Insulator/shielding in DEC power supply

[William Donzelli]

>  If there really is foil inside,
>  I don't know how much EMI suppression it would do,
>  since there is no connection of ground or other way
>  to bleed of any incident energy.  Rather, I'd guess
>  they probably make pretty good reflectors of EMI,
>  instead.  But what do I know, I'm hardly a hardware
>  guy.

Yes, it may be more magnetic. USR ran into a problem with the power
supplies for their rack modems when I worked there - one of the
transformers on the SMPS power supply board(s) leaked a little too
many flux lines onto the closest signal board (NMC?), causing
problems. There was a quick fix with a shield. I suppose it worked on
eddy currents or something.

--
Will