hello eric and group,
This is technique, The shielding properties for an enclosure depend of its round-going conduction properties in X-Y-Z direction. That's what we learned from Faraday's cage. If one applies a conductive coating, the success of this approach depends fully on the success of the full coverage inside. If FA you use to shell covers fixed together, big chances are that their will be partial or full interruptions in the conduction . The size of any interruption you may allow depends of the shielding you require and the wavelength of any to be shielded signal. In general use lambda divided by 40. A shielding cover NEED NOT BE EARHTED, but it does no harm either. Conductive boxes are often used as both shielding and earth means. The thickness of the coating has an impact on the attenuation of low frequency magnetic fields. The thicker the better. In general my conclusion is: do not design to use coatings, use them only if it prevents failure of a test. == CE-test, qualified testing, Consultancy, Compliance tests for EMC and Electrical Safety 15 Great EMC-design tips available ! Visit our site : http://www.cetest.nl The Dutch Electronics Directory http://www.cetest.nl/electronics.htm == -----Oorspronkelijk bericht----- Van: Eric Henning [SMTP:[email protected]] Verzonden: dinsdag 24 februari 1998 21:53 Aan: [email protected] Onderwerp: conductive coatings anybody have any opinions on conductive coatings on plastic for rfi/emi protection? we've been very successful at designing our products to be quiet and immune even in plastic boxes but i've been asked to look into conductive coatings for further protection. i've ordered some spray/brush on coatings but is it a waste of time? I was hoping to find spray can samples but haven't, anybody know of spray bomb coatings? also looking into vacuum application. I guess i'd like to try spray/brush stuff first just to see if it makes any difference. thanks eric [email protected]
