Abstract: A weighing apparatus with electromagnetic force compensation is disclosed, including a load portion having a first compensation or load coil, and a reference portion having a second compensation or reference coil. An associated permanent magnet system is provided in the form of a partially closed housing having an intermediate wall on which flat permanent magnets are mounted, preferably in pairs. The load coil and the reference coil are arranged on opposite sides of the intermediate wall, thereby providing a compact arrangement which is easy to assemble and which has particular properties in regard to mutual decoupling of the two compensation coils.

Abstract: An electronic balance includes a system in which a current supplied to a force coil in response to a load applied to the balance is caused to alternate in direction at such a time interval as to permit of no oscillations and in which the measured value is obtained by subtracting the product of the current in the negative direction and a time fraction t.sub.2 for which the same flows from the product of the current in the positive direction and a time fraction t.sub.1 for which the same flows, the sum of said time fractions t.sub.1 and t.sub.2 being equal to each of said time intervals.

Abstract: A force measuring device of the electromagnetic compensation type is disclosed. The force measuring device includes a coil moving in a magnetic field, a display unit and a control circuit which returns the coil to its original position and supplies the display with the value of the forces being measured at substantially the same time. The device is also disclosed including a variable integration constant in the control circuit to provide a quicker response to small disturbances thus making the balance insensitive to vibrations.

Abstract: This invention relates to weighing apparatus of the electromagnetic load compensation type including a load or compensation coil connected with the load receiving member, and a reference coil connected with the frame for movement independent of the load receiving member, characterized in that the load and reference coils are arranged within separate air gaps of the magnetic field produced by a permanent magnet system mounted on the weighing apparatus frame. In one embodiment, the permanent magnet system includes a permanent magnet having a rotationally symmetrical field, and a magnetic yoke arrangement including an annular outer pole shoe arranged in concentrically spaced relation about an inner pole shoe. An annular ferromagnetic member is arranged in concentrically spaced relation between the inner and outer pole shoes for defining the air gaps in which the reference and load coils are arranged, respectively.

Abstract: An electronic weighing device is described wherein a Hall effect device and its associated magnetic field is used to provide an electrical signal proportional to the weight of an object and the signal is used to operate a display device. In one embodiment the Hall effect device and a magnet are mounted between a base platform and the weighing platform of the scale to respond to relative motion therebetween and the weighing platform is supported from the base platform by a plurality of resilient support members.

Abstract: An improved weighing apparatus of the electromagnetic load compensation type is disclosed, characterized by the provision of a stationary permanent magnet system including two oppositely arranged pairs of spaced parallel flat magnet members that cooperate to define a common air gap. The compensation current coil, which is connected for movement with the movable load-receiving member, is of a flat annular configuration and is contained in the plane of the air gap extending between the magnet members of each pair. The magnet members of one pair are magnetized oppositely from those of the other pair, whereby the magnetic field established across the portion of the air gap between the permanent magnet members of one pair is of a direction opposite that established between the permanent magnet members of the other pair. Consequently, not only can the compensation current for a desired compensation force effect be reduced, but also, the manufacture of the permanent magnet system is greatly simplified.

Abstract: An improved balance of the electromagnetic load-compensation type is disclosed wherein, in order to improve the temperature-dependent performance of the balance and to reduce the size and amount of operating space required, the load compensation coil (54) is transversely mounted on the balance beam (36) with the plane of the coil extending normal to the longitudinal axis of the balance beam. The load-compensation system also includes a permanent magnet (74) mounted on the balance housing adjacent, spaced from and parallel with the compensation coil, the permanent magnet being magnetized in a direction causing the magnetic field lines to extend parallel with the longitudinal axis of the balance beam, whereby current flowing through the load compensation coil reacts with the magnetic field of the permanent magnet to produce a force on the balance beam that compensates for the load applied to the balance.

Abstract: A scale of the electromagnetic force compensation principle, having a stationary permanent magnet system with an air gap and at least one coil positioned in the air gap, the coil being acted upon via a position sensor and a variable-gain amplifier by a compensation direct current dependent on the load of the scale, wherein the compensation direct current flows through a measuring resistor from both ends of which a signal dependent on the load of the scale is tapped off and fed to an analog/digital converter, and further electric circuits are connected therewith which permit an alternating current to flow, in addition to the compensation direct current, through the coil and the measuring resistor and including a regulating or adjusting device which modifies the amplitude of the additional alternating current in such a manner that the joulean heat generated in the coil and in the measuring resistor by the compensation direct current and by the additional alternating current is at least approximately load-indepe

Abstract: A differential weighing system is provided which includes a primary suspension having an associated weigh pan for receiving a commodity to be weighed, a secondary suspension having a natural frequency matched to that of the primary suspension, and an electrical displacement transducer for producing an output in accordance with the relative displacement between the two suspensions. Damping to ground is provided for each suspension in combination with damping of the relative movement between the suspensions. The two inputs of a differential amplifier are connected to the outputs of a pair of sensing coils of the displacement transducer. A low pass filter having a cutoff frequency at or near the natural frequency of the suspensions is connected to the output of the differential amplifier.

Abstract: An electromagnetic force-compensating weighing appliance has at least two levers engaged at one of their ends in supporting relationship to a load scale, and each connected at their other ends to a respective compensating coil, the compensating coils being symmetrically disposed in the air gap of a single magnet unit, and the levers being pivotally supported between their ends on fixed supports.

Abstract: Weighing apparatus of the electromagnetic load compensation type is disclosed, including a load support connected for movement relative to a frame, a mechanical-transmission ratio-establishing lever connecting the load support with a compensation coil arranged for displacement relative to a permanent magnet arrangement connected with the frame, a position-responsive circuit for supplying compensation current to the coil for creating an electromagnetic force that reacts with the permanent magnet field to maintain the load support in its initial no-load condition, and indicating means for displaying the magnitude of the applied load as a function of the compensation current. To permit the use of the lever in different lever-ratio-establishing environments without the use of attendant balancing weights, the compensation coil is tapped to define a pair of coil portions (28a, 28b) that are alternately energized by a switching device (42) to apply different forces upon the load support.

Abstract: Conventional electrical scales having independent weighing channels for a reference weight and the actual load with subsequent division of the resulting load signal by the reference signal to furnish the final output cannot furnish a final output signal independent of accelerating disturbances in a large critical frequency region, since changes in load change the dynamic behavior of the load channel. To substantially decrease variations in the final output signal due to such accelerating disturbances, the load signal is additionally coupled to the reference channel by means of at least one frequency-dependent network.

Abstract: An improved weighing apparatus of the electromagnetic load compensation type is disclosed, including a correction loop connected between the output terminal of the synchronizer and the input terminal of the pulse length modulator for varying the regulated load signal from the PID regulator to produce a corrected regulated load signal which compensates for digitalization errors produced by the synchronizer. In one embodiment, the correction loop includes an integrator circuit for superposing on the regulated load signal an inverted integrated error voltage the magnitude of which is a function of the operation of the synchronizer relative to the mark signals. In a second embodiment, the correction loop includes an integrator circuit that periodically applies to the regulated load signal a constant reference voltage of opposite polarity. Preferably, the reference voltage is applied simultaneously with the periods of supply of the compensation current.

Abstract: An electromagnetically compensated balance whose magnetic circuit comprises a permanent magnet and a pole shoe associated with each of the two poles of the magnet, one of the pole shoes bounding an air gap in the circuit, includes an induction coil mounted for movement in the air gap, a load carrier movable relative to the circuit under the weight of a carried load, and a force transmitting train connecting the coil to the load carrier for balancing the force exerted by the carried load on the load carrier by a force generated by current flowing in the coil. The force transmitting train includes a force transmitting member fastened to the coil. At least a major portion of the force transmitting member is confined in a space defined between the air gap and the other pole shoe.

Abstract: Weighing apparatus of the electromagnetic load compensation type is disclosed, including a permanent magnet system connected with the stationary frame, a compensation coil connected with the movable scale member, a system for supplying compensating current to the coil to produce a force for returning the movable scale member to its initial no-load position, and an indicating device for displaying the magnitude of the load applied to the movable scale member as a function of the compensating current, characterized by the mounting of a slotted generally U-shaped conductive metal plate in spaced insulated relation concentrically about the core portion of the permanent magnet system. After the weighing apparatus has been completely assembled, the leg portions of the plate are transformer connected with an alternating-current source for calibrating and/or conditioning the permanent magnet system.

Abstract: A digital platform scale having a base and movable cover thereon with a lever system in the base converting vertical movement to horizontal lever movement, spring means connected to the base and lever to counter-balance the lever movement and a differential transformer connected to the lever system and to an electrical digital readout to display weight, an improvement is provided that disposes the spring horizontally in the base and connected to the lever system at its point of maximum movement. A differential transformer is interposed as part of the connection between the spring and the lever system and axially aligned with the spring.

Abstract: A balancing scale or electromagnetically compensated weighing apparatus has an independently actuatable and temperature-sensitive magnetic device for balancing a load member; the magnetic device forms a magnetic circuit, and includes a temperature-sensitive corrective device affecting the circuit in at least two locations, so as to substantially temperature-compensate the magnetic circuit over a predetermined temperature range.

Abstract: A weighing system is disclosed of the electromagnetic compensation return-to-neutral type including first and second series-connected compensation coils connected with the weighing pan support, a supply of compensating current connected with the compensation coils, a periodically operable position-responsive switch connected in parallel across the first compensation coil for dividing the compensating current into a continuous first current portion which generally corresponds with the preloading effect of the load support, and a second portion that is periodically supplied to the first coil for periods of time that are a function of the magnitude of the load applied to the load support, and an indicating device responsive only to the second compensating current portion for indicating the magnitude of the load as a function of the compensating current required to return the load support to its neutral position, characterized by the provision of an impedance component electrically connected in parallel with, and

Abstract: A calibratable electromagnetically compensating precision balance having a weighing and taring device, in the form of a pan support, is provided with a parallel guide. The output from the balance is fed to an analog-digital converter which has its output coupled, via a minicomputer (calculator), to a display. A reference weight is provided for the balance. The reference weight is externally switchable for its weight determination, i.e., from outside the housing of the balance. A lifting mechanism is provided to lift the pan from the support. A method for compensating the parameters of the above-described calibratable electromechanical balance which can influence sensitivity and accuracy, involves determining and recording the actual value (M) of reference weight, under the prevailing operating conditions using the balance. Forming a quotient from the actual measured value (M) and the set (given) value (m) of the reference weight, the quotient being expressed in the form of a factor (F).

Abstract: An electromagnetically compensating beam balance has a balance housing, a am and a fixed counterweight. Weight changing means, which change the weighing range (scale) by substitution, are provided on the load receiving side. A parallel guidance system is provided. Rods which accept only horizontal forces are coupled between a load carrier and the housing. Vertical flexure elements, which accept vertical forces, are coupled between the beam and the load carrier.

Abstract: The magnet system of a top-loading precision balance with electromagnetic load compensation is fixedly fastened in an aluminum alloy frame constituting the fixed link in the parallelogram suspension for the weighing pan. Distortion of the frame under thermal stresses due to the different coefficients of expansion of the ferrous metal of the magnet system and the light metal of the frame is prevented by openings in the frame walls spacedly surrounding the portions of the frame wall fixedly fastened to the magnet system.

Abstract: Undesired temperature variations in scales having a force-compensating coil carrying a load dependent current are reduced by an additional heat generator mounted near the coil. The heat generated by the latter is controlled to compensate for changes in heating power dissipated by the force-compensating coil.

Abstract: The system controls the weights of individual charges of product or material accumulated by feeding material, preferably at a high "bulk" flow rate and then at a relatively low "dribble" flow rate, into one or more buckets or hoppers. As material is accumulated within each bucket, the system compensates against the effects of vibrational forces and flow rate and, upon termination of material accumulation, it corrects dribble time and final weight by respectively adjusting the bulk and dribble weights for the next charge, all with respect to an electronically established set weight corresponding to the desired weight of each charge. A linear voltage differential transformer (LVDT) senses the position of each bucket and provides electrical signals which are utilized by interface and control circuitry to control charge weight and provide an internal reference. The control system is particularly suited for use in combination with packaging systems.

Abstract: Weighing equipment for weighing a load which is included in a mechanical system with a natural frequency of oscillation which depends on the size of the load, for example in a crane, includes a transducer influenced by the load and which delivers a signal corresponding to the weight of the load. The equipment includes a tunable band exclusion filter connected to the transducer for filtering the signal, in which the signal influences the tuning of the filter so that its anti-resonance frequency follows said natural frequency of the oscillation.

Abstract: A load analyzer is provided for use with an automotive vehicle in which sensors having relatively reciprocal elements are arranged between the load bed and the axles of the vehicle. The load bed is spring biased relative to the axles, so that loading of the vehicle forces the load bed downward, thereby altering the relative position of the elements of the sensors. Each sensor provides a signal indicative of the relative position of its elements. An indicator responds to the signal by indicating the weight present in the load bed, as derived from the magnitude of the sensor signal, which in turn is proportional to the spring constant of the springs supporting the load bed relative to the axles. The indicator is adjustable so that it may be recalibrated by placing a known weight in the vehicle load bed and adjusting the output indication to correspond to that weight.

Abstract: A method of producing signals for a damping control of an electric measurvalue indicator, especially an electromagnetic precision balance, having an active filter or impedance transformer located in a branch which filters out the a.c. voltage is disclosed. Transient signals in the form of a.c. voltages with different frequencies are applied to the output of the active filter or transformer in the noise range. Sequentially tapped values of the a.c. voltages are compared in the noise range with previous values. A circuit for producing signals for a damping control of an electric measured-value indicator includes a comparator connected with the low ohmage output of a filter or impedance transformer. The comparator is provided with a switchable voltage storage device to which a differentiating element and an amplifier are connected. When a.c.

Abstract: A balance relatively insensitive to vibration of its support has a weighing pan mounted on a pan carrier which is one of the two normally vertical members of a parallelogram linkage, the other members being the stationary balance casing and two links hingedly interposed between the pan carrier and the casing. A solenoid assembly opposes displacement of the pan carrier under the weight of a load on the pan. The pan carrier is hingedly coupled to one arm of a lever fulcrumed on the balance casing whose other arm carries a counterweight in such a manner that inertial forces acting on the pan carrier and counterweight respectively during vibratory motion of the casing oppose each other.

Abstract: Weighing apparatus of the electromagnetic compensation type is disclosed, wherein the compensation coil means is continuously supplied with a first component of compensation current which at least partially compensates for the no-load preloading effect of the movable pan carrier system, said coil means being periodically supplied with a second component of compensation current which is a direct function of the magnitude of the load being weighed. Indicating means are provided which are responsive to the magnitude of the second current component to present a visual indication of the magnitude of the load being weighed. In one embodiment, separate sources of compensation current and counter pulses are provided, while in a second embodiment the compensation current is obtained from a pulse generator supplied with a high frequency voltage from the source which provides the counting pulses.

Abstract: A weight measuring apparatus, wherein a weight sensitive element is connected to a metallic moving member of a weight sensitive element displacement-to-electrical inductive transducer. The moving member is made as a plate positioned in the clearance between two inductance coils of said transducer secured on the casing, their windings being arranged on armour cores. The winding of the first inductance coil is connected to a high-frequency oscillator, whereas the winding of the second inductance coil is electrically connected to a metering circuit. The weight measuring apparatus is characterized by high accuracy of measuring, quick action and high resolution.

Abstract: An electromagnetic, compensating force-measuring or weighing device having at least one working coil movable in an air gap of a magnet system. At least two members for temperature compensation are positioned at different, spaced apart points. The compensating effect of these members on the active part of the system jointly produce a temperature compensating value which is optionally approximately equal to the exact value of the actual temperature curve. The members may be in the form of a plurality of minute particles of nonretentive material having a high negative coefficient of saturation magnetization distributed in the active part. The members may be formed of the afore-mentioned material and be positioned on the active part or be PTC or NTC resistors so positioned.

Abstract: Weighing apparatus of the electromagnetic load compensation type is disclosed including protective shield means for protecting an asymmetrically arranged compensation coil against stray magnetic-flux and particles of contaminants, thereby to improve the accuracy of load measurement.

Abstract: A beamless dynamometer or weighing device comprising a coil movable in the orking gap of a fixed magnet, the coil and magnet forming part of an electromagnetic compensation circuit for the dynamometer or device, and an arrangement for guiding movement of the coil within the working gap comprising an air bearing formed of a fixed guiding cylinder and an air-mounted slidable sleeve connected to the coil; preferably two coils are provided, each connected to a separate slidable sleeve, one sleeve being disposed inside the cylinder and the other sleeve outside the cylinder with the cylinder being formed of an annular jacket suppliable with compressed air which, in use, vents into the gap between the sleeves and cylinder, one sleeve being arranged to be acted upon by the force or mass to be measured and the other sleeve carrying a reference mass.

Abstract: A beamless dynamometer or weighing machine has a work coil positioned in a working air gap of a magnet arrangement. A pair of elastic links of trapezoid-shaped construction are attached to a bracing part. The median axis of the work coil is arranged within a trapezoid bounded by arms and sides of the links. The magnet arrangement is positioned in space bounded by the links.

Abstract: Weighing apparatus of the electromagnetic load compensation type is disclosed including zero-position detector means for generating a position signal that is a function of the extent to which a loaded weighing pan or the like is displaced from its no-load position, and regulating means responsive to said position signal for generating a compensating current for displacing the weighing pan toward its no-load position, characterized by the provision of filter means connected between the zero-position detector and the regulating means for suppressing the undesired extraneous interference acceleration signals produced, for example, by external shock or vibration forces imparted to the weighing apparatus. In one embodiment, the filter electrical components are constant, and in a second embodiment, means are provided for varying the electrical characteristics of at least some of the filter components as a function of the load applied to the weighing pan.