This circuit, which can be built with several CMOS gates, was found in the March 1996 issue of Electronics Now magazine. The circuit has the base frequency determined by R1 and C1.
This interesting automotive alarm was found in a 90's Popular Electronics. The circuit uses...
Using the 4001 integrated circuit, this latching relay can employ any general-purpose transistor. The...
The PA222 integrated circuit used in this project from an American 1967 documentation is not...