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 #1784
Joined: Tue Oct 28 2008, 02:30AM
Location: Rochester, MN, USA
Posts: 14
All,
I had started a thread about my little induction heater experiment a few weeks ago, but had to leave it due to a business trip. The inverter portion of the heater is now "finished," but it's behaving strangely & I'm at a bit of a loss. I'm certainly new to the field of building these inverters, so I'm hoping that I've just made some silly error that someone will be kind enough to point out.
The inverter that I've constructed is based fairly faithfully on the design found here:
For clarity, I've labeled several points in the schematic:
P1, P2 -- Where power is supposed to be applied: 60-120V AC
P3 -- The DC positive high voltage supply: simply rectified & filtered AC.
P4 -- The DC common/ground node.
P5 -- The DC positive low voltage input: a 5:1 reduction of the AC input, rectified & filtered (but before the power goes into the 7812 regulator). The 5:1 transformer sends 60-120 V AC to 12-24 V before it enters the regulator, which should feed the IR2153 chip with a constant 12 V supply.
P6 -- The output (to matching inductor & tank -- not built yet) -- where oscilloscope traces are obtained.
Here is my mystery: When I feed this creation with the intended 60-120 V AC, it does produce oscillations, but they appear to be superimposed on top of a strong 60-cycle signal, even though everything *should* be rectified long before that point. When I tie pins P3 and P5 together (so that the MOSFETS are fed from the same supply voltage as the IR2153 chip) and hook it up to my low voltage bench power supply, it produces clean oscillations. Here are some examples:
Pins P3 and P5 tied together and fed from about 15 V DC:
And now for the "bad" behavior...
Pins P3 and P5 separated, in "normal" operating configuration, fed with 60 V AC at Pins P1 and P2:
2 us/div horizontal
(intermediate horizontal zoom level)
2 ms/div horizontal
Any ideas? Any suggestions will be greatly appreciated!
Registered Member #1784
Joined: Tue Oct 28 2008, 02:30AM
Location: Rochester, MN, USA
Posts: 14
Also, I should note that although I can't hook up my oscilloscope directly to the DC supplies when it's powered by the mains (since it isn't isolated), I have hooked up a pair of reversed LED's to see if the high and low voltage DC supplies were producing AC or DC (i.e., DC would light one LED, AC would light both). Only one of the LEDs lit, indicating that either the supplies really are DC, or any 60-cycle oscillations occur while superimposed on top of a positive DC component.
This doesn't really rule anything out as far as I can tell, so I doubt it's significant, but I thought I'd mention it.
Registered Member #95
Joined: Thu Feb 09 2006, 04:57PM
Location: Norway
Posts: 1308
I would say that's normal. Your induction heater is running from a fullwave rectified supply, with an absolutely minimal filter capacitor. (24µF total if I saw all of them) Your DC supply will be pulsed DC rather than flat-line DC.
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.
inverter behaving strangely (for induction heating)
