Abstract: A rotation detector for a magnet wheel which is high-resolution, precise and at the same time only requires the space of a single differential Hall IC, has combined on a single electronic component the circuitry equivalent to at least two differential Hall IC's. The electronic component derives a digital signal sequence that has a frequency twice the frequency of a signal that can be derived from a single differential Hall circuit by coupling the output signals of the differential Hall circuits. Additionally, only three Hall sensors are required to form the difference signals necessary to derive the digital signal sequence by using one Hall sensor as a reference for the remaining two Hall sensors.

Abstract: A circuit configuration for contactless detection of the rpm of a rotating gear wheel includes two identical firmly mounted and magnetically prestressed Hall sensors being mutually spaced apart by a center distance equal to one-half the tooth pitch of a gear wheel whose rpm is to be detected. Each of the Hall sensors includes at least one pair of identical Hall generators having signal paths and being driven with an impressed control current or impressed control voltage. Voltage/current converters are each coupled to the signal path of a respective one of the Hall generators and each have an output. An evaluation circuit links together the outputs of the voltage/current converters connected to one of the Hall sensors and the outputs of the voltage/current converters connected to the other of the Hall sensors in phase opposition.

Abstract: A filter circuit suitable for integration has first and second voltage/current converters. A signal source is coupled to the first voltage/current converter. A capacitor is coupled to the second voltage/current converter. An amplifier is coupled to the capacitor and has an output forming a filter output. The voltage/current converters have outputs fed to the capacitor in phase opposition to one another.

Abstract: An integrated circuit is encased in non-magnetic material and electrically connected to a Hall sensor. A permanent magnet is mounted for movement with respect to the Hall sensor to cause the Hall sensor to produce an output signal for setting a reference value.

Abstract: An integrated constant-current source having an operational amplifier with an inverting input to which a reference voltage is feedable, and an output; a first stage to which the output is coupled and by which the output voltage of the operational amplifier is converted to a first current, the first stage being in a circuit wherein a reference resistor is connected from which, for coupling a voltage dropping across the reference resistor, the reference resistor is coupled to a non-inverting input of the operational amplifier; and a second stage coupled to the output of the operational amplifier for converting the output voltage of the operational amplifier to a second current, the second stage being in a circuit wherein a current reflector is connected for supplying an output current which is constant in a first approximation, the integrated constant current source includes a third stage coupled to the output of the operational amplifier and converting the output voltage thereof into another current, the third

Abstract: Magnetic gate, including a magnet having a magnetic pole with an at least partly flat surface, a semiconductor chip having an integrated circuit, a mechanically permeable metal piece, and means attaching the semiconductor chip to the magnetically permeable metal piece for minimizing mechanical stresses acting on the chip to eliminate piezo effects and method of production thereof.

Abstract: Magnetic gate, including a magnet having a magnetic pole with an at least partly flat surface, a semiconductor chip having an integrated circuit, a mechanically permeable metal piece, and means attaching the semiconductor chip to the magnetically permeable metal piece for minimizing mechanical stresses acting on the chip to eliminate piezo effects and method of production thereof.

Abstract: Magnetic gate, including a magnet having two poles, one of the poles having an at least partly flat surfaces, a magnetically permeable metal piece bridging the magnetic flux of the magnet from one to the other of the poles, and a semiconductor chip having an integrated circuit, the semiconductor chip being piezoelectrically unsensitive and being applied to the permeable metal piece, and method of production thereof.