This circuit operates from 25 to 65 kHz depending on the transducer used and the settings. We found it in the Radio Electronics magazine of July 1985. The 9V to 12V power supply is not given.
Found in a 90’s Popular Electronics, this circuit applies to almost any operational amplifier. With...
This circuit is suitable for calibrating old oscilloscopes. It was found in a 1980s documentation. It...
We found this circuit in the April 1979 Radio Electronics magazine. Note the filter capacitor bank...