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 #1656
Joined: Wed Aug 27 2008, 03:28PM
Location: Pittsburgh PA
Posts: 53
Hi every one.
I have heard/read that you can use 2 zener diode in antiseries to protect the MOSFET's from being damaged. The project is a Flyback driver (that will eventually be audio modulated). From what i hear it would be between the source and gate. The MOSFET's im using are IRFP450's. I have blown up close to 5 of them so far and i want to protect the remaining ones i have. If any one could shed some light on this subject i would very thankful. I'm still getting used this driver. ( this is the driver ))
Registered Member #2893
Joined: Tue Jun 01 2010, 09:25PM
Location: Cali-forn. i. a.
Posts: 2242
Yes they go between the source and the gate.
I wouldn't go for that driver though. I've built it before, and not only does it love to explode mosfets the audio modulation sucks. It's very distorted.
If you want to make an audio modulated driver the sg3525 is the way to go. I've had no problems with it and by adjusting the frequency you can get anywhere from 50kv to 10kv out of a flyback. (lower frequency = more volts less amps).
Registered Member #3490
Joined: Wed Dec 08 2010, 11:55PM
Location: The Granite State
Posts: 34
I built the driver you posted too and had nothing but problems until I switched to the IRFP250Ns.I originally tried using IRF640s and had horrible results soundwise and longevity wise.With the 250Ns I now get decent sound but the arc is nothing to write home about.No problems with overheating or failures but I should point out I'm only powering the thing with a modified 12 volt battery charger.Havent got around to pushing my luck yet with higher voltages.I'd say try it out with the 250N and throw in that zener arrangement you spoke of.I'm saying this because it sounds as though you've already built everything.Grenadiers circuit looks like a nice alternative and theres a schematic around here by Jan Martis that I've seen several examples of that seem to work really well too.Either way keep us posted!
Registered Member #1656
Joined: Wed Aug 27 2008, 03:28PM
Location: Pittsburgh PA
Posts: 53
Grenadier wrote ...
Yes they go between the source and the gate.
I wouldn't go for that driver though. I've built it before, and not only does it love to explode mosfets the audio modulation sucks. It's very distorted.
If you want to make an audio modulated driver the sg3525 is the way to go. I've had no problems with it and by adjusting the frequency you can get anywhere from 50kv to 10kv out of a flyback. (lower frequency = more volts less amps).
I just found that one today, though no local place has the IC i need so i have to order it online. But yeah, thats the next step in my building. Thanks ^_^
Registered Member #2628
Joined: Fri Jan 15 2010, 12:23AM
Location:
Posts: 627
Also, if you can, use a bipolar TVS diode with the respective clamping voltage of the gate's maximum ratings. (G-S)
TVS will stop those fast transients that zeners could miss. Also, Ive spared myself quite a bit of IGBTs and mosfets by putting a TVS diode from S-D (or E-C) at slightly under the rating of the device. protects nicely from overvoltage transient events. TVS come in pretty high voltage ratings, so they are far more versatile for this purpose then zeners IMO.
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.
Zener diode based MOSFET protection
