The PA222 integrated circuit used in this project from an American 1967 documentation is not common today. The circuit can deliver higher power with lower fidelity.
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...