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???
12/15/11 08:50
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Msg Score: +1
 +1 Good Answer/Helpful		 #185097 - Length irrelevant to this case
Responding to: ???'s previous message
The specification of such a high voltage is to be able to send much power with low current.

But the cable length doesn't really matter - at the lengths that CAT-5 is specified to work with the network, the voltage loss isn't too important.

The important thing here is that you can't send more power just because the cable is shorter. All it means is that you will get a slightly lower voltage loss in the cable. But every meter of the cable will still see the same current.

Next thing - if you send 3.3V directly over the cable, it will not be PoE. And you still must keep the current low, so with less than a tenth of the voltage you could send less than a tenth of the power for the same current.

List of 33 messages in thread
TopicAuthorDate
DEJA VU.....CAT-5 ( R(J) - 45) )            01/01/70 00:00      
   PoE versus PoE+            01/01/70 00:00      
      poe+ didn't arrived yet.            01/01/70 00:00      
   So what . . .            01/01/70 00:00      
      Good info            01/01/70 00:00      
         Length irrelevant to this case            01/01/70 00:00      
            yes...            01/01/70 00:00      
            Cable length            01/01/70 00:00      
               It Can Be Calculated            01/01/70 00:00      
                  Super            01/01/70 00:00      
                     Is the Cabled Power Necessary??            01/01/70 00:00      
                        Not for clocks            01/01/70 00:00      
                           nice            01/01/70 00:00      
                  LTC            01/01/70 00:00      
               UUps            01/01/70 00:00      
                  One way            01/01/70 00:00      
                     EMI.            01/01/70 00:00      
                        price performance            01/01/70 00:00      
                        Baudrate + number of jumps means way more            01/01/70 00:00      
                           yes.            01/01/70 00:00      
                              But the slaves didn't need Internet access            01/01/70 00:00      
                                 Correct?            01/01/70 00:00      
                                    Not sure why            01/01/70 00:00      
                                       Not sure why?            01/01/70 00:00      
                                          If already drawing cables to slaves then one antenna easy            01/01/70 00:00      
                                             GSM vs GPS            01/01/70 00:00      
                                                GPS modules can be had very cheap            01/01/70 00:00      
                                                   cheaper            01/01/70 00:00      
                                                      where            01/01/70 00:00      
                                                      Don't think so            01/01/70 00:00      
                                                         I'm still...            01/01/70 00:00      
         What voltage and what current...            01/01/70 00:00      
            transmit...            01/01/70 00:00      

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