Common Sources of Electromagnetic Interference

In this technology-filled world, electromagnetic interference is increasingly becoming a problem. EMI can negatively affect electronics preventing them from running correctly. This is why shielding EMI is so important when designing new products. It is essential to ensure products have proper EMI shielding.

When it comes to EMI, there are many sources. Let’s go over a few of the main ones.

  • High Powered Electromagnetic Pulse (HEMP) – This source of EMI can disable electrical equipment. It is often used in military applications. Examples of HEMP devices are an EMP cannon, an E-Bomb, and a high-powered microwave weapon (HPM).
  • Railroad and Mass Transit Systems – The primary source of EMI from railroad and mass transit systems is the railroad engine’s propulsion systems. Many issues derive from EMI from these systems. Some of these issues include:
    • Train control system’s emissions
    • Train signaling systems and associated computer operating codes
    • Track train control circuits
    • High voltage contact switching
    • Right away emission sources
  • Medical Equipment – Medical facilities have numerous EMI sources. Let’s go over a few:
    • X-ray units
    • MRI systems
    • Life support devices such as infusion pumps, ventilators, and cardiac defibrillators
    • Electrical surgical units and associated equipment
    • Patient telemetry and assistance equipment such as motorized wheelchairs
  • Ambient EME – Examples of Ambient EME sources are AM/FM radio, television, and utility power grid transmission. Ambient EME can also occur from natural occurrences, such as lightning and solar magnetic storms. The effects of ambient EME on sensitive electronic systems are burnouts and latch-ups.

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