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.
In this circuit the LED lights up when the input voltage drops below the value set in the trimpot. The...
This circuit was obtained from a 2005 Linear Technology manual. The circuit is self-powered and can...
Damped sine oscillations can be produced when short pulses are applied to the input of this...