I'm new here and I'm looking for someone to help clarify the AUX winding of a transformer, more specifically in a switched psu.
I see schematics where it's being used either as feedback or voltage input to an ic on the primary taken from a winding on the primary (at least that's how it seems to me). Here lies my confusion.
My understanding is a magnetic field created in primary creates a flux in secondary that outputs different voltages dependent on winding/s. So how can there be a second winding on the primary side that induces voltage in the hot side used as an AUX? Am I missing something simple like are the windings really on the secondary but the pins are connected to primary/hot side?