Talk:Eurocard (PCB)

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"1 U is 44.45mm, and cards come in various multiples of this size. A 3U Eurocard is 100mm x 160mm ... A double or 6U Eurocard is 216mm x 160mm ". I read this as: 1U = 44.45mm, 3U = 100mm, 6U = 216mm? Maybe these multiples are correct, but the math is not intuitive. Perhaps someone in-the-know can clarify the rationale behind those measurements. Ds13 20:05, 2004 Feb 25 (UTC)

I changed this so the maths worked, then did more searching and found that the cards are smaller than the maths suggests. Someone else needs to fix this! --Ian 28 June 2005 14:51 (UTC)

A recent edit has left us with strange math again: 1 U is 44.45mm ... 3U Eurocard is 100mm x 160mm ... 6U Eurocard is 233.5mm x 160mm Remember, citing sources is considered good style. --Ds13 June 28, 2005 22:11 (UTC)

The edit was just me reverting my previous edit as I'm pretty sure it was wrong. Further reading suggests that even though the multiple (U) is 44.45mm, the cards themselves ar less than this, and in fact appear to be the sizes quoted in the article. I was kind of hoping that a real expert would wander along. I'll try an encourage a chap here at work to review the article and add his expert views (and maybe the odd suitable source!) --Ian 1 July 2005 13:24 (UTC)

The two defining sources for the Eurocard architecture are IEC 60297-3 and IEEE 1101.1 (extended in IEEE 1101.10 and IEEE 1101.11)There is a nice illustration of a Eurocard subrack in an article of mine http://www.erni.com/DB/News/pdf/cpciH110.pdf The Eurocard rack and card dimensions are reiterated in the FAQ of PICMG http://www.picmgeu.org/whats_new/faq.htm --68.101.40.60 04:02, 27 August 2005 (UTC)

I have explained the modularity in my edit which I hope I saved properly. The confusion that you have discovered is that the U height properly refers to the height of the subrack in a 19" equipment rack and is equal to 1.75". A 3U subrack is 5.25 inches high and accepts a 100 mm high Eurocard. A 6U subrack is 10.5 inches high and accepts a 233.35 mm high Eurocard. Ok, so you wonder where that extra 33.35 mm came in.

Well, that is the space which is allotted to the subrack supporting structure (card guides, extrusions and or sheet metal) that would be between an upper 3U Eurocard and a lower 3U Eurocard so that the top of the upper 3U Eurcard would line up with the top of a 6U Eurocard and the bottom of the lower 3U Eurocard would line up with the bottom of a 6U Eurocard.

The Eurocard system is a strange mixture of subrack heights in 1.75 inch increments, card slot widths in 0.2 inch increments and card sizes in 100 mm height increments and 60 mm depth increments.--Mmunroe 8 July 2005 05:58 (UTC)

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(drawing should include dimensions)