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 #989
Joined: Sat Sept 08 2007, 02:15AM
Location: São Paulo, Brazil
Posts: 476
Hi all,
I was made my first sucess on SSTC, I get 15cm sparks with 400W~ power input :D
Now I wanna now how to increase the Power of my SSTC before going to the fullbridge version.
I am using two IRFP250 running at Half-Wave Retified 127VAC, the two caps of the Bridge are 680nF 250V~ Siemens capacitors and two MUR860 Diodes in parallel with the D-S of mosfets. The power supply have a variac on it, so I can control if I get something wrong on the way.
My GDT part have two 5R resistors on the Gate of Mosfet, I didnt put the zeners because I think it was unescessary (My GDT is 1:1:1). On the driver side I have two TC4429 (inverted) with 330nF Polypropilene cap bank ( I tryed with 1uF Polypropilene cap bank, and my mosfets died :( )
I am using no Interrupter. My secondary is 30cm of 30AWG wound in 4' tube. My topload have 6pF (Sphere).
Registered Member #56
Joined: Thu Feb 09 2006, 05:02AM
Location: Southern Califorina, USA
Posts: 2445
Since you are pretty much maxed out voltage wise with your mosfets, you best bet would be to increase the current. The preferable way to do this is by increasing coupling, which can be done by winding the primary closer to the secondary, and spacing out the turns a little. I think that the best coupling could be had by winding the turns directly on the secondary spaced out to cover the lower 1/3 of the secondary, but of course it would be impossible to insulate.
After you have increased coupling as much as you can before it starts to ark over, the next step would be to start reducing the turn count--the less turns that more output you will get. Of course, at some point your transistor will explode, which means you have too few turns, so you probably want to add a few more.
After that the only way to go is with a bigger transistor, the rif460 is a pretty common choice...
Registered Member #229
Joined: Tue Feb 21 2006, 07:33PM
Location: Romania
Posts: 506
I remember that Steve Wards maximized the output of his SSTCs just using a seried capacitor with the primary, around 0.5 x Cres, so a DRSSTC-like setup. The curent in the primary will increase by canceling more primary inductance. An increased coupling will help too. Use heavy insulated stranded wire like THIS wound directly on the secondary. Increase slowly the input with a variac and observe possible corona in a dark room. In this way you will know the height of the primary coil.
Registered Member #989
Joined: Sat Sept 08 2007, 02:15AM
Location: São Paulo, Brazil
Posts: 476
My primary is exact over the secondary, when I turned on the first time, I see a glow between primary and secondary, but it stops when I put the low side of the Secondary to the Ground.
Registered Member #1025
Joined: Sun Sept 23 2007, 07:53PM
Location: Czech Rep.
Posts: 566
I think it is always worth to leave an air gap between your primary and secondary and rather play with the hight and number of turns. The fact you see the glow is not good. My experience is that the tight winding of primary straight on the secondary (despite the presence of insulation) is decreasing the output. Air has much higher resistance than any plastic material you can get... If you check all the high power SSTC or DRSSTC projects on the web you will see they always keep an air gap between the windings so it must have a reason.
(This is also a message for Ken M, maybe you are right but only for the low power coils...)
I wish you good luck and not too many death transitors in your high power tunning...Don't forget to send us some pictures
BTW: I also noticed that your primary is made of very tiny wire, you should get real piece of copper for primary of a high power coil...
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.
Increasing SSTC power
