ECTI Association

Regular Article - Can you put EMC in your heart ?

Associate Professor Dr. Werachet Khan-ngern
King Mongkut’s Institute of Technology Ladkrabang (KMITL),
Bangkok, Thailand


Wow....w....w. Some readers may expect to find a pure electrical, electronics and telecommunication and information technology (ECTI) article in this e-journal. This article may give you some disappointments because this article presents the experience concerned with electromagnetic compatibility (EMC) on various ECTI engineering.


I will start with the confusing of most ECTI engineers on EMC issue. Then, EMC concept will be described. The EMC control concept and the Buddhist’s precept are also proposed.


EMC and some confusing!

Some ECTI engineers said that


“EMC is mainly concerned with telecommunication!”


“No low frequency or zero hertz concerns with the EMC”


“EMC is only the standard in EM filed”


“There is no link between EM and bio-effect”


“EMC is only the standard and regulation to be mandatory”


“EMC is no the electromagnetic disturbance” and more about.


I have spent over 16 years in EMC including research, providing industry solution and some international networking. I realize that there are still a lot of EMC confusing along with ECTI engineer as above mentioned.


What is EMC?

International Electrotechnical Commission (IEC) defines the meaning of EMC refer to IEC 50(161)


“The ability of an equipment or system to function satisfactorily in its electromagnetic environment without introducing intolerable electromagnetic disturbances to anything in that environment”


This sentence is the formative document. I propose the simplified EMC meaning as follows:


“EMC world is all friendly EM matters”


The main concept is to guide that all EM products can stay and work together without any EM problem. It is not only for EM equipment/product but also for bio-effect.


EMC and some correction!

Yes, in the previous EM research, many EMC issues concern with telecommunication engineering and dominate with EMC research field. When I have a look back and count the EMC research topics on EMC Zurich symposium, one of a longest EMC conference over 30 years of history, there are a big number on telecommunication research and publication. Therefore, some engineers conclude that EMC is related only in high frequency ranges. In fact, the EMC range is scoped at zero hertz up to 300 GHz which is cover all ECTI area. The frequency beyond 300 GHz is out of the EMC scope due to ionizing phenomena.


In case of bio-effect, most of people focus only on device, equipment and system. It is true by the terminology of EMC. Mankind, the most important thing in the earth, faces with EM environment 24 hours per day. We cannot avoid the EM effect. If the EM exposure is higher than the emission limit-line, we can say that “This is not complied with the EMC concept”. In the human sense, we should conclude that the EMC is also concerned with the bio-effect.


We need EMC standard to maintain the suitable design and productivity to answer to three concerned groups: manufacturers, users and monitors. We need to issue the acceptable standards and regulations for all groups. There are a lot of electrical and electronic products in the world. EMC standards and regulation are dynamic due to the technology change. Those EMC standards and regulations can be either mandatory or recommendation.


EMC is not meaning for zero EM emission. We can accept some EM disturbances if their levels are under our emission limit line.


EMC components

EMC is composed of three components:


EMI source or noise source,


Victim or EM receptor, and


EM coupling or EM linking.


EM noise source can be man-made and natural noise source. Normally, noise source generates EM noise caused by high (or some) power operation. Where the victim or receptor is very sensitive to the EM, require a very good take care. The EM coupling between noise source and victim is very important. The coupling path can be both by conduction and radiation.


The EMC control concept

We can control three EMC components. Firstly, we can start to control by suppressing the EMI from the noise source. It is a good thing to do due to the primary of disturbance. If we can suppress the EMI, it will be easy to control the rest.


The receptor, such as PC, microcontroller or TV monitor, is so sensitive. Therefore, we need to increase the immunity of the receptor. The addition of surge suppression in the switching mode power supply (SMPS) is an example of immunity increasing.


If we cannot control both of noise source and receptor immunity, we still do the other way to control the unwanted signal (noise). The communication concept is to receive wanted signal and avoid any unwanted signal. So, if we can separate wanted frequency on unwanted frequency via the conduction, we can do filter the unwanted frequency out. Sometime the unwanted signal can interfere via the air. Shielding technique should be applied by reflection and absorbing techniques.


EMC control techniques and Buddhist’s precept matching

From the EMC components, we can control the EMC using basic concept of oriental philosophy, particular in Buddhist’s precept. I would like to propose the matrices, as shown in table l, to lead the understanding between the technology concept and the human mind concept.


Table 1. shows the matching between the EMC control techniques and the Buddhist’s precepts. Noise source is unwanted signal is the primary thing of badness. Good suppression is a main key of EMC control. In many cases, we cannot control outside source we have to face noise sources. Increasing the EM immunity is the alternative technique to comply with the EMC concept. Two coupling methods can be controlled using filtering and shielding techniques depend upon conduction or radiation coupling.


EMC components EMC control Buddhist’s precept Matching
Noise source Reducing the noise level badness suppression Noise source = badness
Receptor Increasing the receptor immunity Keep and maintain goodness Increasing Immunity = keep goodness
Coupling Conduction: using filtering
Radiation: using shielding
Clean up your mind Keep only wanted signals

Table 1. The matrices of EMC component matching


More EMC information at


The EMC control concept and the Buddhist’s precept are proposed to match the technology and the philosophy. EMC is a kind of technology and philosophy. The EMC confusing and its corrections are described EMC is also horizontal concept for all engineering area. ECTI engineers should reduce any repetition and time waste with the balanced concept of its performance, reliability, safety and EMC during design stage, productivity stage and testing stage. Then, “Can you put EMC in your heart?”

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