Re: [SI-LIST] : Re: approximations for partial self inductance - WHY

About this list Date view Thread view Subject view Author view

From: GARY ROSEN (gmr@appsig.com)
Date: Mon Mar 19 2001 - 13:49:52 PST


Doug McKean wrote:

> ------------------------------------------------------------
> Okay, well here goes ...
>
> It's easy to see that if a signal trace had a return trace as a
> wire (shown by a dotted line), the following would cause
> the creation of a loop.
>
> |
> |
> |
> +----------+
> . |
> return . | signal
> trace . Loop | trace
> . |
> +----------+
> |
> |
> |
>
> Obviously from this construction, the inductance of the

^^^^^^^^^^ ???

>
> return wire would be less than if the return wire was
> underneath and following the longer path of the signal
> trace. Thus, my questioning the path of less inductance
> rule.
>

But wouldn't the *total* inductance - taking into account
the mutual inductance of the coupled traces - be less
when the return path is underneath (and thus closely coupled
to) the signal trace? You are counting only the self-inductance
of the respective traces (obviously less for the shorter path).

I think "mutual inductance" essentially quantifies your idea
about the Lorentz force (omitted here for brevity).

- Gary Rosen



**** To unsubscribe from si-list or si-list-digest: send e-mail to
majordomo@silab.eng.sun.com. In the BODY of message put: UNSUBSCRIBE
si-list or UNSUBSCRIBE si-list-digest, for more help, put HELP.
si-list archives are accessible at http://www.qsl.net/wb6tpu
****


About this list Date view Thread view Subject view Author view

This archive was generated by hypermail 2b29 : Thu Jun 21 2001 - 10:11:15 PDT