Answer Happy

Q3 (a) (b) Suppose that you are an EMC test engineer working in a company producing DVD players. The company's Research and Development (R&D) department has come up with a new player design, which must be marketed to the USA in 3 months. Your primary responsibility is to ensure that the product passes all the EMC tests within the stipulated time frame. (i) (ii) Describe all the EMC tests that should be conducted on the DVD player. (4 marks) (ii) If it was found that the Switched-mode Power Supply (SMPS) radiated emission exceeds the permitted limit at 50 MHz. Recommend two (2) EMC best practices in the design of the SMPS circuit to overcome this situation (6 marks) The Line Impedance Stabilization Network (LISN) measures the noise currents that exit on the AC power cord conductor of a product to verify its compliance with FCC and CISPR 22 from 150 kHz to 30 MHz. (i) Briefly explain why LISN is needed for a conducted emission measurement. (6 marks) Illustrate the use of a LISN in measuring conducted emissions of a product. (4 marks)