scholarly journals Re-design of Precision Signal Conditioning Circuit for detecting Schumann Resonance

2021 ◽  
Author(s):  
Rohith Bikkina
Author(s):  
Ismael Payo ◽  
J. L. Polo ◽  
Blanca Lopez ◽  
Diana Serrano ◽  
Antonio M. Rodríguez ◽  
...  

Abstract Conductive Hydrogels are soft materials which have been used by some researchers as resistive strain sensors in the last years. The electrical resistance change, when the sensor is stretched or compressed, is usually measured by the two-electrode method. This method is not always suitable to measure the electrical resistance of polymers-based materials, like hydrogels, because it could be highly influenced by the electrode/sample interface, as explained in this study. For this reason, a signal conditioning circuit, based on four-electrode impedance measurements, is proposed to measure the electrical resistance change when the gel is stretched or compressed. Experimental results show that the tested gels can be used as resistance force/pressure sensors with a quite linear behaviour.


2021 ◽  
Author(s):  
ARUN K ◽  
LEKSHMI M S ◽  
SUJA K J

Abstract Metal oxide semiconductors have been widely used in the eld of gas sensor study. Various researches are being done to improve the sensitivity of the sensing material for applications like breath analyzers. In this work, a theoretical investigation and analysis of the n- type metal oxide for Acetone gas detection are carried out. The rate of change of resistance of the sensing material with respect to the change in the concentration of the target gas is analyzed. Acetone being a reducing gas the resistance was found to decrease for n-type material. The simulations were done using COMSOL Multiphysics and results showed that the resistance of the sensing layer varies with the concentration of the target gas. Also, the performance analysis of sensors has been compared with the experimental results. Further, we have also derived a mathematical expression connecting the relationship between the concentration of gas and the rate of change of resistance. The resistance change is observed to be proportional to the target gas concentration. A signal conditioning circuit was also designed for providing a user-friendly interface for monitoring the gas concentration. The simulation of the signal conditioning circuit was done using Proteus Design Suite. This work will aid researchers to define and predict the behaviour of gas sensors.


2018 ◽  
Vol 18 (18) ◽  
pp. 7544-7550 ◽  
Author(s):  
Aparna Mohan ◽  
Mohanasankar Sivaprakasam ◽  
Boby George ◽  
V. Jagadeesh Kumar

2020 ◽  
Vol 69 (11) ◽  
pp. 8763-8772
Author(s):  
Shahid Malik ◽  
Meraj Ahmad ◽  
Laxmeesha Somappa ◽  
Tarikul Islam ◽  
Maryam Shojaei Baghini

Micromachines ◽  
2019 ◽  
Vol 10 (4) ◽  
pp. 237 ◽  
Author(s):  
Jiawen Chen ◽  
Jianhua Li ◽  
Lixin Xu

In this paper, a highly integrated amorphous wire Giant magneto-impedance (GMI) magnetic sensor using micro electron mechanical system (MEMS) technology is designed, which is equipped with a signal conditioning circuit and uses a data acquisition card to convert the output signal of the circuit into a digital signal. The structure and package of the sensor are introduced. The sensor sensing principle and signal conditioning circuit are analyzed. The output of the sensor is tested, calibrated, and the relationship between the GMI effect of the amorphous wire and the excitation current frequency is explored. The sensor supplies voltage is ±5 V, and the excitation signal is a square wave signal with a frequency of 60 MHz and an amplitude of 1.2 V generated by the quartz crystal. The sensor has the largest GMI effect at 60 MHz with a sensitivity of 4.8 V/Oe and a resolution of 40 nT.


2020 ◽  
Vol 20 (3) ◽  
pp. 1373-1382 ◽  
Author(s):  
Vijay S. Palaparthy ◽  
Shambhulingayya N. Doddapujar ◽  
Gaurav Gupta ◽  
Pallabi Das ◽  
Saurabh Arun Chandorkar ◽  
...  

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