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 #39190
Joined: Sat Oct 26 2013, 09:15AM
Location: Boise National Forest
Posts: 65
TwirlyWhirly555 wrote ...
Most of the time I never used Zeners at all , just used a 12V gate supply , 50V flyback supply .
But it's still a ZVS driver? I very much like the idea of a separate supply for the gates and the flyback transformer. Could you point me to a schematic or description that illustrates what you're doing?
Registered Member #3395
Joined: Thu Nov 04 2010, 08:42AM
Location: Christchurch, New Zealand
Posts: 193
Heisenberg wrote ...
Finally figured out the problem! I removed the 18v zeners and replaced them with 12v zeners and replaced the 150uH inductor with a 55uH inductor and it works! Since I did a couple of things at the same time, I'm not sure which one resolved the issue. Could have been a bad zener, the inductor could have been too big, or maybe the 12v vs 18v zener did it, or maybe a combination of a few different factors.
I'm glad I finally conquered this demon. I'll still play around with different amounts of capacitors and different inductors to find the best results, but at least I have a working ZVS driver at last.
Thanks to all who posted for your help and nudging me in the right direction.
Heisenberg - congratulations and well done on successfully troubleshooting and finding the problem! It's a wonderful feeling to get it working, isn't it? I was sure it would be the zeners, most of my ZVS failures have been attributed to faulty zener diodes, easily overlooked as a relatively trivial component but determines the function almost totally.
From personal experience, from now on I would advise you to put your driver in an enclosure and construct it such that it's easy to replace the inductors, capacitors or the FETs without damaging or putting physical stress on the rest of the circuit. I often experimented by changing the inductors and capacitors and even tried different flybacks too, and it would have been much less stressful if I had taken the time to put it in an enclosure, I wouldn't have had to worry so much about handling it with care and being aware of its fragility.
With the IRFP260s, don't push them over 50V, but other than that have fun and enjoy some safe arcing! See how big you can get the arcs to become :)
Registered Member #3395
Joined: Thu Nov 04 2010, 08:42AM
Location: Christchurch, New Zealand
Posts: 193
woodchuck wrote ...
TwirlyWhirly555 wrote ...
Most of the time I never used Zeners at all , just used a 12V gate supply , 50V flyback supply .
But it's still a ZVS driver? I very much like the idea of a separate supply for the gates and the flyback transformer. Could you point me to a schematic or description that illustrates what you're doing?
Where the positive rail comes in at the top, separate the connection going to the top 470 ohm resistor from the top positive rail. Now, the 12V supply for the gate drive connects to the 470 ohm resistor, and the top positive rail that goes to the inductor is the higher voltage, higher current power supply that powers the flyback.
Registered Member #39190
Joined: Sat Oct 26 2013, 09:15AM
Location: Boise National Forest
Posts: 65
Thank you for this, Kiwihvguy. My first concern upon reading your answer was that providing gate power without flyback power would burn up the MOSFETS. But that's silly. :) Presumably, by the time there is enough voltage on the primary to heat up the MOSFETs, there would be enough voltage on the primary to start oscillation. ;)
Registered Member #58279
Joined: Sat Jan 09 2016, 05:39AM
Location: Houston, TX
Posts: 13
Kiwihvguy wrote ...
Heisenberg wrote ...
Finally figured out the problem! I removed the 18v zeners and replaced them with 12v zeners and replaced the 150uH inductor with a 55uH inductor and it works! Since I did a couple of things at the same time, I'm not sure which one resolved the issue. Could have been a bad zener, the inductor could have been too big, or maybe the 12v vs 18v zener did it, or maybe a combination of a few different factors.
I'm glad I finally conquered this demon. I'll still play around with different amounts of capacitors and different inductors to find the best results, but at least I have a working ZVS driver at last.
Thanks to all who posted for your help and nudging me in the right direction.
Heisenberg - congratulations and well done on successfully troubleshooting and finding the problem! It's a wonderful feeling to get it working, isn't it? I was sure it would be the zeners, most of my ZVS failures have been attributed to faulty zener diodes, easily overlooked as a relatively trivial component but determines the function almost totally.
From personal experience, from now on I would advise you to put your driver in an enclosure and construct it such that it's easy to replace the inductors, capacitors or the FETs without damaging or putting physical stress on the rest of the circuit. I often experimented by changing the inductors and capacitors and even tried different flybacks too, and it would have been much less stressful if I had taken the time to put it in an enclosure, I wouldn't have had to worry so much about handling it with care and being aware of its fragility.
With the IRFP260s, don't push them over 50V, but other than that have fun and enjoy some safe arcing! See how big you can get the arcs to become :)
Thanks! I just got a shipment of new components from Mouser, a bunch of clip-on FET heatsinks, heat transfer pads, some 2.2uF WIMA MKP caps, and some IRFP460s. I wanted to play around with more capacitors by adding additional caps to my tank. One question though, what does one gain by adding more capacitors? I've seen videos of people running ZVS drivers running an induction coil with over 30 caps easy. I ask because I'm using the driver for more than just creating cool arcs, I'm also planning on using it to drive an induction heater to melt aluminum in a graphite crucible.
I wanted to make a smaller version first before I buy one of the big ones from China that includes the pre-formed coils. I am going to hook it up to a water pump and CPU radiator to keep the coils from burning up.
I tried doing induction heating with another driver I had, but the coil got so hot that it started melting the plastic screw terminals that the coil was connected to...but it was working...it turned a pretty thick nail red hot in about 5-10 seconds, but I couldn't run it long enough because of the heat transfer.
Any tips on how to prevent the heat from traveling up the copper coil wire to the PCB? I have a few pretty meaty heatsink/fan combos with peltier that bring the temps down to a frosty -10 degrees. I was thinking about somehow mounting the copper wires between the coil and the PCB to one of those peltiers with some thermal paste and electrically isolating them if using a bare heatsink with ceramic or silicone pads.
I also successfully built a 555 plasma speaker using an IRFP460, but the FET gets so damn hot I needed a dedicated peltier and heatsink just for that FET. I'm waiting on components to construct a more reliable and better plasma speaker using the following instructable:
Sorry for getting off topic there, but you guys have been a great help. Any thought you can offer on using the IRFP460s and what is gained by increasing your cap tank would be awesome.
Registered Member #3637
Joined: Fri Jan 21 2011, 11:07PM
Location: Buffalo, NY
Posts: 1068
Heisenburg;
Next time you order some FET's from mouser or digikey, don't necessarily get IRFP series fets. They're older transistors now at this point and there are far far far better options out there that will perform better at the same or lower price.
A great place to get transistors and other parts is here
since they have a huge selection of overstock parts/discontinued parts. I got some 600 volt 47 amp IGBT's for $1.57 each. They have 1100 pF of gate capacitance.
IRFP250 from newark? $2.88. And it has 2154 pF of gate capacitance, can only handle 200 volts, at 30 amps.
Registered Member #4104
Joined: Fri Sept 23 2011, 06:54PM
Location: Uk .
Posts: 122
woodchuck wrote ...
Thank you for this, Kiwihvguy. My first concern upon reading your answer was that providing gate power without flyback power would burn up the MOSFETS. But that's silly. :) Presumably, by the time there is enough voltage on the primary to heat up the MOSFETs, there would be enough voltage on the primary to start oscillation. ;)
When I ran mine with the separate supply , connecting the 12V gate supply first , the circuit would start to oscillate ( checked with a scope ) and then when the main supply was connected it would work as normal
Registered Member #39190
Joined: Sat Oct 26 2013, 09:15AM
Location: Boise National Forest
Posts: 65
TwirlyWhirly555 wrote ... When I ran mine with the separate supply , connecting the 12V gate supply first , the circuit would start to oscillate ( checked with a scope ) and then when the main supply was connected it would work as normal
Interesting that it would oscillate with just the gate supply. Still, I don't doubt you. Hope mine will behave similarly. In the situation I have, a gentle but reliable ramp-up is much needed, even if I have to hang extra circuitry on to assure that.
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.
Problems getting ZVS driver to work
