| 摘要 |
Provided is an LED drive circuit wherein, when a full-wave rectification waveform is applied to a row of LEDs to cause them to emit light, the luminance of the emitted light increases in the low voltage phase of the full-wave rectification waveform due to the addition of a simple circuit. The LED drive circuit includes the following: a rectifier circuit that outputs a full-wave rectification waveform voltage; a primary light-emitting LED row that includes a first partial LED row wherein a plurality of LEDs are connected in series and a second partial LED row wherein a plurality of LEDs are connected in series; an auxiliary light-emitting LED row wherein a plurality of LEDs are connected in series; a bypass circuit that is connected to the part connecting the first partial LED row and the second partial LED row and that returns the current from the first partial LED row to the rectifier circuit; and a current limiting circuit that limits the current flowing through the auxiliary light-emitting LED row. This LED drive circuit is characterized in that the primary light-emitting LED row and the auxiliary light-emitting LED row are connected in parallel to the rectifier circuit; and in that the bypass circuit blocks the current passing through the bypass circuit in accordance with the current flowing through the primary light-emitting LED row, and controls and blocks the current flowing through the auxiliary light-emitting LED row. |
