In a message dated 04/03/2009, gmvoeth@........... writes:

It needs  to be two identical coils arranged in a series additive fashion 
feeding the  common center
point and the plus minus signals on a 100% Shielded  Underground cable.



Hi Geoff and others,
 
    I see what you are saying, but it is much easier to  invert the problem, 
use differential quad NdFeB magnets on common mild steel  baseplates and a 
single rectangular pickup coil. This gives me over 20x the  voltage output that 
an Alnico U magnet and a relay coil can provide and it is  linear with 
deflection / drift. See the sensor magnet block and coils at 
_http://jclahr.com/science/psn/chapman/lehman/index.html_ 
(http://jclahr.com/science/psn/chapman/lehman/index.html)  You  can also buy lower noise single ended opamps than 
differential ones. 
 
    Regards,
 
    Chris Chapman






In a message dated 04/03/2009, gmvoeth@........... writes:
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  common center
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  Underground cable.


Hi Geoff and others,
 
    I see what you are saying, but it is much easie=
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invert the problem, use differential quad NdFeB magnets on common mild steel=
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baseplates and a single rectangular pickup coil. This gives me over 20x=
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voltage output that an Alnico U magnet and a relay coil can provide and it i=
s=20
linear with deflection / drift. See the sensor magnet block and coils a=
t http://jcla=
hr.com/science/psn/chapman/lehman/index.html You=20
can also buy lower noise single ended opamps than differential ones. 
 
    Regards,
 
    Chris Chapman