Welcome to the NavList Message Boards.

NavList:

A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding

Compose Your Message

Message:αβγ
Message:abc
Add Images & Files
    or...
       
    Reply
    Re: Test your magnetic compass.
    From: Alexandre Eremenko
    Date: 2012 Nov 16, 18:20 -0500

    Bill,
    I don't really understand, why alternating current produces a
    constant magnetic field.
    Ken confirms this but does not explain.
    But this is a phenomenon which I noticed long ago and can even measure
    with my compass. It is about 10 degrees, close to a wall electric switch.
    
    There are also constant magnetic fields produced by nails in the studs
    of an American house. (And by iron rods inside the concrete of Soviet
    houses:-)
    And there is even a simple magnetic devise based on this,
    it is called the stud finder.
    
    But the field produced by AC wiring is stronger.
    
    Alex.
    
    On Fri, 16 Nov 2012, Ken Muldrew wrote:
    
    >
    >
    > On 2012-11-16, at 2:55 PM, Bill Morris wrote:
    >
    >> Can some physicist or power engineer explain how an alternating current can 
    produce a constant magnetic field? Could corona discharge really account for 
    the observation or must we postulate rusty joints in transmission towers 
    acting as rectifiers?
    >>
    > AC power lines produce AC magnetic fields, but you have to be within about a 
    meter of the line for the strength of the B field to equal that of the earth. 
    DC power lines are becoming more popular due to advances in power 
    engineering. Currently there are only about one or two hundred DC high 
    voltage lines worldwide but this number will increase soon (at least power 
    companies seem to be marketing the safety of DC lines pretty aggressively, 
    and they do make sense for technologies such as wind power).
    >
    > Ken Muldrew.
    >
    >
    >
    > View and reply to this message: http://fer3.com/arc/m2.aspx?i=121152
    >
    >
    >
    
    
    
    

       
    Reply
    Browse Files

    Drop Files

    NavList

    What is NavList?

    Join NavList

    Name:
    (please, no nicknames or handles)
    Email:
    Do you want to receive all group messages by email?
    Yes No

    You can also join by posting. Your first on-topic post automatically makes you a member.

    Posting Code

    Enter the email address associated with your NavList messages. Your posting code will be emailed to you immediately.
    Email:

    Email Settings

    Posting Code:

    Custom Index

    Subject:
    Author:
    Start date: (yyyymm dd)
    End date: (yyyymm dd)

    Visit this site
    Visit this site
    Visit this site
    Visit this site
    Visit this site
    Visit this site