Research On Electromagnetic Compatibility Of Electronic Equipment And Preventive Measure

EMC immunity determines the stability and security of the electronic equipment which is running under the electromagnetic environment. Nowadays, with the rapid development of the integrated technology, the electronic equipment is becoming more and more integrated, small and networked. As a consequence, the electromagnetic compatibility shows its importance.There are two ways to improve electromagnetic compatibility of the electronic equipment: The first one is, adopt the concept of electromagnetic compatibility during the designing stage, and take the possibility of electromagnetic interference into account from the circuit designing to the components choosing, so as to improve the ability of anti-interference. The second one is, installing the protective device at the key part or external position of the molding equipment to achieve the ideal effect of electromagnetic compatibility.I have been engaged in the electronic equipment electromagnetic compatibility testing work for nearly seven years and accumulated rich experience on testing. It was 2011 when I was responsible for drafting content of electromagnetic compatibility laboratory research projects in embedded system Zhejiang Province. The main research work of the thesis is:1.Describe the development process, research status review and the significance of the electromagnetic compatibility of electronic products. Introduce three main types of EMC immunity test: ESD, Electrical fast transient immunity and Surge(impact) immunity so as to analyze the interference principle、test methods and requirements. And specify the notice of practical testing.2.The paper comparatively analyzes the characters and the application scope of the four main transient interference absorbing devices(gravitron、voltage-sensitive resistor、transient voltage suppressor、solid discharge tube), proposes the design plan of portfolio anti-jamming circuit and discusses two EMC immunity test cases.The principle of electromagnetic compatibility immunity testing and the testing methods are analyzed and researched in-depth in my paper. Through practical testing, the effective protective measure of gravitron、voltage-sensitive resistor、transient voltage suppressor and solid discharge tube are carried out and compared. The combination anti-jamming circuit plan could be used as reference for R&D department to improve the electromagnetic compatibility of the products. To improve the electromagnetic compatibility of electronic equipment, the advancing of the electromagnetic compatibility and the reducing of the EMI are both needed, so the research and design of the multiple protective device and grouping circuit would be significant to the electromagnetic compatibility field which deserves our attention.