We found this configuration in documentation from the 1980s. It applies to almost any operational amplifier and in this version requires a symmetrical power supply.
This circuit was obtained in the publication 101 Electronics Projects of 1979. The circuit can be...
With this name, we found this electronic stethoscope with a coal microphone in a 1957 Raytheon...
We find this oscillator in a 1980s documentation. The frequency depends on the crystal and the...