ERICSSON CROSSBAR

I have built a crossbar telephone exchange demonstrator using an Ericsson crossbar switch and an Arduino microcontroller. The exchange is configured similar to the Ericsson ARD624-16 PAX, but my setup has only two extensions. The crossbar concept was already patented in 1917 by Swedish telephone engineers Gotthilf Betulander and Nils Palmgren. However, it took until the 1950s before crossbar exchanges were widely accepted. 

The operation of my system is demonstrated here.

The video illustrates the principles of the switch and explains the Arduino control logic.