ELECTRIC CIRCUIT FOR MEASURING THE FREQUENCY OF LASER DOPPLER SIGNALS

摘要

An electric circuit for measuring the frequency of laser doppler signals has at least one counter for counting the signal pulses and a microprocessor for evaluation the count on the counter within a measurement interval. The frequency of laser doppler signals can be measured with high precision. To this end, a blocking element such as an AND gate (2) which controls the pulse counting and is controlled by an additional signal, for example by an automatic band pass, is connected in front of the laser signal pulse counter (4); a time pulse counter (7) which is connected, for example, to a quartz pulse generator (8) and which determines the measurement interval from a predetermined number of pulses is provided; and the laser signal pulse counter (4) and the time pulse counter (7) are connected to a microprocessor (14) which reads out the count on the counters after a measurement interval has elapsed.