This simple trigger circuit was found in a 90’s American documentation. The integrated circuit is the 555.
This simple megaphone is from old documentation, but uses still current components. The circuit is...
Found in a 90s R-E Experimenter Handbook, this circuit has a greater gain than the previous one for...
This 5.1 MHz circuit was found in a 1980s documentation. The frequency is given by the crystal and...