This circuit is from a 1969 RE Experimenters Handbook. The circuit is powered by the voltage of the circuit being tested. Integrated circuits are current.
We found this circuit in an old documentation from the 70s. The text is the original one of the...
The circuit shown in figure is suggested by Maxim in an application note. The operational...
We found this amplifier in a 1990 documentation. The transistors are common, having been made...