Electromagnetic Interference and Power Supply Selection (Part 1)
Electromagnetic interference (EMI) can be a major problem for any business working with electrical equipment for one simple reason. EMI is everywhere. EMI is a consistent feature of the Earth’s ecosystem, which unfortunately provides many natural sources of electromagnetic interference. Additionally, the sun is also a huge source of interruptive radiation.
Generally speaking, dealing with EMI radiation involves only addressing man-made sources. These sources can be considered part of intentional phenomena, such as radio, television, telephony and all manner of other RF signals, or they can be derived via unintentional characteristics of equipment, such as sources appearing due to load distribution, vehicle ignition systems and even some power supplies.
Given the problems that EMI can cause, it is natural for businesses operating electrical equipment to minimise the impact. But designing electrical systems that minimise EMI can be problematical. Before engaging in any such implementation, it is worth bearing in mind that following standard industry practices and techniques, which have been proven to be successful in power supply design, will reap rich reward.
However, designing a power supply for excellent EMI performance may be a technical undertaking, but it is by no means unfeasible. Businesses simply need to apply the appropriate knowledge and experience to the process, and if this is done effectively then the limitation of EMI can be included within a project from the very beginning of its conceptual stages.
One of the most important ways that this can be achieved is by emphasising a heavy focus on the design and layout of the PCB from the earliest stages of the project. This will play a huge role in the amount of emissions produced. Any designer of a power supply should focus attention on eliminating, or at least minimising, any emissions from generator sources. Additionally, minimising the susceptibility of receivers and filtering can also be beneficial.
We will look at some of the solutions to the issue in our next blog post.