Don't be afraid of operational amplifiers (or how to demonstrate the voltage induced in a piece of wire)
2015
Abstract
The paper describes an experimental device that enables to build four circuits with operational amplifier: comparator, voltage follower, non-inverting amplifier and voltage-to-current convertor. The last circuit can be used as a device that indicates small voltages (from 0.1 mV) by LED- The intensity of LED light is proportional to the input voltage (up to 10 mV).
The device can be used in physics teaching to demonstrate a voltage induced in a piece of conductor when a small ferrite magnet moves in its vicinity.