SU871324A2 - Pulse selector - Google Patents

Description

(54) PULSE SELECTOR

I

The invention is hygienic to the technique of ikshulsoy and can be used in p. Diotechnical devices for allocating "VII of a periodic pulse sequence against the background of interference.

Basically auth. St. No. 785986 describes a pulse selector containing serially connected devices for extracting the first pulse, an OR element, j a delay element, a gate driver and an AND element, the second input of which is connected to the input bus and the first input of the division of the first pulse, the second input of which is connected to the second, 5 eye input of the delay element and the output of the counting device, the first input of which is connected to the first input of the element AND, and the second, input to its output, output bus, the second input of the element jg OR and the second input of the forms the gate operator, the second output of which is connected to the third input of the element).

The disadvantage of this device is low reliability selected in terms of interference.

The purpose of the invention is to increase the reliability of selection in interference and in the presence of gaps of pulses.

This circuit is achieved by the fact that in the impedance separator according to ed. St. No.785986, containing a first pulse extraction device connected in series, an OR element, delay elements, a gate forming and an AND element, the second input of which is connected to the input bus and the first input of the first pulse separation device, the second input of which is connected to the second input of the delay element on the output of the counting device, the first input of which is connected to the first input of the AND element, and the BTOpdS input to its output, the output bus, the second input of the OR element, and the second input of the gate generator, the second output of which It is united with the third input of the OR element, the gate driver contains an additional AND element and successively connected additional OR elements and a delay element and a pulse counter, the first input of the pulse counter is also connected to the first input of the additional AND element, the second input from the output of the delay element, the third the input of the OR element and the first input of the additional element OR, the third input - with the additional output of the counting device, the fourth input - from the output of the AND element, and the output - with the first input of the element This And and the second input of the additional element And, the output of which is connected to the second input of the additional element OR, On. 1 shows the structured electrical cxe.vsa of the s-slector of pulses; in fig. 2 - time diagrams. The pulse selector contains the device 1 selection of the first pulse, the element OR 2, the delay element 3, the element OR 4, the additional delay element 5, the additional element AND 6, the additional 7 pulses, the counting device 8, the element AND 9, the input bus H, the output bus 11 , odori gaiter 12 gates. Delay item 3 should not be blocked from restarting and must be re-read each time it is started. There are no restrictions on the choice of delay element 5. The remaining elements of the device are potential type logical elements. Device 1, the element OR 2, the delay element 3, the element OR 4, the delay element 5, the counter 7 are connected in series. The first input element AND 9 is connected to the bus 1O and the input of the device 1. The output of the delay element 3 is connected only to the second inputs of the element OR 2 and the counter 7, the third input of which is connected to the first output of the counting device 8, the second output to the one with the reset inputs device 1 and the delay element 3. The third input of the OR element, 2 is connected to the bus 11 and the reset inputs of the counter 7 and the counting device 8, the output of which is connected to the output of the counter 7, the first input of the element And 6 and the second input of the element 9. The output of the element Delay 5 plug to a second input AND gate 6 whose output is connected to a second input of the OR gate 4. The pulse selector operates as follows. The first pulse of the sequence is extracted by device 1 and through the element OR 2 starts the element of delay 3 (Fig. 2 |;), which delays the pulse of the magnitude of T-i. where T is the period of the following selectable pulses, t is the width of the strobe. Consequently, the temporal pulse position at the output of the delay element 3 corresponds to the beginning of the strobe formation for the second pulse of the sequence. The pulse from the output of the delay element 3 through the OR element 2 restarts it (Fig. 2b and c). This pulse through the element OR 4 launch.et delay element 5 (Fig. 261) and, in addition, entering the counter 7, rewrites in it the reverse binary code of the number of gaps. This code goes to counter 7 from the counting device 8, which is reset to zero in the initial state. According to that, code 11 ... 1 (all units) will be written into counter 7. The output of the counter is the output of its last bit, therefore, when writing code 11 ... 1 at its output through Wits 1 (Fig. 2), the opening elements AND 6, 9. The output pulse, entering the strobe, passes through element AND 9 to bus 11 (Fig. 2 (y) and resets the counter, strobe break), and also through element 2 restarts delay element 3 (fig. 2 b). The latter starts counting the delay anew. Delay element 5 delays signal on the value of T. Therefore, after its launch, the delay element 5 emits a pulse (Fig. 2 c3 and e), co (In Fig.2 {the dotted line indicates the full width of the row.) However, this pulse, arriving at the counting input of counter 7, cannot transfer its last bit, since the counter returns zero to a selectable pulse. the counter does not reflect on the further operation of the device, at the beginning of the formation of each strobe, the counter is set to a state that corresponds to the code received from the recalculated device 8. The recalculation device changes its state The gate is rejected into the signal by a signal from Shiya 11. Therefore, in the absence of gaps in the selectable succession of pulses, the recalculated device to the beginning of the formation of the strobe is always in the state O and the processes discussed above are resumed for each subsequent selected pulse.

If there is no selectable pulse in the strobe (when a pulse is passed), the signal from the output of delay element 5 goes to the counting input of counter 7 and overflows it, which leads to the removal of the last discharge of counter 7 from the output (since it has code 11 ... 1) and closing element AND 9. Thus, when a pulse is passed, the strobe is formed completely (i.e., width f). FIG. 20 expected moments of arrival of the missed pulses are marked by a dotted line.

Since the counter 7 has a certain response time, the pulse from the output of the delay element 5 has time to pass through the element 6 to start the same delay element 5. Therefore, after time f after the end of the strobe, the delay element 3 reappears the pulse (Fig. 2d not) will pass through the AND 6 element, since the AND 6 element is already closed (Fig. 2), since the counter 7 is already installed at the counting input to the zero state.

On a predetermined front of the strobe, the enumerator 8 changes its state, and the non-M-binary code of the number 1, corresponding to the omission of one selection pulse, appears in the non-MM.

Since there is no restarting of delay element 3 when skipping a selectable pulse, it counts the time T - - counting from the beginning of the previous strobe, and UI searches for a pulse at a time ahead of the expected pulse arrival time by the value of f, which corresponds to the beginning of the strobe formation at width 2 (Fig 2b). The impulse from the output of the rear wheel element 3 triggers this delay element 3 through the element OR 2, starts the delay element 5 through the element OR 4 and rewrites the return code from the counting device 8 to the counter 7.

The signal from the output of the last digit of counter 7 will open elements 6 and 9. To overflow the counter 7, in which the reverse binary code of number 1 is installed, two pulses are required at its counting input. Delay element 5 through the time and after its launch starts the first pulse, which is fed to the counting input of counter 7, and through the open element 6 and the element OR 4 again starts the element of delay S, which counts the time t and

the second. the signal from its output overflows counter 7, which leads to the removal from the output of the last discharge of counter 7 and the closure of element 6. And in a IMM manner, during the second skip of a selectable pulse, a strobe 21 wide is formed; . The reasons for the appearance at the output of the delay element 5 an extra pulse (Fig. 2 e) are given above.

At the end of the strobe in the scaling device 8, the binary code of the number 2 will appear, corresponding to the omission of two selectable pulses in addition.

The next impulse from the delay element 3 will arrive at the moment of time corresponding to the beginning of the formation of a strobe 3 T wide. This impulse rewrites the counter code of the number 2 from counter 11 from the counting device 8, as a result of which the strobe 3 wide begins to form. FIG. 2 shows the case of a selective pulse entering this strobe. When this is done, the strobe is terminated and the counting device 8 is reset.

The maximum allowable number of gaps of selectable pulses can be any equal to ω. This number determines the coefficient of the scaling device 8. If t + 1 skips the selectable pulses, then a pulse appears at the other output of the scaling device 8, which resets the device 1 and the delay element 3. After that, the first input pulse passes through the device 1 and through the element OR 2, starts the element of delay 3, thus starting the pulse selector

Counter 7 and scaler 8 should have the number of bits Pr (e 3kf «m) i + 1, i.e. one bit more than required for counting vn pulses. This is necessary so that when writing to the counter 7 of any number smaller than hj, the last digit of the counter 7 is always transferred from 0 to 1, ensuring the beginning of the strobe formation.

The case of two gaps in the selectable sequence of pulses is considered. In the general case, after V skips (where 1 is any number) in the scaling device 8 there will be a binary code of the number i. The reverse code of this number, rewritten into counter 7 at the beginning of the next strsb formation, will cause this strobe to form (i 1) - v ..

The selector forms all gates so that the expected arrival times of the selected pulses correspond to the midpoints of the gates not affected by the width of the latter. Thus, in this pulse selector, high reliability of selection is achieved, since the selectable pulse breaks the gate, the interference, arriving after it, will not pass to the output of the device. In addition, this selector selector provides increased selection reliability in the presence of gaps, since if for gated pulses received without gaps, the probability of their entering a strobe width T is J, then for a pulse received after 1 gap, it does not decrease, since for a pulse arriving after the gaps, the strobe expands to the value (i + l). Therefore, the probability that any pulse of a sequence enters the strobe is constant and equal to CJ ,. Consequently, in this case, the reliability of selection in the presence of i gaps of selectable pulses is twofold (i + 1) times in comparison with known devices. 8 4 8 Fo rmu l a and 3 o b ete n and Pulse selector according to ed. St. No. 785986, from the fact that, with the purpose of ensuring reliable selection under conditions of interference and in the presence of pulses, the gate former contains an additional AND element and sequentially connected additional OR element the delay element and the pulse counter, the first input of the pulse counter is also connected to the first input of the additional element AND, the second input to the output of the delay element, the third input of the OR element and the first input of the additional OR element, the third input to the additional output ohm scaler, a fourth input the output of the AND and the output - to the first input AND gate and a second input of the additional AND gate whose output is connected to the second input of the additional OR element. Sources of information taken into account in examination 1, USSR Author's Certificate No. 785986, cl. H 03 K 5/18, 04.O1.79 (prototype).

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Claims (1)

Formula of Invention Pulse Selector by Auth. St. ¹ No. 785986, due to the fact that, in order to increase the reliability of selection under interference conditions and in the presence of gaps in pulses, the gate generator contains an additional element AND and additional elements OR connected in series and a delay element and a pulse counter, wherein the first input of the pulse counter is also connected to the first input of the additional AND element, the second input to the output of the delay element, the third input of the OR element and the first input of the additional OR element, the third input to the additional output recounting device, the fourth input with the output of the AND element, and the output with the first input of the AND element and the second input of the additional AND element, the output of which is connected to the second input of the additional OR element.