With this circuit, from an old operational datasheet, it is possible to measure the CMRR, rejection in common mode of an operational one. The power supply must be symmetrical.
One of the problems with common 3-terminal regulators is that the internal reference, normally 1.25 V,...
This circuit found in French documentation, works with 15 V logic, but can be modified to TTL or 5...
We found this circuit in a 1972 documentation. The transistor, in fact, is a unijunction that can...