Active sensor circuit with one or more T-network pairs

摘要

A sensor circuit is provided that comprises a first T-network including a first impedance serially connected to a second impedance at a first junction and a first variable resistance sensor element connected at a first end to the first junction and at a second end to ground. The sensor circuit further comprises an operational amplifier having a non-inverting amplifier input terminal connected to ground, an inverting amplifier input terminal connected to the first impedance at a second junction and an amplifier output terminal connected to the second impedance. The sensor circuit also comprises a second T-network including a third impedance serially connected to a fourth impedance at a third junction and a second variable resistance sensor element having first and second sensor element ends. The first sensor element end is connected to the third junction and the fourth impedance is connected to the second junction. The sensor circuit further comprises a constant voltage source connected to the third impedance and to ground. The second end of the second variable resistance sensor clement is connected to a fourth junction intermediate the constant voltage source and ground.