The Research Of Ni-SiC Sensor Low Trigger Chua's Chaotic Circuit Mechanism

SiC, a new type of gas sensitive material, is widely used in various industrial production fields, because of its superior performance. The adsorption performance of CO adsorbed on the SiC(001) surface and the one of Ni-doped SiC(001) surface are investigated by using the DFT-GGA calculation method in this paper. The adsorption characteristic of CO adsorbed on SiC(100) surface and Ni-doped SiC(001) surface are contrastively analyzed based on the changes of bond structures, adsorption energy, density of states, Mulliken population and charge density difference. The results show that bridge site is a favorable adsorption site for CO on SiC(001) surface, and fcc site is sensitive site to CO on Ni-doped SiC(001) surface. The Ni doped can increase the activity of SiC(001) surface, raising the possibility of gas adsorbed on SiC(001) surface. The results are useful to guide the implementation of the adsorption experiment of CO on SiC(001) surface and also have important significance to study on the SiC gas sensor.In order to improve the sensitivity of gas sensor circuit, the Chua's chaotic circuit is introduced in circuit design. The Chua's chaotic circuit is used to detect of low concentration of gas because it is sensitive to the initial value of circuit. We will obtain different chaotic phase track diagram by changing the initial value of circuit to calibrate the concentration of gas. The circuit on the basis of Chua's circuit is upgraded to match the requirements for circuit sensitivity. That makes the sensitivity of the circuit with a qualitative improvement and the performance of the circuit improved. Ulteriorly, we use the analog and digital ways to realize the Chua's circuit and analyze the advantage and disadvantage of them respectively. The feasibility of digital circuit design is proposed.A series of peripheral circuit are designed using the embedded platform based on the sensing circuit, which include the sound and light alarm circuit, display circuit, real-time monitoring circuit. The gas sensor will have relatively fully function, intelligent design, convenient upgrade and integrate products in the future. The products can be widely applied to the industry and daily life, especially the use of coal mine, made the mine mining become more safety.