Device, operating according to the Doppler principle, for measuring the distance travelled by a vehicle

摘要

For contactless measurement of the distance currently travelled by a vehicle, a device operating according to the Doppler principle is used, in which a pulse train having speed-proportional frequency is produced by means of a phase-locked-loop circuit (9); by using the individual pulses as distance increments, they are summed in an adder (11) and the corresponding count is displayed as distance using a display unit (12) (Figure 2). <IMAGE>