| 摘要 |
PURPOSE:To make cyclic check easy by installing a photocell, a flip flop and a display circuit and, when a drop of illuminence that is lower than the criterion level is detected, keeping the illuminence stored and displayed. CONSTITUTION:A lighting-up discriminator for street lighting 10 is constituted of a photoelectric cell PC, a flip flop FF and a display circuit 30. When the photoelectric cell PC detects a prescribed level is higher than the lighting-up level of street light, the flip flop FF is reset. When the cell PC detects a prescribed level is lower than the lighting-up level and the light-out level, an output of a converter C1 is reversed and the flip flop FF is reset. Thereby, AND gate 31 of the display circuit 30 is opened and a light emission diode LD comes to be in a flickering condition. As the setting of the flip flop FF is held, it is in a flickering condition even at the time of the day-time round, and stored and displayed so that a trouble of non-lighting-up at night can be detected. Thereby, the night round and the grievance procedure become unnecessary and the maintenance, easy. |
