EMC Planning

EMC should always go hand in hand with the general design of the product. From the very beginning, designers should consider which noise sources and susceptible circuits they have in their equipment. This makes it possible to physically separate them and avoid problems right from the start rather than having […]

Tour of Lab

Common-Mode Signals and Radiated Emissions

William D. Webb A low-frequency analysis sheds light on the importance of designing circuit return paths in radio-frequency devices to minimize differential current. The most effective way to reduce electromagnetic interference (EMI) from radiated emissions is to control or limit the contributing signals at their source. That is well understood, […]

Is Due Diligence tempered by cost?

The DTI has published a document entitled “Minimizing the cost of meeting the EC Directive on Electromagnetic Compatibility (EMC) 89/336/EEC as amended by EC Directive 92/31/EEC.” The second edition was published towards the end of 1995, and is available from the DTI. This document sets out the minimum actions required […]

Is a custom-made one-off item “placed on the market”?

The UK Regulations make use of the concept of supply rather than placing on the market, which makes the position clearer. Even one-off items are covered by the directive, when they are supplied for an end user.

Are products which have previously been used by an end user outside the EEA, or by the manufacturer or wholesaler, considered second-hand?

No. To be considered second-hand under the EMC Directive, products must have been previously used by an end user within the EEA.

Is all laboratory equipment covered by the educational relaxation?

No. In the UK, only equipment which would not, except for the provisions of Regulation 8, comply with the protection requirements under normal conditions of use, and which is used in education and training establishments for the purposes of experimentation, learning or practical training, is covered by the modified application […]

What happens when the signatory leaves the company?

The certificate is still valid, but signatory can no longer be held responsible for the actions of the company he has left.

How can I show due diligence when assembling products and systems from CE marked sub-assemblies or apparatus?

It is difficult to offer general guidance here as different measures will be needed for the wide variety of possible situations. A computer system assembled from finished products (i.e. keyboard, mouse, monitor and completed box containing boards, disc drives and power supply) may need no further assessment; there is only […]

Do control panels need a CE mark?

If they are sold to an end user for him to integrate into a system, yes. If they are sold only to a machine builder who assembles the final product, no.