RU1487661C - Medium frequency impulse meter - Google Patents

Abstract

The invention relates to a frequency measurement technique. The purpose of the invention is to enhance functionality and increase accuracy. To achieve the goal, a fourth counter 7, a fifth counter 8, a sixth counter 9, an inverter 10, an arithmetic unit 11, a register 12, a first one-shot 14, a second one-shot 15, a third one-shot 16, an OR element 17 were introduced into the average pulse frequency meter. , the fourth one-shot 18. In addition, the arithmetic unit 11 comprises a first division unit 20, a second division unit 21 and a third division unit 22, and the second counter 2 comprises a subtracting counter, a trigger and a switch. The device also contains a first counter 1, a first trigger 3. a third counter 4, a Start button 5, a second trigger 6 and a common bus 19. The device can be used in automatic information processing systems. 2 s.p. f-ly, 3 ill.

Description

The invention relates to frequency measurement techniques and is intended to measure the average frequency of pulses with a static time distribution.

An object of the invention is to enhance functionality and increase accuracy.

In FIG. 1 shows a functional block diagram of a meter of average frequency of pulses; in FIG. 2 is a functional diagram of a second counter; in FIG. 3 is a timing diagram of the meter.

The average pulse frequency meter contains a first counter 1, a second counter 2, a first trigger 3. a third counter 4, a Start button 5. a second trigger 6, a fourth 7, a fifth 8 and a sixth 9 counters, an inverter 10, an arithmetic unit 11, register 12. decoder 13, first 14, second 15, third 16 single vibrators, OR element 17, fourth single vibrator 18 and common bus 19.

The arithmetic block 11 comprises a first 20, a second 2 T and a third 22 division blocks.

The second counter 2 contains a subtracting counter 23 with a preset, an additional trigger 24 and a switch 25.

The counting input of the first counter 1 is the first input of the meter, the synchronization input of the first trigger 3 is connected to the output of the first counter 1 and the counting input of the second counter, the counting input of the third counter 4 is the second input of the meter, the common bus 19 via the Start button 5 is connected to the inverse input the reset of the second trigger 6, the installation input of the first counter 1 is connected to the reset input of the second counter 2, the decoder 13, the first 14, the second 15 and the third 16 are one-shot, the OR element 17 and the fourth one-shot 18 are connected, output which is connected to the input for setting the second latch 6, the reset input of the third

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4 and the fourth 7 counters, the reset input of the second counter 2 and the reset inputs of the fifth 8 and sixth 9 counters, the counting inputs of which are connected respectively to the outputs of the third 4 and fourth 7 counters, the counting enable inputs of which are connected to the output of the first trigger 3, the reset input of which connected to the inverse reset input of the second trigger b and through the inverter 10 with the second input of the OR element 17, the output of the second trigger 6 is connected to the D-input of the first trigger 3, the output of the second counter 2 is connected bit to the input of the decoder 13 and the third in the formation input of the arithmetic unit 11, the first and second information inputs of which are connected respectively to the outputs of the bits of the fifth 8 and sixth 9 counters, the first and second control inputs of the arithmetic unit 11 are connected to the outputs of the first 14 and second 15 single vibrators, the output of the third single vibrator 16 is connected to the control input of the register 12, the information inputs of which are connected to the output of the arithmetic unit 11, the output of the decoder 13 is connected to the direct reset input of the second trigger 6.

In the second counter 2, the subtracting input of the subtracting counter 23 with a preset is combined with the reset input of the additional trigger 24 and is the counting input of the second counter 2, the output of which is the bit outputs of the subtracting counter 23, the preset inputs of which are connected via the switch 25 to the common BUS 19, and loan output - with the synchronization input of the additional trigger 24, the output of which is connected to the write enable input of the subtracting counter 23, and the installation input is the reset input of the second counter 2.

In the arithmetic block 11, the inputs of the dividend of the first 20 and second 21 division blocks are respectively the first and second information inputs of the arithmetic block 11. The third information input of which is the combined inputs of the divider of the first 20 and second 21 division blocks, the control inputs of which are combined and are the first control input of the arithmetic unit AND / the second control input of which is the control input of the third division unit 22, the information inputs of which are connected respectively to the outputs of the 20 th and 21 of the second dividing unit, and outputs a third dividing unit 22 are output of the arithmetic unit 11.

The meter works as follows.

When you press the 5 Start button, the signal with a zero level (Fig. 3.6) sets to

the zero state is trigger 6 (Fig. 3, d) and trigger 3 (FIG. 3, c) and through the inverter 10 supplies a logical unit signal to the input of OR element 17. When the button 5 is released, the logical unit signal is removed from the input

0 of the OR element 17, while the signal at the output of the OR element 17 changes from the level of the logical unit to the level of logical zero, as a result of which the single-vibrator 18 is started. The signal from the output of the single-vibrator 5 18 (Fig. 3, f) sets the counter 2 to the state corresponding to the required measurement time T, counters 8 and 9 to the zero state, sets trigger 6 to the single state, counters 4 and 7 to

0 is the zero state and counter 1 is in the single state. The signal from the output of trigger 6 (Fig. 3d), applied to the D-input of trigger 3, is an enable signal for switching trigger 3 to a single state.

5

coming at its sync input.

After the end of the action of the signal at the output of the one-shot 18 (Fig. 3, e), the next pulse arriving at the first input of the meter (Fig. 3, a) translates the counter 1 into

0 zero state. The signal from the inverted output of counter 1 (Fig. 3.6) subtracts one from the contents of counter 2 and puts trigger 3 in a single state. The output of trigger 3 is a single signal

5 (Fig. 3, d), which allows the counting of counters 4 and 7 (Fig. 3, k, l).

The measurement cycle T begins (Fig. 3e), during which the input pulses from the second input of the meter are counted as counter 4 with the conversion factor K and fed to the counter B (Fig. 3c), and the input pulses from the third input of the meter ( Fig. 3, P2) are recounted by the counter 7 to the coefficient K and fed to the counter 9 (Fig. 3, l).

5 in FIG. Figure 3 shows conditionally the conversion factors of the counters 1, 4 and 7, equal to 4. The measurement time is set by the frequency of pulses arriving at the first input of the meter, the conversion coefficient of the counter 1 and the set volume of the counter 2. When it arrives at the counter 2, it works to subtract the penultimate pulse determining the measurement time, the output of the decoder 13 receives a signal (Figs. 3, i);

5 which sets the trigger 6 to the zero state, while a signal with a zero level will be applied to the D-input of trigger 3 (Fig. 3d) and when the next (last in this measurement cycle) pulse arrives from the output of counter 1 (Fig. 3.6) trigger 3 goes to the zero state and the signal from its output (Fig. 3e) blocks the inputs of counters 4 and 7. The measurement cycle has ended, but at the same time counter 2 goes to the initial state corresponding to the measurement time T , and at the output of the decoder 13, after the end of the measurement cycle, a signal appears, triggering second monostable multivibrator 14 (FIG. 3, n). In FIG. Figure 3 conditionally shows the case when the measurement cycle T is equal to two periods of the frequency of pulses coming from the output of counter 1 (Fig. 3.6). Next, the signal from the output of the one-shot 14 (Fig. 3, p) starts the arithmetic unit 11 to determine the ratio of the average frequencies of the pulses arriving at the second and third inputs of the meter. If the conversion factors of the counters 3 and 6 are equal to K, then at the end of the measurement cycle T in the counters 8 and 9 there will be respectively the results of measurement niT / K and P2T / K, and in the counter 2 the number T. The signal from the output of the one-shot 14 triggers the division blocks 20 and 21 and at their outputs, codes of numbers P1 / K and P2 / K appear respectively. At the end of the signal at the output of the single vibrator 14, a signal appears at the output of the single vibrator 15 (Fig. 3f), which starts the division unit 22 and the code number P1 / P2 appears at its output. Next, a single-shot 16 is started (Fig. 3, m), which writes this result to register 12, the output of which appears a number code equal to the result of the first measurement, and is stored for the next measurement cycle. The signal from the output of the single-vibrator 16 through the OR element 17, similarly to the signal from the output of the inverter 10, triggers the single-vibrator 18 (Fig. 3, f), thereby starting the next measurement cycle.

The second counter (Fig. 2) works as follows.

Upon receipt of the initial state of the signal at the input, the trigger 24 is set to a single state and the signal from its output enters the code of the number set on the switch 25 to the counter 23. After this signal is removed and the input signal is low, trigger 24 returns to zero condition. The counter 23 is ready for operation. The first input pulse will reduce its state by one (this pulse comes at the beginning of the measurement cycle). One period before the end of the measurement cycle, the counter 23 will be in the zero state. At the end of the measurement cycle, a signal arises at the output of the borrower of counter 23, which puts the trigger 24 in a single state and sets the counter 23 to the state determined by the number set on the switch 25.

The expansion of functionality provides an additional opportunity to measure the ratio of the average frequencies of the pulse sequences arriving at two inputs of the device, as well as the ability to measure the deviation of the frequency of one of them from the specified ratio, if it is possible to set both constant and specified from one of the pulse sequences, time measurement.

Improving the accuracy compared with the prototype is achieved by more accurate formation of the measuring interval.

Claims (3)

1. The meter of the average frequency of pulses, containing the first counter, the counting input of which is the first input of the meter, WJEroy counter, the first trigger, the synchronization input of which is connected to the output of the first counter and the counting input of the second counter, the third counter, the counting input of which is the second input a meter, a common bus connected via the Start button with an inverse reset input of the second trigger, the installation input of the first counter is connected to the reset input of the second counter, characterized in that, in order to improve accuracy measuring and expanding functionality, additionally introduced the fourth, fifth and sixth counters, an inverter, an arithmetic unit, a register and sequentially connected decoder, the first, second, third one-shot, OR element and the fourth one-shot, the output of which is connected to the installation input of the second trigger , reset inputs of the third and fourth counters, reset input of the second counter and reset inputs of the fifth and sixth counters, the counting inputs of which are connected respectively to the outputs of the third and fourth meters, the counting enable inputs of which are connected to the output of the first trigger, the reset input of which is connected to the inverse reset input of the second trigger and through the inverter to the second input of the OR element, the output of the second trigger is connected to the D-input of the first trigger, the output of the second counter is connected bit to the input the decoder and the third information input of the arithmetic unit, the first and second information inputs of which are connected respectively to the outputs of the bits of the fifth and sixth counters, the first and second control inputs ar fmeticheskogo unit connected to the outputs of the first and second single vibrators, respectively. the output of the third one-shot is connected to the control input of the register, the information inputs of which are connected to the output of the arithmetic unit, the output of the decoder is connected to the direct reset input of the second trigger. 2. The meter according to claim 1, characterized in that the second counter contains a switch / additional trigger and a subtracting counter with a preset, the subtracting input of which is combined with the reset input of the additional trigger and is the counting input of the second counter, the output of which is a bit outputs of the subtracting counter, the preset inputs of which are connected via a switch to a common bus, and the loan output is connected to the synchronization input of an additional trigger, the output of which is connected to the subtracting recording permission input Meters withstand, and the set input is a reset input of the second counter. 3. The meter according to paragraphs. 1 and 2, taking into account the fact that the arithmetic block contains the first, second and third division blocks, the inputs of the dividend of the first and second division blocks are respectively the first and second information inputs of the arithmetic block, the third information input of which are the combined inputs of the divider of the first and second division blocks, the control inputs of which are combined and are the first the control input of the arithmetic unit, the second control input of which is the control input of the third division unit, the information inputs of which are connected respectively to the outputs of the first and second division units, and the outputs of the third division unit are the output of the arithmetic unit. F. 1