Device for determining the moment when competitors in a race are passing the finish line

摘要

In this system for determining the moment when competitors in a race pass the finish line, each competitor is fitted with a transmitter. Arranged at the finish line are at least two receiving antennas, the signals from which are combined in opposite sense so as to form a difference signal. A system output signal then is produced which has a leading edge that occurs when the difference signal crosses zero. This output signal indicates that a competitor has passed the finish line.