| 摘要 |
<p>PURPOSE:To enable assured alarm setting and confirmation thereof by providing a circuit detecting darkness of the environment, and a device by which output alarm is set and which emits light for a specific time, accompanied by the setting. CONSTITUTION:When light is turned off at a condition that alarm is not set, a phototransister 12 is turned out, differential pulses are generated from a differential circuit 14 to actuate a timer circuit 16, and pulses are generated ten seconds after. A level detection circuit 15 generates its output when the environment thereof is darker than a certain level. In case that the output and the pulses are generated simulteneously, it is regarded that the light is turned off. And, the pulses from the circuit 16 are generated from a gate circuit 8 and fed to a solenoid 29, and then a set switch 17 closes and alarm is set. At the same time, a pulse of around 10 seconds width is generated from an one-shot circuit 19 to turn on a light-emitting device 20. With these procedures, assured alarm setting and confirmation thereof are well conducted.</p> |
