Hi John, EN 55022:1994 does not speak about DC power supplies. Other standards do. Normally the appropriate measurements are done on the AC supply side af any applied DC-power supply. The pitfall is that a good RF attenuating in the supply may hide the conducted emissions from your EUT, while another power supply may lead to serious spectrum problems. Your problem, because power supply manufactueres do not specify RF isolation classes. I suggest you to apply the test described using a basic transformer rectifier combination + simple stabilization circuit (if required), thereby minimizing attenuation and maximizing RF feedtrough. Take care to bridge the rectifier diodes with capacitors, otherwize thay might create interference themselves.
Regards, Gert Gremmen, (Ing) Ce-test, qualified testing ================================== Web presence http://www.cetest.nl CE-shop http://www.cetest.nl/ce_shop.htm /-/ Compliance testing is our core business /-/ ================================== -----Original Message----- From: [email protected] [mailto:[email protected]]On Behalf Of John Stonier Sent: Wednesday, January 23, 2002 6:26 PM To: [email protected] Subject: Conducted emission testing for EN55022 Hi folks My test lab's current interpretation of EN55022 is that DC Mains measurements are not required. Sections 5&6 specify measurements done on mains ports, but do not specify whether it applies to AC or DC mains. There is a reference in section nine that specifies conducted disturbance is measured between the phase lead and the reference ground, as well as the neutral lead and the reference ground. Does anyone know whether DC measurements are required for this standard? John Stonier
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