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 #3114
Joined: Sat Aug 14 2010, 08:33AM
Location:
Posts: 608
I am quit confident in my transformer making since my last three have turned out quite nice and perform very well. I was thinking of winding a secondary for a flyback transformer with 40 awg mag wire.
Possible specs(not finished design):
• 40 awg wire • 24 mm coil per layer • ~303 turns, without gap…~300 turns per layer • 2 sheets of 3m overhead projection sheets • 16.66666666666 layers= 5000 turns • 17 layers • Pointless?
My concern comes from something I read on here along time ago, I don't remember what they said exactly, they said something like, "people try to wind forever but at some point there's a limit and it doesn't produce any more electricity".
If so how would I figure out maximum turns for a given transformer?
Registered Member #1451
Joined: Wed Apr 23 2008, 03:48AM
Location: Boulder, Co
Posts: 661
My concern would be using 40 awg wire. That is about the same diameter as a human hair. It would be extremely tough to get nice layers and you would probably end up breaking the wire. Or maybe not! It's just my opinion.
Registered Member #3114
Joined: Sat Aug 14 2010, 08:33AM
Location:
Posts: 608
Turkey9 wrote ...
My concern would be using 40 awg wire. That is about the same diameter as a human hair. It would be extremely tough to get nice layers and you would probably end up breaking the wire. Or maybe not! It's just my opinion.
I thought about that and i wouldn't attempt this but i have found a cheap source. If it doesn't work its OK not that big of a loss, and if it does work it will be awesome :)
Registered Member #4118
Joined: Mon Oct 03 2011, 04:50PM
Location: MD
Posts: 140
I would be worried about the 40AWG overheating from too much current, and the self-capacitance of the secondary. I would recommend about 35AWG. It should be fairly easy to wind, and can take a lot more current.
Registered Member #30
Joined: Fri Feb 03 2006, 10:52AM
Location: Glasgow, Scotland
Posts: 6706
As you wind more, the self-resonant frequency of the secondary goes down.
If you drive it above its self-resonant frequency, the output will be reduced, because the coil functions as a low-pass filter.
If you drive it below its resonant frequency, then the output will also be reduced, because the core can support less volts per turn the lower the frequency.
So ideally you would calculate the self-resonant frequency before winding to avoid wasting time and materials. Some old tube-era book might be able to help with that.
Registered Member #3114
Joined: Sat Aug 14 2010, 08:33AM
Location:
Posts: 608
Steve Conner wrote ...
As you wind more, the self-resonant frequency of the secondary goes down.
If you drive it above its self-resonant frequency, the output will be reduced, because the coil functions as a low-pass filter.
If you drive it below its resonant frequency, then the output will also be reduced, because the core can support less volts per turn the lower the frequency.
So ideally you would calculate the self-resonant frequency before winding to avoid wasting time and materials. Some old tube-era book might be able to help with that.
Registered Member #3888
Joined: Sun May 15 2011, 09:50PM
Location: Erie, PA
Posts: 649
40awg will probably piss you off to no end when it breaks. I just wound a tesla coil by hand with 36awg and it wasn't too bad, so I'd recommend that if you can get it cheap. solenoids are loaded with thin wire. Two ~1" long x ~0.5" diameter solenoids I had each had over 500ft of 36awg wire on them. Was rather surprised.
Anyways, I think thin, large diameter coils are better for hv flybacks (low turns per layer x many layers.) There's some fancy self capacitance reason for that, but a much simpler reason to me is to help prevent arc over between the layers at the ends. Less turns per layer means less of a potential difference between the start of one layer and the end of the next. I've made transformers with tons of turns per layer and had this problem quite often, and one arc over with such small wire=ruined.
scotch tape will be your friend when working with transparency strips. I should test the conductivity of the glue sometime to really be sure, but I think you could insulate a transformer entirely with scotch tape if you wanted to. It certainly is convenient.
Unless you glue one layer to the next as you go, I'd recommend being very careful, or stopping at several intervals to pour glue into the sides, so that the windings don't start slipping around and deforming your nicely stacked layers.
You'll also want a core similar in shape to the antique AC flybacks (~square window.)
Be very careful with the end of the wire at the start of the coil (the inner end) because it's a pain when it breaks off and you have to dig out a new piece from the first layer.
I'm probably full of other pointless pointers if you want any.
Registered Member #3114
Joined: Sat Aug 14 2010, 08:33AM
Location:
Posts: 608
Forty wrote ...
40awg will probably piss you off to no end when it breaks. I just wound a tesla coil by hand with 36awg and it wasn't too bad, so I'd recommend that if you can get it cheap. solenoids are loaded with thin wire. Two ~1" long x ~0.5" diameter solenoids I had each had over 500ft of 36awg wire on them. Was rather surprised.
Anyways, I think thin, large diameter coils are better for hv flybacks (low turns per layer x many layers.) There's some fancy self capacitance reason for that, but a much simpler reason to me is to help prevent arc over between the layers at the ends. Less turns per layer means less of a potential difference between the start of one layer and the end of the next. I've made transformers with tons of turns per layer and had this problem quite often, and one arc over with such small wire=ruined.
scotch tape will be your friend when working with transparency strips. I should test the conductivity of the glue sometime to really be sure, but I think you could insulate a transformer entirely with scotch tape if you wanted to. It certainly is convenient.
Unless you glue one layer to the next as you go, I'd recommend being very careful, or stopping at several intervals to pour glue into the sides, so that the windings don't start slipping around and deforming your nicely stacked layers.
You'll also want a core similar in shape to the antique AC flybacks (~square window.)
Be very careful with the end of the wire at the start of the coil (the inner end) because it's a pain when it breaks off and you have to dig out a new piece from the first layer.
I'm probably full of other pointless pointers if you want any.
excellent i will give it a try, and if it works i will share.
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.
Pointless endeavor?
