This circuit tunes MW radios to apply the signal to a good audio amplifier. The circuit is from an old documentation. Transistors are general purpose types.
This circuit was found in an American documentation from the 90s. It can be implemented with...
This 2-terminal regulator was obtained from a 1990s National Semiconductor manual. The components admit...
This circuit uses a photocell as sensor and a sensitive relay according the power supply voltage....