Re: Decrement (?) (Re: (Fwd) RE: Longitudinal Waves)

["Tesla list" <tesla-at-pupman-dot-com>]

Original poster: "Jason Johnson by way of Terry Fritz <twftesla-at-qwest-dot-net>" <hvjjohnson13-at-hotmail-dot-com>


----- Original Message -----
From: "Tesla list" <tesla-at-pupman-dot-com>
To: <tesla-at-pupman-dot-com>
Sent: Monday, February 18, 2002 3:40 AM
Subject: Re: Decrement (?) (Re: (Fwd) RE: Longitudinal Waves)


> Original poster: "Cory Roussel by way of Terry Fritz <twftesla-at-qwest-dot-net>"
<imcuddlycory-at-yahoo-dot-com>
>
> Hello Coilers,
>
> Here is a VERY basic question that has BOTHERED ME for
> a long time but i never really got to thinking about
> it too much... In a transformer, why is it that the
> poles are reversed on every cycle (IE AC)!?  Why is it
> necisary that the voltage be changed, and not
> constant...  I dunno these are very simple and i just
> cant figure out even though they are SO simple...
>
>
> Sincerely,
>
>  Cory Roussel


Quite simply, for a current to be induced in a conductor, it has to be
moving relative to a magnetic field (or vice versa, move the field). Put DC
into a transformer winding and you turn the core into an electromagnet
(although it is a closed loop, and you don't do much useful work), so to get
the secondary winding(s) of a transformer to produce a current we need to
create a moving field, so we use AC, which causes the field to build towards
one pole, fall to zero, rise to the opposite pole, fall to zero, and so and
so forth. The core of the transformer serves to "steer" the magnetic field
created by the primary. Of course this is a basic explanation and you can
make it as complex as you want (thats why texts on transformer design are so
thick :-), but it didn't look like you wanted more than a simple
explanation.


<< Jason R. Johnson >>
G-3 #1129
The Geek Group
http://www.thegeekgroup-dot-org/

"The two most common elements in the universe are hydrogen and stupidity."
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