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Delay in 3 meters of wire

Started by amdx February 4, 2014
On Tue, 04 Feb 2014 20:57:37 -0600, Jon Elson <elson@pico-systems.com>
wrote:

>amdx wrote: > > >> >> The current and voltage both have a delay from one end of the wire to >> the other. >> If I'm looking at the voltage across and current through the inductor, >> the 10ns >> delay will not be seen. Both voltage and current will be delayed the >> same amount. >> However the current will have a 90* phase shift compared to the voltage. >> And both voltage and current will have delay of 10ns. >Yeesh, this gets MESSY! The delay from one end of a wire to the >other is kind of a transmission line problem, and you need to know the >impedance of the transmission line to know the propagation velocity.
No, just what the media (the t-line's insulation) is. More specifically, you need to know its epsilon-r.
>Just wire in open air is uncontrolled impedance, so I have no idea >how that works. Now, when you wrap it into a coil, part of the coil >acts as the ground plane for every segment of conductor that acts >as a transmission line. Messier, still!