741 Op Amp Gain Calculator
Here is an operational amplifier circuit with an inverted input. The signal enters pin 2 which is the inverting input. The output signal will therefore be inverted and amplified by a gain value determined by the resistors Rf and Rin..
Just enter the resistor values to see the resulting gain value. When designing an amplifier engineers select easily available standard resistor values to provide the gain need. Hence you should reference the resistor article to select suitable values. The resistor article also shows you the colour code of the resistor.
The negative symbol for the gain signifies that the signal is inverted, because an inverting input is used. Also note that when Rf = Rin gain becomes unity. Unity means 1. This means that the amplitude of the input signal and the output signal will be the same.
For example if you were to use 1K resistors for both Rf and Rin, then the operational amplifier is called a buffer circuit.
This is a non-inverting amplifier. The signal enters pin 3 which is the non-inverting input. The output signal will be amplified by a gain value determined by Rf and R3.
When the feedback resistance is zero the gain becomes unity, hence the circuit acts like a buffer which is commonly found in professional applications.
Author: Peter J. Vis