Abstract: Two magnetic field sensors, ratiometric with respect to their common supply and featuring matched thermal coefficients, are inserted in the two airgaps of a magnetic circuit arranged so that said airgaps appear in series with respect to the magnetic flux generated by the current to be measured, while appearing in parallel with respect to the reference flux generated by a stable permanent magnet. The output signal of one of the sensors is thus proportional to the sum of said fluxes, the other to their difference. Adding and subtracting said signals produces two outputs, one proportional solely to the current to be measured, and the other solely to the reference flux. A feedback loop acts on the common supply of the two sensors in order to hold constant the output proportional to the reference flux, thus producing the effect that drifts with temperature of the magnetic sensitivities are intrinsically compensated for.

Abstract: Two magnetic field sensors, ratiometric with respect to their common supply and featuring matched thermal coefficients, are inserted in the two airgaps of a magnetic circuit arranged so that said airgaps appear in series with respect to the magnetic flux generated by the current to be measured, while appearing in parallel with respect to the reference flux generated by a stable permanent magnet. The output signal of one of the sensors is thus proportional to the sum of said fluxes, the other to their difference. Adding and subtracting said signals produces two outputs, one proportional solely to the current to be measured, and the other solely to the reference flux. A feedback loop acts on the common supply of the two sensors in order to hold constant the output proportional to the reference flux, thus producing the effect that drifts with temperature of the magnetic sensitivities are intrinsically compensated for.

Abstract: Contactless measurement of angular or linear positions is obtained by means of magnetic circuit configurations, biased by a permanent magnet, characterized by two airgaps whose relative geometry is designed to result in magnetic field values whose ratio is a function of the position to be measured. The magnetic field in said airgaps is measured by magnetic field probes, whose output signals are then electronically conditioned to generate a voltage proportional to said ratio. The output signal being function of a ratio, it naturally becomes insensitive to drifts of the magnet working point, or drifts in sensitivity of the magnetic field probes. In one embodiment said ratio of magnetic field values becomes a function of the relative angular displacement of two coaxial shafts, while becoming completely independent from their absolute angular displacement, allowing hence the realization of simple and robust torque sensors.

Abstract: Contactless measurement of angular or linear positions is obtained by means of magnetic circuit configurations, biased by a permanent magnet, characterised by two airgaps whose relative geometry is designed to result in magnetic field values whose ratio is a function of the position to be measured. The magnetic field in said airgaps is measured by magnetic field probes, whose output signals are then electronically conditioned to generate a voltage proportional to said ratio. The output signal being function of a ratio, it naturally becomes insensitive to drifts of the magnet working point, or drifts in sensitivity of the magnetic field probes. In one embodiment said ratio of magnetic field values becomes a function of the relative angular displacement of two coaxial shafts, while becoming completely independent from their absolute angular displacement, allowing hence the realisation of simple and robust torque sensors.

Abstract: An authentication token one side of which features an array of solar cells, of a very thin and flexible type, whereas the opposite side features a display device. The method consists in encoding into a sequence of bright images, interlaced with less bright ones, the code sent by the server. By placing the token in front of the portion of the screen displaying said encoding sequence, the light collected by the array of solar cells it is sufficient to generate the energy required for supplying the token's microprocessor, while the variation in brightness are decoded as to reconstruct the digital word representing the code sent by the server. Said code is then processed by the microprocessor to generate a One Time Password, OTP, then displayed on the display device. The user would then enter said OTP on the login page.

Abstract: The present invention provides current measuring apparatus of the type using magnetic coupling, the apparatus comprising a transformer (Tr) having a gap (E) in which a device (G) is disposed suitable for providing a signal which is a function of the magnetic flux existing in the gap with the primary winding (P) of the transformer conveying the current (I) to be measured. The apparatus includes the improvement of employing a device for separating the high frequency A.C. components from the low frequency A.C. components and the D.C. component of the current to be measured. In addition, a device for providing a second signal proportional to the high frequency A.C. component is used, along with a summing device (.epsilon.) for summing a first signal and the second signal as provided by the device located in the gap.The invention is applicable in the electrical industry to measure current.