A crossbar switch connects multiple inputs to multiple outputs using a matrix of horizontal and vertical relay bars. When a specific horizontal and vertical bar are energized simultaneously, the physical contact at their intersection closes, establishing a dedicated circuit. This design replaced older step-by-step switches in telephone exchanges, offering faster routing and less physical wear before digital switching took over.
Heard on the job
You can still hear the distinct clatter of the crossbar switch in the background of that old exchange recording.
Also heard as
- crossbar
- X-bar