In this paper, we measure the Electromagnetic Interference(EMI) noise of AC/DC converters in lighting devices to enable us to optimize the design of its filters as compared to the conventional filters. Addition of RC filters to the circuit helps in increasing the noise margin, thereby, reducing the noise generated by high-frequency transformers and switching devices. The characteristics of each converter are compared after addition of RC filter to the circuit. To reduce the noise generated by the high frequency band, ranging from 1 MHz to 30 MHz, high frequency transients and switching devices, with a cut off frequency closer to the band, have been designed. The results are measured using an oscilloscope. A reduction in noise is observed in case of a filter designed using a combination of R and C with a cut-off frequency of 1 MHz. The EMI Receiver shows that the noise is significantly reduced on addition of filters and the noise reduction ranges from 2 dBuV to 11 dBuV, respectively.
