About the Electromagnetic Compatibility Society of Australia (EMC)
The EMC Society of Australia is a technical society within the Electrical College of Engineers Australia. It was formed to foster technical exchange on matters related to the branch of electronic engineering known as Electromagnetic Compatibility.
Electromagnetic Compatibility is the engineering endeavour related to minimising or managing interference between electrical and electronic devices. The term “EMC” is often used interchangeably with “EMI” (Electromagnetic Interference) or “RFI” (Radio Frequency Interference), although these are older terms that do not encompass the full breadth of issues considered by EMC.
As the main focal point for EMC in Australia, the EMCSA performs the following functions:
- Participation in Standards Australia Technical Committee TE-003 (Electromagnetic Compatibility);
- Coordination of a bi-annual Australian symposium for EMC;
- Publication of a newsletter;
- Coordination of technical presentations on EMC;
- Liaison with the IEEE EMC Society
What is Electromagnetic Compatibility?
The International Electrotechnical Committee (IEC) definition of EMC is
“the ability of equipment to function satisfactorily in its electromagnetic environment without introducing intolerable disturbances to anything in that environment.”
Note that the definition encompasses the physical properties of the equipment in question as well as the electromagnetic characteristics of the equipment’s operating environment. The environment is defined as the totality of electromagnetic phenomena existing at a given location.
When a piece of electronics can perform its intended function in its intended environment without causing an interference problem, we say that electromagnetic compatibility has been achieved.
A familiar example of an electromagnetic interference is the buzzing that is sometimes heard on a desk telephone when a mobile telephone is close by. The buzzing arises because the mobile telephone is transmitting a powerful pulsed signal to the phone tower, and those signals are “picked up” by the desk telephone’s wires (the electromagnetic field induces RF currents on the wires).
This unwanted current makes its way to the desk telephone’s speaker and an unwanted buzzing occurs, even before the mobile phone itself actually rings, because of transmissions that occur when the call is being set up.
Elements of Electromagnetic Compatibility
EMC engineering is undertaken at many scales, from chip-level considerations to “systems of systems” such as aircraft, ships and buildings.
Phenomena considered by EMC include:
- interference from electronics disrupting radio systems
- interference from radio transmitters disrupting or damaging electronics
- lightning strikes
- electrostatic discharge
- power network “spikes” due to switching or failures
- hazards of radio frequency energy to humans (HERP or RADHAZ)
- hazards of radio frequency energy to fuel (HERF)
- hazards of radio frequency energy to ordnance (HERO).
For interference to occur, three things are necessary:
- (i) Source
- (ii) Coupling Path
- (iii) Victim
Since the source and the victim are sometimes necessary parts of the same system, an important strategy for EMC engineers when solving interference problems is to work on the coupling path. By increasing losses in the coupling path, the amount of interference that reaches the victim from the source can be reduced to a level that is tolerable to the victim.
Join the EMC Society
Membership of the EMC Society of Australia is open to individuals and corporations with an interest in EMC. Student membership is free.