Some info/drawing for building your own hardware:

SlotracingLapcounter1.gif - the drawings for the lapcounter.

SlotracingLapcounter2.gif - the drawings for the lapcounter (Schakelkast).

SlotracingLapcounter3.gif - parts which I used to build my own lapcounter.

SlotracingLapcounter4.gif - the drawings for the lapcounter (Relaiskast).

SlotracingLapcounter5.gif - the drawings for the lapcounter (Sensors).

SlotracingLapcounter6.gif - the drawings for the lapcounter (Startlicht).

SlotracingLapcounter7.gif - the drawings for the lapcounter (XLR-track-Relaiskast).

4 track hardware

2 track hardware