Electromagnetic interference (EMI) is the unintended generation or reception of electromagnetic energy that can disrupt the normal functioning of electronic circuits or devices. The noise comes from outside sources, including other devices and natural sources, and can have a detrimental impact on electronic devices. Understanding what EMI is and its impact on technology is critical to ensuring electronic devices and systems perform as expected and are unharmed by noise and interference.
Nature and Types of EMI
Electromagnetic waves are omnipresent and caused by Gamma rays, X-rays, UV light, visible light, infrared, microwaves, AM/FM radio, and 50/60Hz electric currents. Electromagnetic waves can be a source of electromagnetic interference or EMI. There are two different categories of EMI sources:
- By Intention: EMI can be produced intentionally, such as EMI from cellular communication and AM/FM radio. Unintentional EMI can be noise from electronic devices and appliances, such as inverters or motors.
- By Source: EMI can come from both natural and man-made sources. A natural source of EMI can include electrostatic discharge resulting from a lightning strike. Artificial sources of EMI include devices and machines, such as televisions, treadmills, radios, and fan motors.
Causes and Sources of EMI
EMI is unwanted electrical noise impacting electric power lines. It can harm electronic devices and systems and their performance. Various artificial and natural sources generate EMI, including HVAC equipment and natural UV light. Switching inductive, resistive, and capacitive loads from power supplies, electric motors, ballasts, and heaters can produce EMI.
Effects and Implications of EMI
EMI can negatively impact the function of electronics, resulting in substandard performance, faults, and permanent damage. The noise caused by EMI can result in surges and unintended currents that affect the function of cables. It can cause packet loss, network congestion, and retransmission in wireless receivers. EMI can corrupt, impair, or wipe data from disks, including solid state drives and hard drives. Medical applications can also be impacted by EMI, including lifesaving equipment like pacemakers. Systems that rely on radio or wireless communication can be impacted by EMI, including radios, telephones, and wireless networking equipment, resulting in poor signal or a loss of service.
Managing and Mitigating EMI
Electromagnetic compatibility (EMC) is a machine or device’s capability to operate in an environment with other electronic equipment without interruption from EMI. EMC includes measuring a device’s immunity or susceptibility to EMI. Devices designed with EMC in mind reduce EMI, making them suitable for operating in an environment shared with other devices and equipment.
EMC standards are set by national and regional regulators like the FCC. They provide acceptable EMC standards and EMI limits to ensure devices deliver expected performance and do not interfere with other devices. Design optimization and practical steps can help minimize EMI. Devices and equipment can be outfitted with an active EMI cancellation mechanism that senses and cancels EMI. They can be grounded or isolated using a room enclosed in a conductive material or Faraday cage. Operators can also move or shut down interfering devices to prevent EMI.
Contact the EMI Prevention Experts
The effects of EMI, whether intentional, natural, or artificial, are pervasive and often harmful enough that despite regulations and engineering best practices, not all devices will be safe or fully immune to it. Thankfully, other solutions exist to counteract EMI.
Nanotech® common mode and differential mode nanocrystalline toroid cores reduce asymmetrical EMI currents and motor terminal overvoltage peaks. Our cores reduce damage risks to motors due to currents in the motor bearing that can cause lubrication breakdown, frosting, or fluting. Nanotech® cores act as a choke to prevent unwanted electric currents and absorb noise. Contact us or request a quote to learn more.