This 1967 modeling circuit mimics the whistle of a locomotive. The steam-shrieking wheezing is set in a 2k2 potentiometer.
This circuit is from a 1980s Motorola documentation. The circuit can be made with modern...
This anti-ringing circuit was found in an English documentation from 1996. The integrated circuit is...
This circuit was found in an ancient American documentation. With it is possible to double the...