Power Supply Circuit and Luminaire

摘要

A power supply circuit includes a bridge circuit, a transformer, a rectifying and smoothing circuit, a driver, a feedback circuit, and a power supply section. The bridge circuit converts a direct-current voltage into an alternating-current voltage. The transformer includes a primary winding wire and a secondary winding wire. The rectifying and smoothing circuit converts the alternating-current voltage into a direct-current output voltage and supplies the direct-current output voltage to a direct-current load. The driver controls ON and OFF of the switching element. The feedback circuit receives a detection signal of an output current flowing to the direct-current load and a differential signal obtained from fluctuation of the output voltage and feedback-controls the driver on the basis of the signals. The power supply section generates a driving voltage corresponding to the feedback circuit from the output voltage and supplies the driving voltage to the feedback circuit.

主权项

1. A power supply circuit comprising:
a bridge circuit including at least one switching element and configured to convert a direct-current voltage into an alternating-current voltage according to ON and OFF of the switching element; a transformer including a primary winding wire connected to the bridge circuit and a secondary winding wire magnetically coupled to the primary winding wire; a rectifying and smoothing circuit configured to convert the alternating-current voltage output from the secondary winding wire into a direct-current output voltage and supply the direct-current output voltage to a direct-current load; a first driver configured to control ON and OFF of the switching element; a feedback circuit configured to receive a detection signal of an output current flowing to the direct-current load and a differential signal obtained from fluctuation of the output voltage and feedback-control the first driver on the basis of the detection signal and the differential signal; and a power supply section configured to generate a driving voltage corresponding to the feedback circuit from the output voltage and supply the driving voltage to the feedback circuit.