The disclosure relates to a scale operating according to the principle of electrodynamic force compensation and to a method for its operation. An automatic switchover from a measuring mode to an overload mode is provided for detecting overload forces. In this overload mode the load resistance formed by a coil and at least one measuring resistor is reduced in order to allow a higher coil current at the same output stage power.

Provided is an electronic balance of electromagnetic force type including a weight automatic loading mechanism which can place and remove a weight by its own mechanism without use of either an external balance weight or a built-in balance weight. An electronic balance of electromagnetic force type is provided with a beam equilibrium setting unit that sets two or more equilibrium states of the beam position detecting unit. By making conversion ratios of upper and lower light receiving circuits nonequivalent, an imaginary weight is generated by utilizing the operating principle of the electromagnetic balance of electromagnetic force type.

Provided is an electronic balance of electromagnetic force type including a weight automatic loading mechanism which can place and remove a weight by its own mechanism without use of either an external balance weight or a built-in balance weight. An electronic balance of electromagnetic force type is provided with a beam equilibrium setting unit that sets two or more equilibrium states of the beam position detecting unit. By making conversion ratios of upper and lower light receiving circuits nonequivalent, an imaginary weight is generated by utilizing the operating principle of the electromagnetic balance of electromagnetic force type.

A magnetic bearing assembly (20) comprises a first magnet assembly (34) for generating a first quadrupole magnetic field in a first plane and a second magnet assembly (36) for generating a second quadrupole magnetic field in a second plane. The second plane is arranged parallel to the first plane. The quadrupole magnetic fields exhibit in each case in the planes magnetic field axes arranged at an angle to one another between four poles. A longitudinal axis (A) is defined at right angles hereto by the centres of the quadrupole magnetic fields. At least one diamagnetic element (44) is arranged on the longitudinal axis (A). The first and second magnet assemblies (34, 36) are arranged relative to one another in such a way that the first and the second quadrupole magnetic fields are rotated towards one another about the longitudinal axis (A) by an angular amount which is not a whole-number multiple of 90. Such a bearing arrangement can be used in particular in a magnetic levitation assembly (10) with a lifting assembly (26).

A magnetic bearing assembly (20) comprises a first magnet assembly (34) for generating a first quadrupole magnetic field in a first plane and a second magnet assembly (36) for generating a second quadrupole magnetic field in a second plane. The second plane is arranged parallel to the first plane. The quadrupole magnetic fields exhibit in each case in the planes magnetic field axes arranged at an angle to one another between four poles. A longitudinal axis (A) is defined at right angles hereto by the centres of the quadrupole magnetic fields. At least one diamagnetic element (44) is arranged on the longitudinal axis (A). The first and second magnet assemblies (34, 36) are arranged relative to one another in such a way that the first and the second quadrupole magnetic fields are rotated towards one another about the longitudinal axis (A) by an angular amount which is not a whole-number multiple of 90. Such a bearing arrangement can be used in particular in a magnetic levitation assembly (10) with a lifting assembly (26).

A differential measurement circuit (1) is implemented in a balance with electromagnetic force compensation. The circuit receives input from two photo currents (I.sub.1, I.sub.2) generated by photodiodes (D1, D2) and generates an output signal proportional to their difference. A switch (SW) controls the flow of current through a node (K.sub.) to which the two photo currents are directed, by flipping between two states (z.sub.t1, z.sub.t2) within two phases (t.sub.1, t.sub.2) of a time period T. The switch is controlled so a reference current (I.sub.Ref) from a voltage or current source (U.sub.Ref) is superimposed alternatingly within the time phases on one of the two photo currents which continuously flow into the node. The node lies at the input of an integrator (INT) whose integrator signal (s.sub.INT) can be compared in a comparator (CMP) to a cyclically recurring ramp signal (s.sub.RAMP) which conforms to the time period. At the output of the comparator, a rectangular-shaped comparator signal (s.sub.PWM) can be generated whose duty cycle ratio is defined by the intersection of the integrator signal with the ramp signal and which can be directed to a control input of the switch.

A differential measurement circuit (1) is implemented in a balance with electromagnetic force compensation. The circuit receives input from two photo currents (I.sub.1, I.sub.2) generated by photodiodes (D1, D2) and generates an output signal proportional to their difference. A switch (SW) controls the flow of current through a node (K.sub.) to which the two photo currents are directed, by flipping between two states (z.sub.t1, z.sub.t2) within two phases (t.sub.1, t.sub.2) of a time period T. The switch is controlled so a reference current (I.sub.Ref) from a voltage or current source (U.sub.Ref) is superimposed alternatingly within the time phases on one of the two photo currents which continuously flow into the node. The node lies at the input of an integrator (INT) whose integrator signal (s.sub.INT) can be compared in a comparator (CMP) to a cyclically recurring ramp signal (s.sub.RAMP) which conforms to the time period. At the output of the comparator, a rectangular-shaped comparator signal (s.sub.PWM) can be generated whose duty cycle ratio is defined by the intersection of the integrator signal with the ramp signal and which can be directed to a control input of the switch.

A pot magnet for a plunger coil arrangement includes a housing defining an interior with a housing bottom surface and a circumferential surface extending perpendicularly to the housing bottom A permanent magnet unit is arranged in the interior of the housing and includes a permanent magnet and a pole plate. An annular gap for accommodating a plunger coil of a plunger coil arrangement is formed between a circumferential surface of the pole plate and the circumferential surface of the housing interior. The underside of the permanent magnet is bonded to the housing bottom surface. The pole plate is connected to the housing in a manner decoupled from the permanent magnet by a rigid fastening device and is positioned in such a manner that a lower side of the pole plate faces an upper side of the permanent magnet with a gap formed there between.

A magnetic bearing assembly (20) comprises a first magnet assembly (34) for generating a first quadrupole magnetic field in a first plane and a second magnet assembly (36) for generating a second quadrupole magnetic field in a second plane. The second plane is arranged parallel to the first plane. The quadrupole magnetic fields exhibit in each case in the planes magnetic field axes arranged at an angle to one another between four poles. A longitudinal axis (A) is defined at right angles hereto by the centers of the quadrupole magnetic fields. At least one diamagnetic element (44) is arranged on the longitudinal axis (A). The first and second magnet assemblies (34, 36) are arranged relative to one another in such a way that the first and the second quadrupole magnetic fields are rotated towards one another about the longitudinal axis (A) by an angular amount which is not a whole-number multiple of 90. Such a bearing arrangement can be used in particular in a magnetic levitation assembly (10) with a lifting assembly (26).

A magnetic bearing assembly (20) comprises a first magnet assembly (34) for generating a first quadrupole magnetic field in a first plane and a second magnet assembly (36) for generating a second quadrupole magnetic field in a second plane. The second plane is arranged parallel to the first plane. The quadrupole magnetic fields exhibit in each case in the planes magnetic field axes arranged at an angle to one another between four poles. A longitudinal axis (A) is defined at right angles hereto by the centers of the quadrupole magnetic fields. At least one diamagnetic element (44) is arranged on the longitudinal axis (A). The first and second magnet assemblies (34, 36) are arranged relative to one another in such a way that the first and the second quadrupole magnetic fields are rotated towards one another about the longitudinal axis (A) by an angular amount which is not a whole-number multiple of 90. Such a bearing arrangement can be used in particular in a magnetic levitation assembly (10) with a lifting assembly (26).