Abstract: Surface acoustic wave (SAW) weighing apparatus and related methods are provided for measuring weight of a load employing a displaceable elastic member that is displaced by the load. A piezoelectric SAW transducer is coupled to the elastic member. The piezoelectric transducer along with an amplifier electrically coupled thereto form a delay line oscillator circuit that is configured to generate an oscillating signal in response to displacement of the elastic member by the weight of the load. A magnet is spaced from a Hall effect sensor. The magnet produces a magnetic field, and the Hall effect sensor is configured to measure strength of the magnetic field which is related to displacement of the elastic member and the weight of the load. Circuitry generates frequency data that characterizes frequency of the oscillating signal. The frequency data is related to displacement of the elastic member and the weight of the load.

Abstract: Apparatus and related methods are provided in a surface acoustic wave (SAW) scale for measuring weight of a load. A processor reads a first frequency of a SAW delay line operating in a first mode. A push oscillator injects a frequency similar to but different than the first frequency in order to cause the SAW delay line to operate in a second mode, and the processor reads a second frequency of the SAW delay line operating in the second mode. A difference between the frequencies is calculated and compared to values in a stored table to determine the first mode at which the SAW delay line was operating. Based on a determination of the first mode and the first frequency, the weight of the load is determined. This determined weight can be used to recalibrate an auxiliary weight sensor.

Abstract: Apparatus and related methods are provided in a surface acoustic wave (SAW) scale for measuring weight of a load. A processor reads a first frequency of a SAW delay line operating in a first mode. A push oscillator injects a frequency similar to but different than the first frequency in order to cause the SAW delay line to operate in a second mode, and the processor reads a second frequency of the SAW delay line operating in the second mode. A difference between the frequencies is calculated and compared to values in a stored table to determine the first mode at which the SAW delay line was operating. Based on a determination of the first mode and the first frequency, the weight of the load is determined. This determined weight can be used to recalibrate an auxiliary weight sensor.

Abstract: Apparatus and related methods are provided for automatically recalibrating a SAW scale for changing environmental factors. During a period of time when there is no change to a weight applied to the scale, readings of SAW transducers which relate to weight indications and environmental factor indications are taken for two adjacent operating modes of the scale, and two calibrated weight calculations are made utilizing those readings. The difference in calibrated weight calculations is then related to a variable utilized to transform the readings into weights, which is updated, thereby recalibrating the scale.

Abstract: Apparatus and related methods are provided for automatically recalibrating a SAW scale for changing environmental factors. During a period of time when there is no change to a weight applied to the scale, readings of SAW transducers which relate to weight indications and environmental factor indications are taken for two adjacent operating modes of the scale, and two calibrated weight calculations are made utilizing those readings. The difference in calibrated weight calculations is then related to a variable utilized to transform the readings into weights, which is updated, thereby recalibrating the scale.

Abstract: Apparatus and related methods are provided for automatically recalibrating a SAW scale for changing environmental factors. During a period of time when there is no change to a weight applied to the scale, readings of SAW transducers which relate to weight indications and environmental factor indications are taken for two adjacent operating modes of the scale, and two calibrated weight calculations are made utilizing those readings. The difference in calibrated weight calculations is then related to a variable utilized to transform the readings into weights, which is updated, thereby recalibrating the scale.

Abstract: Apparatus and related methods are provided for automatically recalibrating a SAW scale for changing environmental factors. During a period of time when there is no change to a weight applied to the scale, readings of SAW transducers which relate to weight indications and environmental factor indications are taken for two adjacent operating modes of the scale, and two calibrated weight calculations are made utilizing those readings. The difference in calibrated weight calculations is then related to a variable utilized to transform the readings into weights, which is updated, thereby recalibrating the scale.

Abstract: Apparatus and related methods are provided for automatically recalibrating a SAW scale for changing environmental factors. During a period of time when there is no change to a weight applied to the scale, readings of SAW transducers which relate to weight indications and environmental factor indications are taken for two adjacent operating modes of the scale, and two calibrated weight calculations are made utilizing those readings. The difference in calibrated weight calculations is then related to a variable utilized to transform the readings into weights, which is updated, thereby recalibrating the scale.

Abstract: Apparatus and related methods are provided for automatically recalibrating a SAW scale for changing environmental factors. During a period of time when there is no change to a weight applied to the scale, readings of SAW transducers which relate to weight indications and environmental factor indications are taken for two adjacent operating modes of the scale, and two calibrated weight calculations are made utilizing those readings. The difference in calibrated weight calculations is then related to a variable utilized to transform the readings into weights, which is updated, thereby recalibrating the scale.

Abstract: A weighing apparatus includes a SAW oscillator and a “push oscillator” to force the SAW oscillator into a desired mode of operation. A SAW temperature oscillator and a thermistor are also provided. The frequency of the “push oscillator” is made immune to temperature changes by generating it via a mixer mixing the SAW temperature oscillator with an adjustable fixed frequency oscillator. Long term stability of the SAW temperature oscillator is achieved by periodic calibration with the thermistor.

Abstract: A weighing apparatus includes a base (12) supporting a cantilevered elastic member (14) bearing a load platform (16). The interior of the elastic member (14) is hollowed and is provided with first (20) and second (22) piezoelectric transducers mounted on respective opposed posts. The transducers are arranged substantially parallel to each other with a small gap between them and are coupled to an amplifier (950, 952) to form a “delay line” and a positive feedback loop, to form a natural oscillator.

Abstract: A weighing apparatus includes a SAW oscillator and a “push oscillator” to force the SAW oscillator into a desired mode of operation. A SAW temperature oscillator and a thermistor are also provided. The frequency of the “push oscillator” is made immune to temperature changes by generating it via a mixer mixing the SAW temperature oscillator with an adjustable fixed frequency oscillator. Long term stability of the SAW temperature oscillator is achieved by periodic calibration with the thermistor.

Abstract: A weighing apparatus includes a base supporting a cantilevered elastic member bearing a load platform. The interior of the elastic member is hollowed and is provided with first and second piezoelectric transducers mounted on respective opposed posts. The transducers are arranged substantially parallel to each other with a small gap between them and are coupled to an amplifier to form a “delay line” and a positive feedback loop, i.e. a natural oscillator.

Abstract: A radio frequency synthesizer receives a relatively low frequency input signal and synthesizes from it a high frequency output signal whose frequency can be programmed to change in fine steps, for use e.g. in cordless telephone. The frequency synthesizer includes three linked phase locked loops with a single side band mixer in one embodiment coupling two of the phase locked loops together. This provides an output signal free of in-band frequency spurs within the spacing of two channels. The synthesizer can be integrated in a single chip with a narrowband FM modulation circuit. In spite of using a novel synthesizer to achieve monolithic integration, the user programming interface and control value equations are the industry standard format.

Abstract: In a digital communication system, analog equalization and data recovery are provided with non-linear digital feedback at the receiver, to overcome frequency domain distortion imposed by the communications channel. Digital information from the clock and data recovery circuit is non-linearly filtered and then fed back so as to modulate the threshold of a slicer which receives the signal which has been analog equalized. Thereby any shortcomings in the equalization, slicer, or clock and data recovery are overcome by adjusting the slicer threshold at each clock cycle in response to the recovered clock and data signals.

Abstract: An electronic weighing device includes a lower base plate, an upper load bearing plate, and a load cell coupled to central portions of the upper and lower plates such that the load cell responds to weight on the bearing plate. The upper and lower plates are each notched at a central location, with the notches being offset from each other. The overlapping portions of the notches form a cavity for a central portion of the load cell, The load cell is tapered or reduced in height at opposite ends thereof so that its ends fit between a notched portion of one of the upper and lower plates and a full-thickness portion of the other of the upper and lower plates. The reduced height ends of the load cell are coupled to the upper and lower plates.

Abstract: A weighing apparatus includes a base supporting a cantilevered elastic member bearing a load platform. The interior of the elastic member is hollowed and is provided with first and second piezoelectric transducers mounted on respective opposed posts. The transducers are arranged substantially parallel to each other with a small gap between them and are coupled to an amplifier to form a "delay line" and a positive feedback loop, i.e. a natural oscillator.

Abstract: An electronic weighing device includes a lower electrically conductive plate, an upper electrically conductive plate, a load cell coupled to central portions of the upper and lower plates such that the load cell responds to weight on the upper plate, and a flexible, conductive band coupling the periphery of the upper plate to the periphery of the lower plate. An electronic circuit is coupled to the load cell. The circuit is provided on a board which is mounted on the lower plate close to its center. A pair of bores are provided in the lower plate extending from the circuit board to an edge of the lower plate. A pair of non-conductive rods are coupled to potentiometer on the circuit board. The non-conductive rods extend through the bores from the circuit board to the peripheral edge of the lower plate. The lower plate is provided with a shielded electrical socket which is coupled by shielded cable to the circuit board. A conductive cover is provided over the upper plate, the load cell, and the band.

Abstract: A DC restoration circuit to correct for baseline wandering in a data receiver is provided. A voltage correction circuit is connected to the received data line to adjust the voltage level of the received data dynamically. The voltage correction circuit is controlled by a feedback circuit which includes a voltage detection circuit configured to detect the peak voltage levels or envelope of the received data. This detected level is then compared to a reference level, and the result of the comparison is used as a control signal for the voltage correction circuit.

Abstract: A dual dot clock signal generator consisting of two similar programmable phase locked loops simultaneously generates a video clock signal and a memory clock signal. Both the video clock signal and the memory clock signal may have one of several different frequencies. The generator includes circuitry which detects when one of the selected frequencies is identical to or a submultiple of the other. The comparison circuitry which detects this condition acts to change the frequency of one of the clock signals, and supplies the other clock signal in its place. Both the video clock signal generator and the memory clock signal generator are programmable via their respective internal memories, and the internal memory of the video clock signal generator carries additional information which identifies those video frequencies which are identical to or a submultiple of the frequencies available from the memory phase locked loop.