Try this link for IEC 417 symbols http://w3.hike.te.chiba-u.ac.jp/iec417/ver2.0/html/index.html
John Juhasz Fiber Options Bohemia, NY -----Original Message----- From: geor...@lexmark.com [mailto:geor...@lexmark.com] Sent: Thursday, November 30, 2000 10:45 AM To: emc-p...@majordomo.ieee.org Subject: Polarity Markings on AC Adapters To the safety professionals............ I need some input on a subject for which I am no expert. Typically, our AC adapter suppliers provide units with polarity symbols a la: - + O-----C-----O ...where the -/+ signs are within the circles. The "C" represents the outside of a standard "barrel" connector, and a bold dot in the center of the "C" represents the inner portion of the connector. Such adapters may be polarized in either direction. I was recently asked the standard specifying this polarity symbol, and did not know, and if it is mandatory. Since the connector typically involves only SELV voltages, I could find no specific references to this polarity marking in IEC 60950. Section 1.7.2 would not apply unless a hazard was introduced by the use of an inappropriate polarity adapter with the intended load. Certainly I could search for the basis of this marking, but like many of you, have found that this forum is often the fastest way to obtain such information. Thank you for any information you may be able to provide. George Alspaugh Lexmark International Inc. ------------------------------------------- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Jim Bacher: jim_bac...@mail.monarch.com Michael Garretson: pstc_ad...@garretson.org For policy questions, send mail to: Richard Nute: ri...@ieee.org
