| 摘要 |
Track occupancy detector safety equipment for railways is based on axle counters at each end of an isolated track section. Rail contacts at two counting locations generate axle impulses dependent on the direction of travel. The impulses are also fed to further counters connected in parallel to determine the absolute axle count at the respective counting location. The output from the differential counter is coupled to a comparator which compares the impulse count from adjacent counting locations and delivers a section-free signal to a central evaluator only when the differential counter has returned to its initial condition. |
