| 主权项 |
1. A lighting device for providing power from an AC power source to turn on a light source, comprising:
a pair of input terminals to which the AC power source configured to output an AC current may be electrically connected; a pair of output terminals to which the light source may be electrically connected; a rectifier circuit configured to generate a pulsating current by full-wave rectification of the AC current; a conversion circuit configured to convert the pulsating current from the rectifier circuit into a DC current, and to output the DC current to the pair of output terminals; a constant current circuit configured to make the DC current outputted by the conversion circuit into a constant current and supply the constant current to the light source connected to between the pair of output terminals; and a control circuit configured to control the conversion circuit and the constant current circuit, wherein the rectifier circuit comprises: a pair of first input ends electrically connected to the pair of input terminals, respectively; and a pair of first output ends electrically connected to the conversion circuit, wherein the conversion circuit is a single-ended primary inductance converter, wherein the conversion circuit comprises: a pair of second input ends electrically connected to the pair of first output ends of the rectifier circuit, respectively; a pair of second output ends electrically connected to the pair of output terminals, respectively; a first capacitor connected between the pair of second input ends; a first series circuit comprising a first inductor and a switching element, which are connected in series, and being connected in parallel to the first capacitor; a second series circuit comprising a second capacitor and a second inductor, which are connected in series, and being connected in parallel to the switching element; and a third series circuit comprising a diode and a third capacitor, which are connected in series, and being connected in parallel to the second inductor, wherein the third capacitor is connected between the pair of second output ends, wherein the conversion circuit is configured to output the DC current by on/off of the switching element being controlled by the control circuit, and wherein the third capacitor comprises a high potential-side terminal and a low potential-side terminal, the high potential-side terminal being electrically connected to a first output terminal of the pair of output terminals, the low potential-side terminal being electrically connected to a second output terminal of the pair of output terminals, via the constant current circuit. |
