Hi Chris,  That is a good idea..........The visitors to the Museum are =
mostly tour groups of kids...They love to touch things, and maybe I =
could work something like this up.   I think that would explain the =
Magic very well.
Thanks, Ted
  ----- Original Message -----=20
  From: ChrisAtUpw@..........
  To: psn-l@.................
  Sent: Saturday, July 07, 2007 4:53 PM
  Subject: Re: The Magic


  In a message dated 2007/07/07, tchannel1@............ writes:


    She is often at the computer, by the Sensor, when people visit the =
museum.  One question she gets, is "How does it work"  She understands =
how it is built and all the parts, but when the questions focuses on the =
magnetic field and the coil, she can only discuss their interaction, =
creates a current, like "Magic"


  Hi Ted,=20
        =20
         Movement of a coil in a magnetic changing field does not =
produce a current, but a voltage across the ends of the coil. This =
voltage is proportional to the number of turns, to the area of the coil =
and to the rate of change of the field.=20
         A current flowing in a conductor has a ring magnetic field =
assocciated with it. If you use a circular solenoid, the turns add up to =
give an axial agnetic field.

      I use a school demo system having quad NdFeB magnets on two =
parallel mild steel backplates. I use a relay coil on a handle connected =
to back to back red and green LEDs. You move the coil one way and the =
red LED lights, the other way and the green LED lights. If you move the =
coil more rapidly, the LEDs glow a lot brighter. Why not make up a =
similar model for the museum?


    I have seen a formula explaining the three factors, The Field, The =
Coil, and The Velocity..........
    Could someone tell me or direct me to an explanation of "The Magic"  =
which is really the basic for this type of sensor.


         Regards,








Hi Chris,  That is a good =
idea..........The=20
visitors to the Museum are mostly tour groups of kids...They love to =
touch=20
things, and maybe I could work something like this up.   I =
think that=20
would explain the Magic very well.
Thanks, Ted

  
----- Original Message ----- 
  From:=20
  ChrisAtUpw@....... 
  
To: psn-l@.............. 
  
Sent: Saturday, July 07, 2007 =
4:53=20
  PM
  
Subject: Re: The Magic
  

In a=20
  message dated 2007/07/07, tchannel1@............=20
writes:


  She is often at the computer, by the Sensor, when people =
visit=20
    the museum.  One question she gets, is "How does it work"  =
She=20
    understands how it is built and all the parts, but when the =
questions=20
    focuses on the magnetic field and the coil, she can only discuss =
their=20
    interaction, creates a current, like "Magic"

Hi Ted,=20
  
      =20
  
       Movement of a coil in a =
magnetic=20
  changing field does not produce a current, but a voltage across the =
ends of=20
  the coil. This voltage is proportional to the number of turns, to the =
area of=20
  the coil and to the rate of change of the field.=20
  
       A current flowing in a =
conductor has=20
  a ring magnetic field assocciated with it. If you use a circular =
solenoid, the=20
  turns add up to give an axial agnetic field.

    =
I use a school demo system =
having quad NdFeB=20
  magnets on two parallel mild steel backplates. I use a relay coil on a =
handle=20
  connected to back to back red and green LEDs. You move the coil one =
way and=20
  the red LED lights, the other way and the green LED lights. If you =
move the=20
  coil more rapidly, the LEDs glow a lot brighter. Why not make up a =
similar=20
  model for the museum?


  I have=20
    seen a formula explaining the three factors, The Field, The Coil, =
and The=20
    Velocity..........
Could someone tell me or direct me to an =
explanation of "The=20
    Magic"  which is really the basic for this type of=20
  sensor.

      =20
  Regards,

       Chris =
Chapman=20