Capacitive divider clamped single-ended flyback switching regulated power supply

The figure below shows a single-ended flyback switching regulated power supply using capacitor voltage divider clamping. When VTl is turned on, capacitor C02 is charged, COl is discharged, and about 1/2 of the input voltage is applied to the primary winding N1l of transformer T1; when VTl is turned off, the polarity of the voltage on Nll is reversed, and at the collector-emitter voltage Ucel of VT1 When the input voltage Ui is reached, the diode VD4 is turned on and Ucel is clamped; similarly, when VT2 is turned on, C02 is discharged, C0l is charged, and about 1/2 of the input voltage is applied to the primary winding N21 of T2; when VT2 is cut off, The voltage polarity on N21 is reversed. After VD3 is turned on, Uce2 is also clamped to the input voltage Ui. This circuit is actually a combination of two single-ended flyback conversion circuits. It not only achieves voltage clamping, but also when VTl and VT2 are alternately on and off, the output power is superimposed, doubling the output power of the secondary side.