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2021-09-24, 09:36:21
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Author Topic: Smudge proposed NMR experiment replication.  (Read 38664 times)
Group: Experimentalist
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Posts: 1355
Allow me to physically define my experiment mentioned above for reference.  Viewing the inside face of the left pancake coil (rectangular pcb in my case), we start at the inside center and wind clockwise.  Viewing the inside face of the right pancake coil, we again start at the center and wind clockwise.  These faces are brought together and placed parallel to each other.  The top finish winds are connected together and the bottom start winds are connected together and grounded.  A voltage is applied to the connected start windings and a section of a sense coil is placed between the pancake coils and centered in reference to the start wind connection.  The sense coil axis is parallel to the rectangular wires or traces in my case.

In this configuration, the gradients of the volts-per-turn on each end of the sense coil cancel.  IOW, the E-field and A-field are self cancelling.  The sense coil is also floated above ground by measuring each end with two 10M ohm/3.9pf probes differentially to minimize any parasitic currents.

The sense coil is loaded with say a 1k ohm resistor and the Lenz effect is noted at the input.  What is causing this induction in the sense coil?  It has to be the H-field IMO.

Regards,
Pm

 
   

Group: Professor
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Posts: 1501
Which feeds do you have in mind?

See attached image.

Smudge
   

Group: Professor
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Posts: 2301
See attached image.
I see, but my feed wires were twisted around each other and later I switched to using a coax in place of the twisted pairs.
I think Itsu keeps them together, too unless he inserts a probe over one wire only.
These wires conduct currents in opposite directions so their H-Fields should cancel, when they are close to each other.

See attached image.
   
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