LED LIGHTING DEVICE

摘要

The purpose of the invention is to obtain, with a simple circuit configuration, an LED illumination device having an LED column driven by a pulsating voltage, capable of lighting with little flicker, and also having lighting control capability. The LED illumination device (400) comprises: an LED column (210) including a plurality of LEDs (211) connected in series; a rectifier (460) receiving an AC power supply (202) and outputting a pulsating voltage to the LED column (210); a current limit circuit (420) connected to the LED column (210) in series and having resistor elements (424 to 426); and a control circuit (250) for controlling the current flowing through the LED column (210) by controlling the resistor elements (424 to 426) and thereby controlling the lighting of the LED column (210).

主权项

1. An LED lighting device comprising:
an LED string including a plurality of LEDs connected in series; a rectifier to which an alternating-current power source is input and which outputs an undulating voltage to the LED string; a current limit circuit connected in series to the LED string; and a control circuit configured to control a current flowing through the LED string by controlling the resistor element, thereby to perform light control of the LED string, wherein the LED string includes a first LED string and a second LED string, the LED lighting device further comprises a bypass circuit having a bypass first input terminal connected between the first LED string and the second LED string, and the bypass circuit causes a constant current to flow via the bypass first input terminal in a case where an undulating voltage output from the rectifier is between a threshold voltage of the first LED string and a total threshold voltage of the first LED string and the second LED string, and shuts off the current via the bypass first input terminal in a case where the undulating voltage exceeds the total threshold voltage.