The utility model provides a high-
voltage flyback power supply circuit, which belongs to the field of flyback
switching power supplies and comprises a
transformer T1, an input circuit arranged on a primary side of the
transformer T1 and an output circuit arranged on a
secondary side of the
transformer T1. The input circuit comprises N switching tubes, N divider resistors, N divider capacitors, N driving resistors, N-1 diodes, N-1
voltage stabilizing diodes and N-1 protective resistors, the N switching tubes are sequentially connected in series between the
synonym end of the primary side of the transformer T1 and the ground, the driving end of the first switching tube inputs a driving
signal, and the driving end of the second switching tube inputs a driving
signal; the driving ends of the other switching tubes are respectively connected with a direct-current driving
voltage; the main winding of the transformer adopts a single winding, the process is simple, the reliability is improved, a plurality of switching tubes are connected in series at the
low voltage end, a voltage dividing
capacitor and a voltage dividing
resistor are connected in parallel between the first end and the second end of each switching tube, and only a driving
signal needs to be input at the driving end of the last switching tube at the
low voltage end, so that a driving transformer and a
driving circuit are greatly saved; the cost is reduced.