As I recall, when testing conducted emissions to VDE 0871, it was required to observe noise in the two powered lines with the switch both open and closed, and use the higher result. Some power supplies would in fact give different results if the ground was opened.
An aside: I used to work at Tandy Computer's R&D. When Tandy quit making computers (and I was laid off), I was able to buy a Rhode and Schwarz LISN they scrapped -- for $25. It has the ground switch Muriel describes. When I bought it for Tandy, it cost much, much more! Cortland --------- This message is coming from the emc-pstc discussion list. To cancel your subscription, send mail to [email protected] with the single line: "unsubscribe emc-pstc" (without the quotes). For help, send mail to [email protected], [email protected], [email protected], or [email protected] (the list administrators).
