LED CIRCUIT, ILLUMINATOR, LIGHTING METHOD FOR PLANT CULTIVATION, LIGHTING SYSTEM, PLANT PRODUCTION SYSTEM, PLANT CULTIVATION METHOD, LIGHTING SYSTEM SUBSTRATE, FLOATING MAT FOR HYDROPONICS CULTIVATION, AND SPACE STRUCTURE FOR HYDROPONICS CULTIVATION
PROBLEM TO BE SOLVED: To provide an LED circuit for an illuminator, allowing electric power saving and improvement of production efficiency/productivity of a plant factory.SOLUTION: This LED circuit includes basic circuits 3a and 3b made by parallel connecting forward direction parts 1a and 1b which are directly connectable to AC power, and in which a plurality of LEDs are serially connected, and reverse direction parts 2a and 2b in which a plurality of LEDs are serially connected in the reverse direction to the forward direction part 1a, etc., and is formed by connecting a plurality of the basic circuits 3a, etc. The n pieces of the forming LED satisfy circuit formula [I]: 119(V)&le；LEDnV+ZDnV+RnV&le；128(V), on condition that LEDnV is the sum total of voltage of n pieces of LED； ZDnV is the sum total of voltage of all Zener diodes included in the circuit； and RnV is the sum total of voltage of all current fine-tuned resistance included in the circuit.【課題】 植物工場の省電力化、生産効率・生産性の向上を可能とする照明器具用ＬＥＤ回路を提供すること【解決手段】 交流電源に直接接続でき、複数のＬＥＤが直列接続された順方向部１ａ、１ｂ等と、順方向部１ａ等とは逆方向に複数のＬＥＤが直列接続された逆方向部２ａ、２ｂ等とが並列接続されてなる基本回路３ａ、３ｂ等を備え、基本回路３ａ等が複数接続されることでＬＥＤ回路が構成されており、構成するｎ個のＬＥＤは下記回路式〔Ｉ〕を満たすものとする。〔Ｉ〕１１９（Ｖ）≦ ＬＥＤｎＶ ＋ ＺＤｎＶ ＋ ＲｎＶ ≦１２８（Ｖ）ただし、ＬＥＤｎＶ：ｎ個のＬＥＤの電圧の総和ＺＤｎＶ：回路中に含まれる全ツェナーダイオードの電圧の総和ＲｎＶ：回路中に含まれる全電流微調整抵抗の電圧の総和【選択図】 図１
