This circuit uses a photo-SCR or LASCR that is not a common component today. The relay depends on the load, and the power is supplied by the power grid.
This PUT oscillator circuit has a frequency of 1 Hz. We find it in a General Electric...
This circuit for the car uses LDRs as sensors and does not need to be connected to the lamp. The...
This circuit of an Electronics Now from the 90's produces an intelligent direction signal that has...