Note: The Type 1 Liverpool Simulator has now been superseded by the Type 2 hardware.
The Simulator Interface takes the signals from multiple sensors (up to 12) attached to real bells or teaching dumbbells, and transmits them to a PC in the ringing room running a simulator software package such as Abel, Beltower or Virtual Belfry. Schematics, Eagle PCB designs, firmware source code and full documentation are available on GitHub, and ready made PCBs are available from OSH Park.
12-Bell Simulator Interface
Simulator Interface PCB
The Liverpool Ringing Simulator Project 