초록 ▼

A self-zeroing differential pressure signal generator. A strain gauge separates two areas of potentially differing fluid pressure and generates an electrical signal which varies as the fluid pressure difference varies. The strain gauge electrical signal is applied to the noninverting input terminal

A self-zeroing differential pressure signal generator. A strain gauge separates two areas of potentially differing fluid pressure and generates an electrical signal which varies as the fluid pressure difference varies. The strain gauge electrical signal is applied to the noninverting input terminal of noninverting amplifier, which develops a zeroed output signal. The noninverting amplifier includes a feedback loop which sums a feedback signal from the noninverting amplifier output with a zeroing compensation signal at the inverting input terminal of the amplifier. The zeroing compensation signal is developed by periodically eliminating the zeroing compensation signal and simultaneously exposing the strain gauge to a zero pressure difference. The output signal of the noninverting amplifier is compared to a reference output and a zeroing compensation signal is generated which, when summed with the feedback signal, brings the value of the output terminal to the value of the reference output.

대표청구항 ▼

A method of generating a zeroed pressure signal comprising the steps of: generating an electrical signal which varies as fluid pressure difference varies between two domains; applying the electrical signal to the noninverting input of an operational amplifier; applying a feedback signal from the out

A method of generating a zeroed pressure signal comprising the steps of: generating an electrical signal which varies as fluid pressure difference varies between two domains; applying the electrical signal to the noninverting input of an operational amplifier; applying a feedback signal from the output of the operational amplifier to the inverting input of the operational amplifier; periodically eliminating the pressure difference between the two areas; determining a compensation signal to be summed with the feedback signal at the inverting input of the operational amplifier to adjust the output signal of the operational amplifier to the value of a reference signal; and thereafter summing the determined compensation and feedback signals at the inverting terminal while pressure differences are allowed to occur between the domains.