This is a commercial circuit from the year 1958. Transistors are germanium types and transformers and coils are hard to fild today. The circuit is destinated to the reception of medium wave stations.
This interesting logic circuit was found in a manual of neon lamp applications. | Clique na imagem...
This circuit is from an American publication from 1970. It uses a coal microphone, which is...
This adjustable regulator uses the 741 and power transistors and can supply a current of up to 1...