Abstract: A calibrated load cell includes a monolithic load beam having a first region, a second region on a distal end of the load beam from the first region for receiving a force from a load, and a third region arranged between the first and second regions, wherein the third region comprises a recess on one side of the load beam. A strain gauge is arranged in the recess for detecting a deformation of the third region from the load and for generating a strain gauge output signal proportional to the deformation of the third region. The load cell also includes a microcontroller arranged in the recess for receiving and processing the strain gauge output signal to produce a load cell output signal that represents the load on a load cell output cable. The microcontroller transforms the strain gauge output signal based on calibration parameters to produce the load cell output signal as a calibrated load cell output signal.

Abstract: A proximity detector includes a sensor providing a proximity reading. The proximity detector is capable of comparing the reading to a rising threshold level and a falling threshold level, wherein the falling threshold level is less than the rising threshold level. The proximity detector filters the proximity reading through three low pass filters using a three different time constants to generate three filtered readings. While the proximity detector is in the no material present state, the proximity detector will enter the material present state when the second filtered reading is less than the difference between the first filtered reading and the falling threshold. While the proximity detector is in the material present state, the proximity detector enters the no material present state when the third filtered reading is greater than the sum of the first filtered reading and the rising threshold.

Abstract: A method for determining a concentration of a chemical of interest in a recirculating analyte system includes the steps of selecting a first indicator threshold, measuring the flow rate of the recirculating analyte system, controllably adding a known amount of reagent to the recirculating analyte system at an known flow rate, repetitively measuring an indicator of the recirculating analyte system downstream from the addition of the reagent, and computing the concentration of the chemical of interest of the recirculating analyte system when the indicator measurement crosses the indicator threshold.

Abstract: A proximity detector includes a sensor providing a proximity reading. The proximity detector is capable of comparing the reading to a rising threshold level and a falling threshold level, wherein the falling threshold level is less than the rising threshold level. The proximity detector continuously stores a minimum reading value for the proximity reading. The proximity detector will report the presence of granular material only if the proximity reading remains less than the falling threshold level and within an epsilon value of the minimum reading value for a predetermined period of time.

Abstract: A proximity detector includes a sensor providing a proximity reading. The proximity detector is capable of comparing the reading to a rising threshold level and a falling threshold level, wherein the falling threshold level is less than the rising threshold level. The proximity detector continuously stores a minimum reading value for the proximity reading. The proximity detector will report the presence of granular material only if the proximity reading remains less than the falling threshold level and within an epsilon value of the minimum reading value for a predetermined period of time.

Abstract: A method for determining the total alkalinity (TA) in a recirculating water system without adversely impacting the pH of the water includes the steps of selecting a pH threshold (ThpH), measuring the flow rate of the moving body of water (fS), controllably adding a known amount of acid to the recirculating water system at an acid flow rate (fA), repetitively measuring the pH of the recirculating water system downstream from the addition of the acid, and computing the total alkalinity of the recirculating water system when the pH measurement falls below the pH threshold.

Abstract: A system for controlling water within an aquatic facility includes a water chemistry controller, a variable rate water pump adapted to move water in the facility, and a variable rate motor driver operationally coupled to the water pump for variably energizing the water pump. The variable rate motor driver is coupled to the water chemistry controller to allow the water chemistry controller to manage the operation of the water pump.

Abstract: A system for controlling water within an aquatic facility includes a water chemistry controller, a variable rate water pump adapted to move water in the facility, and a variable rate motor driver operationally coupled to the water pump for variably energizing the water pump. The variable rate motor driver is coupled to the water chemistry controller to allow the water chemistry controller to manage the operation of the water pump.

Abstract: Methods and devices for audio amplification suitable for hearing aid, hearing aid fitting, and diagnostic purposes include audio amplification having at least one variable gain channel configured to provide relatively higher gain at low levels, rapid gain compression at intermediate levels converging to linear gain at high signal levels, and slow feedback control of the compressive gain. Several such audio channels may be provided in a hearing aid or diagnostic device, and instantaneous gain compression is preferred. An analog implementation provides nonlinear elements in a feedback path to simulate a multiple feedback band-pass non-linearity cochlear filterbank hearing model (MFBPNL), while a digital implementation uses logarithmic representations of signals to minimize functional components in a multiple band-pass non-linearity cochlear filterbank hearing model (MBPNL). When used as a hearing aid, annoying amplification of weak sounds during brief interruptions of sustained intense sounds is prevented.

Abstract: A one-way communications pathway between two integrated circuits comprises a VCSEL array of one or more light emitters on a first integrated circuit, coupled to a photo-detector array on a second integrated circuit. The photo-detector array comprises a number of detectors which is greater than the number of activated light emitters, such that light from each emitter is imaged onto one or more detectors. Each detector generates an electrical current signal when illuminated by the emitter light. Individual electrical current signals from multiple illuminated detectors are selected via switches, and routed through a summing junction. The resulting summed signal is amplified and converted to a digital output signal.

Abstract: An apparatus for use in an ultrasonic imaging system adapted for generating synthetic focus images in real-time. The apparatus employs an integrated circuit architecture which is scalable and can be employed to construct real-time synthetic focus ultrasonic imaging systems having a large number of transducer array elements. The apparatus utilizes one field programmable gate array per image channel for data storage and sub-image generation. Each field programmable gate array includes on-chip block memories to store digitized ultrasonic signal return echo data and at least one block memory used to store data associated with each ultrasonic transmitter-receiver array pair. Logic inside the field programmable gate array calculates memory addresses during image generation to generate a time-of-flight surface and to form sub-images.

Abstract: A method and apparatus for calibrating load cells in the filed after the uncalibrated load cells have been installed. Two known weight conditions are used in conjunction with a storage device in which the uncalibrated load cells are installed. The method will calibrate the load cells, calculate load cell offsets, scale factor differences between load cells, and flexure/stresses in a supporting structure which rests upon the uncalibrated load cells.

Abstract: A method and apparatus for calibrating load cells in the filed after the uncalibrated load cells have been installed. Two known weight conditions are used in conjunction with a storage device in which the uncalibrated load cells are installed. The method will calibrate the load cells, calculate load cell offsets, scale factor differences between load cells, and flexure/stresses in a supporting structure which rests upon the uncalibrated load cells.

Abstract: A three-wire sensor interface for field wiring of conventional on/off type control sensors that delivers power to the sensor, provides a normally open control output from the sensor and, concurrently, provides a normally closed control output from the sensor. The sensor interface includes a plurality of external terminals including a normally open external terminal for electrically connecting to zero, one, or more normally open load devices to control the operation of the normally open load device, and a normally closed external terminal for electrically connecting to zero, one, or more normally closed load devices to control the operation of the normally closed load device. A plurality of interface terminals are preferably electrically coupled between the sensor interface and the sensor and include a normally open control terminal and a normally closed control terminal.

Abstract: A capacitive sensor array is adapted to be disposed in a reservoir containing fluid or material along an axis of measurement of the fluid or material to determine the level of fluid or material contained within the reservoir. The sensor array includes a plurality of reference electrodes, wherein the capacitance of each of the electrodes varies in accordance both with the extent of the array's immersion in the fluid or material and the dielectric constant of the fluid or material. The plurality of reference electrodes preferably includes a lower electrode adapted to be immersed within the fluid or material in the reservoir and whose capacitance provides an estimate of the dielectric constant of the fluid or material contained within the reservoir.

Abstract: A remote telemetry system utilizing dual communication pathways comprising low-cost remote communications devices operating on existing wire-based communications systems, wireless communications systems, and/or a combination thereof, to provide real-time reading and control of the remote telemetry units. A central controller directs the operation of the remote telemetry units and receives data from the remote telemetry units. The central controller is configured to utilize a conventional broadcast communications channel to transmit commands to individual remote telemetry units, each of which is assigned a unique identification code. Signals broadcast from the central controller are received at receivers associated with each remote telemetry unit, which performs a directed operation if a unique identification code included in the broadcast signal matches the identification code assigned to the remote telemetry unit.

Abstract: A balanced charge pump sensor circuit (switched capacitor) for measuring the capacitance of a sensor element includes a switching circuit having a charging state during which the sensing element is connected to a relatively fixed upper reference voltage source. The switching circuit has a discharging state during which the sensing element is connected to a summing node, typically at some different voltage between the upper and lower reference voltages. As a result of this switching action, a packet of charge is transferred from the higher voltage connection to the lower voltage connection, the quantity of charge depending on the voltage difference between these two connections and the capacitance of the sensing element at the time the connections are changed. The circuit includes a current source, a differential amplifier having a non-inverting input terminal and an inverting input terminal, a voltage divider, and a charge integrating capacitor.

Abstract: A sensor package for proximity detectors adapted for use with materials having a significant angle of repose. The sensor package includes a hollow housing defining a cylindrical main body adapted to house proximity detection circuitry and a non-planar tip disposed on one end of the housing adjacent the main body. The tip portion is preferably tapered in its diameter from a dimension generally equal to the diameter of the main body to a dimension less than the diameter of the main body. The tip is adapted to house a sensing element electrically coupled to the proximity detection circuitry and disposed on an inner bottom surface of the tip portion. Preferably, the taper of the tip is selected to substantially match the angle of repose of the materials to be sensed, and may take on a wide variety of shapes including cone, frustum, pyramid, round and hemispherical.

Abstract: A user input device is disclosed adapting the electronic components of a time-domain reflectometry material level sensor to replace traditional user input devices such as push-buttons, control knobs, and variable sliders. An electrical conductor is arrayed beneath an input panel, such that when a high permittivity or high conductivity material is placed in proximity to the conductor, the characteristic impedance of the conductor is altered at that point, reflecting electronic pulses transmitted through the conductor. The reflected electronic pulse is received by the associated electronics, and the position of the material along the conductor subsequently determined. By segmenting the conductor into virtual regions, each corresponding to an individual "button", discrete input may be received by the device based upon the placement of the material within specific virtual regions.