Total temperature probe buffer amplifier

摘要

The elimination of undesirable thermally induced changes of electrical characteristics of signal components is accomplished three operational amplifier circuits. The first operational amplifier provides electrical power to a system critical component and produces a reference output signal composed of the desirable function produced by the system critical components plus the undesirable thermally induced signal components produced by the changes of the electrical characteristics of two identical lead wires connected to the system critical component. The second operational amplifier circuit senses the voltage drop in one of the two identical lead wires attached to the critical component. The second operation amplifier produces a sensing output signal that changes in value with the undesirable thermally induced changes of the electrical characteristics of one of the lead wires. Since the two lead wires are identical in resistance characteristics the sensing output signal varies proportionately with the total undesirable electrical signal components encountered. The third operational amplifier circuit is a subtraction circuit producing a system output signal proportionate with the difference between the reference output signal and the sensing output signal. The result is a system output signal with all undesirable thermally induced signal components eliminated.