Found in an old Popular Electronics this circuit can also be adapted to be used as a shield. In this version the control can trigger loads from the light that falls on an LDR.
This circuit is from the 80's, making use of components of the time. What the circuit does is...
This circuit was found in a 1980s Signetics documentation. The integrated circuit is from the era. The...
We found this alarm in a 1992 documentation. The circuit has several timings and the relay can...