| 摘要 |
PURPOSE:To achieve convenience and safety when a door is opened by detecting the opening/closing condition of the door, detecting surrounding light when the door is opened, and by forming a circuit by which a floodlight is irradiated when the surrounding light is dark. CONSTITUTION:By a magnet MG mounted on a door, a lead switch SW is actuated according to the opening or closing of the door. Surrounding light is detected by a photoconductive cell Cds. By a power source battery BATT, for the burning of a lamp L and NAND gates IC1m IC2, IC3, a circuit composed of transistors Q1, Q2, resistance R1-R5 is actuated. When the door is closed, the lead switch SW is closed and the lamp L is not burnt. Only when the level of the surrounding light is not more than the specified under the condition of the door opened, the lamp L is burnt. By means of the circuit, safe light is irradiated as required when the door is opened, and it is economical, as the safe light is switched off when the surrounding light is bright. |
