My thoughts at first blush. RJ45 is an often misused term, since it refers to an Universal Service Order Code (USOC; a now disused system).
RJ45 plug and jack constructions are based on essentially the same model as RJ11 types. Electrical spacings and materials can be assumed the same. These plugs and jacks can not handle "significant" currents without melting. These jacks and the common use of tinsel cords led (in part) to the test programs in UL 1863 and the 1.3 A current limit for telecommunication network connected ports in ยง6.1 of the 60950-1 standards. I note that UL 1863 tests all plugs and jacks at 2.2 A for certification purposes. This current limitation is *per contact*, so if we were to assume 1.3 A X 4 pairs, it is conceivable that 5.2 A could be delivered into the load. This begs the question of where the signals will be present and the voltages that will exist on the ports to deliver the data payload to the teevee. In NA, TNV limits are 60Vdc and 42.4 Vpk, except when ringing or "other signals" (meaning: message waiting and the like) are present. If the data payload causes excursions in excess of TNV limits, you're no longer able to treat these ports as TNV. This means the normal operating voltages need to be reduced *or* unpowered pairs must be used. Considering the power requirements are 200W, that's not difficult, since the load only needs three of the pairs, but that could reduce bandwidth to unacceptable levels and eliminates the typically separate receive pair at the source end. This might not be unacceptable for the application, unless the teevee is also intended to be an interface device back to the network. Trying to make modular plugs and jacks fit into an RFT-V application may be unworkable, due to insulation requirements. In the context of product safety, I think this idea needs a significant amount of massaging before it can move toward any practical system *if* modular plugs and jacks are to be used. Peter Tarver [email protected] - This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. To post a message to the list, send your e-mail to <[email protected]> All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc Graphics (in well-used formats), large files, etc. can be posted to that URL. Website: http://www.ieee-pses.org/ Instructions: http://listserv.ieee.org/request/user-guide.html List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas <[email protected]> Mike Cantwell <[email protected]> For policy questions, send mail to: Jim Bacher: <[email protected]> David Heald: <[email protected]>
