We found this circuit in an English publication from the 1980s. The circuit uses current components and can be tuned for frequencies between 300 and 1500 Hz.
This circuit is designed to activate an automotive alarm after 8 minutes of activation. Of course...
This is one of the channels of an amplifier suggested by Westinghouse in 1970s documentation. The circuit...
This astable multivibrator, well known to all, was found in the Raytheon transistor application manual of...