[SI-LIST] Re: What is correctly placement of Transformer? Locate Near IC or RJ45 CONN? Why?

Thanks for your kindly reply, and if this rule of thumb can be used 
in POE(Power Over Ethernet) as well?

Binchuan, Wang



--- In si-list@xxxxxxxxxxxxxxx, "Curt McNamara" <CurtM@...> wrote:
>
> Since Ethernet wiring can be routed through areas with AC, the=3D20
> possibility of accidental connection of AC to Ethernet exists.
> This is why the transformers are rated in KV. Safety standards
> have minimum spacings that must be maintained between dangerous=3D20
> signals (in this case Ethernet) and low voltage signals 
(sometimes=3D20
> identified as SELV). The easiest way to enforce this is to keep=3D20
> the Ethernet transformer near the edge of the PCB and keep 
traces=3D20
> and planes away from line-side Ethernet signals and the 
transformer.
> 
>                                       Curt=3D20
> 
> Curt McNamara. P.E.=3D20
> Senior Electrical Engineer=3D20
> Logic Product Development=3D20
> 411 Washington Ave. N Suite 101=3D20
> Minneapolis, MN 55401=3D20
> Tel 612-436-5178=3D20
> Fax 612-672-0443=3D20
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should =3D
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> 
> -----Original Message-----
> From: si-list-bounce@... [mailto:si-list-bounce@...] =3D
> On Behalf Of =3DAA=3DFC=3DA5=3DC8
> Sent: Sunday, February 26, 2006 7:52 PM
> To: si-list@...
> Subject: [SI-LIST] What is correctly placement of Transformer? 
Locate =3D
> Near IC or RJ45 CONN? Why?
> 
> 
> Hi all,
> 
> Do you know whta's the correct placement of transformer of 
10/100=3D20
> Ethernet?=3D20
> 
> Should it be placed near Ethernet control IC or near RJ45 CONN? 
For what =3D
> reasons? EMI? Function?=3D20
> 
> Why?
> 
> If you can help to give me some information is appreciated.
> 
> Thanks you in anticipation,
> 
> Binchuan, Wang
> 
> 
> 
> 
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