SU1707571A1 - Digital meter of time position of the center of video pulses - Google Patents

Abstract

The invention can be used in digital measuring devices, in particular in digital angle transducers. The purpose of the invention is to simplify a digital meter while maintaining technical characteristics and functionality. The digital time meter of the midpoint of the video impulses contains the pulse generator 1, the HE elements 2 and 3, the pulse distributor 4, the D-trigger. 5 and 6, the four elements AND 7-iO, the element OR 11 and the counter nm-. 12. 4 ill.

Description

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The invention relates to a pulse technique and can be used in

digital measuring devices.

A device for determining the center of the video signal is known, which contains a threshold circuit whose output is connected to a delay line with 2n + 1 taps symmetrically located with respect to the middle output, 2n of HE elements, (n + 1) AND elements, and OR element with (n + 1) inputs to which are connected the outputs of all (n + 1) elements AND, whose inputs through the elements are NOT symmetrically connected to the terminals of the delay line.

The disadvantage of the device is the low accuracy of determining the center of the video signal. To increase accuracy, it is necessary to increase the number of pins of the delay line, which leads to a significant complication of the device.

A digital temporal position meter for the middle of rectangular video pulses is known, containing a W-element I, two triggers, a generator and a counter, the output of which is connected to the first input of the first trigger (RS flip-flop), the output connected to the first input of the first element I, and the second input - with the first input of the element And, to another input of which the output of the second trigger (counting) is connected, the input of which is connected to the generator output, the output of the second element And is connected to the input of the counter and the output of the first element And, the second input of which connected to the output of the pulse for generators. In this case, the first stroke of the second element I is the device's input, and the output of the counter through the pulse shaper is connected to the output of the device.

The disadvantage of the meter is its limited functionality, since the considered digital meter of the temporary position of the center of the rectangular video pulses is able to determine the desired parameter for only one pulse.

In the practice of measurements, the problem of determining the midpoint of two arbitrarily located rectangles is often encountered: 1.: video pulses of a perfect duration, for example, during pulsing, averaging operations with the aim of improving the accuracy in digital time pulses.

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The closest in technical terms to the proposed technical solution is a digital temporal position meter for the center of video pulses, comprising a clock pulse generator, a pulse distributor (for four T-series), first and second RS-triggers, first and second D-triggers, first and second elements NOT, the four elements AND, the element OR, and the pulse counter, the information input of which is connected to the output of the element OR, the first, second, third and fourth inputs of which are connected respectively to the outputs of the first, second first, third and fourth elements II, the input of the pulse distributor is connected to the output of the clock pulse generator; the first, second, third and fourth outputs of the pulse distributor are connected respectively to the first inputs of the first, third, second and fourth elements And, the second input of the first element And connected to the direct output of the first RS trigger, whose S input is the first input of the meter, the second input of the second element I is connected to the direct output of the first D-trnger, the second input of the third element I is connected to the direct input the output of the second RS flip-flop, whose input is the second input of the meter, the second input of the fourth element I is connected to the direct output of the second D-flip-flop, the D inputs of the first and second D-flip-flops are connected to the single logic signal bus, the output of the first D-flip-flop connected to the output of the first element NOT, the input of which is connected to the first input of the meter, the C-input of the second D-trigger is connected to the output of the second element NOT, the input of which is connected to the second input of the meter, the R-inputs of the first and second RS-triggers and D-triggers connected between oboj, to the input R of the counter pulses and with the output of the counter complements, which is

output meter.

The considered digital time meter of the midpoint of the video pulses allows to determine the source parameter both for a single video pulse, and p for ;; Ц.Cm. impulses, due to its disadvantage is the complexity of the circuit (design).

The aim of the invention is to simplify the digital time meter.

the position of the center of the video pulses while maintaining the technical characteristics and functionality.

The goal is achieved by the fact that in a digital time meter the midpoint of video pulses, containing a pulse generator, pulse distributor, the first, second, third and fourth elements AND, the OR element and a pulse counter, the counting input of which is connected to the input of the element OR, the generator output pulse is connected to the input of the pulse distributor, the first output of which is connected to the first input of the first element AND, the output of which is connected to the first input of the element OR, the second output of the pulse distributor n the first input of the third element AND, the output of which is connected to the third input of the OR element, the third output of the pulse distributor is connected to the first input of the second element AND, the output of which is connected to the second input of the OR element, the fourth output of the pulse distributor is connected to the first input of the fourth element And, the output of which is connected to the fourth input of the OR element, the D inputs of the first and second P-flip-flops are connected to the bus of a single logical signal, the C input of the first D-flip-flop is connected to the output of the first HE element, whose input Pogo is the first input of the meter, the C-input of the second D-flip-flop is connected to the input of the second element NOT, the input of which is the second input of the gauge, the R-inputs of the first and second D-trngers are interconnected with the R-input of the counter pulses and with a pulse timer overflow output, the direct output of the first D-flip-flop is connected to the second input of the second element, And the direct output of the second D-flip-flop is connected to the second input of the fourth And element, the output of the pulse counter overflow is an output. the meter, the second input of the first element And is connected to the first input of the meter, and the second input of the third-element And - with the second input of the meter.

In addition, the pulse distributor contains a pulse counter with outputs in a paraphase code and four elements, moreover:: -: cd counter is connected to the second inputs of the first and second elements And, and to the input of the pulse distributor, direct output

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the low-order bit of the counter is connected to the first input of the first element II, the output of which is connected to the second input of the fourth element I and to the fourth output of the pulse distributor, the inverse output of the low-order bit of the counter is connected to the first input of the second element And, the output of which is connected to the second the input of the third element And with the third output of the pulse distributor, the direct output of the highest bit of the counter is connected to the first input of the fourth element And, the output of which is connected to the second output of the pulse distributor, inverse th output MSB of the counter is connected to a first input of the third AND gate, whose output is connected to the first output distributor pulses.

Changing the connection in the proposed digital meter greatly simplifies its device in comparison with the known meter while maintaining the technical characteristics and functionality, R results exclude two RS-n-iggeres, and exclude 1, the decoder from the pulse distributor.

FIG. 1 shows the CTpyKTvpnan diagram of a digital meter and the midpoint position of the video pulse $ 2 in FIG. 2 — the time diagram of the meter operation; Fig. 3 is a structural diagram of a pulse distributor {in Fig. 4 - a timing diagram of the operation of the pulse distributor.

The digital time meter of the midpoint of video pulses contains a pulse generator 1, elements HE 2 and 3, a pulse distributor 4, two D-flip-flops 5 and 6, elements AND 7-10, element OR 11 and a pulse counter 12. The digital meter has the first 13 and second 14 inputs and output 15.

The output of the generator 1 clock pulses connected to the input of the distributor 4 pulses. The input of the first element NOT 2 is connected to the second input of the first element I 7 and the first input 13 of the digital meter. The output of the first element NO 2 is connected to the C input of the first D-flip-flop 5, the direct output of which is connected to the bird's gokha of the second sigmo.nt. g I.P. Ch. l mt- .. element HE 3 is connected to the second input of the third element I 9 and the second

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input 14 digital meter. The output of the second element is NOT 3 connected to. The C-input of the second D-trnger 6, whose direct output is connected to the second input of the fourth element AND 10. The first output of the distributor 4 pulses is connected to the first input of the first element AND 7, the second output to the first input of the third element And 9, the third output - with the first input of the second element And 8 and the fourth output - with the first input of the fourth element And 10. The outputs of the elements 7 7-10 are connected respectively to the first - fourth inputs of the element OR 11, the output of which is connected to the information input of the pulse counter 12. D-inputs of the first 5 and second 6 P-triggers are connected to the bus of a single logical signal. The R inputs of the first 5 and second 6 D-flip-flops are interconnected, with the inputs R and the overflow output of the pulse counter 12, and with the output 15 of the digital meter.

The distributor 4 pulses contains the input 16, the outputs 17-20 and includes a counter 21 pulses and four elements And 22-25.

The input of the pulse counter 21 is connected to the second inputs of the first 22 and second 23 elements And and the input 16 of the distributor 4 pulses. The forward output of the low-order bit of the counter 21 is connected to the first input of the first element I 22, the output of which is connected to the second input of the fourth element And 25 and the fourth output 20 of the distributor 4 pulses. The low-voltage output of the counter 21 is connected to the first input of the second element AND 23, the output of which is connected to the second input of the third element AND 24 and the third output 19 of the distributor 4 pulses. The forward high-order output of the counter 21 is connected to the first input of the fourth element I 25, the output of which is connected to the second output 18 of the distributor 4 pulses. The inverse high-order output of the counter 21 is connected to the first input of the third element AND 24, the output of which is connected to the output 17 of the distributor 4 IMGULES.

The digital meter operates trace / kgdnm about r.h tom.

We consider the operation of a digital meter in accordance with the time diagrams of its work for the case of

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determining the temporal position of the middle of two video pulses (figure 2). about

According to figure 2 we get

L L L L A L H + Lg1g + s, 4 + cg + I +

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where Ј J0 |. . - fixed interval

time from the desired midpoint between the centers of two rectangular video pulses to the output pulse being generated (it is required that Ј edd const); C - the duration of the first

input pulse arriving at input 13,

/ Ј - the duration of the second.

input pulse arriving at input 14} -. tj - time interval between

the falling edge of the first and leading edge of the second input pulses} C, is the time interval between the falling edge of the last (in this case, the second) pulse and the output pulse generated. Convert the expression (1):

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(3)

The operation of multiplying the time interval by the pulse frequency is equivalent to filling this time interval with pulses of the corresponding frequency.

As follows from expression (3), the temporal position of the output pulse generated by the counter 12 is strictly (up to one discrete) fixed relative to the middle between the centers of the two original right-angle video pulses (figure 2).

In the initial state, the first 5 and second 6 D-triggers, as well as the pulse counter 12, are reset to zero (they are in zero states). Kkpul- «sy from the output of the generator 1 pulses affect the input of the distributor A pulses, which produces four series of pulses shifted relative to each other in time. JQ (FIG. A). In this case, on the first 17 and second 18 outputs of the distributor A pulses, pulses with a frequency of f / A are formed, and on the third 19 and fourth

with frequency f / 2. As a result, the element And 8 transmits pulses with a frequency f / 2 to the second input of the element OR 11 and further to the input of the counter 12 pulses. The indicated state of the circuit is stored in the time interval C, (Fig. 2). With the appearance of the second pulse at the input 1A (FIG. 2), a single logical signal arrives at the second input of the element AND 9, allowing the passage of pulses from the second output of the distributor A of the pulses through the element 9 to the third input of the element OR 11 s

20 outputs - pulses with frequency f / 2,) 5 frequency f / A. As a result from the exit

element OR 11 to the information input of the pulse counter 12 pulses arrive at the frequency S / Af as. the OR 11 element summarizes the couples passing through the elements AND 8 and 9. With the appearance of the second pulse at the input 1A, the element HE 5i is triggered

where f is the frequency of the pulse generator 1. Since the second inputs of the elements And 7-10 are zero logic signals, these elements do not transmit pulses to the inputs of the element OR 11 and further to the information input of the counter 12 pulses.

With the appearance of the first pulse at the input 13 (FIG. 2), a single logical signal is received at the second input of element 7 and permits the passage of pulses from the first output of the distributor 4 pulses through the element 7 at the first stroke of element 11 with frequency f / a. As a result, from the output of the element OR 11 to the information input of the counter 12 pulses, pulses are received at a frequency of f / A. With the appearance of the considered pulse at input 13, the element HE 2 is triggered and outputs to the C input of the first T) Trig.p. 5 zero logic, but the P-flip-flop 5 retains the zero state, since it triggers a positive differential voltage on the C input. This state of the circuit is maintained in the time interval $ (Fig. 2).

On the falling edge of the first pulse (input 13) at the output of the element NO 2

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with frequency f / 2. As a result, the element And 8 transmits pulses with a frequency f / 2 to the second input of the element OR 11 and further to the input of the counter 12 pulses. The indicated state of the circuit is stored in the time interval C, (Fig. 2). With the appearance of the second pulse at the input 1A (FIG. 2), a single logical signal arrives at the second input of the element And 9, allowing the passage of pulses from the second output of the distributor A of the pulses through the element 9 to the third input of the element OR 11 s

f / A frequency. As a result from the exit

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element OR 11 to the information input of the pulse counter 12 pulses arrive at the frequency S / Af as. the OR 11 element summarizes the couples passing through the elements AND 8 and 9. With the appearance of the second pulse at the input 1A, the element HE 5i is triggered

outputs to the C input of the second D-flip-flop 6 a zero logic level, but the D flip-flop 6 saves the zero state in the same way as in the previous case. This state of the circuit is maintained in the time interval Ј2 (Fig. 2).

On the falling edge of the second pulse (input 1A), a positive voltage is generated at the output of the NOT 3 element, and the D-thrung 6 is set to one state, since its single input is affected by a single logical signal. As a result of the termination 1 of the action of the second pulse at the input 1A, the single logical signal is removed from the second input of the element AND 9 and the last is locked, and c. as a result of setting D-triggers 6 into one state, the latter generates a single logical signal to the second input of element 10. And the pulses with frequency f / 2 from the fourth output of

a positive differential on the 45 splitter A is formed and passes through the Yarn element, and the D-flip-flop 5 sets -10 to the fourth input of the OR 11 element, into a single state, since. in which they are summed up from a pulse, its D-input acts as a single loop, passing through an AND 8 element of a constant signal. Thus, as a result of the termination of the first impulse, a single logical signal is removed from the second input of the element 7 and the last is locked, and as a result of the installation of the first 0-trigger 5 in one state, this signal enters the second input of the element 8 the first input of which receives pulses from the third output of the distributor A pulses

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the same with the frequency f / 2. As a result, from the output of the element OR t1 to the input of the counter 12 pulses, pulses pass. frequency f. This state of the circuit is maintained at a time interval (see Fig. 2).

The pulse of the overflow of the pulse counter 12 D-flip-flops 5 and 6 are reset to the zero state, the pulse counter 12 also goes into the zero state, and output 11 is outputted to output 15. 1707571

barrel pulse, the temporary position of which is shifted relative to the desired point between the centers of the first and second pulses by time,

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At input 16, pulses from generator 1 (stabilized quartz oscillator) are continuously supplied. Duplex binary counter 21 with outputs in. the paraphase code is continuously operating in the -count mode with a conversion factor of 4 (Lig.4, outputs Q1, Q1, Q2, Q2). The second inputs of the elements And 22

As can be seen from Fig. 1, the circuit of the digital meter of the temporal position jg of the center of the video pulses is symmetrical with respect to the inputs 13 and 14, as a result of which the initial pulses can be arranged randomly in time, "

those. the second impulse (at input 14) of mo-, 5, and 23 stR ° is detected by impulses generating ahead of the first, impulses can - arbitrarily overlap one another and even coincide. Thus, the proposed scheme of a digital meter is invariant with respect to the 20 temporary location of the initial pulse 1 and, since the direct and inverse outputs of the lower bit of the counter 21 act on their first inputs, respectively, two series of pulses shifted in time are formed at the outputs of the And 22 and 23 elements. with a frequency of f / 2 (figure 4, exits 19 and 20). Two series of shifted, in time, pulses with a frequency of Ј / 4 are formed by elements AND 24 and 25, since the first inputs of these elements receive signals from the inverse and direct outputs of the highest bit of counter 21, respectively, and these elements are gated And 2h and 25 impulses with a frequency of f / 2 with lzykhom elements And, respectively, 23 and 22 (figure 4, outputs 17 and 18) The pulses generated at the output 17. at a frequency of f / 45 are superimposed on the pulses generated at exit 19 at a frequency of f / 2 (Fig. 4). The situation is similar with outputs 18 and 20. Imposing these series of pulses on each other does not disturb the operation of the digital meter, since the pulses from $ 17 and 19, as well as from outputs 18 and 20, are used non-simultaneously.

pulses.

The proposed digital time meter for the midpoint of video pulses can operate in the mode for determining the temporal position of the midpoint of one rectangular video pulse applied to either of its two inputs 13 or 14. To do this, an initial impulse is given to one (any) input and zero logic signal. The operation of the digital meter in this mode is similar to the previous mode, only the corresponding D-flip-flop connected to the input to which the logical zero is applied, all the time is in the zero state, and the pulse counter 12 is filled with pulses of frequency f / 4 and f / 2 at appropriate intervals. The temporary position of the output pulse (output 15) is shifted relative to the center of the initial pulse by a constant delay time

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One more mode of operation of the digital meter is possible when determining the temporal position of the middle of one - the video pulse. To do this, you need to combine the inputs 13 and 14 to submit the original impulses. As a result, an output impulse, i.-w.v.o.:; Cs; - .7 :: og:; ::: e :: oo; from: h; с, --- н ;; у- io relative to the middle of the initial pulse for a constant delay time

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The distributor 4 pulses works as follows.

At input 16, pulses from generator 1 (stabilized crystal oscillator) are continuously supplied. Duplex binary counter 21 with outputs in. the paraphase code is continuously operating in the -count mode with a conversion factor of 4 (Lig.4, outputs Q1, Q1, Q2, Q2). The second inputs of the elements And 22

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And 23%, they are controlled by pulses of

torus 1 and, since their first inputs are acted upon by the direct and inverse outputs of the low-order bit of counter 21, two series of time-shifted pulses with frequency f / 2 are formed at the outputs of elements AND 22 and 23 (FIG. 4, outputs 19 and 20). Two series of shifted, in time, pulses with a frequency of Ј / 4 are formed by AND 24 and 25 elements, since the first inputs of these elements receive signals from the inverse and direct high-order outputs of the counter 21, respectively, and these elements are gated And 2h and 25 pulses with a frequency of f / 2 with lzyma elements And, respectively, 23 and 22 (figure 4, the outputs 17 and 18). Impulses generated at the exit 17. at a frequency of f / 45 are superimposed on the pulses generated at exit 19 at a frequency of f / 2 (Fig. 4). The situation is similar with outputs 18 and 20. Imposing these series of pulses on each other does not disturb the operation of the digital meter, since the pulses from $ 17 and 19, as well as from outputs 18 and 20, are used non-simultaneously.

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The proposed digital time meter for the midpoint of video-pulses is much simpler than the known technical solution, since with the same technical characteristics and functionality, two RS-flip-flops and a decoder are excluded from the pulse distributor. Thus, the hardware costs for the implementation of a digital meter, which could be used in digital measuring technology, which require averaging the temporal position of video pulses, for example, digital angle meters, are reduced.

Formula iobr e geni

Digital time meter of the midpoint of video pulses containing a pulse generator, pulse distributor, first and second D-triggers, first and second elements NOT, first, second, third and fourth elements AND, element OR and pulse counter, the counting input of which is connected to element output .OR, the output of the pulse generator is connected to the input of the pulse distributor, the first output of which is connected to the first input of the first element AND, the output of which is connected to the first input of the element OR, the second output of the distributor and The pulses are connected to the first input of the third element AND, whose output is connected to the third input of the OR element, the third output of the pulse distributor is connected to the first input of the second element AND, the output of which is connected to the second input of the OR element, the fourth output of the pulse distributor is connected to the first the input of the fourth element H, the output of which is connected to the fourth input of the OR element, D- the inputs of the first and second B-triggers are connected to the bus of a single logical signal, the C input of the first D-flip-flop is connected to the output of the first electric The NOT, whose input is the first input of the meter, the C input of the second D-flip-flop is connected to the output of the second element NOT, the input of which is the second input of the gauge, the R-inputs of the first and second U-flip-flops are connected between: with R-count input

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With the pulse and with the pulse counter overflow output, the direct output of the first D-flip-flop is connected to the second I input of the second element, And the direct output of the second D-flip-flop is connected to the second input of the fourth And element, the output of the pulse counter overflow is the meter output, which differs in order to simplify the meter, the second input of the first element I is connected to the first input of the meter, and the second input of the third element I with the second input of the meter, while the pulse distributor contains a pulse counter with outputs paraphase 5sod and four elements And, and the counter input is connected to the second inputs of the first l of the second element And, and to the input of the pulse distributor, the direct low-level counter of the counter is connected to the first input of the first element And whose output is connected to the second input of the fourth element And with the fourth output of the distributor m-pulsop, the inverse output of the low-order bit of the counter is connected to the first input of the second element And, the output of which is connected to the second input of the third element And and to the third output of the pulse distributor, The direct output of the most significant bit of the counter is connected to the first, the input of the fourth element I, the output of which is connected to the second output of the pulse distributor, and the input of the high bit of the counter is connected to. the first input of the third element And, the output of which is connected to. the first output of the pulse distributor.

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Claims (1)

Claim A digital mid-temporal position measuring instrument containing a pulse generator, a pulse distributor, first and second D-flip-flops, first and second elements NOT, first, second, third and fourth elements AND, an OR element and a counter 'q pulses, counting input which is connected to the output of the element. OR, the output of the pulse generator is connected to the input of the pulse distributor, the first output of which is connected to the first input of the first element AND, the output of which is connected to the first input of the element OR, the second output of the distributor pulse is connected to the first input of the third AND element, the output of which is connected to the third input of the OR element, the third output of the pulse distributor is connected to the first input of the second AND element, the output of which is connected to the second input of the OR element, the fourth 2 'output of the pulse distributor is connected to the first input of the fourth AND element, the output of which is connected to the fourth input of the OR element, D inputs of the first and second D-triggers 3 (connected to the pin of a single logic signal, the C-input of the first D-trigger is connected to the output of the first element It is NOT, the input of which is the first input of the meter, the C-input of the second D-trigger is connected to the output of the second element NOT, the input of which is the second input of the meter, the R-inputs of the first and second D-triggers are interconnected with the R-input of the counter As for the pulses and with the pulse counter overflow output, the direct output of the first D-trigger is connected to the second I input of the second AND element, the direct output of the second D-trigger is connected to the second input of the fourth AND element, the pulse counter overflow output. is the output of the meter, characterized in that, in order to simplify the meter, the second input of the first element And is connected to the first input of the meter, and the second input of the third element And is connected to the second input of the meter, while the pulse distributor contains a pulse counter with outputs in the paraphase code and four And elements, and the counter input is connected to the second inputs of the first and second And elements, and to the pulse distributor input, the direct output of the least significant bit of the counter is connected to the first input of the first And element, the output of which is connected inen with the second input of the fourth element And and with the fourth output of the pulse distributor, the inverse output of the least significant bit of the counter is connected to the first input of the second element And, the output of which is connected to the second input of the third element k and to the third output of the pulse distributor, the direct output of the highest discharge of the counter is connected to the first input of the fourth element And, the output of which is connected to the second output of the pulse distributor, the inverse output of the highest order counter ^ is connected to. the first input of the third element And, the output of which is connected to the first output of the pulse distributor.