No abstract

Light Emitting Diode (LED) lamps are used as a replacement of "old-fashioned" or incandescent lighting sources, as they reduce the amount of energy consumed. As a sideeffect of more efficient energy usage they produce electrical noise. This noise reduces the efficiency of information signal transfer when Power Line Communications (PLC) are used. This study focuses on the noise signatures of LED lamps which have a direct impact on the information transfer of the PLC channel. The contribution of this study is that two categories of noise characterisations are given. First is equations describing the maximum and minimum bounds of the lamp noise current. This is useful in calculating channel throughput where an equation for the noise is required. For example, the Shannon-Hartley theorem. Second is a methodology to determine individual frequencies in the spectrum of harmonics emanating from the lamp. Both these characterisations will aid in designing communication schemes for PLC. An unexpected result of this study was to find LED lamps which had inadequate or no Electromagnetic Interference (EMI) filters. These lamps produce noise in orders of magnitude higher than properly filtered LED lamps.