The integrated circuit used in this 70's application is not common today. The circuit consists of a small audio amplifier with few external components.
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...