Operational amplifier

An operational amplifier, or op amp, is an integrated circuit that amplifies the voltage difference between two signal inputs. The + input is non-inverting and the − input is inverting: these signs do not mark the power connections. A separate supply provides the energy for the output signal.

Negative feedback returns part of the output to the − input. With suitable feedback, external resistors set a useful, predictable gain. The output is limited by the supply, and real chips also have signal and speed limits. Check the exact device’s pinout: the triangle is a function, not a package drawing.

SparkVille’s observatory hunts for stars that are barely visible to the eye. An op amp boosts the small voltage from a light sensor so the measuring instrument can read it more easily. The power supply provides the energy for the larger output signal.