Newsgroups: comp.dcom.lans.ethernet
Subject: Re: strange ethernet electric problem
References:  <[email protected]>          
Robert Redelmeier  writes:

> peancor  wrote in part:
> > We tried powering the laptop (and the system) to an outlet
> > unrelated to the first one and all worked but i do not know
> > what conclusion extract from that. 
> 
> Something is different from that electrical outlet.
> Either power or ground less noisy.
> 
> As other posters have correctly pointed out, low frequency
> isn't going to be a problem.  

If you use shielded Ethernet cables and you have high enough 
current flowing on the Ethernet cable shield this could be 
a problem.... can cause problems to sensitive electronics 
on either end of the cable.  

> But any high frequency, high
> power switchers can be.  

True.

> Those VFDs might not have high
> primary shaft speed, but that does not correlate to the
> switching frequency which might easily be in the kHz.

-- 
Tomi Engdahl (http://www.iki.fi/then/)
Take a look at my electronics web links and documents at 
http://www.epanorama.net/