Abstract: A bleeder current control method. The bleeder current control method includes the following steps: The rectifier bridge transmits a post-bridge input signal to the power system. The shaping circuit obtains the post-bridge input signal and shapes it into a bleeder current reference signal, the bleeder current reference signal is inversely correlated with the initial post-bridge input signal. Acquiring a current sampling signal representing the bleeder current, and comparing the error of the current sampling signal with the bleeder current reference signal to obtain an error signal. The current sampling signal is controlled according to the error signal, so that the current sampling signal is output based on the waveform of the bleeder current reference signal. Thus, a reliable and full-time sine wave envelope signal is provided to the power system, so as to reduce the loss caused by the bleeder current to the power system.

Abstract: The application discloses a ripple suppression circuit and a ripple suppression method for quasi-resonant flyback power supply, wherein the ripple suppression circuit comprises a compensation circuit and a control circuit, the compensation circuit configured to generate a compensation signal based on bus voltage, and the control circuit configured to compare a first signal and a second signal to provide a first control signal to control the power switch of the quasi-resonant flyback power supply turning from the on state to the off state. Wherein the first signal is compensated by the compensating signal. Compared with traditional power switch control mode of quasi-resonant flyback power supply, the application takes the bus voltage as a part of the first signal, and compares the first signal with the second signal, then controls the status of the power switch according to the comparison result.

Abstract: The application discloses a power supply control circuit, a power supply control method, and a flyback switching power supply. The power supply control circuit is configured to power a wide voltage output circuit, having an input terminal coupled to an input voltage, having an output terminal configured to output a power supply voltage. The power supply control circuit comprises a boost circuit, the boost circuit comprising a first switch tube and a switch control circuit, the switch control circuit coupled to a control terminal of the first switch tube. The switch control circuit is configured to control the first switch tube to start switching action when the input voltage is less than a preset voltage, and configured to control the first switch tube to stop switching action when the input voltage is greater than the preset voltage. The switch control circuit comprises a charge and discharge circuit, a first comparison circuit and a trigger circuit.

Abstract: A bleeder current control method. The bleeder current control method includes the following steps: The rectifier bridge transmits a post-bridge input signal to the power system. The shaping circuit obtains the post-bridge input signal and shapes it into a bleeder current reference signal, the bleeder current reference signal is inversely correlated with the initial post-bridge input signal. Acquiring a current sampling signal representing the bleeder current, and comparing the error of the current sampling signal with the bleeder current reference signal to obtain an error signal. The current sampling signal is controlled according to the error signal, so that the current sampling signal is output based on the waveform of the bleeder current reference signal. Thus, a reliable and full-time sine wave envelope signal is provided to the power system, so as to reduce the loss caused by the bleeder current to the power system.