PSN-L Email List Message

Subject: Re: Chapman's sensor Design
From: "GPayton" gpayton@.............
Date: Fri, 23 Jul 2010 11:46:29 -0500

Thank you Kay & Bob.  Both have been very helpful.

I've ordered the 38 ga.wire and glass epoxy unclad PCB to make the coil.

After checking into the cost of the SEP sensor from the UK, and (estimating 
the possible weight) estimating the shipping from the UK to me in Texas; it 
would be almost $700 US dollars!  OUCH

If they read the PSN site: I wished they would get a U.S. distributer. I 
know they would benefit in sales.

So, I am going to try to build one of this type.  I might say that I tried 
in the 2008-9 period, before moving to Texas.  I do not have near the 
facilities or tools available now that I did then.  (Say a prayer for me.) 
It is going to be difficult.  However, my alternatives are few.

Bob, I guess that I am a maverick.  In looking at these various designs and 
drawings, I can't help but wonder about possible modifications.  For 
instance, the number of turns in a coil.  To me, for a given amount of gauss 
increasing the number of turns cutting the flux, the angle that they cut and 
the speed determine the output voltage.  So, following drawings EXACTLY may 
be a matter of choice.  The amplification of that output is a factor too.

Enough of my soapbox speech.  I appreciate everyone's input, and I am sure 
it helpful for other novices too.

Best Regards,
Jerry

--------------------------------------------------------------------------------


  ----- Original Message ----- 
  From: Bob McClure
  To: psn-l@..............
  Sent: Friday, July 23, 2010 9:26 AM
  Subject: Re: Chapman's sensor Design


  I prefer the following block magnets:

  http://www.gaussboys.com/ndfeb-magnets/B5012.html
  Model: B5012
  Size:  50mm long x 25mm wide x 12mm thick
  Price: $11.00 each

  An assembly of two quarter-inch thick steel plates, four magnets, and a 
one-quarter inch gap will yield a field of almost 7,500 gauss. A rectangular 
coil of 1100 turns of #38 wire will yield an output of ~80 volts per meter 
per second. The coil resistance is only 340 ohms, and you can easily use 
resistive shunt damping with negligible loss of output.

  See: http://sites.google.com/site/bobmcclure90/horiz

  Bob


  On Thu, Jul 22, 2010 at 11:46 PM, Kay Wyatt  wrote:

    Jerry,
    they are magnitized through the thickness.  I order mine through K&J 
Magnetics at http://www.kjmagnetics.com
    The part number is
          BX0X02

    1" x 1" x 1/8" thick
    Grade N42 - Nickel Plated
    Magnetized thru Thickness

    Hope this helps.
    Kay



      ----- Original Message ----- 
      From: GPayton
      To: psn-l@..............
      Sent: Thursday, July 22, 2010 8:30 PM
      Subject: Chapman's sensor Design



      Looking closely at the drawings on this page, I am not certain about 
the magnetization of the required sets of magnets.  Are they magnetized from 
end-to-end or through the thickness?

      Most magnets I have found online, so far, have been through the 
thickness, but I am not sure what is shown on the drawing.  Anyone know?
      Thanks,
      Jerry

--------------------------------------------------------------------------


        Here is the link to Chris Chapman's coil design and instructions
        http://www.jclahr.com/science/psn/chapman/lehman/index.html










Thank you Kay & Bob.  Both have been very =

helpful.  


 


I've ordered the 38 ga.wire and glass epoxy unclad PCB to make the=20
coil.  


 


After checking into the cost of the SEP sensor from the UK, and =
(estimating=20
the possible weight) estimating the shipping from the UK to me in Texas; =
it=20
would be almost $700 US dollars!  OUCH  


 


If they read the PSN site: I =
wished they=20
would get a U.S. distributer. I know they would =
benefit in=20
sales.


 


So, I am going to try to build one of this type.  I might say =
that I=20
tried in the 2008-9 period, before moving to Texas.  I do not =
have=20
near the facilities or tools available now that I did then.  (Say a =
prayer=20
for me.)  It is going to be difficult.  However, my =
alternatives are=20
few.


 


Bob, I guess that I am a maverick.  In looking at these =
various=20
designs and drawings, I can't help but wonder about possible=20
modifications.  For instance, the number of turns in a coil.  =
To me,=20
for a given amount of gauss increasing the number of turns cutting the =
flux, the=20
angle that they cut and the speed determine the output voltage.  =
So,=20
following drawings EXACTLY may be a matter of choice.  The =
amplification of=20
that output is a factor too.


 


Enough of my soapbox speech.  I appreciate everyone's input, =
and I am=20
sure it helpful for other novices too.


 


Best Regards,


Jerry








 


  
----- Original Message ----- 

  From:=20
  Bob=20
  McClure 
  
To: psn-l@.............. 

  
Sent: Friday, July 23, 2010 =
9:26 AM

  
Subject: Re: Chapman's sensor=20
Design

  

I prefer the following block magnets:

http://www.gau=
ssboys.com/ndfeb-magnets/B5012.html
Model:=20
  B5012
Size:  50mm long x 25mm wide x 12mm thick 
Price: =
$11.00=20
  each

An assembly of two quarter-inch thick steel plates, four =
magnets,=20
  and a one-quarter inch gap will yield a field of almost 7,500 gauss. A =

  rectangular coil of 1100 turns of #38 wire will yield an output of ~80 =
volts=20
  per meter per second. The coil resistance is only 340 ohms, and you =
can easily=20
  use resistive shunt damping with negligible loss of =
output.

See: http://sites.goo=
gle.com/site/bobmcclure90/horiz

Bob


  
On Thu, Jul 22, 2010 at 11:46 PM, Kay Wyatt =
<kwyatt@.............> =

  wrote:

  
    

    
Jerry,

    
they are magnitized through the=20
    thickness.  I order mine through K&J Magnetics at http://www.kjmagnetics.com

    
The part number is 

    

    

      
      

        
          

    
1" x 1" x 1/8" thick
Grade N42 - Nickel Plated
Magnetized thru Thickness

    
 

    
Hope this helps.

    
Kay

    
 

    
 

    
 

    

    

    

    
      
----- Original Message ----- =


      
From:=20
      GPayton 

      
      
Sent: Thursday, July 22, =
2010 8:30=20
      PM

      
Subject: Chapman's sensor=20
Design

      


      
 

      
Looking closely at the drawings on this page, I am not =
certain about=20
      the magnetization of the required sets of magnets.  Are they=20
      magnetized from end-to-end or through the thickness?

      
 

      
Most magnets I have found online, so far, have been through =
the=20
      thickness, but I am not sure what is shown on the drawing.  =
Anyone=20
      know?

      
Thanks,

      
Jerry

      

      

      

      
        
 

        
Here is the link to Chris =
Chapman's coil=20
        design and instructions

        
http://www.jclahr.com/science/psn/chapman/lehman/index.ht=
ml

        
 
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