Abstract: A weighing device has not only a scale cell which weighs an object and outputs a weight signal indicative of the measured weight value but also a vibration-detecting load cell for detecting the vibrations of the floor to which the scale cell is set such that the effects of the floor vibrations can be subtracted from the weight value detected by the scale cell. The vibration-detecting load cell has attenuation-adjusting members adhesively attached to strain-generating parts of its load-sensitive element such that the attenuation constant of the load cell is thereby increased at least by a factor of 2. The usable dynamic range of the load cell can thus be increased while the load cell is kept compact. Butyl rubber members can be used for this purpose.

Abstract: A load cell for detecting a load imposed thereon and for improving the productivity thereof. The load cell includes a strain inducing device (1) made of metal and including a strain generating area (6) for generating a strain as a function of the load, and a strain sensor (40) including a metal substrate (41) having a strain detecting element (43) formed thereon for detecting the strain generated at the strain generating area (6) of the strain inducing means (1). The strain sensor (40) is mounted on the strain inducing device (1) with the metal substrate (41) welded thereto.

Abstract: To facilitate the adjustment of the accuracy and servicing maintenance of the electronic weighing apparatus, the weighing apparatus comprises a load cell and a signal processing circuit for processing a load signal from the load cell to provide a weight signal indicative of the load. The load cell includes a strain inducing element capable of producing strains in proportion to the load imposed thereon, and a bridge circuit, having a pair of strain gauges fixed on the stain inducing element and a plurality of resistors. A load signal is taken from a junction between the strain gauges and reference voltage signals are taken from junctions between the resistors. The load signal and the reference voltage signals are supplied to the signal processing circuit.

Abstract: A load cell for use in detecting a load imposed thereon which includes a strain inducing unit (1) having a longitudinal axis and including a strain generating area (6) for generating a strain as a function of the load, and a strain sensor (40) including a substrate (41) having a strain detecting element (43) formed thereon for detecting the strain generated at the strain generating area (6) of the strain inducing unit (1). The strain inducing unit (1) includes a fixed rigid body (2), a movable rigid body (3), first and second beams (4) connecting the fixed rigid body (2) and the movable rigid body (3) together, and an intermediate plate structure (30) fixed to and positioned between the fixed and movable rigid bodies (2 and 3). The intermediate plate structure (30) has a cut space (P) defined therein at a location intermediate between the fixed rigid body (2) and the movable rigid body (3).

Abstract: A combination of a weighing cell (C) with a displacement sensor (S) is disclosed, in which the weighing cell (C) includes a strain inducing element (1) having a strain generating region (55) at which strain is generated in response to application of a load thereto, and a strain gauge (56) for detecting the strain generated in the strain generating region (55), and the displacement sensor (S) includes a fixed rigid component (10), a movable rigid components (11) forming a weight element, a generally elongated beam member (20) rigidly secured at opposite ends to the fixed and movable rigid components (10, 11), respectively, so as to extend between the fixed and movable rigid components (10, 11), and a displacement detecting element (23) mounted on the elongated beam member (20) for outputting an electric signal of a magnitude proportional to the amount of displacement of the movable rigid component (11) in a direction generally perpendicular to the elongated beam member (20).

Abstract: A method of manufacturing individual strain sensors (20) each comprised of a generally rectangular substrate (21) having first and second major surfaces opposite to each other, a strain detecting element (23) formed on the first major surface of the substrate and having at least one pair of strain sensing areas (23a), and a pair of grooves (24) defining respective areas (21a) of low rigidity and formed in the second major surface of the substrate (21) at respective locations adjacent the opposite ends of the substrate (21) while extending across the width of the substrate with the strain sensing areas (23a) of the strain detecting element (23) positioned in register with the respective grooves (24). The strain sensors (20) are prepared from a single plate material (30) of any suitable size having first and second surfaces opposite to each other and eventually forming respective substrates (21) of the individual strain sensors (20).

Abstract: A load sensor is made of a load-sensitive element made preferably of an aluminum alloy, a bridge circuit with strain gauges made preferably of tantalum nitride and formed on the load-sensitive element, and two operational amplifiers with their non-inversion input terminals connected respectively to the signal output terminals of the bridge circuit and their inversion input terminals connected to each other through a temperature-sensitive resistor having a positive second-order temperature coefficient and a precision resistor. The resistance values of these resistors are adjusted so as to compensate for the first-order and second-order temperature coefficients of the temperature-dependent output from the bridge circuit.

Abstract: A weighing apparatus has a scale cell and a dummy cell, both similarly structured and cantilevered. A load to be measured is applied to the free end of the scale cell and a standard weight is attached to the free end of the dummy cell. Analog electrical signals from these cells are converted to digital data. The effect of the standard weight is removed from the digital data from the dummy cell to obtain the effect of external vibrations which effect is multiplied by a suitable coefficient dependent on the applied load and subtracted from the digital data from the scale cell.

Abstract: A load cell has a cantilever-type load-sensitive element with an upper beam and a lower beam, each having formed thereon a pair of strain-generating parts which generates a strain corresponding to an applied load. Only one of these two beams has an indented part formed on its surface and strain-detecting elements are attached to its bottom surface at positions corresponding to the strain-generating parts. A moisture-proof sheet is attached to the beam to completely seal the interior of this indented part to protect the strain-detecting elements from humidity and moisture.

Abstract: Strain gages are attached to respective strain sensing areas of the strain generator of a load cell. Those strain gages which are mounted on expansive sides of the strain generator are connected in series with each other, and those strain gages which are mounted contactive sides of the strain generator are connected in series with each other, forming first and second series-connected circuits. The first and second series-connected circuits are connected in series with each other as a half bridge. A load applied to the strain generator is detected by an output signal produced from the junction between the first and second series-connected circuits. A temperature compensating resistor for compensating for a temperature-dependent change in the output signal due to a change in the temperature of the strain generator is connected in a circuit separate from the half bridge.

Abstract: A weight sensing apparatus has a weight sensor provided with a load cell for producing an output signal indicative of the weight of an article, and a support for supporting the weight sensor. The apparatus includes oscillation sensing means provided in the vicinity of the load cell for producing an output signal indicative of an oscillation component caused by floor oscillation, a summing amplifier for adding the output signal from the load cell and a signal which is the inverse of the output signal from the oscillation sensing means, and signal processing means for processing the output of the summing amplifier to remove an oscillation component contained in the output signal from the load cell. The oscillation component is caused by oscillation received by the weight sensor from its surroundings.

Abstract: A zero-point adjustment unit for a weighing device is comprised of a rough adjustment circuit, a fine adjustment circuit and a central processing unit. The central processing unit adjusts the zero-point of the weighing device by receiving a no-lead weight signal outputted from the weighing device and controls the output signals from the rough and fine adjustment circuits.

Abstract: Data from weighing devices of a combinational weighing system are transmitted through a multiplexer and sample-and-hold circuits and are converted into digital signals by an analog-to-digital converter. Values of these digital signals are constantly monitored and a specified number of these values are used to determine stability conditions of the weighing devices. Only the weight data from stabilized weighing devices are used for combinational calculation.

Abstract: Herein disclosed is a double integral type A/D converter for converting an analog signal into a digital signal. The A/D converter (includes), as circuit elements an integrator having its one terminal made receptive of one of an unknown input voltage and a reference voltage; a comparator connected with the output of the integrator and including a transistor having its collector or drain opened; and an offset correction circuit connected between the output of the comparator and another terminal of the integrator for feeding back the output of the comparator. The offset correction circuit including a series circuit of a switch, a resistor R.sub.0 and an auto-zero capacitor C.sub.0. The converter also includes a flip-flop made responsive to the output signal of the comparator for switching the operational mode of the integrator from an integration mode to an offset correction mode; and a counter for counting the inverse integration period of the reference voltage.

Abstract: A combinational weighing system with a plurality of weighing devices employs at least three central processing units such as microprocessors. One keeps monitoring the weight information from the weighing devices and analyzes stability of weight data. Another one controls the charging and discharging of the weighing devices. The third performs combinational computation to select a combination. The system has increased flexibility regarding operation and adjustments, and allows efficient methods of zero-point and span adjustment of weighing devices. Its compact unitized input-output unit allows the user to operate the system interactively.

Abstract: An electronic weigher includes a load cell for producing as an output an electric signal proportional to a load, an operational amplifier for amplifying the electric signal produced by the load cell, A/D converter for converting an output signal produced by the operational amplifier into a digital signal, a bias circuit for delivering a dummy signal for test purposes to the operational amplifier, and a switch disposed between the bias circuit and the proportional amplifier for applying the dumy signal to the operational amplifier, wherein amplification circuitry from the operational amplifier to the A/D converter is diagnosed by operating the switch.

Abstract: A signal processing circuit for a weighing apparatus comprises an amplifier circuit for amplifying a weight signal outputted from a weighing device, an active filter which serves to attenuate noise components in the weight signal from the amplifier circuit, and switches for selecting whether the active filter should function as a filter or a buffer according to a predetermined timing schedule.

Abstract: A combinational weighing system with a plurality of weighing devices employs at least three central processing units such as microprocessors. One keeps monitoring the weight information from the weighing devices and analyzes stability of weight data. Another one controls the charging and discharging of the weighing devices. The third performs combinational computation to select a combination. The system has increased flexibility regarding operation and adjustments, and allows efficient methods of zero-point and span adjustment of weighing devices. Its compact unitized input-output unit allows the user to operate the system interactively.

Abstract: A multiple input signal high-speed analog-digital converter circuit for digitizing, by means of an A/D converter, an output signal from a multiplexer which successively delivers multiple input signals applied thereto. Two sample/hold circuits which receive the output signal from the multiplexer repeatedly sample and hold the signal, and a changeover switch keeps one of the sample/hold circuits on hold while the other sample/hold circuit samples the output signal from the multiplexer. While one of the sample/hold circuits is holding the signal, the other sample/hold circuit is sampling another signal so that the A/D conversion time of multiple input signals is capable of being reduced by the sampling time.

Abstract: A combinational weighing system with a plurality of weighing devices employs at least three central processing units such as microprocessors. One keeps monitoring the weight information from the weighing devices and analyzes stability of weight data. Another one controls the charging and discharging of the weighing devices. The third performs combinational computation to select a combination. The system has increased flexibility regarding operation and adjustments, and allows efficient methods of zero-point and span adjustment of weighing devices. Its compact unitized input-output unit allows the user to operate the system interactively.