Abstract: A digital load cell includes an EEPROM that is permanently attached to the counterforce along with a temperature sensor and a plurality of strain gages. The strain gages are mounted on the counterforce in the electrical configuration of a full wheatstone bridge. The EEPROM and bridge are connected to a flexible circuit that is detachably connectable in electrical communication with circuits including a processor and an analog-to-digital converter, which can be mounted permanently on a local circuit board physically separated from the EEPROM. The local circuit board operates in a manner so that the EEPROM can be programmed to store the calibration/correction factors that are to be applied by the processor to the digital weight signals from the analog-to-digital converter. The local circuit board is associated with, and alternatively can be removably attachable to, the counterforce.

Abstract: Load shift compensation of a strain gage load cell is accomplished by connecting a pair of fixed resistors in series across the output of a bridge circuit incorporating the load cell strain gages. The junction point between the series resistors is established at a desired signal level by a digital to analog converter connected thereto or by a voltage divider network so that, in effect, a part of the resistance of the resistors required to achieve load shift compensation is made to shunt a pair of the strain gages in the bridge circuit. The required signal level may be established by positioning weights on the scale platter at different positions parallel to the longitudinal axis of the load cell beam and adjusting the signal level at the junction point between the shunting resistors until a desired degree of compensation is achieved. The digital correction value required at the input of the digital to analog converter to achieve compensation is stored in the memory of the scale computer.

Abstract: A weighing in motion (WIM) apparatus and method in which scale platforms are provided exhibiting a high rigidity selected to achieve a relatively high natural frequency response characteristic. These platforms are combined with instrumentation wherein load cell derived signal outputs are digitized at a conversion or sampling rate effective to permit an identification of amplitude data correlative to vehicle weight. In particular, the sampling rate is selected so as to isolate and detect peak amplitude output of the system which is directly correlatable to truck weight. The invention derives from a recognition that, during the dynamics of movement of a vehicle such as a truck over the rigid scale platform structures, there occurs a decoupling of the mass of the truck from the scale permitting its response to the weight of the truck without significant loss of natural frequency bandwidth.

Abstract: Weighing apparatus including variable capacitance load sensing means, a capacitance detection circuit, an analog to digital convertor and microcomputer control means is automatically verified for accurate operation. The capacitance detection circuit is provided with a computer controlled verification switch by which the value of a parameter, such as resistance in an attenuation circuit, can be changed. Automatic verification of correct operation is obtained by periodically, with no weight on the scale, obtaining a first weight reading, operating the verification switch to change the parameter and obtaining a second weight reading. The difference between the two readings is a verification value and is compared to a stored verification value obtained in the same manner during calibration and stored for later use. If the difference between the obtained and stored verification values exceeds an allowable limit, the scale may be disabled from further weighing.

Abstract: This invention relates to an improved digital scale arrangement which employs apparatus for generating an electrical analog signal representing the weight on the scale mechanism. The analog signal is then converted to a digital representation of the weight on the scale under control of a microprocessor or microcomputer. The microcomputer then further processes the digital representation and causes it to be displayed. In accordance with the present invention, a fully automatically operating arrangement is provided for verifying the correct operation of the analog portion, the converting portion, and the digital portion of the arrangement. In addition, the arrangement is also employed to automatically correct the span of the scale under control of the results of the verification operation.

Abstract: A scale is disclosed which includes a digital display unit for conveying information. A display verification method and system are employed for determining whether a plurality of information conveying segments forming the indicators of the display unit are properly conveying information. Individual segments of the display unit are operated under control of a microprocessor. Segment status determining circuitry determines the operative status of each of the segments by sequentially monitoring a voltage drop indicative of the current passing through an LED comprising that segment. The status determining circuitry produces status information which is stored in the microprocessor memory and compared with data indicative of the information the display should convey if it is properly functioning. If the comparison indicates that one of the segments is not properly conveying the information, warning messages are displayed which indicate maintenance procedures are required.

Abstract: The invention relates to a scale system which employs a microcomputer forming an integral part of the analog to digital conversion means in which the microcomputer controls the sequence of operations for performing the conversion, accumulates and stores digital data derived during the conversion of the analog signal and combines and processes that data to provide the digital output data resulting from the conversion, all in addition to performing other scale functions. The invention relates to an improved multicapacity weighing and computing digital scale having a triple slope analog-to-digital conversion means. The analog weight signal is integrated for a time interval which is fixed for a given scale capacity range which would generate substantially the same integrator output level in response to a full capacity weight signal for the selected scale capacity as would be generated by a full capacity weight for all other scale capacities.

Abstract: The invention relates to a scale system which employs a microcomputer forming an integral part of the analog to digital conversion means in which the microcomputer controls the sequence of operations for performing the conversion, accumulates and stores digital data derived during the conversion of the analog signal and combines and processes that data to provide the digital output data resulting from the conversion, all in addition to performing other scale functions. The invention relates to an improved multicapacity weighing and computing digital scale having a triple slope analog-to-digital conversion means. The analog weight signal is integrated for a time interval which is fixed for a given scale capacity range which would generate substantially the same integrator output level in response to a full capacity weight signal for the selected scale capacity as would be generated by a full capacity weight for all other scale capacities.

Abstract: The invention relates to a scale system which employs a microcomputer forming an integral part of the analog to digital conversion means in which the microcomputer controls the sequence of operations for performing the conversion, accumulates and stores digital data derived during the conversion of the analog signal and combines and processes that data to provide the digital output data resulting from the conversion, all in addition to performing other scale functions. The invention relates to an improved multicapacity weighing and computing digital scale in which switch means are provided to change the weight indication from pounds to kilograms and visa versa at any time either before or during a weighing operation. Provision is made to also convert all the weight limits and any stored tare weight. In addition, the unit price and total price or value display is either cleared or else converted from price per pound to price per kilogram and the total price recomputed.

Abstract: This invention relates to an improved digital weight measuring and computing apparatus with automatic zero correction which automatically corrects the zero indication of the apparatus.The weight measuring apparatus comprises a scale which employs a load cell and strain gauge to develop an analog voltage representing the weight on the scale. An analog-to-digital converter is then employed to change the analog voltage into a digital representation of the load on the scale. The digital converter provides a digital indication in addition to the digital indications employed to indicate the weight on the scale. The additional digital indication represents fractions of the least weight increment indicated of the weight on the scale. The additional digital indication is then employed to control the generation of a zero correction factor and this factor is then combined with the weight indications from the scale to indicate the correct weight of articles placed on the scale.

Abstract: Improved electronic scale system for weighing, computing a value and printing a label showing the weight, price per unit weight and the computed value for each of a plurality of successive articles. An integrated circuit microcomputer is periodically supplied with the article weight from a load cell scale and is supplied with the price per unit weight either from a manual keyboard or automatically from a commodity plate in a label printer. After the system corrects for scale error, checks for scale no motion, compensates for any tare weight and checks various interlocks, the microcomputer computes an article value. A no motion signal is generated by the microcomputer when a predetermined number of successive weight measurements deviate from one another by no more than a predetermined small fractional weight less than the least significant weight digit used by the microcomputer in computing an article value.

Abstract: Improved electronic apparatus for weighing, computing a value and printing a label showing the weight, the price per unit weight and the computed value of each of a plurality of successive articles. A microcomputer is supplied with the article weight from a load cell scale and with the price per unit weight either from a manual keyboard or automatically from a commodity plate in a label printer. Tare weight is entered through a plurality of switches, each of which represents a different tare weight. When one of the tare switches is actuated, a timer is started. If a second tare switch is then pushed before a predetermined time interval is measured by the timer, the tare weight represented by the two switches are added together to obtain the total tare weight. After the system corrects for zero error, checks for scale motion, compensates for the total entered tare weight and checks various interlocks, the microcomputer computes an article value and causes a label to be printed.

Abstract: Improved electronic apparatus for weighing, computing a value and printing a label showing the weight, the price per unit weight and the computed value of each of a plurality of successive commodities. An integrated circuit microcomputer is supplied with the article weight from a load cell scale and with the price per unit weight either from a manual keyboard or automatically from a commodity plate in a label printer. The microcomputer includes an arithmetic logic unit, data registers and a sequence controller which is programmed to cause the microcomputer to correct for scale errors, to check for no motion of the scale, to compensate the measured gross weight for any tare weight, to check various interlocks, to compute an article value and to cause a label to be printed for the article. Input data to the microcomputer and output data from the microcomputer is multiplexed through interface circuitry.

Abstract: In a plural scale system such as a parts counter having a minor scale for measuring the weight of a known number of sample parts and a major scale for measuring the weight of an unknown number of parts to be counted, apparatus for indicating when the scales are zeroed. Circuitry is provided for automatically correcting the weight outputs from each scale for a limited amount of zero errors. A digital display indicates the corrected weight on one of the scales. When the corrected weight on any of the other scales is on zero, an indicator light associated with such scale is illuminated.

Abstract: Improved apparatus for weighing and computing a value for articles. An integrated circuit microcomputer is supplied with the gross article weight from a scale and with price per unit weight data from a manual keyboard. Tare weight data may be entered either through the manual keyboard or automatically from the scale. The microcomputer computes a net weight and a value for each weighed article. The net weight, the price per unit weight and the value are indicated on a digital display and may be printed on a label. Filtering circuitry prevents jitter in the article weight supplied from the scale to the microcomputer and the display caused by small vibrations in the article or the scale.