| 摘要 |
PROBLEM TO BE SOLVED: To provide a lighting device with high power efficiency and low noise.SOLUTION: The lighting device comprises a power conversion circuit and a control circuit. The power conversion circuit includes a main switching element, a synchronous rectifier element, a coil, and a capacitor, and converts DC power supply to supply the converted power to a light-emitting diode (LED) load connected in parallel with the capacitor. The control circuit performs ON/OFF control on the main switching element and the synchronous rectifier element. When a current flowing in the coil reaches a first preset value, the main switching element is turned off and after the lapse of a predetermined time, the synchronous rectifier element is turned on, by the control circuit. Also, after a polarity of the current flowing in the coil is inverted from a polarity of the first preset value, the synchronous rectifier element is turned off and after the lapse of a predetermined time, the main switching element is turned on, by the control circuit. |
