Originally this circuit was created to produce synchronism pulses in TV cameras SSTV (Low scan frequency), however it can be adapted for other purposes. The integrated circuits are common TTL.
We find this microphone voice effect in 1992 documentation. The vibration of the relay contacts...
This circuit for the car uses LDRs as sensors and does not need to be connected to the lamp. The...
Found in a Popular Electronics from the 90s, this circuit can be made with current equivalent...