X3T9.2/91-047 Accredited Standards Committee X3, INFORMATION PROCESSING SYSTEMS* Document Number: X3T9/IR91/008 Project: N/A Reference Document: Date: 17 April 1991 Reply to: Gene E. Milligan Seagate Technology Inc. OKM 251 P.O. Box 12313 Oklahoma City, OK 73157-2313 (405) 324-3070 FAX: 324-3794 VOICE MAIL: (408) 439-2800 -3- x 4370 (800) 553-3557 -3- x 4370 R. Chard PYLE NATIONAL Limited Sherbrook Road Daybrook GB - Nottingham NG5 6AT United Kingdom FAX: 44 602 20 88 96 Subject: D.C. Power Connectors for Personal Computer Peripherals At a recent X3T9 interface standards meeting, a representative of one of the connector manufacturers raised concern over the dimensioning of the subject connectors. He listed a number of problems including intermittent contact, extremely high insertion force, and, after use of excessive force, the potential for reverse insertion. He proposed that X3T9 add the required dimensioning and a specification on insertion and withdrawal forces in one of their interface standards. Since one half of the connector is included in multiple cables from computer power supplies and the other half is included in a wide variety of peripherals, the requested action seemed inappropriate. Instead X3T9 decided to advise the connector standardization community of the noted problem and request that they determine the appropriate course of action. The issue is a thorny one. The connector is shipped on an extremely wide variety of equipments with the installed base and ongoing shipments numbering multiple millions of units per year. A nearly random assortment of these equipments is expected to plug together in the field. Jim McGrath of Molex has made a dimensional proposal which I have attached to help identify the connector we are referring to. At the moment there has not been any agreement reached on his proposal. In fact we are requesting that your committee address the issues involved. *Operating under the procedures of The American National Standards Institute. X3 Secretariat: Computer and Business Equipment Manufacturers Association Tel: (202) 737-8888 311 First Street, N.W., Suite 500, Washington, DC 20001-2178 Fax: (202) 638-4922 X3T9 does not plan to address the proposal further but does request that you keep us advised on the issues and outcome on a liaison basis. I am sure there are several connector representatives who will want to contribute to this effort. I presume they would include Jim McGrath who brought up the issue and Chuck Brill, of AMP, who provided me with the information regarding your committee. In addition through the X3T9 liaison we will be able to distribute a resultant draft to a large sampling of computer and peripheral manufacturers for their reaction. Please let me know if there is anything else that X3T9 might consider doing regarding this issue. Thanks for your help. Regards, G.E. Milligan X3T9 International Representative cc: David Rundle IEC SC48B Secretary (FAX: 717 561-6179) Judy Anderson EIA Kate McMillan X3 Secretariat Del Shoemaker Chair X3T9 Attachments: McGrath to Lohmeyer 10 December 1990