Method of improving pressure sensor measurement by passive current compensation
First Claim
1. A return current balancing circuit for use with a pressure sensor having a return current which varies with temperature, the return current causing voltage fluctuations in a conductor that couples the pressure sensor to ground, comprising:
- a first voltage supply terminal coupled to a first supply voltage (V+),a return current terminal coupled by the conductor to ground and providing a return path for the return current,a second voltage supply terminal coupled to a second supply voltage (V-), the second supply voltage having a lower potential than said ground, anda variable resistive circuit connected between said return current terminal and said second voltage supply terminal, the resistive circuit having a resistance which varies with temperature, whereby a variable current flowing through the resistive circuit substantially reduces the return current.
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Accused Products
Abstract
A simplified method and apparatus for electronic pressure control with compensation for current operating temperature and pressures in which computer memory is employed for storing a plurality of firmware models which characterize the effects of temperature and pressure variations on (1) fluid flow through the flow restrictor, (2) the temperature sensor, and (3) the pressure sensor, so that control signals can be generated which compensate a plurality of thermally coupled sensors for changes in current operating temperatures and pressures.
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Citations
6 Claims
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1. A return current balancing circuit for use with a pressure sensor having a return current which varies with temperature, the return current causing voltage fluctuations in a conductor that couples the pressure sensor to ground, comprising:
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a first voltage supply terminal coupled to a first supply voltage (V+), a return current terminal coupled by the conductor to ground and providing a return path for the return current, a second voltage supply terminal coupled to a second supply voltage (V-), the second supply voltage having a lower potential than said ground, and a variable resistive circuit connected between said return current terminal and said second voltage supply terminal, the resistive circuit having a resistance which varies with temperature, whereby a variable current flowing through the resistive circuit substantially reduces the return current. - View Dependent Claims (2, 3, 4, 5, 6)
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Specification