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 #1938
Joined: Sun Jan 25 2009, 12:44PM
Location: Romania
Posts: 701
My first SSTC is a high frequency solid state tesla coil. Complete construction details here: my blog In only uses one mosfet (IRFP 460) and runs on 50V to 100V input voltage.
Registered Member #1938
Joined: Sun Jan 25 2009, 12:44PM
Location: Romania
Posts: 701
Thank you all for the appreciation.
@raff, the IRFP460 produced better results then the IRFP260, but it is true that the coil was already tuned for the IRFP460 when I tested the 260 (without re-tweaking it for the new mosfet). However with the IRFP 260 I had no sparks, not even when touching the breakpoint with the screwdriver.
@Mads, I suspect it is ~4.6MHz, but I currently do not have the tools to measure it correctly.
Registered Member #1025
Joined: Sun Sept 23 2007, 07:53PM
Location: Czech Rep.
Posts: 566
Hi, Cool - I like the simplicity.
I have few comments. How you can be sure your FET is turned on fully? I mean, this concept is originally developed for bipolar transitors. And same question from the other side - How you can be sure, that your gate is not exposed to overvoltage. I suggest as solution to use some transils or zeners to clamp the voltage at 15V. Than you could add few more turns until the diodes get hot (but not too much). Than you can be sure your FET gets what she needs. It’s just a suggestion but might be improvement for your concept.
Registered Member #152
Joined: Sun Feb 12 2006, 03:36PM
Location: Czech Rep.
Posts: 3384
I have been thinking about this concept too, your design could probably be improved by putting a diode in series with the drain (to not distort the sine wave) and using a gate self-biasing circuit (so the FET conducts only a fraction of the cycle like in a VTTC). Of course the gate voltage should be always clamped by two 20V "back to back" zeners.
Registered Member #1938
Joined: Sun Jan 25 2009, 12:44PM
Location: Romania
Posts: 701
Mates, Dr. Kilovolt, thanks for the good suggestions.
Indeed, most probably, the gate is driven in overvolted mode and this might just be what it needs to fully open the mosfet but... will kill it eventually.
I was thinking of adding a zenner myself, so I'll check this and report back. I would like to know more on the purpose of "Than you could add few more turns until the diodes get hot (but not too much). " To obtain resonance, I've moved the primary+feedback coils closer or further over the secondary coil (embedded inside the visible tube).. Regarding the Mosfet.... SHE? never knew that
Dr.Kilovolt, I would need more details for the self-biasing gate circuit .
To power this coil, I'm using a 24V/10A max power source. The alternating current goes through a voltage tripler (3x3300uF caps), so I get aprox. 100V when no load is connected. The problem is that there are some high voltage spikes going back to my power source. What protection should work best?
vasil also suggested connecting small caps between he wires comming from the coil and the ground.
currently the driver circuit is not shielded, should this be of any concern? The RF field is quite strong in the close proximity of the operating 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.
High Frequency Solid State Tesla Coil
never knew that 