FREQUENCY METER WITH AUTOMATIC SELECTION MEASUREMENT RANGE

Abstract

Frequency meters with automatic selection of the measurement limit are used to measure the frequency of the input signal, which varies in a wide range. Signal frequency meters (frequency meters) are one of the most numerous groups of measuring instruments that are widely used in various fields of technology. There are a large number of frequency meters, which are based on different principles. At the same time, the issue of creating frequency change meters, which have a principle of operation different from well-known systems, is still relevant.
 The aim of this work is to develop an electrical signal frequency meter with automatic selection of the measurement limit, based on a new principle of frequency measurement, which has not been used before. An approach to the construction of frequency meters with automatic selection of the measuring range is proposed. The measurement is performed using a low-frequency single-band frequency meter. Pulses traveling with the frequency of the input signal are pre-formed. Pulses are counted on the meter formed by series-connected decadal meters for a specified time, after which, using a logic circuit, sequentially analyzes the states of the meter outputs, starting from the output corresponding to the maximum distribution coefficient. The analysis is performed to determine the output of the divider, the frequency value of which is greater than the maximum corresponding to the penultimate digit of the single-band low-frequency frequency meter and does not exceed the maximum frequency corresponding to its last digit. After that, the input of the single-band low-frequency frequency meter is connected to the selected meter output and the frequency is changed with the indication of the number and the automatically selected range. An approach to the automatic measurement of the frequency of the input signal, which varies widely, is proposed.
 The proposed method allows, using simple and affordable means of circuit construction, to make a frequency meter with automatic selection of the measurement limit. In the future, the proposed frequency meter can be used in measuring the frequency of the signal from non-destructive testing, which will expand the range of its technical means used in measuring the frequency of the signal from non-destructive testing.