My quick take on Gary's question (below) of central versus distributed power supplies is that I suspect his suspicions are correct. My experience says that distributed supplies are a better solution from an EMC standpoint (but not necessarily from a cost standpoint).
The real answer is that "it depends." The trick is in identifying the factors on which it depends. That's what engineering is all about. Either approach can be made to work given enough effort. Cheers, Jacob Z. Schanker, P.E., CPEng Director of Agency Compliance California Microwave 716 242 8454 (voice) 716 242 8427 (fax) [email protected] ---------------------------------------> original message follows: Hi EMCers, For PSUs for each of say 17 cards in a telecoms 19" rack, an alternative is one PSU card at the end of the rack. However this means long (backplane?) busses of supplies. I suspect that EMI would be worse for the alternative central PSU solution. Is this the case in anyones experience? And are there solutions offerable with such a brief brief? And any literature on WEB or elsewhere? Thanks in advance Gary. ```````````````````````````````````````````````````````````````` ___ ___ ___ ___ /__/| /\ /__/| /\ /__/\ /__/\ /\ /| | |/ /\ \ | |/ /\ \ / _\/ / \ | |\ \|| |-- /__\/\ |-- \ /__\/\ | /__/ | | | | \ || |/ / \/ |/ \/ / \/ \__|| \__/_/ |/ \|/ |/ ELECTRONIC & SOFTWARE DESIGN AND DEVELOPMENT ~~~ Gary Allen ~~~ ~~ Graduate Hardware Engineer ~ ~~ ~ ~~~ Paragon Solutions Ltd. ~ Web Site www.paragon.co.nz~ ~~ ~~~ PO Box 30 449 ~ ~~ ~ Time Zone GMT + 12 hours ~~ ~ ~~~ Lower Hutt ~ ~ ~~~ Voice direct +64 04 570 3875 ~~ ~ ~~~ Wellington. ~~ ~~ Fax +64 04 570 3888 ~~ ~~ ~~~ New Zealand ~~~ ~ Email [email protected] ~~~ ~~ ````````````````````````````````````````````````````````````````````````` `
