Analysis of the Rectification Case of Electromagnetic Compatibility Conducted Emission of a Vehicle Projection Lamp

The automotive electronics (projection lamp) was tested according to the requirements of GB 18655–2002 “Limits and methods of measurement of radio disturbance characteristics for the protection of receivers used on board wehicles”, and the test result of conducted emission voltage method was higher than the test limit, which did not meet the requirements of the standard. The main circuit of the projection lamp contains a buck DC/DC converter, which drives the LED with constant current. Conduct conducted emission fault diagnosis by analyzing the conducted emission checklist and the cause of non-conformity, and finally find the interference source through the analysis of test data and the targeted analysis of characteristic spectrum, and make the conducted emission voltage method of the projection lamp meet the limit requirements of Class 5 of GB 18655–2002 standard with the minimum engineering cost.