Patent ID: 7132838

Claim:
A sensor circuit comprising: 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; 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; 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 being connected to the third junction and the fourth impedance being connected to the second junction; and a constant voltage source connected to the third impedance and to ground, the second end of the second variable resistance sensor element being connected to a fourth junction intermediate the constant voltage source and ground.