SU1228253A1 - Minimum duration pulse discriminator - Google Patents

Abstract

The invention relates to a pulse technique. It can be used to select from an arbitrary pulse sequence of pulses, the duration of which does not exceed the specified one. The purpose of the invention is to increase the reliability of selection - is achieved by separating pulses less than a specified duration from a sequence of pulses with an arbitrary duration and arbitrary intervals between them as a result of organizing the formation of strobe pulses with which the input signals are compared along the front and rear edges of each input pulse. The selector contains Differentiating 1, 2 and 3 and threshold 4, 5, 6 and 7 elements, gate formers 8 and 9, logical elements (LE) AND 10 and 11 - OR 15, 16 and 17, triggers 12, 13 and 14, input 18 and output t9 buses, gate formers 8 and 9, the functional scheme of which is given in the description of the invention, contain two single vibrators, a delay element and LE I. I. f-ly, 3 ill. "L 1c N9 00 N9 SL CO Sh-W W Fig. /

Description

i 1

The invention relates to a pulse technique and is intended to be selected from an arbitrary pulse sequence of pulses, the duration of which does not exceed the specified one.

The purpose of the invention is to increase reliability, selection by allowing pulses to be less than a specified duration from a sequence of pulses with a VOLUNTARY duration and an arbitrary interval between them due to the organization of the formation of strobe pulses with which the input signals are compared along the front and rear edges of each input pulse .

FIG. 1 shows a block diagram of a pulse selector with a minimum duration; in fig. 2 - structural diagram of the gate driver; FIG. 3 shows timing diagrams explaining the operation of the device.

The pulse selector of the shortest duration contains three diffusing elements 1, 2 and 3, the four threshold elements 4-7, two formers 8 and 9 gates, two elements 10 and 11, three triggers 12, 13 and 14, three elements OR 15, 16 and 17, input 18 and output 19 tires. The input of the differentiating element 1 is connected to the input bus 18, and the input code is connected to the inputs of the threshold elements 4 and 5, the output of the threshold element 4 is connected to the input of the gate generator 8, the first output of which is connected to the first inputs of the element 10 and the trigger 12, and the second output - with the first inputs of the element 11 and trigger 13, the second input of which is connected to the first input of the element OR 15 and the output of the element 11, the second input of which is connected to the output of the threshold element 5 and the second input of the element 10, the output of which is connected to the second inputs of trigger Era 12 and the OR 15 element, the output of which is connected to the input of the gate generator 9, the first output of which is connected through the series-connected differentiating element 2 and the threshold element 6 to the first input of the OR element 16, and the second output through the series-connected differentiating element 3 and the threshold element 7 is connected to the second input element OR 16, the output of which is connected to the first input of the trigger 14, the output of which is connected to the transceiver bus 19,

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and the second input with the output of the RShI element 17, the first input of which is connected to the output of the trigger 12, and the input, to the output of the trigger 13.

The formers 8 and 9 contain serially connected input 20 of the former, the first one-shot 21, delay element 22, element 23, the second one-shot 24. The input of the driver 20 is connected to the second input of the element 23, the output of the one-shot 21 is connected to the first 25 exit of the gate former, and the output of the one-shot 24 is connected to the second 26 output of the gate driver.

The device works as follows.

In the initial state on the bus 18, the outputs of the formers 8 and 9, the triggers 12, 13 and 14 and the bus 19 of the device, there are no signals. The sequence of selectable pulses from the bus 18 is fed to the input of differentiating element 1 (FIG. 2, a), which generates short impulses of positive (negative) polarity on the front (rear) front of the input pulses, which are fed to the inputs of threshold elements 4 and 5 ( Fig. 2 b). Threshold elements 4 and 5 are triggered by pulses of positive and negative polarity, respectively, and short impulses of positive polarity are produced on their outputs. Thus, at the output of the threshold element 4, a sequence of short is formed. pulses coinciding in time with the leading edges of the pulses on the bus 18 (FIG. 1c), and at the output of the threshold element 5, a sequence of short pulses coinciding in time with the falling edges of the input pulses (FIG. 2g).

The pulses from the output of the threshold element 4 are fed to the input of the imaging unit 8 “The imaging unit 8, when short impulses arrive at its input, generates at its first or second outputs a gate pulse of a given duration t. In this case, if the time interval between the arrival and the previous pulses exceeds t, then the selector pulse is formed at the first output of the driver, if it does not exceed, then at the second one.

The strobe pulse formation is carried out as follows. In the initial state, the signals at the outputs

single vibrators are absent. When the first short pulse arrives at the input 20, the one-shot 21 produces a strobe pulse of duration t, which is fed to the first output 25 of the driver and to the input of the delay element 22. The pulse from the output of the one-shot 21, delayed by the delay element 22, arrives at the first input of the element 23. The delay time is chosen 1.5-2 times longer than the duration of short pulses from the outputs of the threshold elements 4 and 5. Therefore, the first pulse with input 20 to the output element And 23 does not pass. The same thing happens when the next pulses arrive at the input 20 if their time shift relative to the preceding ones exceeds t, since in this case the one-shot 21 returns to the initial state by the time these pulses arrive. If this shift does not exceed i, then the one-shot 21 by the time of arrival of the next pulse to the input 20 does not have time to return to the initial state and does not react to the incoming pulse. However, in this case, at the first input of element 23, there is a permitting signal from the output of delay element 22, the pulse from input 20 through element 23 passes to the input of one-shot 24, and the last produces a gate pulse of duration I, which enters the second output 26. Thus, in any case, when short pulses arrive at the input 20 of the imager, a strobe pulse of duration t is formed at its first (Fig. 2d) or second (Fig. 2c) output.

The pulses from the output of the threshold element 5, coinciding in time with the falling edges of the input pulses, arrive at the inputs of the And 10 elements (Fig.2 :) “;) and 11 (Fig. 2i), if the second inputs of these elements receive the enabling signals from the outputs the driver 8, which is possible only in the case when the duration of the input pulse, with the falling edge of which coincides in time, the pulse at the output of the threshold element 5, does not exceed i. Otherwise, by the time of the formation of the rear edge of the input pulse, the strobe pulse is finished and there are no enable signals at the second inputs of the And 10 and 11 elements.

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Under the action of 11 pulses from the outputs of the elements 10 and 11, the triggers 12 and 13 are set to the opposite state. Triggers 12 and 13 are reset to the initial state at the end of the pulses in the gate from the outputs of the former 8. If triggers 12 and 13 are in the initial state, then they do not change their state under the action of the gate pulses.

As a result, at the outputs of the flip-flops 12 and 13, a sequence of pulses is formed, the back edges of which are shifted in time by the value of i relative to the leading edges of the input pulses, whose duration does not exceed t (Fig. 2j, K, respectively). The pulses from the outputs of the triggers 12 and 13 through the element OR 17 arrive at the first input of the trigger 14 (Fig. 2 .l). Thus, a sequence of pulses is formed at the first input of the trigger 14, the back edges of which are shifted by the time L relative to the leading edges of the input pulses of duration not more than t.

The pulses from the outputs of the elements And 10 and 11, coinciding in time with the falling edges of the input pulses of the duration, through the element

 no more than L

CRT 15 postayuyut to the input of the shaper 9 (Fig. 2. -). Shaper 9 when short pulses arrive at its input from the output of an element OR 15

 similarly to the shaper 8, it produces at its first and second outputs: strobe pulses with a duration of (fig.2i, 0, respectively). The back edges of the strobe pulses from the output of the imaging unit 9 using differentiating elements 2 and 3 and threshold elements 6 and 7, operating ayologically with differentiating element 1 and threshold element 5, generate short pulses of positive polarity, which through the element OR 16 are fed to the second input trigger 14 (Fig. 2p). Thus, a sequence of short pulses is formed at the second input of the trigger 14, shifted by time i with respect to the falling edges of the input pulses with a duration of no more than t. By the back edges of the pulses from the first input, the trigger 14 is set to the state opposite to the initial one, and by short pulses from the second input to the initial state.

As a result, at its output, and consequently, on the selector bus 19, a sequence of pulses is formed that repeats the original one, with the exception of pulses, the duration of which is longer than the specified one (Fig. 2p).

Thus, this pulse selector of the minimum duration, in contrast to the known, allows

arbitrary impulse AFTERNO-

Select the pulses, the duration of which does not exceed the specified one, regardless of whether the interval between the front (rear) fronts of the original pulse sequence exceeds the specified duration of the pulses.

Claims (2)

1. Pulse selector of minimum duration, containing the first differentiating element, the input of which is connected to the input bus, the first and second threshold elements, the inputs of which are connected to the output of the differentiating element, and the first and the first trigger connected in series, the second input of which is connected to the first input of the first element AND, characterized in that, in order to increase the reliability of selection by providing the possibility of selecting less than a predetermined duration from a sequence of pulses by an arbitrary duration and an arbitrary interval between them, two gate formers, the second element And, the second and third, /, the differentiating elements, the third and fourth threshold elements, the second and third triggers, the first, second and third elements of the LII, whereby the entrance Q 0 five five The first gate driver is connected to the output of the first threshold element, the first output is from the first input of the first element I, and the second output is connected to the first inputs of the second element And and the second trigger, the second input of which is connected to the first input of the first RSII element and the output of the second element And, the second input of which is connected to the output of the second threshold element and the second input of the first element I, the output of which is connected to the second input of the first element OR, the output of which is connected to the input of the second gate driver, the first The output of which is through a series-connected second differentiating element and a third threshold element connected to the first input of the second element OR, and a second output through a series-connected third differentiating element and a fourth threshold element connected to the second input of the second OR element, the output of which is connected to the first input of the third trigger whose output is connected to the output bus, and the second input is connected to the output of the third element OR, the first input of which is connected to the output of the first trigger, and the second input is connected to you by the second trigger. 2. The selector of claim 1, about tl and - the fact that the gate driver contains serially connected first one-shot vibrator, delay element, And element and second one-shot, and the input of the first one-shot is connected to the input of the gate former and the second input element exit - with the first code of the gate driver, the second output of which is connected to the output of the second one-shot. and tt p gp pn P Editor M.Tovtin Compiled by A.Kartsev Tehred I. Veres Proofreader T. Kolb Order 2296/57 Circulation 816 Subscription VNIIPI USSR State Committee for inventions and discoveries 113035, Moscow, Zh-35, Raushsk nab., 4/5 Production and printing company, Uzhgorod, Projecto st., A P -S Jl L P L A AND -t t -t t t -t t -t -t -t t -t t t t t (pt / g. J