Abstract
Magnetic sensors are widely used in the fields of navigation, transportation, robotics, automation, and medical equipment, and the performance requirements of sensors are getting higher and higher. In this article, a bimodal magnetic sensor with two advantages of a large number of processes and low noise is proposed. The sensor consists of a 640μH core-wound inductor in series with a 100pF capacitor. When the external magnetic field changes, the magnetization state of the core in the inductor changes, the inductance value also changes, while the resonant frequency and impedance value of the sensor change with the magnetic field.<br>In this paper, the giant magnetic impedance characteristics of the RLC series circuit were analyzed, and the relationship between magnetic permeability, inductance value, and external magnetic field was established, and the series resonant frequency of the circuit was simulated to calculate the characteristics of the circuit with respect to the inductance variation.Then, two test systems were set up to test the resonance frequency versus magnetic field and the noise characteristics of the sensor.<br>In impedance mode, the effects of capacitance, drive signal frequency, and static bias magnetic field on the sensor noise floor were first analyzed to determine the optimal parameters of the sensor. When the series capacitance of the sensor is 100pF, the drive signal frequency is 1MHz, and the static bias magnetic field is 7.66Oe, the sensor has the optimal performance with an equivalent noise floor of about $200 p T / \sqrt{H z} @ 1 H z$,an impedance rate of change sensitivity of 160.6%/Oe, and a linear range of about 2Oe.In the frequency mode, the sensor operates linearly up to 25Oe, and using a logistic regression model to fit the resonant frequency to the magnetic field variation, the fit reaches 0.9974, and when the static bias magnetic field is about 7.66Oe, the sensor sensitivity is about 47kHz/Oe.<br>Not only that, with commercial components costing only ¥10 and excellent performance, the sensor has great market potential compared with other common different kinds of magnetic sensors on the market.
Published Version
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call