SPOJE.NET

Technická dokumentace

Uživatelské nástroje

Nástroje pro tento web


howto:electro:gigabit_poe

Rozdíly

Zde můžete vidět rozdíly mezi vybranou verzí a aktuální verzí dané stránky.

Odkaz na výstup diff

howto:electro:gigabit_poe [2014/12/11 17:20] (aktuální)
Řádek 1: Řádek 1:
 +====== Gigabit PoE (802.3af) ======
  
 +  * http://​en.wikipedia.org/​wiki/​Power_over_Ethernet#​Power_capacity_limits
 +  * http://​forum.mikrotik.com/​download/​file.php?​id=10417&​sid=6fc2e8eb2c2daca423ee4b91e19a1405
 +  * http://​www.dipolnet.cz/​poe_-_iee_802_3af_and_iee_802_3at_bib746.htm
 +
 +  * **C = 100nF** (ceramic, stacked tin foil,...)
 +  * **L = 300uH**
 +    * Ferrite material 43 or 61 (toroid FT-37-61)
 +    * https://​www.youtube.com/​watch?​v=t8mB6xz2NPI
 +
 +{{http://​www.valal.sk/​upload/​savefile_php/​uploads/​eb025411ea.png}}
 +{{http://​www.infocellar.com/​networks/​new-tech/​PoE/​cable2.gif}}
 +{{http://​electronicdesign.com/​site-files/​electronicdesign.com/​files/​uploads/​2014/​01/​fig1.gif}}
 +
 +===== Experiments =====
 +
 +  * I've decoupled all of 8 gigabit ethernet conductors using 100nF ceramic capacitors and the link was still OK.
 +  * I've shorted + and - of 3 meters 100M ethernet pair through FT-50-61 toroid choke. For 4 and more windings it did not affected the link. When removing the winds the link quality was getting gradually worse.
 +  * I've put FT-50-61 toroid choke on + of the same pair and from 9-10 winds and up it prevented the ethernet from linking. When trying less winds the link quality was gradually better.
 +  * It's not good idea to use wire with 0.2mm diameter for more than 3A (too much voltage drop, too much heat). So probably 2A should be maximum.
howto/electro/gigabit_poe.txt · Poslední úprava: 2014/12/11 17:20 (upraveno mimo DokuWiki)