This simple Morse Code oscillator was found in a 1980s American documentation. The power supply should be powered with 5V and the integrated can be the 7400.
This circuit was suggested by Linear Technology in a 1980s documentation but can be implemented with...
This circuit is recommended by Texas Instruments in the datasheet of the TL317, equivalent to...
Unlike the previous circuit, this circuit has a low impedance input. The components can be changed to...