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
A magnetic field moving perpendicular to a coil of wire will induce a current. Now I have many coils around a laminated core of iron. Is there any difference in the voltage induced, other than the added volts per turn, if the outer diameter of the coil is close to the diameter of the laminated core, or if there are so many turns that the laminated core diameter is small compared to the diameter of the coil?
I guess what I am interested in knowing is will the core saturate if the core is small compared to the coil of wire?
Registered Member #160
Joined: Mon Feb 13 2006, 02:07AM
Location: Melbourne, Australia
Posts: 938
Any core will saturate if you put enough current into the coil. If you look at the electromagnet in hair clippers it seems that the core is small compared with the windings, and this is connected directly to the mains, but because of the impedance it only pulls minimal current. The saturation is a function of flux density, that determined by magnetic flow within cross sectional area, flow being determined by how many amperes per turn can go into a given reluctance. So it depends on how many amps you pump into it.
Registered Member #190
Joined: Fri Feb 17 2006, 12:00AM
Location:
Posts: 1567
IamSmooth wrote ...
A magnetic field moving perpendicular to a coil of wire will induce a current.
Although the answer might be the same, my question pertains to generation of current, as stated in the thread title, and not the application of current to a coil. What happens to the current induced in coil by a moving magnetic field if the core is small relative to the coil?
I guess another way I could ask the question is if 100 turns around the core results in 100v from a moving magnetic field, what happens if there are 200 turns? Will there be 200v? If I increase to turns to 1000 will there be 1000v? I am not talking about theory where the voltage is proportional to N turns, but in practice where there are a multitude of other factors.
The reason I ask this is because I have a stator where the wire is tightly wrapped around the core. I would say there are about three layers of wire making 105 total turns. I am curious what would happen if I add another 3 layers of wire. Is there a point in practice when adding more turns will not significantly increase wattage as the voltage gain becomes less and the resistive losses increase?
Registered Member #347
Joined: Sat Mar 25 2006, 08:26AM
Location: Vancouver, Canada
Posts: 106
If you have a core of constant size, and have a certain number of turns of wire around it, and a constant current through that coil, increasing the diameter of that coil won't significantly change the induced flux in the core.
For a shunt wound or series wound brush motor, adding more turns to the stator will increase the flux, up until saturation. This will cause the motor to run slower and produce more torque. It may also effect the ideal brush timing, so may cause more brush arcing.
Registered Member #162
Joined: Mon Feb 13 2006, 10:25AM
Location: United Kingdom
Posts: 3141
There are several sub-problems in your question, I'll try to highlight the basic principles that will affect your setup. For a fixed arrangement of rotor and stator, the core will be most likely to be saturated when there is NO current in the coil.
As you put amp-turns loading the flux in the core will be REDUCED, until at a certain amp.turns in the stator there will be NO flux passing through the core within the windings (ideally).
So as you draw more current the voltage will reduce.
Adding more turns will give proportionately more volts and less amps.
The short answer is - you can't get more electrical power out than you put mechanical energy in. The number of turns determines high voltage at low current for many turns OR low voltage at high current for many turns.
But the direct answer to your initial question is that adding more turns will not affect core saturation.
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.
Inducing a current in a coil
