Hall-Effect Sensor Technique for No Induced Voltage in AC Magnetic Field Measurements Without Current Spinning

Accurately sensing AC magnetic field signatures poses a series of challenges to commonly used Hall-effect sensors. In particular, induced voltage and lack of high-frequency spinning methods are bottlenecks in the measurement of AC magnetic fields. We describe a magnetic field measurement technique that can be implemented in two ways: 1) the current driving the Hall-effect sensor is oscillating at the same frequency as the magnetic field, and the signal is measured at the second harmonic of the magnetic field frequency, and 2) the frequency of the driving current is preset, and the measured frequency is the magnetic field frequency plus the frequency of the current. This method has potential advantages over traditional means of measuring AC magnetic fields used in power systems (e.g., motors, inverters), as it can reduce the components needed (subsequently reducing the overall cost and size) and is not frequency bandwidth limited by current spinning. The sensing technique produces no induced voltage and results in a low offset, thus preserving accuracy and precision in measurements. Experimentally, we have shown offset voltage values between 8 and 27 μT at frequencies ranging from 100 Hz to 1 kHz, validating the potential of this technique in both cases

Hall-Effect Sensor Technique for No Induced Voltage in AC Magnetic Field Measurements Without Current Spinning

Accurately sensing AC magnetic field signatures poses a series of challenges to commonly used Hall-effect sensors. In particular, induced voltage and lack of high-frequency spinning methods are bottlenecks in the measurement of AC magnetic fields. We describe a magnetic field measurement technique that can be implemented in two ways: 1) the current driving the Hall-effect sensor is oscillating at the same frequency as the magnetic field, and the signal is measured at the second harmonic of the magnetic field frequency, and 2) the frequency of the driving current is preset, and the measured frequency is the magnetic field frequency plus the frequency of the current. This method has potential advantages over traditional means of measuring AC magnetic fields used in power systems (e.g., motors, inverters), as it can reduce the components needed (subsequently reducing the overall cost and size) and is not frequency bandwidth limited by current spinning. The sensing technique produces no induced voltage and results in a low offset, thus preserving accuracy and precision in measurements. Experimentally, we have shown offset voltage values between 8 and 27 μT at frequencies ranging from 100 Hz to 1 kHz, validating the potential of this technique in both cases

Динамические эффекты в магнитной жидкости с микрокаплями концентрированной фазы во вращающемся магнитном поле

Variation in the shape of microdrops of a highly concentrated magnetic colloid resulting from phase separation in a magnetic fluid has been studied. It has been found that even weak magnetic fields (such as those comparable to the geomagnetic field) substantially influence the geometry and behavior of microdrops. Different configurations of microdrops in a rotating magnetic field have been considered. The occurrence of a rotation moment that acts on a macrodrop of a magnetic fluid in a rotating magnetic field has been shown. The rotation moment is due to the rotation of concentrated phase microdrops inside the macrodrop. The macroscopic rotation frequency of a drop’s surface as a function of the applied magnetic field frequency and strength has been measured.

Remagnetization Core Losses In The Massive Amorphous FeCoYb Alloy

In this paper were studied the influence of magnetic field frequency and induction on the total core power loss � which is divided into eddy current loss, hysteresis loss and anomally losses of the bulk amorphous alloy. The total core power loss of the investigated bulk amorphous alloy increases with magnetic field frequency and peak induction. It follows a power relation similar to what has been observed in classical ribbons. In the investigated alloy in addition to losses due to magnetic hysteresis and eddy currents, other additional losses are present. However additional losses, emerging simultaneously to the component associated with migration relaxations are very weakly dependent on the frequency and temperature.