Abstract: An amplifier circuit for amplifying a change in a resistance value of a magnetic resistance element is formed by connecting a first and a second current mirror circuits having the same structure in cascode, so that a voltage change is amplified without using a capacitive coupling. Hence, a high-pass filter is not created as a parasitic circuit, whereby a gain is maintained high in the low frequency region and a low frequency characteristic is excellent. Further, since control electrodes of transistors which form each current mirror circuit are grounded through the capacitance, a noise is reduced without using a conventional feedback circuit. This eliminates an influence of the feedback circuit over a high frequency characteristic, and therefore, a high frequency characteristic becomes excellent.

Abstract: A magnetic sensor including a magnetoresistance effect element directed to prevent deterioration in the detection sensitivity occurring due to inversion of the magnetization of a plurality of ferromagnetic thin film stripes forming the magnetoresistance effect element with respect to the initial direction during the repeated operations, the magnetic sensor being arranged in such a manner that the magnetoresistance effect element is disposed at a position deviating from the center of the magnetic pole surface of a cylindrical magnet, preferably at a position deviating in a direction perpendicular to a direction in which the magnetic object to be detected is moved. The thus-employed arrangement enables a bias magnetic field to be applied to the magnetoresistance effect element in parallel to the deviation direction. Therefore, the magnetization of all of the plurality of the ferromagnetic thin film stripes forming the magnetoresistance effect element can be caused to face the same direction.

Abstract: A switching arrangement for a signal processing comprises a sensor for sensing a movable part and having an inductivity, and a control reflecting circuit connected with the inductivity of the sensor, the current reflecting circuit having a transistor with a base which is directly connected with the inductivity of the sensor, the current reflecting circuit having one side connected with a voltage supply and another side connected with a resistance at which a measuring signal is pickable, and the current reflecting circuit actuates a current amplification.

Abstract: A waveform shaping circuit shapes a waveform by comparing an output signal generated by an electromagnetic coil in response to a change in an incident magnetic flux to a reference voltage in a comparator. The circuit prevents waveform shaping error due to rapid fluctuations in the output signal. The waveform shaping circuit includes a high-pass filter that removes low-frequency components having frequencies not higher than a cut-off frequency from the output signal of the electromagnetic coil and that has at least two different attenuation characteristics with respective cut-off frequencies, a voltage limiting circuit for switching between the attenuation characteristics of the filter in response to the amplitude of the output signal of the electromagnetic coil by limiting the amplitude of the output signal to a maximum voltage, and a comparator for comparing the filtered output signal with a reference voltage and generating a shaped output signal in response.

Abstract: A first magnetically coupled film sensing element and a second magnetically coupled film sensing element are arranged to change resistance in response to a magnetic filed when biased by a current through the elements. A current carrying conductor spaced from the elements sets the magnetization in the elements. A transfer function of the elements is adjusted by varying the current through the elements or the current through the conductor.

Abstract: A geartooth sensor is provided with a circuit which determined a threshold magnitude as a function of the minimum value of a first output signal from a magnetically sensitive component and an average output signal from a magnetic sensitive component. Circuitry is provided to determine the average signal. The minimum signal is then subtracted from the average signal and the resulting signal is doubled before being scaled by a predetermined fraction and then compared to the original output signal from the magnetically sensitive component. This circuit therefore determines a threshold signal as a function of both the minimum signal value and the average signal value and, in addition, enables the resulting signal to be scaled to a predetermined percentage of this difference for the purpose of selecting a threshold value that is most particularly suitable for a given application.

Abstract: A magnetic detecting apparatus including a magnetic sensor for detecting the displacement of a member which is detected by a variation in the voltage, a sampler for sampling the voltage detected by the magnetic sensor at the required period, and a voltage power supplier for supplying the required power supply voltage to the magnetic sensor only while the sampler samples the voltage.

Abstract: A magnetic-field sensor has an array of split-drain transistors connected in parallel, each having a first, a second, and a third drain electrode, and a negative reference current generating transistor. A biasing circuit is utilized to bias the split-drain transistors in the saturated state, and to actuate the negative reference current generating transistor to generate a negative reference current. A first, a second, and a third current mirror are all controlled by a reference voltage. The second current mirror is coupled to the second drain electrode of each of the split-drain transistors to keep the reference voltage at a reference level. The first current mirror is coupled to the first drain electrode of each of the split-drain transistors to generate a first sensed current, and the third current mirror is coupled to the third drain electrode of each of the split-drain transistors to generate a second sensed current.

Abstract: A magnetic detector, such as is used in a frequency generator, for detecting the rotational rate of a motor includes magnetic resistance elements and an operational amplifier. The magnetic resistance elements have a predetermined resistance ratio and are connected serially between a power source and ground. The common node between the two magnetic resistance elements serves as an output terminal for providing an output voltage. The output voltage from the output terminal being supplied to one of the two input terminals of the amplifier. The voltage from a resistance voltage divider disposed between the power source and ground is supplied to the other input terminal of the amplifier. A change of the resistance ratio between the two magnetic resistance elements is effected by a resistor disposed in series with the elements or in parallel with one of the elements.

Abstract: An improved magnetic sensor for use in measuring the position, velocity and/or direction of movement of an object having alternating zones of different magnetic conductivity in the direction of movement, comprises a permanent magnet member having a pole face facing the moving object and having an axis transverse to the direction of movement thereof. A pair of sensor elements are mounted on the permanent magnet pole face, one on each of the opposite sides of the magnet axis in the direction of movement of the object. A laminated flux bar having strips of ferromagnetic material of high permeability and strips of ceramic material having low permeability is mounted on the pair of sensor elements.

Abstract: The feedback current for the flux-locked-loop of a DC-SQUID is conductively supplied directly to the input circuit of the SQUID rather than to a separate feedback or modulation coil that is inductively coupled to the SQUID, thereby eliminating the feedback or modulation coil and simplifying construction of an integrated SQUID module.

Abstract: A portable electromagnetic field exposure dosimeter includes a triaxial fite-loaded coil sensor, a group of amplifiers and bandpass filters, a data control board, and a computer. The triaxial sensor receives electromagnetic radiation along three orthogonal axes for measurement which is channelled through a group of amplifiers and then bandpass filtered into three frequency signal ranges. One frequency range corresponds to exposure at 60 Hz and two of its harmonics. The second frequency range corresponds to high frequency pulsed energy. The third frequency range reflects body motion of a tested individual. The data control board converts such filtered signals into digital code and controls the flow of the converted data to random access memory and to the computer. The computer performs a Fast Fourier Transform on the converted data from the 60 Hz frequency range and then stores or displays the analyzed data as a function of frequency and time.

Abstract: A SQUID fluxmeter, which object is to accurately measure magnetic flux even if the input magnetic flux is largely changed in a short time, includes an 1-input superconducting OR gate for outputting pulses to the number of i in response to one input pulse from a SQUID, an AC bias current source for outputting a current I.sub.C of variable frequency 4if to a bias input node of the OR gate, an up/down counter for counting pulses from the SQUID and a control circuit for outputting a control signal CSi to the AC bias current source corresponding to the time differential value of the count value C1 of the counter and present value i. The response speed of the magnetic flux feedback through the feedback coil to the SQUID in response to the magnetic flux input to the SQUID is thereby made i times higher than that in the prior art.

Abstract: A planar SQUID magnetometer for detection and measurement of an applied magnetic flux is disclosed wherein a planar microwave-resonant element overlaps a Josephson device incorporated in a high-T.sub.c superconducting, thin-film SQUID device, thereby providing inductive coupling between the planar microwave-resonant element and the SQUID device. When the microwave-resonant element is excited by incident high-frequency microwave radiation, the intensity of reflected microwave radiation varies in response to a magnetic flux applied to the SQUID device in accordance with non-linear oscillatory behavior of the microwave-resonant element due to inductive loading by the SQUID device. The microwave-resonant element and the SQUID device are preferably fabricated photolithographically on a single substrate.

Abstract: In an electronic article surveillance (EAS) system, a frequency-dividing transponder that responds to detection of electromagnetic radiation of a first predetermined frequency by transmitting electromagnetic radiation of a second predetermined frequency that is a frequency-divided quotient of the first predetermined frequency, includes an active strip of amorphous magnetic material having a transverse uniaxial anisotropy defining a magnetomechanical resonant frequency in accordance with the dimensions of the strip at the second predetermined frequency when magnetically biased to be within a predetermined magnetic field intensity range so as to respond to excitation by electromagnetic radiation of the first predetermined frequency by transmitting electromagnetic radiation of the second predetermined frequency; and a tripole strip of magnetic material of such coercivity and so disposed in relation to the active strip of magnetic material as to create a magnetomechanical resonance in the active strip at the firs

Abstract: A magnetoresistor (MR) and a non-magnetoresistor (NMR) are formed of indium antimonide or other magnetoresistive material in thermal proximity to each other on an integrated circuit substrate (100). Hall effect shorting strips (104) are formed on the magnetoresistor (MR) to make it much more magnetoresistive than the non-magnetoresistor (NMR). A current mirror (80) causes equal constant currents (I2) which do not vary with temperature to flow through the magnetoresistor (MR) and non-magnetoresistor (NMR), such that magnetoresistor and non-magnetoresistor voltages are developed thereacross respectively. The magnetoresistor and non-magnetoresistor voltages vary equally in accordance with temperature. The magnetoresistor voltage also varies in accordance with applied magnetic flux. A comparator (66) subtracts the non-magnetoresistor voltage from the magnetoresistor voltage to produce an output signal (Vout) with the temperature variation canceled, and which thereby varies only in accordance with magnetic flux.

Abstract: In integrated storage circuits which receive energy only via a coil in a contactless manner and which also execute the data exchange, the integrated storage circuit loads the coil to a greater extent dependent upon the data read. It is possible to detect this load variation in the device feeding the coil. Detection is more reliable as the load variation is greater. However in the case of a high coil load, the voltage across the coil decreases to such an extent that, after rectification, it is no longer sufficient to reliably energize. The supply voltage for the storage circuit is generated by means of a voltage increase circuit during the increased load. The voltage increase circuit is controlled by the data.