This Texas Instruments circuit is from the 80's. However, it can be implemented with modern operating systems. The power supply must be symmetrical.
This circuit, which uses only common transistors, was obtained from a 1988 publication, but can be...
This circuit was found in a 1980s documentation. Modern general purpose transistors can be used....
We found this circuit in a publication for radio amateurs of 1976. The operational amplifier is a...