Abstract: A magnetostrictive position sensor achieves an improved signal to noise ratio by implementing several electronic control features, including: enclosing a waveguide within an approximately tubular return conductor, adjusting the energy of an interrogation pulse and then clamping the waveguide, tracking the peak voltage of a sensed signal, cutting off the signal of a pickup during the time period outside of a signal time frame, adjusting the pass band of a filter based on an interrogation rate and waveguide length, zeroing and scaling a signal without digitizing the signal, and avoiding noise from an interrogation voltage generator.

Abstract: A magnetostrictive position sensor achieves an improved signal to noise ratio by implementing several electronic control features, including: enclosing a waveguide within an approximately tubular return conductor, adjusting the energy of an interrogation pulse and then clamping the waveguide, tracking the peak voltage of a sensed signal, cutting off the signal of a pickup during the time period outside of a signal time frame, adjusting the pass band of a filter based on an interrogation rate and waveguide length, zeroing and scaling a signal without digitizing the signal, and avoiding noise from an interrogation voltage generator.

Abstract: A position sensing head combines a sensing element and a simplified electronic module to enable operation with one wire, in addition to a circuit common, for providing power and transmitting a signal, while separating the sensing head from signal conditioning circuits by over 10 meters. The simplicity of the electronic module allows the use of basic electronic components that operate at more than 225° C. The signal is a variable frequency impressed onto the one wire, which can be read by a frequency meter. Another signal, such as a position or temperature, can be impressed onto the one wire at the same time as the first signal. The second signal is of a different frequency range so that it will not interfere with the first. A demodulator circuit can separate the two signals. The sensing element construction allows for locating up to three active elements measuring the same target.

Abstract: A position sensing head combines a sensing element and a simplified electronic module to enable operation with one wire, in addition to a circuit common, for providing power and transmitting a signal, while separating the sensing head from signal conditioning circuits by over 10 meters. The simplicity of the electronic module allows the use of basic electronic components that operate at more than 225° C. The signal is a variable frequency impressed onto the one wire, which can be read by a frequency meter. Another signal, such as a position or temperature, can be impressed onto the one wire at the same time as the first signal. The second signal is of a different frequency range so that it will not interfere with the first. A demodulator circuit can separate the two signals. The sensing element construction allows for locating up to three active elements measuring the same target.

Abstract: A contactless sensor utilizes analog and digital circuitry to provide direct interchangeability with a simple potentiometric sensor, matching all of the electrical properties of a potentiometer, including supply voltage range, power supply current, output voltage range, and having three connection terminals. The contactless sensor operates with voltages from 2 to 30 volts direct current, which includes all of the common industrial sensor power supply voltages: 5V, 10V, 24V, and +/? 15V. The contactless sensor utilizes a total current of less than 0.005 amperes, and its output voltage range includes the power supply rails. These improvements combine to enable the contactless sensor to be a direct replacement when a potentiometric sensor is removed from service.

Abstract: Method and apparatus are disclosed for electronic simulation of a potentiometer, and for providing a potentiometric output voltage that is representative of a parameter. The invention also teaches a non-contact type of sensor apparatus producing an output voltage that is indicative of a value of a sensed physical parameter. Electrical characteristics of a potentiometer are simulated by implementing a novel combination of analog and digital circuit techniques. Some of these characteristics include low input current, wide power supply voltage range, and an output voltage range that includes the power supply voltages. The present invention also teaches a sensor comprising electronically simulated potentiometer circuitry and a non-contact sensing element.

Abstract: An apparatus is disclosed for measuring a variable angular position of a movable part. The apparatus comprises at least two resonators formed by coupled slow-wave structures, and at least two movable targets having electrodynamic profiles, the targets also having a variable angular position. The angular position of the target is representative of the angular position of the movable part. An electromagnetic field is excited in the resonators at a frequency at which electromagnetic parameters of the resonators depend upon the position of the targets. A change in the angular position of the targets therefore causes a change in electrodynamic parameters of the resonators. The change in the electrodynamic parameters of the resonators is converted into a reading, such as an output voltage, which is indicative of the measured angular position.

Abstract: An apparatus is disclosed for measuring one or more parameters of a variable physical structure, at least one of the parameters being fluid level, position, velocity or acceleration. The apparatus includes an electromagnetic sensing element comprising at least two electrically conductive members that are electrically insulated from one another. A distributed capacitance and a distributed inductance are each formed along a length of the sensing element. The inductive reactance is at least ten percent of the capacitive reactance, thereby allowing the capacitance to be distributed, rather than acting as a “lump capacitance”. The distributed capacitance enables shaping of the electric and magnetic fields around the electromagnetic sensing element so that disturbance by nearby electromagnetic fields, conductors, and dielectrics is minimized. When the apparatus is configured as a fluid level sensor, the capacitance is affected by the permittivity and the level of the measured fluid.

Abstract: An apparatus is disclosed for measuring the angular position of a movable part. The method and apparatus comprise at least two resonators formed by coupled slow-wave structures, e.g. coupled spirals, and a movable target. The angular position of the target is representative of the angular position of the movable part. A change in the angular position of the target causes a change in electrodynamic parameters of the resonators. The change in the electrodynamic parameters is converted to a reading of angular position of the target with respect to the resonators. An electromagnetic field is excited in the resonators at a frequency at which electromagnetic parameters of the resonators depend upon the position of the target.

Abstract: A capacitive fluid level sensor is disclosed that operates without the use of a float, wherein coplanar sensing electrodes disposed onto a dielectric substrate and positioned proximate a dielectric wall of a vessel containing a fluid, form a fringing field capacitance that changes in accordance with changes in the level of the fluid. The electrodes are electrically insulated from the measured fluid. The electrodes are sized and spaced to maximize response of the capacitance to changes in the level of the fluid, while minimizing the effects of the dielectric wall. The sensor is fabricated such that it can be positioned against the outside of a dielectric wall of a vessel, or embedded within a dielectric material. A low permitivity spacer and shield assembly are taught which reduces sensitivity to electric fields external to the vessel.

Abstract: A method and apparatus are disclosed for monitoring a linear position, such as the distance between a sensing element and a movable object, and/or related parameters, such as displacement, direction, speed, velocity, and/or acceleration. The method utilizes a sensing element and an electrically conductive portion of the movable object, or a conductive target coupled to the movable object. The apparatus includes at least one sensing element formed by a section of a coupled slow-wave structure. The sensing element is connected to an RF or microwave generator, and an electronic circuit that converts at least one electromagnetic parameter of the section of the coupled slow-wave structure into a position reading. Electric and magnetic fields excited in the sensing element are split so that most of the electric energy is concentrated inside of the sensing element, while most of the magnetic energy is concentrated outside of the sensing element.

Abstract: Inductive position sensors and circuit configurations are disclosed for the measurement of linear, rotary, or curved position along a motion axis. The simplified sensor structures combine one or two parts of a movable core element with a simple planar substrate having first and second inductances connected in series. Movement of the core element in parallel to the planar substrate causing the impedance of at least one of the inductances to change. Simple circuit configurations are taught by which the impedance change is converted into a useful output signal that indicates position along the motion axis.

Abstract: An improved delay line with an input and an output is disclosed wherein a signal passing through the delay line from the input to the output can be optimized regarding the delay line component size, delay time, and signal configuration. The design and use of more than one impedance conductor is taught. The impedance conductors are arranged in specific alignments with each other and with dielectric bases to result in reduced component size, increased delay time, and to adjust the signal configuration. Further optimization of these features is taught through the use of a shield cover in specific alignment to the impedance conductors and dielectric bases.

Abstract: An improved delay line with an input and an output is disclosed wherein a signal passing through the delay line from the input to the output can be optimized regarding the delay line component size, delay time, and signal configuration. The design and use of more than one impedance conductor is taught. The impedance conductors are arranged in specific alignments with each other and with dielectric bases to result in reduced component size, increased delay time, and to adjust the signal configuration. Further optimization of these features is taught through the use of a shield cover in specific alignment to the impedance conductors and dielectric bases.