SU945818A1 - Digital frequency metr - Google Patents

Description

The invention relates to a measurement technique and can be used in information control and processing systems.

Digital frequency meters are known that contain generators, drivers, switches, counters, and logic elements based on the principle of counting the number of pulses generated one for each period of the measured frequency for a certain precisely defined time interval f 1 j.

The disadvantage of these devices is the impossibility of measuring the algebraic sum of the frequency for one period of time.

The closest to the invention in its technical essence is a device with a direct reading of the average for the time T value of the frequency, containing three input pulse shapers sequentially connected

a pulse, a pulse divider, a controllable key and a counter, the second input of which is connected to the second input of the pulse divider and the output of the latter through the reset shaper C2.

A disadvantage of the known device is the inability to measure the frequency fgj {for one time interval Tc, since the time for determining the input frequency is equal to ZTz-Td, where Tu is the time for determining each frequency and Tdo is the time required for alternate connection of signals to the device and then find the algebraic. sum of frequencies.

The purpose of the invention is to expand the functionality of the device by measuring the algebraic sum of frequencies in a single cycle Tc.

This goal is achieved in that a digital frequency meter containing three input pulse drivers is connected in series to a pulse generator, a pulse divider, a control key and a counter, the second input of which is connected to the second input of the pulse divider and the output of the latter through a pulse pulse generator , the first element And, the first trigger, the second element And, the second trigger, the third element And, the delay element and the OR element, connected in series by the single vibrator and the third trigger, the output of which is connected to the first input of the element I, the second input of which is connected to the output of the first shaper of input pulses and the second input of the second element H, the first input of which is connected to the input of a single vibrator, while the output of the second shaper of the input pulses is connected to the second input of the third trig Gera, the output of the third input pulse generator is connected to the second input of the third element .And the second input of the OR element, the output of which is connected to the second input of the controlled key, and the output of the delay element ki is connected to the second input of the second trigger. FIG. 1 is a block diagram of a digital frequency meter; in fig. 2 time diagram of the operation of the device The device contains shapers 1-3 input pulses, element. And k, triggers 5 and 6, one-shot 7 element And 8, trigger 9 element And 1 pulse generator 11, delay element 12, - OR element 13, pulse divider l, control key 15, reset pulse shaper 16 and counter 17. Device works as follows. In the initial state, at the output of the flip-flops 5 and 9 there is a logical zero, at the output of the flip-flop 6 there is a logical one. The signals at the outputs of the formers 1-3, respectively, are shown in FIG. 2 (a, bi) Each pulse of the signal of frequency f from the output of shaper 2 sets the trigger 5 to one (Fig. 2c), which allows the passage of pulses of frequency f c out of the shaper 1 through element 4 (Fig. 2d). First pass A pulse arriving through element C, arriving at the counting input of trigger 6, causes a trailing edge to produce a logical zero at its output, and the second one passing through element t drives the trailing edge 6 to return the trigger 6 to its initial state (Fig. 2e). the one-shot 7 of Fig. 2 e) is triggered, which returns the trigger 5 to the original condition. At the output of element 8, a sequence of pulses is obtained in which during the measurement time Tp there is no number of pulses equal to the number of pulses of the signal of frequency fj (Fig. 2 g). Thus, the number of pulses at the output of element 8 during the measurement time T 1 corresponds to the value of the frequency difference. Each pulse from the output of element 8 puts the trigger 9 into one state (Fig. 2 and), thus providing the possibility of the signal passing from the output of the imaging unit 3 through element 10 (Fig. 2 to), the output signal of which passes through the element 12 (Fig. 2l) causes the trigger 9 to be reset to its initial state, and the passage through the element 13 forms, at its output, together with the signals from the output of the former 3, a new sequence of pulses (Fig. 2m). Thus, the number of pulses in this sequence during the measurement time T is greater than the number of signal pulses from the output of the imaging unit 3 with frequency f. by an amount numerically equal to the number of pulses fi, fB As a result, the counter 17 will record, during T.1 s, a certain number numerically equal to the value of f. . C If required, simply measure the frequency of a signal, it should be connected to the input of the third driver 3 input pulses. Formula. The invention has a digital frequency meter containing three input pulse drivers, a pulse generator connected in series, a pulse splitter, a control key and a counter, the second input of which is connected to the second input of the pulse splitter and the output of the latter through a reset pulse driver, characterized in that capabilities, the first AND element, the first trigger, the second AND element, the second trigger, the third AND element, the delay element and the OR element, Consequently, a one-shot and a third trigger, the output of which is connected to the first input of the element I, the second input of which is connected to the output of the first fortior of input pulses and the second input of the second element And, the first input of which is connected to the input of the single vibrator, with the output of the second pulse former of the input pulses dinene with the second input of the third trigger, the output of the third driver input pulses connected to e 6 the second input of the third element And the second INPUT element OR, the output of which is connected to the second controllably move key, and the delay element output coupled to a second input of the second flip-flop. Sources of information taken into account during the examination 1. P. Ornatsky. Automatic measuring devices. Kiev, Technique, 1965. p. 32k, 2. P. Ornatsky Automatic measuring devices. Kiev, Technical, 1965, p. 320.

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Claims (1)

Formula. inventions A digital frequency meter containing three input pulse shapers, a pulse generator, a pulse divider, a controlled key and a counter, the second input of which is connected to the second input of the pulse divider and the output of the latter through a reset pulse shaper, characterized in that, in order to expand the functionality, the first AND element, the first trigger, the second AND element, the second trigger, the third AND element, the delay element, and the OR element, in series with a single one-shot and a third trigger, the output of which is connected to the first input of the element And, the second input of which is connected to the output of the first driver of the input pulses and the second input of the second element And, the first input of which is connected to the input of the one-shot, while the output of the second driver of the input pulses is connected to the second input of the third flip-flop, the output of the third driver input pulses is connected to the second input of the third aND gate and a second input of the OR gate, whose output is connected to a second input of controllable _t of the key, and the output of the delay element 5 is connected to a second input of the second flip-flop.