• Journal of Magnetics
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• v.18 no.2
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• pp.159-162
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• 2013

We present how to optimize the operation condition including frequency of the orthogonal fluxgate sensor in this paper. The orthogonal fluxgate sensor was fabricated with a Co-based amorphous wire with 10 mm long and 100 ${\mu}m$ in the diameter and a 270-turn pickup coil wound on the amorphous wire. In order to investigate the frequency dependence of the sensitivity, output spectra of the sensor which was connected by using a coaxial cable with various lengths of 0.5-5 m were measured with a RF lock-in amplifier. The maximum sensitivities were obtained at different frequencies according to coaxial cable lengths. It was found that the optimal operation frequencies, at which maximum sensitivities were appeared, were almost identical to the frequencies of impedance resonance. The maximum sensitivity and optimal operation frequency were 1.1 V/Oe (${\approx}$ 11000 V/T) and 1.25 MHz respectively.

• Journal of the Korean Magnetics Society
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• v.22 no.6
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• pp.200-203
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• 2012

In this study, we have investigated that the operation frequency dependences of the output properties of the orthogonal fluxgate sensor which was fabricated with a ferrite core. An orthogonal fluxgate sensor should be operated in as high as possible frequency to enhance its sensitivity in the case of small sized sensor, because sensitivity of the sensor is proportional to cross section area, winding number and operation frequency. In this study, we investigated the correspondence of the frequency dependence of output and the reactance (inductance and capacitance) of pickup coil and cable. Experimental results represented that we could obtain maximum output (= sensitivity) at optimal frequency which is near LC resonance frequency of the pickup coil and cable.

• Journal of the Korean Magnetics Society
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• v.23 no.3
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• pp.94-97
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• 2013

Orthogonal fluxgate sensor was fabricated with cylinder-shaped NiZn ferrite core, Cu wire through the core and pickup coil wound on the core, and the bias current effect on the output sensitivity of it was investigated. The output ($$\sim_\sim$$ sensitivity) of the sensor was largely dependent on the operation frequency, and the tendency of sensor output was similar to that of the impedance of pickup coil. The maximum output was obtained by adding the DC bias current of which value was over 50% of the excitation current. The output was saturated when the DC bias current was larger than 50% of the excitation current.

• Journal of the Korean Magnetics Society
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• v.19 no.1
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• pp.17-21
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• 2009

In this study, we have investigated that the excitation current and operation frequency dependences of the output properties of the orthogonal fluxgate sensor which was fabricated with a Co base amorphous wire and a pick-up coil. The output signal increased linearly with increase of the excitation current below 0.3 A, and decreased with increase of the excitation current over 0.6 A. It was also found that the output increased sensitively with increase of operation frequency below 1.3MHz. The output was 3.8 V at the frequency of 1.3MHz while 1.32 V at 1MHz.

• Proceedings of the Korean Magnestics Society Conference
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• 2008.12a
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• pp.32.1-32.1
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• 2008

• Proceedings of the Korean Magnestics Society Conference
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• 2008.12a
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• pp.271.1-271.1
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• 2008

• Journal of Magnetics
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• v.16 no.4
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• pp.453-456
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• 2011

Demagnetization for a tube sample which was made of a galvanized steel sheet was performed by applying a magnetic field with a decrement to remove the remanent magnetization of the material. An orthogonal fluxgate magnetic field sensor was used to measure a magnetic field created from a ferromagnetic material. To evaluate the remanent magnetization, the measured magnetic fields were separated into two magnetic field components by the remnant magnetization and the induced one. The horizontal and the vertical bias fields should be controlled separately during demagnetization to remove the horizontal and the vertical components of the remanent magnetization of the tube sample.