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 #5323
Joined: Fri Jun 15 2012, 02:14PM
Location:
Posts: 104
In the case where a 100v@10ma diode is series connect with a 2nd 100v diode (but due to manufacturing tolerances the 2nd diode is actually 9ma), I understand that the reverse breakdown voltage of the two series diodes will be approximately 200v... but is the forward current capacity of the two series diodes limited to 9ma?
Registered Member #5323
Joined: Fri Jun 15 2012, 02:14PM
Location:
Posts: 104
I did a poor job stating my question, I will reframe it
When placing diodes in series, the amount of voltage they can collectively handle while remaining in a safe operating range effectively doubles (+/-), but does the diode's ability to handle current (before being destroyed because of too much current) also combine?
Stated differently, can a diode's ability to handle current be increased by placing a 2nd diode in series or will the current handling capacity always be the limited by the weakest diode in the series?
Registered Member #1403
Joined: Tue Mar 18 2008, 06:05PM
Location: Denmark, Odense C
Posts: 1968
Here is a good paper showing the difference between increased voltage handling by series connection and increased current handling by parallel connection.
Registered Member #72
Joined: Thu Feb 09 2006, 08:29AM
Location: UK St. Albans
Posts: 1659
GammaRay wrote ...
... I understand that the reverse breakdown voltage of the two series diodes will be approximately 200v...
yeah, well, not really, not in practice. Diodes have lots of other parameters, parameters you have no right to expect to be well matched between two random diodes. The one that really bites you in the bum is reverse recovery time. A forward biased diode stores a lot of charge, a bit like a large, poorly specified capacitor. As the two series diodes get reverse biased, stored charge flows out of the junctions, maintaining a very low voltage across the diodes. Eventually, one runs out of charge, and gets the full reverse voltage slapped across it. Ouch. Unless it's avalanche rated, exceeding the PIV by a factor of 2 doesn't do it a whole lot of good.
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.
Series diodes - forward current capacity question
