Twilight switch triggered by photoelectric component - uses bistable flip flop to switch on lamp circuit and prevents switch-off through time switch

摘要

The twilight switch has a photoelectric element which uses a flip-flop to close a switch in a load circuit. The load circuit contains at least one light. The switch has a further device preventing the photoelectric component from disconnecting the circuit because the light has switched on. The switching component operated by the flip-flop at the onset of twilight is a time switch, at whose output is a relay closing the load circuit. An AC feed-back circuit with transistor is provided between its output and the flip-flop.