This circuit switches on an external load after a certain interval given by the capacitor. The circuit is from a documentation from the 80s. The load depends on the relay used.
Found in documentation from the 1990s, it uses a sound effects integrated circuit, the SN7677 from...
We found this circuit in a 2005 documentation. The circuit uses an infrared piezo sensor...
This circuit is from a 1979 publication, using displays of 7 segments of common cathode. The...