The Voltage Regulating Process of Parallel Switching Power Supply
If the mains voltage rises, the voltage on C1 will also rise, the current flowing through L1 is large, and L1 stores more energy; when VT is turned off, the upper negative and lower positive electromotive force generated by L1 is high, and the electromotive force charges C2, making the voltage U0 is elevated.
In order to ensure that the voltage across C2 does not rise when the mains voltage rises, the pulse signal sent to the VT base can be narrowed, the VT conduction time is short, the current flowing through the winding L2 is short, and the L2 energy storage is reduced. The electromotive force generated when VT is turned off decreases, the charging current to C2 decreases, and the voltage across C2 falls back to the normal value.
