ORXJ-1 is a 5port Xpressnet junction. It is designed for use with any Xpressnet device.
This do-it-yourself (DIY) Xpressnet junction provides some features that may be useful. The best feature is that you only need to assemble the some RJ12 plugs to get a working Xpressnet junction. The other parts are optional.
All documentation: https://gitlab.com/rocrail/GCA/tree/master/orxj-1
Last version is 0.5
Schematics and PCB artwork was created with KiCad, an Open Source (GPL) PCB Suite.
The parts are available all over the world. To see the specs of the used parts click on the links below.
|amount||part / link|
|5||6 port RJ12 modular jack|
|4||2 port screw terminal|
|2||LED 3mm, 2mA|
|1||Multi pin connector|
|1||Elko, 1000µF, 35V|
|1||Elko, 100µF, 16V|
|1||Voltage regulator 7812|
There is also a Reichelt shoping cart. But they deliver only to germany. Anyway, there is a real chance to get these parts at your local electronic dealer.
Building is quite easy.
If you use the internal power supply you have to use a heatsink for the 7812 regulator.
The heatsink has to be big enough to dissipate the heat from the 7812 depending on the power loss over the regulator.
You connect a 18V AC transformer and your xpressnet devices have a consumption of 500mA.
The power loss equals ((18V -0,7V) x 1,41 -12) x 0,5A = 6,1965 W
Check your pcb for shortcuts, especialy between the pins of the RJ12 jacks.
connect a 12V transformer and measure if the power supply works.
Read the chapter "usage" and test your pcb with Xpressnet devices.
The Heatsink is NOT GND, it is 0,7V above GND. If you don't like it you have to isolate the regulator from the cooler using plastic screws and glimmer
use with 12V over Xpressnet cable (e.g. from the command station)
use with external regulated 12V DC power supply
use with external 12 to 24V AC transformer
If you have trouble building or using ORXJ-1 please write a post in the hardware section of the Rocrail forum.
This is Do It Yourself Hardware. If you burn down your house or have to call the doctor there is no one responsible than you