Abstract: A measuring transformer comprises a ferromagnetic core having a central branch. The central branch comprises at least one unit that is surrounded in part by an electrical conductor in the form of a U. Each unit of the central branch of the core has two outer air gaps and one or more central air gaps. Each outer air gap has length, that when measured in the longitudinal direction of the unit, is longer than the sum of the lengths of the one or more central air gaps. At least one magnetic sensor is contained in a central air gap of each unit and the central branch includes a total of at least two magnetic sensors. The measuring transformer is especially well suited for use in multifunction measuring instruments.

Abstract: A circuit arrangement for finding a sum of electrical power outputs for use in a multi-phase electricity meter is disclosed. The circuit arrangement comprises a plurality of multiplier circuits arranged in sequence. The sequence of multiplier circuits has two poles which form the output poles of the circuit arrangement. Each multiplier circuit comprises a Hall element, an amplifier, and a polarity reversing switch.

Abstract: A semiconductor light modulator is disclosed. The light modulator comprises a semiconductor body and a waveguide for guiding light rays formed in the body. The waveguide comprises waveguide sections of first and second types formed alternately in a series. Each waveguide section of the first type is delimited at least in part by a depletion zone. A voltage U may be applied for controlling the size of the depletion zone delimiting the sections of the first type to vary the ability of the sections of the first type to guide light. Illustratively, when the voltage U is near zero, the light confining characteristics of the sections of the first and second type are substantially identical, so that light rays are guided along the waveguide from one section to another.

Abstract: A device for use in connection with electricity meters incorporating current transformers is disclosed. The device detects saturation incidents of the magnetic cores of the transformers, thereby reducing measurement errors.

Abstract: An inventive Hall element formed from semiconductor material is disclosed. The inventive Hall element comprises a plurality of interconnected portions formed in a common semiconductor layer. Depending on how the portions are interconnected, the Hall element may detect the sum or difference of magnetic field values. The invention enables the realization of very large Hall elements which can be used in electrical meters to measure a magnetic field produced by an electric current.

Abstract: A transformer system for measuring electrical current includes an electrical conductor having first and second conductor portions. The first conductor portion conducts electrical current in one direction and the second conductor portion conducts the electrical current in an opposite direction. The first conductor portion produces a magnetic field H.sub.a and the second conductor portion produces a magnetic field H.sub.b. A coil having a non-ferromagnetic core is positioned between the first and second conductor portions so that the axis of the coil is substantially parallel to the magnetic fields H.sub.a and H.sub.b. The separation between the outer circumferential surface of the coil and the first and second conductor portions is the minimum distance for avoiding a voltage breakdown therebetween for a predetermined maximum electrical current in the conductor portions. At least one ferromagnetic shield surrounds the first and second conductor portions for shielding the coil from external magnetic fields.

Abstract: A driving device for controlling the driving frequency for a stepping motor includes a voltage control pulse generator for producing electrical pulses for driving the stepping motor. The pulse generator includes an RC network providing a time base for the pulse width and the operating frequency of the electrical pulses. The RC network includes at least one controllable resistance and a capacitor connected to control the controllable resistance by the charging and discharging of the capacitor.

Abstract: In an integrable Hall element, which includes a semiconductor layer of a single conductive type, a plurality of current electrodes adapted for being connected to an energy source, and wherein at least one current electrode and two sensor electrodes are located on a surface of the Hall element, and the one current electrode has a first connecting contact forming a first energy source pole, the improvement comprises the one current electrode being approximately located in the center of a line connecting the sensor electrodes.

Abstract: A method and apparatus for embossing a pattern having a microscopic relief structure, such as, for example, an optical diffraction grating, onto a layer of thermoplastic material is disclosed. A small circular region of a flexible embossing die is pressed against the thermoplastic layer by means of a punch. A fraction of the corresponding small circular region of the thermoplastic layer is then heated from the rear by a beam of radiant energy. The process may be repeated at all points on the thermoplastic layer where the pattern is desired.

Abstract: A measuring transformer for measuring a current flowing in an electrical conductor is disclosed. Illustratively, the transformer comprises a three legged ferromagnetic core whose center leg at least partially surrounded by the electrical conductor. The center leg defines a center air gap and two outer air gaps, the center gap containing a magnetic field snesor and one outer gap being located at each end of the center leg. The two outer gaps are longer than the center gap when measured in the longitudinal direction of the center leg. The center leg and the magnetic sensor may form a single construction element. This configuration permits an especially precise, simple, and dependable installation of the measuring transformer, without worsening non-linearities or phase errors, while improving air-gap tolerances.

Abstract: A circuit arrangement for the input circuit of a meter for simultaneously measuring two electrical quantities is disclosed. The circuit includes a current transformer including a primary winding, two substantially equal secondary windings and a pulse amplitude modulator associated with each secondary winding. Connections are made from each secondary winding to one terminal of its associated and non-associated pulse amplitude modulators, respectively. The circuit can be manufactured simply and economically while providing a high quality meter. Other embodiments provide additional advantages.

Abstract: A card, such as a credit card or identification card, includes electronic circuitry which permits its identification by an identifying device. More particularly, optical radiation is transmitted from the identifying device to the card to be identified. The radiation is modulated with information by a modulating device included in the card and is retransmitted to the identifying device.

Abstract: The present invention is an arrangement for measuring electrical power. The arrangement comprises a conductor traversed by an electrical current i and a voltage-to-current converter for transforming an electrical voltage u.sub.N into a proportional supply current i.sub.N for a Hall element. The Hall element is adapted to produce an intelligence containing output signal .+-.u.sub.H proportional to the product (.+-.i.u.sub.N) of the current i and the voltage .+-.u.sub.N. The Hall element is arranged in an air-gap of a ferromagnetic core that is excited by the current i. A voltage-to-frequency converter transforms the Hall element output voltage .+-.u.sub.H into a proportional output frequency. The voltage-to-frequency converter includes a capacitor for integration purposes and at least two signal sources. The power measuring device also includes a switch for periodically switching a signal proportional to the signal .+-.u.sub.H and for switching said signal sources to compensate for an offset voltage.

Abstract: A method and apparatus for converting an electrical signal into a proportional frequency is disclosed. Modulation of the output frequency resulting from polarity switching cycles having half-periods of unequal duration and capacitor voltages which might be non-zero at the time of polarity reversal are substantially avoided. This permits faster and more precise calibration.

Abstract: A security blank includes a sheet, and an elongated security thread connected to the sheet. The security thread may be identified upon being irradiated by electromagnetic radiation by a recognizable signature from radiation scattered therefrom; the cross-section of the security thread is other than circular or rectangular and is substantially constant over a prearranged portion of the length thereof.

Abstract: The present invention is an electrical circuit for use with a four-pole device. The four-pole device has two input connections and two output connections. The output of the four-pole device is measured at one output relative to a base potential present at the other output.The electrical circuit comprises a two-poled switch, which is connected in such a manner, that in its first position a signal source is connected with the first input of the four-pole device and the output of an amplifier is connected with the second input of the four-pole device. In the switch's second position, the signal source is connected with the second input of the four-pole device and the output of the amplifier is connected with the first input of the four-pole device. The output of the four-pole device, which is at the base potential, is connected to an inverting input of the amplifier, while the non-inverting input of the amplifier is connected to a constant reference voltage (U.sub.R).

Abstract: A magnetic field sensor having a lateral bipolar magnetotransistor incorporating only a single emitter region and whose base region is incorporated as a well in the surface of a silicon substrate of the reverse material conduction type. The P/N junction of the base region with the silicon substrate is reverse biased by means of at least one secondary collector contact. The emitter region must be kept as shallow than 0.5 .mu.m or be so lowly doped with impurity atoms that its resistivity is greater than 100 ohms per square or both. The sensitivity of the magnetic field sensor is approximately 100%/Tesla.

Abstract: The present invention is a one-phase stepping motor having a predetermined direction of rotation. The motor comprises a rotor having 2p permanently magnetized poles on its outer surface. The rotor is surrounded by a coil, which when energized forms the main stator poles. Auxiliary pole arms extend into the space between the coil and the rotor.The rotor and coil are stored in a two-part housing which magnetically isolates the motor. The auxiliary pole arms extend inward from the top and bottom surfaces of the housing and are formed integrally therewith.The arrangement of the auxiliary pole arms serves to determine the direction of rotation of the rotor. Illustratively, the auxiliary pole arms are divided into groups. Within each group, the auxiliary pole arms are at a distance from the rotor that decreases gradually or in stages in the direction of rotation of the rotor.This one-phase stepping motor is especially suitable for driving counting mechanisms in electricity meters.

Abstract: In a system for optical display and photo-electric scanning of the contents of a counter equipped with counting wheels, and wherein each counting wheel includes a plurality of numeral members visually distinguishable from the periphery thereof, a coded optical marking member is associated with each numeral member of a respective counting wheel. The coded optical marking member includes at least one optical surface element, and the optical marking members of the counting wheels extend along respective rows, and may be scanned by a light ray moving along a corresponding row. The improvement includes one of the members being superimposed at least in part onto another of the members in a corresponding row, and being partially light-transmitting, while each optical surface element is light-reflective, so that the numeral members are visible upon being illuminated with diffuse light, but wherein a light ray directed onto a respective optical surface element is reflected therefrom.

Abstract: A circuit including a magnetic sensing device for measuring magnetic fields is disclosed. The output of the magnetic sensing device is amplified by an amplifier and feedback to the magnetic sensing device. A potentiometer comprising two resistors R.sub.1 and R.sub.2 is connected between the output of the amplifier and ground. The feedback signal is taken from the common terminal of the two resistors. When circuit parameters are appropriately chosen, a magnetic field measuring circuit which is linearly responsive to changes in magnetic field intensity and relatively temperature independent results.