SU911359A1 - Method and device for measuring pulse signal frequency - Google Patents

Description

The invention relates to electrical measuring technology and can be used to digitally measure the frequency of impulse signals.

A digital frequency meter is known, in which the sum of the fractional parts of the period at the beginning and the end of the measurement interval to the period of the measured frequency is determined and the number obtained is added to the number of pulses reduced by 1, recorded by the counter of frequency meter 1

The disadvantage of the known method of measuring the frequency of the pulse signals and the device implementing it is low speed.

The closest to the present invention is a method for measuring the frequency of pulse signals based on filling the measurement interval with pulses of the measured frequency, filling the interval after each pulse of the measured frequency with the pulses of the generated frequency until the end of the measurement interval ends often, adding units to the number of full periods of the measured frequency, if the sum of the fractional parts at the beginning

and the end of the period is greater than the period of the measured frequency. The device for its implementation contains counters, triggers, AND, OR elements, differentiating circuits, pulse frequency multiplier 2.

The disadvantage of the method for measuring the frequency of the pulse signal and the device for its realization is

10 low speed, due to the fact that after the end of the measurement interval, some additional time is needed to return to the zero state of the counter.

The purpose of the invention is to increase the measurement speed of frequency.

The goal is achieved by the fact that in the method of measuring the frequency of the pulse signal 20, based on counting the pulses of the measured frequency during the measurement interval, counting the number of pulses of the reference frequency stored in the portion of the period of the measured frequency at the beginning and end of the interval, the unit from the number of pulses the measured frequency for the measurement interval, if the sum of the fractional parts of the periods at the beginning and end of the measurement interval is less than the period of the measured frequency pulses, or adding one to the number of pulses measured If the sum of the fractional parts of the periods at the beginning and end of the measurement interval is equal to twice the period of the measured frequency pulses, with each pulse of the measured frequency, the number of pulses is equal to

The number of pulses of the reference frequency deposited in a part of the period of the measured frequency at the beginning of the measurement interval is summed up by the number of pulses with the number of frequency pulses proportional to the number of full periods of the measured frequency pulses from the beginning of the measurement interval during the time after the arrival of the next measured frequency pulse. opergadium of summation, taking into account the new value of the number of complete periods, until the end of the measurement interval comes before the end of the period and measured frequency.

in device for method, containing the first counter, the second counter, the input of which is connected to the output of the first element I, the first and second inputs of which are connected to the input frequency reference bus and the output of the first trigger, respectively, the first and second inputs of the latter are connected to the input bus of the measurement interval and through the second element AND to the input bus of the measured frequency, respectively, the third counter, the decoder, the multiplier, the driver, the two OR elements, the fourth and fifth counters, the third AND divider with by a division factor, a group of elements And and a generator of pulse trains, the inputs of which are connected respectively to the output of the second element and, the input bus of the reference frequency and the outputs of the second counter, and the output connected to the first input of the first element OR, BJJXOD with a divider c. a constant division factor is connected to the input of the third counter, the outputs of which are through a group of elements And are connected to the installation inputs of the fourth counter, the output of which is connected to the input of the fifth counter / informational outputs of which are connected to the decoder, the first output of which is connected to the subtracting input of the first counter, and the second output 7 to the first input of the second OR element, the second input of which is connected to the second inputs of the group of elements AND and through the second element AND to the input bus of the measurement interval, and the output to orogo element .or - a summing input of the first counter pulse input frequency multiplier

the pulses are connected to the input bus of the reference frequency, the setting inputs of the frequency multiplier pulses are connected to the outputs of the first counter, the output of the frequency multiplier pulses through the third element I is connected to the input of the fourth counter, and the second input of the third element I is connected to the bus of the measurement interval and through the driver with the pulse input decoder.

FIG. 1 isobrine timeline; in fig. 2 - functional device diagram.

The device contains a generator of 1 bursts of pulses, which includes trigger 2, element 3 OR, counter 4 and group of elements 5 I, trigger 6, elements 7 and 8 AND, element 9 OR, multiplies frequency 10, the first counter 11, second counter 12, element 13 OR, divider 14 with a constant division factor, element 15 AND, FO 1ravatel 16, counter 17, a group of elements 18 AND ,, counters 19 and 20, decoder 21, input bus 22 reference frequency FO, input bus 23 measurement interval Tk | m, input width 24 of measured frequency F, {.

The device works in the following way ..

By a command (coming from, from the starting pistol), the trigger 16 is set to the state allowing the pulses to pass through the element 8 and to the second counter 12 of the fractional part of the frequency being measured. Trigger b is set to the first pulse state of the measured frequency FK, coming through element 7 I, from the input bus 24. Thus, element 8 And the resolution will be applied for the time t / i, during which the eterson frequency pulses from the output bus 22 on the counter 12 fractional part of the measured frequency, in which the number of pulses will be calculated

N FO- t.4

After the arrival of each successive pulse of the measured frequency F, the generator of 1 burst of pulses produces a burst of pulses N as follows. The NI code is rewritten from the counter 12 of the fractional part of the measured frequency to the counter 4 through the group of elements 5 I. Each pulse F. sets trigger 2 to the state

1I 11 I

allowing the passage of reference pulses FO through element 3 OR to the subtractive input of counter 4 before zeroing, through which the trigger

Claims (2)

1. Authors certificate of the USSR 152255, G 01 R 23/10, 1962. 2. Authors certificate of USSR 415596, G Og R 23/02, 1971. n n n  ". pn m