This circuit generates sinusoidal signals between 300 and 3000 Hz. We find a 303 Circuits from the 90's. The operational ones are types with FET. The power supply must be symmetrical.
We found this circuit in the Linear Applications Handbook of the National Semiconductor of 1994....
This simple continuity tester, whose configuration can be found several times on this site, is...
This circuit is from old documentation. The operational amplifier is uncommon nowadays. The...