This simple wireless microphone circuit for the MW band was found in an old American documentation. The coil is the oscillator of an old MW radio.
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...