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've heard all kinds of reasons: 50hz because it fits into the metric system, 50hz because it was just the first frequency that was used...
For the US I've heard that Tesla thought 60hz was the best; 50hz wasn't good enough so an engineer upped the frequency to 60hz and people wanted it just like that; 60hz because that was close to what the turbines could spin at during the that time; 60hz because it fit into the time table (60 seconds). I even heard someone say that 60hz was a good frequency for the electric chair.
Registered Member #2463
Joined: Wed Nov 11 2009, 03:49AM
Location:
Posts: 1546
When Westinghouse needed to operate an alternative to the Edison DC system for lighting, the 25 cycle they had used for the first Niagara-Mohawk system, created flicker with lightbulbs at the time. 60 Hz did not
Registered Member #30
Joined: Fri Feb 03 2006, 10:52AM
Location: Glasgow, Scotland
Posts: 6706
In the early days of Tesla's AC system, he tried power frequencies as high as 167Hz. Parts of Canada used to use 25Hz, and German railways still use 16.7Hz.
This is a legacy from before rectifiers sturdy enough to drive around on a train were developed: they used series wound brush motors fed with raw AC, and the lower frequency made more torque, because the inductance of the motor didn't limit the current so much.
Aircraft use 400Hz because it makes the electrical plant lighter. (The opposite problem to railways, where if anything the heavy electrical gear would give a locomotive better grip.) The newer ones have a power frequency that varies over a wide range depending on engine speed.
So as you can see the choice of frequency is a compromise, and most equipment would not choose 50 or 60 if it had the choice. Modern switched mode power supplies convert it to DC and then invert it again at a more favourable frequency, often 100kHz or more. They will run off any mains voltage and frequency from 95 to 260V, 50 to 400Hz, and even DC. So your laptop or plasma TV would probably run fine off one of Tesla's early generators. Or Edison's, it wouldn't care.
Registered Member #30
Joined: Fri Feb 03 2006, 10:52AM
Location: Glasgow, Scotland
Posts: 6706
Why would the power factor be bad? Most power supplies have a PFC front end now, and those work at any frequency. I have one here that claims to work from 47-440Hz plus DC.
Registered Member #2901
Joined: Thu Jun 03 2010, 01:25PM
Location:
Posts: 837
47 is higher than 16 or 25 isn't it? The lower the frequency the more energy the PFC has to store to supply the switched mode power supply during the troughs.
PS. oops, nevermind ... didn't read your post correctly.
Registered Member #3637
Joined: Fri Jan 21 2011, 11:07PM
Location: Buffalo, NY
Posts: 1068
I do love the way 60 hz sounds. Maybe it's also a good thing, as I probably couldn't stand hearing a constant high pitched squeal if the frequency was in hearing range.
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.