This circuit was obtained from an American 1980s documentation. The frequency depends on the crystal and the circuit may be a PNP that reaches the generated frequency.
Found in documentation from the 1980s, this circuit can be used with other operational ones. The...
This circuit is from an old publication from 1977 and can be implemented with more modern...
This control for a small servomotor with a current of a few hundred milliamps was found in an...