Found in a 1990 Hobbyst Handbook this circuit has an output power of a few tens of watts and serves as reinforced for the car's sound. The speaker can be 2 or 4 ohm.
The integrated circuit used in this project is not common today, but it can be implemented with more...
Found in an American publication from 1969, this circuit can be adapted to be used as a shield....
This current meter with many scales was found in a 80s American documentation. The operational amplifier...