Self-zeroing pressure signal generator
First Claim
1. 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.
1 Assignment
0 Petitions
Accused Products
Abstract
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.
73 Citations
11 Claims
-
1. 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.
-
-
2. A self-zeroing pressure signal generator for measuring the static pressure of a fluid, the signal generator comprising:
-
a pressure transducer generating a fluid pressure level signal; means for establishing a known pressure difference on the pressure transducer; means for generating a zeroing compensation signal; a comparator comparing the fluid pressure signal to the zeroing compensation signal and generating a compensated fluid pressure signal thereby; and means for initiating calibration of the compensated fluid pressure signal by actuating the means for establishing the known pressure difference and by adjusting the output of the means for generating a zeroing compensation signal to provide a compensated fluid pressure level signal of a predetermined value. - View Dependent Claims (3, 4, 5, 6)
-
-
7. A self-calibrating pressure differential sender comprising:
-
a pressure transducer dividing two pressure domains and generating an uncompensated pressure difference signal related to the pressure difference between the domains; a plurality of amplifier stages for amplifying the output of the pressure transducer; the plurality of amplifier stages including a compensation amplifier stage for converting the uncompensated pressure difference signal into a compensated pressure difference signal; a compensation offset circuit generating an output signal for calibrating the compensation amplifier stage; a valving system for connecting the two pressure domains; and a clock for initiating periodic adjustment of the output signal of the compensation offset circuit including actuation of the valving system to establish a pressure equilibrium between the two domains. - View Dependent Claims (8, 9, 10, 11)
-
Specification