This is the Voltage Follower used to transfer or copy a voltage from a first circuit (Vin) to a second circuit (V out),with gain rate is equal to 1 only, that is AV = Vout/Vin = 1 ; Vout = Vin.
The input has high impedance, and the output is low impedance.
It prevents the first circuit from loading of the second circuit, the output current don’t lower.
We used the op-amp IC LM741 for this operation that is easily and low cost.
Unity Gain Follower by IC LM741
This be Unity Gain Follower by IC LM741 circuit, Use for fine impedance tall from go to low. Be compared as the bumper of electronics circuit well. By this easy last circuit extend a contract that go out to pin 2 be making expansion ratio equals to one. make Vout = Vin