SMPS basic functionality

Yeah, this is basic, but it shows the function, next step is to use a vcvs to play the role of the opto-isolator and make a feedback circuit ;)

Or, I just played around with it a little.

Op-amp with 0V negative rail +5V positive rail. 1V/V amplification, positive reference to logic train, negative to blue line (output of smps), output of op-amp to 1k resistor to MOSFET, when the output voltage reaches +5V it cuts the logic train signal, thus shutting the smps "off", saving energy until the capacitor drains enough to rebegin the pulsing, but I tuned this for +5VDC output, I would suggest setting the op-amp to whatever you desire the output voltage to be and possibly use a voltage amp on the logic train to boost that as well so the op-amp can compare the two, cause I utilized the op-amp as a comparator :)

ETJAKEOC Ah I see, thank you :-) Would you mind sharing your modified version with me/us? Thank you, God bless you.

Topology Flyback.. low power smps design.. try to make half Bridge

@glossywhite all done for you, posted it up a little while ago, hope you enjoy

Thank you.