We found this light relay circuit in year 2000 documentation. The relay is 6 V and the circuit includes a power supply. It can be used to control various devices from the incident light in the LDR.
In the figure we have the receiver of a sequential remote control operating at a frequency in the range of...
This circuit is from an American 1967 documentation and can be implemented with modern equivalent...
We found this circuit in a French publication from the 1980s. The coils L1 and L2 are formed by 4...