A tension measuring method installs a reel having a cylindrical coil forming part on a cable to be measured, forms a coil by winding a conductor around the coil forming part, measures a magnetic hysteresis loop of the cable by supplying a current to the coil to generate a magnetic field, and computes a tension of the cable using a parameter determined from the hysteresis loop. A magnetic field sensor and a magnetic flux sensor are provided inside a through hole in the coil forming part, and the cable is positioned inside the through hole. The magnetic field is varied so that the hysteresis loop includes a near-saturation magnetization region, to measure the hysteresis loop using the sensors. The parameter is selected from a magnetic flux or a magnetic flux density, a remanent magnetization, a coercivity, a magnetic permeability, and a hysteresis loss in the near-saturation magnetization region.

Various examples of a high frequency, inductor and transformer core loss characterization and measurement method and system for arbitrary waveforms are disclosed herein. A system and method for determining core loss of a magnetic core can include generating a waveform to excite a first test circuit which comprises an excitation circuit, a circuit under test (CUT) comprising the magnetic core, and an inductance circuit having an inductor connected in parallel to the CUT. The method includes measuring a first current, when the first test circuit is excited. The method includes disconnecting the CUT from the first test circuit to form a second test circuit. The method includes generating the waveform to excite the second test circuit, and measuring a second current, when the second test circuit is excited. The power loss for the magnetic core is calculated based on an input voltage and the first and second measured current.

A magnetic sensor system includes a magnetic field generator and a magnetic sensor. The magnetic sensor includes a plurality of MR elements. The plurality of MR elements are each configured so that a bias magnetic field in a second direction orthogonal to a first direction is applied to a free layer, and to change in resistance with a strength of a magnetic field component. A maximum strength of the magnetic field component applied to each of the MR elements is greater than or equal to 1.2 times the strength of a bias magnetic field.

The iron loss of an iron core excited by an inverter power supply is reduced. A modulation operation-setting device 1430 for the inverter power supply controls a maximum value Hmax and a minimum value Hmin of a field intensity H in at least one minor loop such that the loss (iron loss, copper loss, and switching loss) of the entire system is less than the loss of the entire system when an electric device is operated with a target waveform (excluding harmonics).

The invention provides method for making high coercivity magnetic materials based on FeNi alloys having a Llo phase structure, tetratenite, and provides a system for accelerating production of these materials. The FeNi alloy is made by preparing a melt comprising Fe, Ni, and optionally one or more elements selected from the group consisting of Ti, V, Al, B, C, Mo, Ir, and Nb; cooling the melt and applying extensional stress and a magnetic field. This is followed by heating and cooling to form the L10 structure.

A detection device, including: one or a plurality of magnetic coupling elements configured to have one or a plurality of coils; and a detection unit that measures or calculates an effective resistance values of the magnetic coupling elements or an effective resistance value of a circuit including at least the magnetic coupling elements and determines a presence or absence of a foreign substance based on a change in the effective resistance value.

An apparatus for monitoring a magnetic core, wherein the apparatus provides a measurement winding which is magnetically coupled to the magnetic core to be monitored, a comparison inductance which is electrically connected in series with the winding and an electronic processing unit which is designed to determine the saturation behavior of the magnetic core to be monitored. The electronic processing unit is configured to record a first electrical signal occurring at the measurement winding and a second electrical signal occurring at the comparison inductance in response to an electrical measurement signal applied to the measurement winding, and to determine the saturation behavior of the magnetic core to be monitored on the basis of the first and second electrical signals. This makes it possible to easily monitor the saturation behavior of a magnetic core and to reliably detect the occurrence of saturation of the magnetic core.

A magnetic characteristic measuring apparatus measures a magnetic characteristic of a sample having a core wound by a primary coil and a secondary coil with high accuracy at high frequency. The apparatus includes: an air-core coil wound by a primary coil and a secondary coil; and a capacitor. The primary coil of the sample, the primary coil of the air-core coil and the capacitor are serially connected, and the capacitance C.sub.L of the capacitor is selected as 1/3.sup.2L.sub.aC.sub.L1/.sup.2L.sub.a, wherein L.sub.a is an inductance of the air-core coil at a frequency /2n.

A detection device, including: one or a plurality of magnetic coupling elements configured to have one or a plurality of coils; and a detection unit that measures or calculates an effective resistance values of the magnetic coupling elements or an effective resistance value of a circuit including at least the magnetic coupling elements and determines a presence or absence of a foreign substance based on a change in the effective resistance value.

A detection device, including: one or a plurality of magnetic coupling elements configured to have one or a plurality of coils; and a detection unit that measures or calculates an effective resistance values of the magnetic coupling elements or an effective resistance value of a circuit including at least the magnetic coupling elements and determines a presence or absence of a foreign substance based on a change in the effective resistance value.