Ancient_Hacker wrote:

Franc Zabkar wrote:
What is the function of the primary-secondary coupling capacitor (eg
http://tinyurl.com/ha435) in a SMPS? I ask this because I suspect it
may be the cause of a video "hum" issue.

I think it's there to provide a bit of RF grounding for the secondary
circuits.

No.

See my reply.

Graham