32 results about "Barkhausen effect" patented technology

A pulse signal generator using a magnetic device that can cause a large Barkhausen effect, comprises means having a number of pits and projections and generates pulses according to the behavior of these, the means being capable of moving the pits and projections in a first or second direction, the pits and projections being disposed in the moving direction with some of the projections missing or some of the pits filled. The value of the ratio between the time interval of pulses generated by portions other than a projection-missing portion and the time interval of pulses generated by the projection-missing portion or the value of the ratio between the time interval of pulses generated by portions other than a pit-filled portion and the time interval of pulses generated by the pit-filled portion differs between when the pits and projections move in the first or second direction.

A recording paper having a magnetic material-containing layer, that includes a magnetic material that generates a large Barkhausen effect and a filler, and is disposed between pulp layers containing a pulp.

The present invention provides a security functional thin film and a security product containing such a thin film. The security functional thin film is of an amorphous structure, and possesses soft magnetic characteristics. Large Barkhausen effect can be detected along the in-plane preferred direction of magnetization; and the Large Barkhausen effect significantly attenuates, or no such signal can be detected, in a direction perpendicular to the in-plane preferred direction of magnetization. The thin film has a thickness of 20-300 nm, and the thin film also possesses element encoding characteristics that can be authenticated by experts. The security functional thin film of the present invention can be fabricated by magnetron sputtering web coating process. The security product provided by the present invention has a security information layer formed of the security functional thin film, and can be combined with other security characteristics for use in fabricating security materials such as security threads, security tapes, paper security strip-like inserts, or security labels, and others. Compared with conventional anti-counterfeiting technologies, the instant security functional thin film has more hidden security information, and facilitates enhancement of safety performance of security products.

The present invention provides a magnetic wire and a recording medium. The magnetic wire includes a magnetic metal wire, and the surface of the magnetic metal wire is covered with an insulating material layer. The magnetic wire has a coercive force of 30 A / m or less and has a Barkhausen effect.

A transfer paper for electrophotography contains a pulp fiber and a magnetic material for generating a large Barkhausen effect. An average dehydration speed S 1 a (an average value (% by mass / second) of dehydration speeds S 1 of 5 sheets of paper) is 0.15 or less. The dehydration speed S 1 is represented by (W 1 a-W 1 b) / 30. Here, W 1 a represents a moisture content ratio (% by mass) of the paperafter moisture conditioning, and W 1 b represents a moisture content ratio (% by mass) of the paper after a dehydration process including leaving the paper in a 80 DEG C. environment for 30 seconds after moisture conditioning.

A baggage management gate including an exciting coil, a detecting coil and signal processing unit. The exciting coil forms an alternating magnetic field in a passage to an area from which manages objects to be carried in or carried out. The detecting coil detects a variation in the alternating magnetic field when magnetization of a magnetic material showing a large Barkhausen effect is reversed in the alternating magnetic field. The signal processing unit determines as to whether the magnetization reversal occurs in the alternating magnetic field due to the large Barkhausen effect or not, based on a signal detected by the detecting coil. The signal processing unit includes amplifier that amplifies the signal detected by the detecting coil with plural different amplification factors and output the amplified signals with each of the plural different amplification factors.

The invention provides a defect and stress non-destructive detection system and non-destructive detection method based on pulsed eddy current and Barkhausen, belonging to the field of non-destructive detection. The system includes an excitation signal generator, a digital-to-analog converter, a power amplifier, an excitation coil, a Hall sensor, a signal amplification circuit, a data acquisition card and a computer. On the basis of eddy current detection, the present invention uses a mixed wave of a rectangular wave and a triangular wave as an excitation signal for ferromagnetic materials. The rectangular wave band in the first half of the mixed signal produces a pulse eddy current phenomenon, and the triangular wave band in the second half produces a Barkhausen effect. , use the signal time domain averaging method to process the signal in segments, realize the separation of the eddy current signal and the Barkhausen noise signal, and extract the feature and data processing of the signal separately, so as to realize the simultaneous online detection of the surface defects, stress and microstructure state of ferromagnetic materials , and realize the identification of hidden defects of ferromagnetic materials and the prediction of unformed defects and life. The invention can work reliably for a long time, has high sensitivity, simple method, intuitive display, high efficiency and feasibility, and the like.