Power Supply Circuit and Luminaire

摘要

A power supply circuit includes a rectifying circuit, a power-factor improving circuit, a bridge circuit, a transformer, a rectifying and smoothing circuit, first and second drivers, a power supply section, and a control section. The rectifying circuit converts an alternating-current input voltage into a rectified voltage. The power-factor improving circuit improves a power factor of the rectified voltage and converts the rectified voltage into a direct-current voltage. The bridge circuit converts the direct-current voltage into an alternating-current voltage. The rectifying and smoothing circuit converts the alternating-current voltage into a direct-current output voltage. The first driver controls a switching element. The second driver controls the power-factor improving circuit. The power supply section converts the direct-current voltage into a driving voltage corresponding to the first and second drivers. The control section controls supply of the driving voltage to the first and second drivers and a stop of the supply.

主权项

1. A power supply circuit comprising:
a rectifying circuit configured to rectify an alternating-current input voltage and convert the alternating-current input voltage into a rectified voltage; a power-factor improving circuit configured to step up the rectified voltage to improve a power factor of the rectified voltage and convert the rectified voltage into a direct-current voltage; a bridge circuit including at least one switching element and configured to convert the 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 second driver configured to control the conversion of the direct-current voltage by the power-factor improving circuit; a first power supply section configured to convert the direct-current voltage output from the power-factor improving circuit into a driving voltage corresponding to the first driver and the second driver; and a control section configured to control supply of the driving voltage to the first driver and the second driver and a stop of the supply of the driving voltage.