In the figure we have a simple way to produce tone in a piezoelectric transducer. The frequency depends on the capacitors and the supply can be done with voltages from 1.5 to 6 V.
This circuit was found in the September 1976 issue of Radio Electronics magazine. The circuit is...
We found this circuit in a 1995 documentation. It operates in the 3.5 MHz band that corresponds to the 80...
This 3-decade operating range VCO was found in a 90s Popular Electronics. The circuit uses...