TechTHURSDAY – Electro-Magnetic Compatibility (EMC)

Electro-Magnetic Compatibility (EMC) is the ability of an electronic device to function without interfering with or interference from another electronic device.

The EMC Directive 2014/30/EU requires that electronic devices emit no conducted or radiated electro-magnetic frequencies which might cause them to affect other devices (such as crackling on the radio, or worse, erratic function). In addition there may be concern about the effects of other devices or circumstances on the electronic device itself and its robustness in continuing to function as it should. Such concerns include voltage surges, drop-outs and effect of radiated frequencies on the device for instance from mobile phone interference.

For many years now D.G. Controls Ltd has carried out its own EMC testing. A crucial element of CE marking, we always test for EMC emissions (Conducted and Radiated) against the Residential standards, since we know many of our beacons and sounders are used in offices, residential homes and commercial premises. There is also an industrial standard which is slightly more relaxed on acceptable emissions, but since we are not always able to define the end-use of our products we would always err on the side of caution. When considering Conducted Emissions, both the Quasi-Peak (QP) and the Average (AV) emissions (measured in decibels microvolt or dBuV) need to be below the limit line as defined within the respective standard. Interestingly this is not the case with some competitor products which we run “out of interest” through our equipment and find that they are actually compliant to neither the industrial nor the residential standard!

 

Having our own test equipment means that at every single stage of the PCB design process we can evaluate EMC compliance; our in-house knowledge about this commonly considered “black-art” has increased exponentially as we have taken on the challenge of designing more complex circuitry which is fully compliant:

 

All deegee beacons and sounders are supported by a Declaration of Conformity which sets-out the EMC status, compliance with the Low Voltage Directive, and the IP (Ingress Protection) rating. Full technical reports including the actual data can be issued where a client specifically requests one, but requirement for these often only comes from the military or public services sector.

If you require any assistance with these documents please make contact initially with our Sales Department, who will ensure your enquiry is dealt with by the most appropriate support member.