Using the 555 and 7400 this circuit was found in the September 1977 Radio Electronics magazine. The power supply must be made with a voltage of 5 V.
This circuit is from old European documentation. R1 depends on the output voltage of the...
This circuit can be used in an experimental link for educational purposes. based on an integrated 4093....
This circuit provides just over ½ W to a small speaker. We found this configuration in an old...