SU1236384A1 - Digital frequency meter - Google Patents

Abstract

This invention relates to a radio measurement technique and can be used in information control and processing systems. The purpose of the invention is to expand the functionality of a digital frequency meter, which, in addition to measuring the frequency of a single signal f or the difference between two frequencies f2-f3, measures the algebraic sum of three frequencies f, f 2 3 to achieve the goal, a push-pull distributor 10 pulses and circuits 11 and 12 are introduced into a digital frequency meter sync. In addition, the frequency meter contains shapers of 1.2 and 3 pulses, elements AND 4 and 8, triggers 5 and 6, one-oscillator 7, generator 9 clock pulses, element OR 13, divider 14 pulse frequency, control key 15, driver 16 pulse reset and counter 17. The synchronization circuit contains two D-flip-flops, the element is NOT and the element I. 1 C.p. f-ly, 3 ill. § (L N5 t and F1 / e. 1

Description

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

The purpose of the invention is to expand the functionality of a digital frequency meter, which, in addition to measuring the frequency of a single signal f, or the difference: two frequencies fj-f, makes it possible to measure algebraic three frequencies. Fig. 1 shows the principle circuit of a digital frequency meter; 2 shows time diagrams of the operation of the device; on fig.Z - schematic diagram of one of two similar schemes. synchronization.

The digital frequency meter contains (FIG. 1) pulse generators 1-3, the first element A And, Triggers 5 and 6, the one-shot 7, the second element And 8; 9 clock pulse generator, push-pull valve 10 pulses, synchronization circuits .11 and 12, element 13, divider frequency 14, control of the first key 15, driver 16 for reset pulses, counter 17,

The synchronization scheme (). Contains triggers 18 and 19 ;, element NOT 20 element 21, consistently with the first driver 1 pulses connected first element 4., first: trigger 6, second element 8, the first diagram 11 of the screening element OR 13, the key 15 and the counter 17 are controlled. In series with the second pulse driver 2-. Trigger 5 is turned on, the output of which is connected to the second input of the element AND 4 whose first input is connected to the second input of the AND 8 element “In series with the third generator 3, a second synchronization circuit 12 is turned on, the output of which is connected to the second input of the element 13. 13. In series with the generator 9 clock pulses are connected to the pulse frequency divider 14 and the reset pulse shaper 16, the output of which is connected to the second input of the counter 17 and the second input of the pulse divider 14, and the input to the first input of the control key 15. One input the vibrator 7 is connected to: 8th trigger trigger b, and its output - to the second trigger input 5. Distributor outputs 1 O pulses

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The connectors are connected with the first inputs of the synchronization circuits 11 and 12, and the input p of the pulse distributor 10 is connected to the generator output 9 clock pulses.

Digital frequency meter works as follows.

In the absence of input signals, trigger 6 is in unit

10 state, and the trigger 5 and the triggers of the counter 17 - in zero. On the indicator board of the counter 17, zero readings are displayed.

Ka; kdy impulse from the output of the second

15 of the former 2 with the frequency f, (FIG. 26) places the flip-flop 5 into a single state (FIG. 2 c), leading to the opening of the element 4 through the second input. Acting from the exit of the first

JO shaper 1 pulses of frequency f ,, (fig.2a), passes through the element 4 and 4 (fig.2g) and triggers a trigger with common input 6 (fig.2d). The very first impulse of the falling edge

25 sets the trigger 6 to the zero state, prohibiting the passage of the pulses of the frequency fj through the element 8, the transfer of the trigger 6 and the single state to the zero sets one 3Q vibrator 7, the output 1-1 pulse of which (FIG. 2 e) returns the trigger 5 to the zero state This prohibits the pulsing of pulses through element H 4. The next pulse of frequency fj from the output of shaper 2 again triggers trigger 5 into a single state, after which the described process of rotation of pulses is repeated. In this case, at the output of the element AND 8, a pulse sequence appears in which, during the measurement time T, the total number of pulses equals the difference in the number of pulses of the frequencies fj and fj (Fig. 2g). This after-. Pulses are fed to the input of the first synchronizer 11, in which they are synchronized by the frequency of odd impulses of the clock generator, which are fed to the first input of the synchronizer 11 from the distributor output

10 pulses (Fig.2K). In this case, each pulse arriving at the second input of the synchronizer 11 corresponds to only one odd such a 5th pulse at its output (FIG. 2m). In a similar way, pulses are generated at the output of the second synchronizer 12, to the first input of which

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even clock pulses are applied (fig.2l), and to the second input are pulses from the output of shaper 3 with frequency -fj (fig, 2h). 1a, the output of the synchronizer 12 in this case appears with even pulses of the clock generator 9, which follow with a frequency f, since only one even clock pulse corresponds to each output pulse of the driver 3 (fig.2n). From the outputs of circuits 11 and 12, synchronization of a sequence of pulses arrives at the inputs of the element OR 13, which performs their summation (2 °). Thus, the number of pulses at the output of the element OR 13, which will record the counter 17 during the measurement, is equal to the sum of two sequences of pulses, the sequence of frequency f and the sequence of frequency difference fj-fj, i.e. In this case, the ratio of the frequencies between these sequences is completely irrelevant, since the counter 17 records their sum in any case, both with f, f -f, and with f, f2 3, if there is an exact coincidence in time of any pulse sequences with a pulse of another sequence, the counter 17 will also fix them separately, since the odd and even clock pulses that pass through synchronizers 11 and 12 do not coincide in time.

The synchronization scheme (fig.Z) works as follows.

In the initial state, the trigger 18 and 19 are in the zero state. At the output of the element And 21 at the same time will be low. If the time of the positive clock pulses at the input C of the trigger 18 with the input pulses arriving at the input D of the same trigger coincides, it is transferred to a single state. At the output of element 21, a high potential appears, since at its two inputs, single potentials now act. Such a state cxeNfti will last until the input clock C at trigger 19 from the element NOT 20 clock pulse by its falling edge does not transfer trigger 19 also to the unit state. Since the input element And 21 connected to the inverse

the output of the flip-flop 19, a potential of zero appears, and the potential of the element 21 also appears at zero potential. Upon termination of the input pulse at the input D of the trigger 18, the circuit returns to the initial state. When the next input pulse arrives at the input D of the trigger 18, the operation of the circuit is repeated. Thus, at the output of the element 21, pulses are generated, the duration of which is equal to the duration of the clock pulses, which follow with the frequency of the pulses acting on the input D of the trigger 18 and strictly temporally tied to the clock pulses supplied to the input C from the distributor 10 pulses (FIG. .one).

Claims (1)

1. Digital frequency meter containing three input pulse drivers, serially connected clock generator, pulse frequency divider, control key and counter, the second input of which is connected to the second input of the pulse frequency divider and the output of the latter through the reset pulse generator, serially connected first element I , the first trigger and the second element PI, the OR element, the output of which is connected to the second input of the controlled key, are connected in series with a single vibrator and the second trigger, output D of which is connected to the second input of the first element I, the first input of which is connected to the output of the first shaper of input pulses and the second input of the second element I, the first input of which is connected to the input of a single vibrator, while the output of the second shaper of the input of pulses is connected to the second input of the second trigger, o tl and h a yu and u with. In order to expand the functionality, two synchronization circuits and a push-pull pulse distributor are introduced in it, the input of which is connected to the output of the clock generator, and the outputs are connected to the first inputs of the synchronization circuits whose outputs are connected to the inputs of the OR element, and the second the input of the first synchronization circuit is connected to the output of the second element I, and the second input of the second synchronization circuit is connected to the output of the third driver of the input pulses. 2, the frequency meter according to claim 1, that is, each synchronization circuit contains two B-triggers, an AND element and an NOT element, with the C input of the first D-flip-flop combined with the input of the HE element and Editor S. Patrushev Compiled by I. Fedorov Tehred G.Gerber Proofreader Y. Sirohman 3085/47 Circulation 728 Subscription VNIIP of the USSR State Committee for inventions and discoveries 113035, Moscow, Zh-35, Raushsk nab., 4/5 Production and printing company, Uzhgorod, st. Project, 4 It is the first input of the synchronization circuit, and the D input of the first D-flip-flop is the second input of the synchronization circuit, the direct output of the first D-flip-flop is connected to the D-input of the second D-flip-flop and the first input of the And element whose output is the output of synchronization, the output element is NOT connected to the C-input of the second D-flip-flop, the inverse output of which is connected to the second input of the element I.