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RE: Static Discharge - An issue to be added to the technical issu es list

Title: RE: Static Discharge - An issue to be added to the technical issu es list

Yair,
you have questions that many people have (including myself), and probably few if any have the answers they are willing to share.


These are my opinions is response to your questions:

1)
a) the best model would be for a CAT-3, CAT-5, and CAT-6? fully coupled cable, 8 x 8 matrices of RLGC (this does not exist)

b) next best would be treating the 4 pair cable as 8 separately charged 50 ohm lossy coax cables

c) the next best would be to use a separately charged lumped cap (4000 to 6000 pf?) on each RJ-45 pin to ground


1.1) I think that this would work, but determining the TBD's is hard to do, since there is coupling in any real cable.
Also, when the RJ-45 is plugged in, the pins can mate in any order, so multiple modes can be stimulated:
differential mode (within a pair), pair to pair mode (from one pair to other pairs), and common mode.


2) cable discharge applies to any cable, in our case: CAT-3, CAT-5 (5E), CAT-6, etc...
The better the cable performance, often the worse the charge retention is, and the higher the voltages could be.

We can always find a test condition that blows things up, the hard part is finding a test condition that properly covers most

of the real world installations. No fair plugging into ethernet ports which are riding on say a Van de Graf generator.


- Rick