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 #190
Joined: Fri Feb 17 2006, 12:00AM
Location:
Posts: 1567
I took a center-tapped transformer and connected each half to its own rectifier/capacitor. My plan was to connect the negative side of one to the positive side of the other for a common lead. This way I would have +15v and -15v with respect to the common. However, current flows between the two.
Do I need to connect the common to the center tap?
Sorry for the double post, but is this my only solution using single diodes using this type of topology? I am not looking for solutions using 555 timers or other devices.
[Edit: Oh no, now we know that you knowingly double posted out of pure malice!]
Registered Member #2123
Joined: Sat May 16 2009, 03:10AM
Location: Bend, Oregon
Posts: 312
Just have a full wave bridge across the outer 2ndry xfmr windings and use the center tap as common return. What you have in your second diagram will have 60 Hz ripple.
Registered Member #1875
Joined: Sun Dec 21 2008, 06:36PM
Location:
Posts: 635
You don't even need a center tapped transformer necessarily, since the capacitors should ideally split the voltage themselves, but if you have one then you might as well use it. When I made this circuit it was just transformer -> rectifier -> capacitive divider + balancing resistors.
Registered Member #2463
Joined: Wed Nov 11 2009, 03:49AM
Location:
Posts: 1546
For 60 years the full wave, center tap transformer, rectifier was used.
Any half wave rectifier connected to a transformer has a problem with wasted metal in the winding. For a given regulation the wire size has to be bigger because the winding has only 1/2 cycle to furnish the power needed by the load. It idles and takes up coil area half the time. That factor means bigger cores with their losses. And worse, in the half wave rectifier it throws a 2f back on the line.
scan is Ghirardi, A Radio Physics Course 2nd. Ed Murray Hill Books New York 1932. (great book to learn how to read with; electronics can be learned later)
Registered Member #30
Joined: Fri Feb 03 2006, 10:52AM
Location: Glasgow, Scotland
Posts: 6706
You do need the center tap, in case you draw slightly different currents from the + and - rails.
Look at the "split rail" schematic on the last page of this PDF to see how it's done.
Radiotech, what is this old vacuum tube stuff?
The split rail power supply is just two "full wave center tap" rectifiers, as you call them, one providing a positive supply, and the other with its diodes turned backwards to provide a negative supply.
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.
tying a +15v and -15v supply
