[TriEmbed] I2C range extension

[John Vaughters]

 From a product specification perspective, PoE is going to take into account the full 100 meters and then you could factor in about a 10 times safety ratio. You could engineer the amps based on type of wire and the current limits relative to length, but realize that the insulation is pretty thin as well. Based on the information from this email string, I suspect you could easily use PoE in a custom engineered standard and have plenty of power to spare, while maintaining safety. But that statement is based on much shorter cable runs than 100 meters, which I feel confident most of us will not use. If you DO use the full 100 meters, I would definitely not violate the specification. CAT 5 was never designed for power and the ratings are more of a limitation based on the minimum CAT 5 specifications. 
Concerning the high voltage and switching DC-DC supply idea, you would have to run the calculation on the efficiency curve of voltage drop and power supply given by the DC-DC converter. The more voltage you drop the more power you loose, so this could be a self-defeating plan and more costly in upfront costs as well as operation costs. Although, most of us could care less about the operation costs; being so little. There would probably be an optimum power draw combination in that situation, which would depend on the characteristics of the DC-DC converter. If you are sticking to the PoE specification, for sure you will never see 13W of power at your Pi, but you could probably make it work.
John Vaughters

     On Friday, October 2, 2015 12:01 PM, Jim Ray via TriEmbed <triembed at triembed.org> wrote:
   

 #yiv1516966814 #yiv1516966814 -- _filtered #yiv1516966814 {font-family:Calibri;panose-1:2 15 5 2 2 2 4 3 2 4;} _filtered #yiv1516966814 {font-family:Tahoma;panose-1:2 11 6 4 3 5 4 4 2 4;}#yiv1516966814 #yiv1516966814 p.yiv1516966814MsoNormal, #yiv1516966814 li.yiv1516966814MsoNormal, #yiv1516966814 div.yiv1516966814MsoNormal {margin:0in;margin-bottom:.0001pt;font-size:12.0pt;}#yiv1516966814 a:link, #yiv1516966814 span.yiv1516966814MsoHyperlink {color:blue;text-decoration:underline;}#yiv1516966814 a:visited, #yiv1516966814 span.yiv1516966814MsoHyperlinkFollowed {color:purple;text-decoration:underline;}#yiv1516966814 p.yiv1516966814MsoAcetate, #yiv1516966814 li.yiv1516966814MsoAcetate, #yiv1516966814 div.yiv1516966814MsoAcetate {margin:0in;margin-bottom:.0001pt;font-size:8.0pt;}#yiv1516966814 span.yiv1516966814EmailStyle17 {color:#1F497D;}#yiv1516966814 span.yiv1516966814BalloonTextChar {}#yiv1516966814 .yiv1516966814MsoChpDefault {} _filtered #yiv1516966814 {margin:1.0in 1.0in 1.0in 1.0in;}#yiv1516966814 div.yiv1516966814WordSection1 {}#yiv1516966814 >Ethernet will give you 100m or 328 ft range. With Raspberry Pi weighing in at 0.5 W, 13 W power budget with PoE is a lot. 
  
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