Hi Peter: Back on July 11, you posted a question asking about the safety and EMC requirements for dialers. I meant to respond, but got busy and forgot. Did you get the info you needed?
I am not sure what you mean by "dialer," but in my mind this usually refers to a device that is placed in the phone line in series with a TE such as a fax machine or phone. The dialer intercepts the DTMF digits dialed by the TE and, for certain dialed numbers, redirects the call to a different number. Typically, the dialer is co-located with the TE, although sometimes it is placed in the telephone closet with the PBX. Is this the type of device you are asking about? I have designed a few such devices in the past, and have treated them as ITE devices that are subject to the EMC Directive and the Low Voltage Directive. This would suggest EN 55022, EN 55024, EN 60950, etc. A key issue that is somewhat unique to dialers relates to the safety isolation. Typically there is a mix of TNV-3, TNV-2, and SELV circuits inside the dialer, so that providing the required safety isolation in all operational modes can become a problem. There are a couple of ways to address this issue, depending on what other types of interfaces appear on the dialer. Aside from the safety isolation issues, the remaining compliance problems are similar to other types of ITE. Joe Randolph Telecom Design Consultant Randolph Telecom, Inc. http://www.randolph-telecom.com ------------------------------------------- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. To cancel your subscription, send mail to: [email protected] with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Jim Bacher: [email protected] Michael Garretson: [email protected] For policy questions, send mail to: Richard Nute: [email protected]
