We design a novel type of switching power supply which is an integration of flyback type and half-bridge resonant typology. Based on signal flow graph and division of functional modules of the circuit, we elaborate on the design principle, functions of different modules and working process of the switching power supply. By using three-terminal adjustable shunt regulator TL431, LD7535 and L6599, the voltage control of the power supply and voltage stabilizing are realized by regulating the pulse width and pulse frequency, respectively. The power factor is increased by adopting active power facto...
