This high quality circuit with complementary symmetry was found in an Electronics World of 1966. It can be made with modern transistors like the BD or TIP series.
We found this circuit in a 1977 Radio Shack documentation. The circuit should be powered, for...
This sound or voice relay was found in a Popular Electronics. It includes an amplification stage and can be...
This crystal-controlled circuit was obtained from a 1980s documentation. The power supply should be 5...