Hi Terry. You wrote: <I understand in many industrial applications a low voltage DC power supply is used to power equipment and this may be even hundreds of feet away from the supply. The filter of the supply would not be effective since the power supply connection /the antenna `could be' well beyond what the radiated test covers effectively. It would be due diligence to have the camera filtered at the input or at least tested to prove compliance.>
Good points. But a Video Camera and Power supply sold in the same box as a CE marked 'system' is likely to have a 2 metre/6' lead between the camra and PSU, and this I based my comments on. You are absolutely right to point out the 'antenna' effect of a long unfiltered cable, but the effect of that once above 30MHz resonance (1/4wave = 2.5M) on radiated emissions is unpredictable, and for that reason alone I wouldn't try to CE mark a camera that didn't include filters in the supply input if it was to be used with a long supply cable. I feel that a camera and power supply designed and intended to be used a long distance (>5 metres) apart would be difficult to include in the same CE declaration, and should really be tested and CE marked individually. However just about all applications such as this have short power supply cables and so this isn't really anything to lose sleep over I suppose. Interesting point, the equipment/d.c.power supply/ long wire thing, let's see if anybody else has any thoughts.... Anyone? Chris Duprés Surrey, UK.
