And SELV applies to your links how?
I don't think I ever referred to SELV.
THe question ask only those above: i.e. when is non-isolation is acceptable and when it is not, and if there are different application classes, and what safety mean are required.
For example when is it...
Yes,
Its very common to have non-isolated AC-DC converter ICs such as this circuit from TI:
http://www.ti.com/lit/an/slyt391/slyt391.pdf
Also there are very simple direct regulation schemes such as this:
http://ww1.microchip.com/downloads/en/appnotes/00954A.pdf
Also there non-isolated...
I’m looking at a project to make a electronic tranformer for use within a product, and driving its teathered external devices for a control system. I want to make the output AC voltage configurable between 24VAC and 120VAC. This can easily be done with PWM of the AC signal and a feedback path...