Found in an old Popular Electronics, this circuit warns when a remote lighting system is not working. The circuit uses an LDR as a sensor and the components used are quite common today.
This additional bell circuit was found in the February 1994 Electronics Now magazine. The...
This low-frequency circuit for alternating signals is from an early American 1980s documentation. The...
This circuit is from a 1967 US publication. The configuration can serve as a basis for designs...