1. AC Inlet & AC Input Filter
Inductor ( L )
Capacitor (C )
AC Input Filter :
Reducing and filtering Noise from AC line.

2. Bridge Rectifier & Filter
Bridge Diode
Capacitor
Convert AC voltage into DC voltage by rectifying and smoothing AC.

3. Reduce the high voltage to a lower voltage.
Converter
Reduce the high voltage to a lower voltage.
Power MOSFET , PWM IC Control : Control the high frequency switching pulse width and frequency to stabilize the output.
SW Transformer : Step down the voltage with a high frequency transformer.

4. Rectifier and Output Filter
Diode
Capacitor
Turning the AC into DC and filtering smoothing the ripple of the rectified voltage

5. Feedback Circuit
Check error from secondary side and transfer to primary side (Control circuit)
Optocoupler : Isolation and transfer signal from secondary to primary.
Error Amplifier : Control output voltage is stability.