This 1967 Ferranti circuit uses company components. These transistors can be replaced by modern equivalents. The sensor is an LDR.
Found in a 90s Popular Electronics this circuit has its gain given by R2. This component can be...
This circuit was obtained in an English publication of the 80's, finding applications in...
This circuit was found in a 1977 Radio Shack documentation. The circuit is TTL, which must be...