TinaTi is a free Electronic circuit drawing and
simulation tool You can draw, simulate and test Your idée, with some limits regarding component choice, size and complexity in free version. And usage environment.
This is a so called IA amplifier.
A circuit drawing is the start point of most
constructions, but rarely simpel as this one.
This could bee included infor exampel an analog temperature sensor amplifier.
Usually You start with some kind of real testcircuit