Found in a 1967 American electronics magazine, this circuit has an input impedance of 2000 ohms. The circuit can be built with modern equivalent transistors.
When the light falling on the sensor is cut off, the SCR fires, powering the lamp. Remember that...
When the sensor is wetted by a spray caused by someone falling into a pool or even by a wave...
This traditional TTL anti-clock setting was found in a 1993 American documentation. The circuit...