The configuration shown was found in an old Poptronics but can be easily assembled using a common calculator photocell. The relay is according to the supply voltage.
Obtained from a 1980s Signetics documentation, this circuit uses a common integrated circuit at the...
This circuit that can be used as a three-tone domestic bell has a traditional configuration that...
With 3 transistors, we found this receiver in a documentation from 1966. The circuit has an output...