sequential (71) RJ45 (Protocol) the direction of current flow

 https://wodewangzhishime.blogspot.com/2023/02/httpswodewangzhishime.html?m=1

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Ref: https://chihaukam.blogspot.com/2024/12/let-me-tell-you-real-story.html?m=1

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John: The 1st picture is an operational amplifier.  4.5 V- 0.5 v = 4 V.

Me: Ok.

John : Now, see the 2nd picture.   (-0.5v) - (-4.5v) = 4 V.

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Me: Yes, it's 4 V as well.  But, the direction of current flow is different..

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John: See the 2nd picture.  (Rd+) Should connect to 3. However,  if I let (RD +) connect to 6, the difference between them is the same.