Breaking News
Comments
Newest First | Oldest First | Threaded View
Page 1 / 2   >   >>
David Ashton
User Rank
Author
Re: PoE seems DOA - how does it scale to kW?
David Ashton   1/24/2014 6:24:41 PM
NO RATINGS
Hi Bert...I'm never gonna hear the end of this now, am I??   :-))

The ones I have made I've just chopped off 6 inches of a cable, and used 2 Panduit IDC sockets.  So a pair of wire cutters and a pair of water pump pliers for the IDC sockets.  Not a soldering iron in sight!!

I must admit, it's easier to just buy them, but being able to make them has got me out of trouble a few times...

Bert22306
User Rank
Author
Re: PoE seems DOA - how does it scale to kW?
Bert22306   1/24/2014 4:53:24 PM
NO RATINGS
Hey David. I don't mean to pry, but ... did you need a soldering iron? Or just a crimp tool? :)

David Ashton
User Rank
Author
Re: PoE seems DOA - how does it scale to kW?
David Ashton   1/24/2014 4:44:37 PM
NO RATINGS
On the question of the two unused pairs for 100Base-T,  I have made - and you can buy - splitters that do exactly that - send two different ethernet signals down one cable.  Handy when you have a PC and a printer in the same room and not enough cables.  But as we move to Gig Ethernet I won't be able to use these tricks.

Bert22306
User Rank
Author
Re: PoE seems DOA - how does it scale to kW?
Bert22306   1/24/2014 3:06:19 PM
NO RATINGS
Oh, on the second question, in principle those 4 conductors dedicated to power in 100BASE-TX could have been used as a second Ethernet, yes. I mean, instead of providing power. But then when 1000BASE-T came along, there were no spare conductors. All eight copper wires are used for the one GigE link already. So as of now, 10/100/1000BASE-T cards have to be set up by default the same way.

Bert22306
User Rank
Author
Re: PoE seems DOA - how does it scale to kW?
Bert22306   1/24/2014 3:01:06 PM
NO RATINGS
Tunrayo, yes, in the sense that if a switch port provides PoE, it won't harm a host that doesn't use PoE.

In the case of 100BASE-TX, the power is sent over the fiur unused conductors of the Cat-5e or Cat-6 cable. In faster copper Ethernets, it is a DC component that the NIC would ignore.

Tunrayo
User Rank
Author
Re: PoE seems DOA - how does it scale to kW?
Tunrayo   1/24/2014 11:22:13 AM
NO RATINGS
@Bert. Are these PoE ports compatible with NIC cards on PCs and Laptops? Could a PoE currently in use for VoIP be re-configured as a data connection?

zewde yeraswork
User Rank
Author
Re: PoE seems DOA - how does it scale to kW?
zewde yeraswork   1/23/2014 3:45:34 PM
NO RATINGS
Interesting--does anuyone else see laptops going PoE?

Arshe100
User Rank
Author
Los Mejores Abogados de Palma de Mallorca a Su Servicio
Arshe100   1/23/2014 10:16:21 AM
NO RATINGS
Abogados en Palma de Mallorca ofrece servicios legales para empresas y particulares a un precio razonable

[url=http://www.abogadosenpalmademallorca.com/]abogadosenpalmademallorca.com[/url][url=http://www.abogadosenpalmademallorca.com/]www.abogadosenpalmademallorca.com[/url]

David Ashton
User Rank
Author
Re: PoE seems DOA - how does it scale to kW?
David Ashton   1/22/2014 5:43:59 PM
NO RATINGS
We use POE a lot where I work.  We just put Voip phones on and the phone gets network - and power - from the wall socket and passes the network on to the PC on the same desk.   We have personal video conference units that also work with POE but so far no PCs, not even Laptops.  I can see laptops going POE if they can get the power requirements down a bit - maybe non-hard disk types that work with the cloud, like Chromebooks?  I've just been putting in a heap of wireless access points and those also work on POE - you just run a cat 6 cable to where you want them and they get power and network from it.  It's also great for sensors, security cameras, etc.

I think one advantage is that you have one beefy power supply in the ethernet switch rather than lots of little ones for the individual devices.    Better efficiency..  But then there's a fair bit of loss in the cables as well, so it's a case of "swings and roundabouts" I suppose....  I think POE works at up to 100V, so not huge currents...but ethernet cables weren't intended for power.

Bert22306
User Rank
Author
Re: PoE seems DOA - how does it scale to kW?
Bert22306   1/22/2014 5:17:10 PM
NO RATINGS
Yeah, you got it. There's no big deal here. From the beginning of time, well, almost, some telephone instruments got all they needed from ma bell, and others ALSO had to be plugged into your AC mains. The automakers simply want to expand their options in PoE, to save on copper cabling.

Page 1 / 2   >   >>


Datasheets.com Parts Search

185 million searchable parts
(please enter a part number or hit search to begin)
Radio
LATEST ARCHIVED BROADCAST

What are the engineering and design challenges in creating successful IoT devices? These devices are usually small, resource-constrained electronics designed to sense, collect, send, and/or interpret data. Some of the devices need to be smart enough to act upon data in real time, 24/7. Specifically the guests will discuss sensors, security, and lessons from IoT deployments.

Brought to you by:

Like Us on Facebook
Special Video Section
The LTC2380-24 is a versatile 24-bit SAR ADC that combines ...
In this short video we show an LED light demo to ...
02:46
Wireless Power enables applications where it is difficult ...
07:41
LEDs are being used in current luxury model automotive ...
With design sizes expected to increase by 5X through 2020, ...
01:48
Linear Technology’s LT8330 and LT8331, two Low Quiescent ...
The quality and reliability of Mill-Max's two-piece ...
LED lighting is an important feature in today’s and future ...
05:27
The LT8602 has two high voltage buck regulators with an ...
05:18
Silego Technology’s highly versatile Mixed-signal GreenPAK ...
The quality and reliability of Mill-Max's two-piece ...
01:34
Why the multicopter? It has every thing in it. 58 of ...
Security is important in all parts of the IoT chain, ...
Infineon explains their philosophy and why the multicopter ...
The LTC4282 Hot SwapTM controller allows a board to be ...
This video highlights the Zynq® UltraScale+™ MPSoC, and sho...
Homeowners may soon be able to store the energy generated ...
The LTC®6363 is a low power, low noise, fully differential ...
See the Virtex® UltraScale+™ FPGA with 32.75G backplane ...
Vincent Ching, applications engineer at Avago Technologies, ...