A self-powered power supply circuit for a flyback power converter

The invention relates to a self-supply circuit for a flyback power converter. A bus voltage supply module supplies power to a control chip after the bus is powered on. After the control chip is powered on, the primary winding of the transformer is controlled to work by the power supply control module, and the secondary auxiliary winding of the transformer obtains voltage from the coupling of the primary winding to supply power to the secondary winding of the transformer. The power supply module of the secondary winding of the transformer is charged to supply power to the control chip. The switching module turns off the power supply output of the bus voltage supply module to the control chip after the secondary winding power supply module of the transformer is fully charged. After the powersupply module of the secondary winding of the transform is charged, The bus voltage is cut off, and the auxiliary winding supplies power to the control chip alone. If the power supply module of the secondary winding of the t