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Magnetization reversal in a Wiegand wire induces a pulse voltage in the pickup coil around the wire, called the Wiegand pulse. The Wiegand sensor features the Wiegand wire and the pickup coil. The amplitude and width of the Wiegand pulse are independent of the frequency of the magnetic-field change. The pulse is generated by the Wiegand sensor, which facilitates the use of the Wiegand sensor as a power supply for equipment without batteries. In order to meet the power consumption requirements, it is necessary to maximize the energy of the pulse signal from the Wiegand sensor, without changing the external field conditions. The distributions of the magnetic field generated from the applied magnet in air and in the Wiegand wire were simulated before the experiments. Simulation predicted an increase in the magnetic flux density through the center of the Wiegand wire. This study determined that the magnetic flux density through the center of the Wiegand wire, the position of the pickup coil, and the angle between the Wiegand sensor and the magnetic induction line were the main factors that affected the energy of a Wiegand pulse. The relationship between these factors and the energy of the Wiegand pulse were obtained.

A fast magnetization reversal in a twisted FeCoV wire induces a pulse voltage in a pick-up coil wound around a wire. The Wiegand sensor is composed of this magnetic wire and the pick-up coil. As the output pulse voltage does not depend on a changing ratio of the applied magnetic field to switch the magnetization of the wire, the Wiegand sensor is used for to perform rotation and other detections. Recently, the Wiegand sensor has attracted significant attention as a power supply for battery-less operation of electric devices and for energy harvesting. In this study, we propose a concept of obtaining an intrinsic pulse voltage from the Wiegand sensor as its power source, and demonstrate its effectiveness in circuit simulation. The equivalent circuit for the Wiegand sensor is expressed by the intrinsic pulse voltage, internal resistance, and inductance of the pick-up coil. This voltage as a power source and circuit parameters are determined by MATLAB/Simulink simulation. The output voltage calculated using the equivalent circuit of the Wiegand sensor agrees with the experimentally measured results.

We previously demonstrated an efficient method of wireless power transmission using a Wiegand sensor for the application in implantable medical devices. The Wiegand sensor has an advantage in inducing sharp pulse voltage independent of the drive frequency. A down-sized receiver coil for wireless power transmission within blood vessels has been prepared, which enables medical treatment on any part of a human body. In order to develop practical applications of the Wiegand sensor as implantable medical devices, the circuit design is important. The circuit parameters in the circuit model of the Wiegand sensor must be clearly identified. However, a fast reversal of magnetization of the magnetic wire used in the Wiegand sensor, known as a large Barkhausen jump, and the induced nonlinear pulse signal make the inductance of the receiver coil time-dependent and inconsistent as conventionally considered in circuit analysis. In this study, the voltage and current responses of a wire-core coil are analyzed, and the time-dependent inductance is determined. The results showed that the inductance depends on the magnetization state of the wire, which can be negative during the fast reversal of magnetization.