The operational amplifier is arguably the most useful single device in analog electronic circuitry. When you apply them in the circuits, you must know their basics and functions. As for the function ...

In a balanced op-amp circuit, the op-amp inputs see equal impedances looking into the circuit. Balanced circuits provide better performance by cancelling some input errors and have a simple R F /R I ...

Op-amps are among the most widely used electronic devices, and are designed into many consumer, industrial, and scientific devices. General purpose, standard op amps sell for well under one dollar.

And here it is, modelled using LTSpice. It is the same circuit as the classic simple precision rectifier (set to pass the negative half-sine), but with the non-inverting input of the op-amp connected ...

These days there a large number of sensors and analog circuits that are “controller friendly” meaning that their output signal is easily interfaced to the built-in Analog to Digital Convertors (ADCs) ...