bothered, and it works fine now.
I found I could fix my frazzled secondary coil by soldering the wire carefully back together and wrapping the whole coil in electrical tape. This seemed to have much the same effect as Steve said epoxy coating does: the sparks stay dim and crawl over the tape, instead of forming bright arcs and burning things.
Why did you put a power switch on the front? I always like to be well out of the range of sparks and "flying silicon bits" when I throw the switch.
Registered Member #89
Joined: Thu Feb 09 2006, 02:40PM
Location: Zadar, Croatia
Posts: 3145
Then my 18 inch secondary needs to do 2 meter arc to be just competing with you. d00d.
I used a similar geometry of strike rail and solenoid primary, and had very similar problems. I got serious flashovers from primary to secondary that eventually burnt clean through the secondary windings and stopped the coil working. I took a few turns off the top of the primary, and raised the secondary as far as I could. I guess I should rebuild the primary as a cone, but I couldn't be bothered, and it works fine now.
Yep, coupling seems pretty high to me, too. I figured out that steve ward's DR1 has base of secondary beggining just about the top of (helical) primary.
I also use very similar coupling as EVR, it may be too high, I don't know.
Why did you put a power switch on the front? I always like to be well out of the range of sparks and "flying silicon bits" when I throw the switch.
Isn't the remote-interrupter switch enough?
Maybe he could sell the pwer supply cable with small box and 'kill switch' on the end
Registered Member #15
Joined: Thu Feb 02 2006, 01:11PM
Location:
Posts: 3068
wrote ...
Maybe you should move to epoxy coating of the secondary winding? Its actually considerably easier than many layers of varnish, and seems to stand up to a lot of flash-over abuse. The arcs just spread out across the epoxy surface, rather than breaking a pin sized hole in the insulation and then causing burning and carbonization.
Also, from my experience, you can often get away with the strike rail sitting at the same height as the last primary turn (so long as the arcs are coming from the toroid). Its too bad that you already have 3 of them built up so nicely and now you need to modify the design.
Thanks, good tip. I have been exploring different types of secondary coatings - these were done with acrylic coating, but i'm not happy with the results.
What type of epoxy have you had success with?
Will also have to move primary strike rail down, tonite i'll play with the distance. No biggy on modifying these. These are prototypes, so all this rework was anticipated. I'm sure when i'm done testing, these things will be beat to hell with duct tape holding pieces together, etc... But, then again, thats the whole fun of it!!!
wrote ...
. . . . power switch on front . . .
The power switch on the front only turns on the control logic and cooling fan. Also, these are prototypes, so the only person going to operate them are myself.
For the final units, i plan on using a twinax cable (two conductor) and have a modulator input to the system and also a DC bus enable signal which will power the relays turning on the dc bus from the external modulator. That is one plan right now.
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.
DRSSTC III System - Final Prototypes and FIRST LIGHT!!!
It took over 3kW of power to do it though.
