SU1725151A1 - Device for measuring disagreement of periods of two pulse generators with close frequencies - Google Patents

Abstract

The invention can be used to determine the difference in the periods of the pulse generators. The device contains two pulse generators 1, 2, two shaper 3, 4 pulses, shaper 5 single pulses, four elements AND 6-9, block 10 elements, element 11, two delay elements 12.13, controllable element 14 delay, two counter 15.16 pulses, trigger 17, time relay 18. 2 Il.

Description

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The invention relates to the field of electrical and radio measurements and can be used to determine the difference between the periods of pulse generators.

The aim of the invention is to increase the measurement speed.

Figure 1 shows the structural diagram of the device; 2 shows timing diagrams for the operation of the device.

A device for measuring the divergence of periods in two pulse generators with similar frequencies contains pulse generators 1 and 2, shapers 3 and 4 pulses, shaper 5 single pulse, elements 6-9, block 10 elements AND, element 11, element 12 and 13 delays, controlled delay element 14, counters 15 and 16 pulses, trigger 17 and time relay 18.

The output of the pulse generator 1 through a serially connected driver 3, the elements And 7 and 8, the counter 16 and the block 10 elements And connected to the output of the device. The input of the relay 18 is combined with the output of the element And 8 and the second input of the trigger 17, and the output is connected to the control input of the unit 10 and through the element 13 to the input of the zero setting of the counter 16, the output of which through the series-connected element 9 and the element 11 is connected to the second the input element And 8. The output of the pulse generator 2 is combined with the first input element And 6 and the input element. 12 delays, the output of which is connected to the second input of element 7 via a serially connected controllable element 14 of delay and shaper 4. The output of shaper 5 is connected to the first input of trigger 17, the output of which is connected to the second input of element 6, while the counting input the counter 15 is connected to the output of the element 6, and the output to the control input of the controllable delay element 14.

The device works as follows.

In the outgoing state, the counter 16 is zero (the initial zeroing circuit is not shown), at the outputs of all its bits and at the inputs and output of the And 9 element signals occur, the level of which corresponds to logical O, and at the output of the EK 11 element and the second input of the And 8 is a signal whose level corresponds to a logical 1.

Pulse generators 1 and 2 produce pulses with close repetition periods TI and T2, respectively. The signals of the pulse generator 1 are received respectively at the input of the imaging unit 3, and the pulse generator 2 through the element 12

N

delays and a controllable element 14 of the input delay of the former 4. The formers 3 and 4, under the action of signals arriving at their inputs, generate pulses of strictly constant duration n and G2, respectively (Fig. 2a, b), and in principle the same pulse duration of the formers 3 and 4 (t G2). These pulses are fed to the inputs of the element And 7, at the output of which the signal takes place only in the case of mutual temporary imposition of input signals. The pulses at the output of the element And 7 appear as groups (Fig. 2b), and the number N of pulses in the group is directly proportional to the divergence of the periods Ti, T2, i.e.

G1 + G2

where T (Ti -12).

Pulses from the output of the element And 7 through the element And 8, open at the second input, pass to the counting input of the counter 16, to the second input of the trigger 17 and to the input of the relay 18.

At the end of the group of pulses from the output of the element And 8 at the outputs of the bits of the counter 16, a code of number N occurs, inversely proportional to the divergence of the following periods Ti and T2, and relay 18 is triggered, which has a delay of more than the maximum possible period of the pulse generator 1 and 2. Under the action of a pulse from the output of the relay 18, the code of the number N from the outputs of the bits of the counter 16 is rewritten through the elements AND of the block 10 to the outputs of the device, and then through the delay element 13 the counter 16 is whipped, then the device New ready for measurement.

Element I 9, together with element NOT 11, prevent overflow of the counter 16 and itself in the operation of the device in the case of DT - 0. When the discharge bits of the counter 16 appear at the outputs, the maximum possible number NMBKC 2П - 1, where n is the number of counter bits 16, at the output of the element AND 9 and the input of the element 11, a signal appears whose level corresponds to logical 1, and at the output of the element 11 and the second input of element 8 appears a signal whose level corresponds to logical O, the element And 8 closes on the second the input, and the pulses from the output element And 7 ne Esta supplied to the count input of the counter 16.

The presence on the device outputs of the code of the number Mmax means that the divergence of the DT of the following periods satisfies the condition

Lt P + T2

L I TP

Mmax

If during a long time interval after switching on the device, the code corresponding to zero is fixed at the outputs of the bits of the counter 16, then using the shaper 5 a pulse is generated, under which the trigger 17 is set to such a state that at its output and at the second input of the AND element 6, a signal appears whose level corresponds to a logical one. As a driver 5, for example, a differentiating circuit can be used, connected via a key in the form of a button to a power source. In this case, the formation of a pulse is accomplished by pressing a button. Under the action of the signal from the output of the trigger 17, the element 6 opens at the second input and the pulses from the output of the pulse generator 2 begin to flow through the element 6 to the counting input of the counter 15. The contents of the counter 15 begin to increase by one with the arrival of each pulse, and with it discrete variation of the delay time of the controlled element 14, for which the code at the outputs of the bits of the counter 15 is the controlling one. A change in the delay time of the controlled delay element 14 leads to a change in the total delay time. The delay time of the element 12 is chosen sufficient to complete the transients in the element 6 and 6, the counter 15 and the control element 14 after the next pulse generator 2 signal. As a result of changing the total delay time, the time shift between the pulses of the formers 3 and 4 changes. imposing the pulses of the formers 3 and 4 on each other at the output of the element And 7, a pulse is formed, which passes through the element And 8 to the second input of the trigger 17, the latter is transferred, at its output and the second in de AND gate 6 is the signal whose level corresponds to the logic O. The element 6 is closed and the second input pulses cease to act on the count input of the counter 15, the time delay element 14 controllably stops vary.

At the end of the pulse group and the end of the measurement process, the output

the device code corresponds to the period discrepancy or (when Mmax is reached) to the value AT - O.

Thus, the proposed device, in comparison with the known, allows to measure the difference between the periods of two generators with a smaller expenditure of time, and also to fix the cases of difference between the periods AT, the measurement of which is limited by the volume

used pulse counter.

Claims (1)

Apparatus of the Invention A device for measuring the divergence of periods and two pulse generators with similar frequencies, comprising a series-connected first pulse generator, a pulse shaper and an And element, a series-connected first block counters And whose output is the output of the device, as well as a second pulse generator, the second shaper pulses and a time relay whose output is connected to the control input of the element block And through the first delay element to the zeroing input of the first pulse counter, wherein the output of the second pulse shaper is connected to the second input of the first And element, characterized in that, with in order to improve the measurement performance, a single pulse pulse former, a trigger, a second, third and fourth And element, a second pulse counter, an NOT element, as well as the second delay element connected in series and a controllable delay element whose output is connected to the input of the second pulse shaper, and the control inputs to the output of the second counter pulses, with the output of the first element I through the second element I connected to the counting input of the first pulse counter, the input of the time relay and the second trigger input, the first input of which is connected to the output of the single pulse former, the output of the first pulse counter through the series-connected third element AND and the element NOT connected to the second input of the second element And the output of the second pulse generator is connected to the input of the second delay line and through the fourth element And is connected to the counting input of the second pulse counter, and the trigger output is connected to the second input of the fourth element I.