Honeywell International Inc.

Richard A Kirkpatrick, Ii

Richard Alan Davis

Ron Foster

Steve R Foote

Rajiv R Singh

Ulrich Bonne

Yue Liu

Mark Robert Plagens

Syed M Shahed

Aziz Rahman

A sensor system for detecting the presence of at least one specific component in a fluid medium such as an exhaust gas. A sensor is mounted in a sensor body for detecting the presence of at least one specific component and providing a representative signal that is transmitted to a remote receiver for processing. A power source such as a thermopile provides power for the sensor and the transmitter. Preferred are sensors that detect a plurality of different components in the gas and provide a distinct signal for each component. A preferred transmitter is designed to transmit at a low duty cycle so as to conserve power. A preferred sensor is electronic, has the capability for self-diagnostics and self-calibration, and causes a change in current when exposed to the component, such as a functionalized field effect transistor.

Wireless gas composition sensor system

Methods of and systems for balancing the capacitance of a common series capacitive circuit in a semiconductor-based sensor, such as a humidity sensor, are described. Relative humidity sensors can provide measurements via a series capacitive circuit including a humidity-sensitive dielectric separating a common top plate and first and second bottom plates associated with a first and second capacitor, Cxand Cx. For proper operation, the common top plate should be in capacitive balance. Capacitive balance can be achieved by creating voids within and/or along the common top plate of the sensor. A system for creating voids can include a precision cutting instrument, a measuring device for enabling the measurement of capacitance of at least one of the common series capacitive circuit, Cxand Cx, and power provided from a voltage source.

Methods and systems for capacitive balancing of relative humidity sensors having integrated signal conditioning

Methods of and systems providing high reliability relative humidity sensors having integrated signal conditioning are described, providing a series capacitive circuit including a humidity-sensitive dielectric, a common top plate and first and second bottom plates associated with a first and second capacitor, respectively. Changes in humidity affect the humidity-sensitive dielectric thereby causing changes in the capacitive value of said series capacitive circuit. The system includes a common top plate; a common humidity-sensitive dielectric formed under said common top plate; a first series capacitor Cx1 including a first bottom plate formed under said common humidity-sensitive dielectric opposite said common top plate; a second series capacitor Cx2 including a second bottom plate formed under said common humidity-sensitive dielectric opposite said common top plate; wherein said first series capacitor Cx1 and said second series capacitor Cx2 commonly share said dielectric and commonly share said common top plate and are arranged in a series capacitor circuit configuration within a semiconductor system. A sampling voltage source can provide a fixed voltage through said series capacitive circuit.

Relative humidity sensor with integrated signal conditioning

A temperature compensation circuit is provided for use in conjunction with a Hall effect element in which the temperature compensating resistors, or epitaxial resistors, are not placed in the signal loop as portions of the feedback loops of amplifiers. The circuit therefore permits a higher degree of linearity and temperature compensation without inducing the problems that are normally caused by varying voltage potentials across the epitaxial resistors. One embodiment of the circuit also provides a means for clamping, or truncating the output voltage of the circuit to a preselected percentage of the supply voltage even though the supply voltage may vary during the operation of the device. The circuit utilizes several external trimmable resistors to perform final adjustment on the circuit in order to permit individual variations from component to component to be compensated.

Circuit for limiting an output voltage to a percent of a variable supply voltage

A current regulator is provided for a two wire sensor and comprises first and second conductors arranged to provide a sensor output current, a first resistance and a current reference coupled across the first and second conductors, and a second resistance and sensor load terminals coupled across the first and second conductors. An amplifier has first and second inputs and an output. The first input is coupled to a first junction between the first resistance and the current reference, the second input is coupled to a second junction between the second resistance and the sensor load terminals, and the output is connected to the second input. The amplifier controls a first voltage at the first junction to be substantially equal to a second voltage at the second junction.

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Richardson, TX, United States of America

Richard A Kirkpatrick, Ii