Power supply circuit and LED driving system using same

• Main Authors: HE YINGYAN, LIU GUOQIANG
• Format: Patent
• Language: Chinese; English
• Published: 28.10.2022
• Subjects: APPARATUS FOR CONVERSION BETWEEN AC AND AC, BETWEEN AC AND DC,OR BETWEEN DC AND DC, AND FOR USE WITH MAINS OR SIMILAR POWERSUPPLY SYSTEMS; CONTROL OR REGULATION THEREOF; CONVERSION OF DC OR AC INPUT POWER INTO SURGE OUTPUTPOWER; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER; ELECTRIC HEATING; ELECTRIC LIGHTING NOT OTHERWISE PROVIDED FOR; ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR; ELECTRICITY; GENERATION

The invention provides a power supply circuit and an LED driving system applying the same, the power supply circuit comprises a linear conversion circuit, a first capacitor and a DC-DC conversion circuit, alternating current input is rectified to obtain first rectified voltage, the linear conversion circuit receives the first rectified voltage, the output end is connected with the first capacitor, and after the power supply circuit is started, the first capacitor is connected with the DC-DC conversion circuit. The linear conversion circuit controls the first rectified voltage to charge the first capacitor within a time period when the first rectified voltage is close to a valley bottom position; the DC-DC conversion circuit receives the first capacitor voltage and performs power conversion to output a power supply voltage. In the LED driving system applying the power supply circuit, at least part of the linear conversion circuit and the DC-DC conversion circuit can be integrated with the LED driving circuit i