Ögat På: EMC från bricka till bricka, del 13

Vi fortsätter att betrakta vår figur: ”EMC från bricka till bricka” och går vidare till eventuell anslutning till närmaste skärm; i dagligt tal kallad: ”jordning”. EMC måste tas om hand i alla delar, såväl på elektrisk som mekaniskt, och på alla nivåer i en utrustning på ett systematisk och planerat sätt.

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A Simple Method to Identify Hidden Pulsed Interference Signals in Radiated Emission Measurements

In certain applications it is of highly importance to be able to identify unintentional pulsed interference sources. One reason is that this kind of interference can cause severe performance degradation of modern digital wireless communications. In this paper we show that pulsed interference sources can be identified by standard radiated emission measurements performed in the frequency domain.

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A Review of the principal EMI Coupling Paths – The key to understanding and preventing or solving EMI problems Part 1

Part 1: Conduction Paths .  As briefly described in our introductory Article N°1 ( Issue #2-2015 of EE Magazine), ElectroMagnetic Interference is a Source/Coupling Paths/Victim situation, the basis for an overall understanding of EMI control in order to reach a satisfactory level of compatibility (EMC). We also said that reducing the interference at the source itself, or at the victim’s levels, were most of the time unpractical. Therefore, the only remaining area for action is in general the coupling path, which implies understanding the coupling mechanism.

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The Ten Commandments for EMC, part 5

Most designers . and installers of electrical equipment agree that shielded cables are a good way to achieve EMC. But many times I have seen big money thrown ”down the drain” because of overconfidence to the cable shield effects and ignorance of its proper use and design.

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Ögat På: EMC från bricka till bricka, del 12

Vi fortsätter . att betrakta vår figur: ”EMC från bricka till bricka” och går vidare till skyddsledare (PE). EMC måste tas om hand i alla delar, såväl på elektrisk som på mekanisk systemnivå, och på alla nivåer i en utrustning på ett systematisk och planerat sätt.

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Do we really need the EMC requirements?

Robotic lawn movers, . small autonomous robots, are becoming more and more popular in the gardens. With a minimum effort the garden is kept tidy, without the noise and emissions from a petrol engine. But how about EMC-related emissions then? And will the lawn mower co-exist with other products?

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Dilemman och EMC

En redaktörs reflektioner . Ibland kan EMC-frågor resultera i dilemman där motstående behov/krav behöver hanteras.

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Overview of the Civilian and Military EMC norms

Preamble . As briefly described.in our introductory Article N°1 (Issue #2-2015 of EE Magazine), ElectroMagnetic Compatibility is both a functional neccessity – equipments must operate in their intended environment without being disturbed nor causing disturbances to other devices- and a society requirement: interfering with radio/TV broadcast, radio-communications and other RF services is illegal and punishable by laws. Since consumers cannot be easily prosecuted as guilty for using an equipment that is causing interference, the most efficient way of controlling this EMC situation is to apply stringent limits to manufacturers, such as the products they put on market will ”never” (exceptional situations accounted) cause interference.

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The Ten Commandments for EMC, part 4

EYE ON . It is relatively easy to achieve good attenuation (> 80 – 100 dB) of electromagnetic fields using a compact metal shield. In most practical cases, the shield is not complete, there are almost always openings, i.e. slots, windows and apertures. It is mainly these imperfections in the shield that determines the overall shielding effectiveness of the box.

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