| 摘要 |
<p>PROBLEM TO BE SOLVED: To provide a light emitting diode composite circuit and an illumination device using it preventing all light emitting diodes from becoming turn-off even when the light emitting diodes and bypass elements connected parallel to the light emitting diodes become turn-off also. SOLUTION: This illumination device is constituted so that plural light emitting diodes PD are serially connected to constitute a serial circuit 1, and further, Zener diodes ZD being plural bypass elements are serially connected to constitute bypass circuits 2, 3, and a connection point between the Zener diodes ZD of the serial circuit 2 and the connection point between the Zener diodes ZD of the serial circuit 3 are alternately connected at every the connection point between the light emitting diodes PD of the serial circuit 1 so that the Zener diode becomes antiparallel to the light emitting diode. At this time, when the same current as the current flowing through the light emitting diodes PD of the serial circuit 1 is made to flow through the Zener diodes, the Zener diode ZD having an yield voltage larger than the sum of the forward drop voltage of the light emitting diodes anti-parallel connected between the anode terminal and the cathode terminal of the Zener diode ZD is used.</p> |
