29 Dec
2003
29 Dec
'03
1:02 p.m.
Should I
get continuity between the s-shaped swigglely lines?
NO!. Those should be
open-circuit both ways! transformer between it and the mains.
I have never seen an SMPSU with a mains isolation transformer. Yes, I
have seen PSUs that start with a mains transformer (giving, say, 20V),
and then use a switching regulator to bring that down to 5V (or
whatever), but I've never seen one with a 1:1 isolating transformer
(remmeber that 200V electrolytic, there is rectified mains in that PSU).
-tony