| 摘要 |
PROBLEM TO BE SOLVED: To provide a power supply circuit capable of coping with a wide range of a DC voltage to a high frequency AC voltage.SOLUTION: The power supply circuit 14 of an LED lamp 10 includes booster elements 145(145a-145c) for boosting an input voltage by self-induction electromotive force, rectification units 141, 142 and a smoothing unit 143 connected with the booster elements 145 and converting AC to DC, and a driver unit 144 for adjusting the output current to an LED lighting unit 15. The driver unit 144 monitors the output current, flowing based on the impedance of a path of the output current flowing to the LED lighting unit 15, and adjusts the output current to the LED lighting unit 15 by switching in a high frequency region, with the output voltage where an AC voltage is superposed on a DC voltage.SELECTED DRAWING: Figure 2 |
