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 #3781
Joined: Sat Mar 26 2011, 02:25AM
Location:
Posts: 701
ok, so i insulated all the pins on the bottom so no more arcing, and the sound quality is pretty darn good. I heatsinked the mosfet with an old processor heatsink from a computer with a built in fan and i used dielectric grease. the mosfet does not even get warm after 10 minutes of use! Although the arc volume is really low... any way I can increse it?? I'm also wondering what I should put on the ends of the arcing wires? like nails?
Registered Member #3637
Joined: Fri Jan 21 2011, 11:07PM
Location: Buffalo, NY
Posts: 1068
Camp Badger wrote ...
ok, so i insulated all the pins on the bottom so no more arcing, and the sound quality is pretty darn good. I heatsinked the mosfet with an old processor heatsink from a computer with a built in fan and i used dielectric grease. the mosfet does not even get warm after 10 minutes of use! Although the arc volume is really low... any way I can increse it?? I'm also wondering what I should put on the ends of the arcing wires? like nails?
You can increase it by running your 555 timer on a separate 12 volt power supply and putting more juice through the mosfet. That should increase arc length & arc strength, which means louder music.
Registered Member #3766
Joined: Sun Mar 20 2011, 05:39AM
Location:
Posts: 624
Increasing the voltage will also increase the load on the FET drastically. I literally had an icecube sitting on top of mine and it still blew when I put 24V in for more than a couple minuets (I was running it for a half hour before though...) I'm jealous of how cool yours is running, mind posting some pics of the circuit? Also, I put a piece of plexiglass behind mine to reflect the sound. It helped.
Registered Member #1875
Joined: Sun Dec 21 2008, 06:36PM
Location:
Posts: 635
You'd get more volume if you put a voltage amplifier stage between your sound source and the ac coupling capacitor. A 741 configured for a gain of maybe 5 would probably do nicely.
Just don't exceed your device's voltage rating. There are failure modes other than overheating.
Registered Member #3610
Joined: Thu Jan 13 2011, 03:29AM
Location: Seattle, WA
Posts: 506
The greatly increased heating is due to the FET absorbing the very high voltage spikes created which increase as you increase the supply voltage. If you add a snubber to absorb these the FET will run much cooler. I've pushed 50V into a 555 based flyback driver without blowing anything. Highest output I've measured so far was 76kV into a HV probe.
Registered Member #3781
Joined: Sat Mar 26 2011, 02:25AM
Location:
Posts: 701
ok, I attached a picture of the finished working schematic and circuit.
I have a couple questions; is it safe to measure the amperage on the high voltage output with a multimeter or will the meter break? And can I wind my own flybacks in order to create a better one, or is it easier just to buy them? Also would wiring flybacks in series create a bigger arc, like this one http://www.youtube.com/watch?v=RiPR15T8Vbk?
I brought it in to school today, mostly to show my friends and physics teacher, but I ended up getting interviewed for our school news station and of course everyone wants to know when i will have a better/louder version of it.
Registered Member #3610
Joined: Thu Jan 13 2011, 03:29AM
Location: Seattle, WA
Posts: 506
You can measure the output current, but put the meter in the grounded side of the circuit. I also recommend using an analog meter as the digital ones are likely to get confused or damaged.
Registered Member #3781
Joined: Sat Mar 26 2011, 02:25AM
Location:
Posts: 701
The MOSFET gets hot after a few minutes of 19v but the sound quality and volume is significantly better, the FET is rated at 250v, if I get a 500v one would it be able to withstand 40v without getting to hot?
Registered Member #1875
Joined: Sun Dec 21 2008, 06:36PM
Location:
Posts: 635
Switching to a higher voltage FET will generally create more heat for the same current unless you are avalanching which I don't believe you are. Just use more heatsinking and a fan.
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.
555 Timer Plasma Speaker
