SU1228252A1 - Device for generating difference frequency pulses - Google Patents

Abstract

The invention relates to automation and computer technology and can be used to select a small frequency difference between two pulse sequences, for example, in control circuits of redundant highly stable pulse generators. The purpose of the invention is to increase the resolution and accuracy of the formation of differential frequency pulses. The device contains elements HE 3, 4, elements AND 5-9, elements OR 10-12, shapers 13, 14 and 16 of the falling edge of the pulse, shaper 15 of the leading edge of the pulse, triggers 17-20, selectors 21 and 22 of the pulses of the minimum duration. Additional introduction into the device of three triggers, four pulse formers, two pulse selectors of the minimum duration and two elements of IL, ensures stable operation of the control trigger, and also prevents the passage of spurious pulses to the output triggers and, accordingly, to the device outputs in the presence of frequency deviations in two compared sequences . 3 il. N9 S 00 to SP to

Description

four

The invention relates to automation and computing and can be used to isolate ma

four

frequency differences of two pulse sequences, for example, in scams of control of operation of redundant highly stable pulse generators.

The purpose of the invention is to increase the resolution and accuracy of generating differential frequency pulses by ensuring the stable operation of the control trigger, and also by eliminating the passing spurious pulses on the output triggers and, accordingly, on the outputs of the device in the presence of frequency deviations in two compared sequences x

Fig. 1 shows a block diagram of a device for generating differential frequency pulses; 2 and 3 are diagrams of his work.

A device for generating differential frequency pulses contains input buses 1 and 2, elements HE 3 and 4, elements AND 5-9, elements IHSH 1 11, 12, drivers 13 and 14 of the rear edge of a pulse, 15 - the front of a pulse, 16 - the front edge pulse triggers 17-20, selectors 21 and 22 pulses of the shortest duration, output buses 23 and 24. Pulse selectors 21 and 2-2 contain a delay element and an element I, one of which is connected to the input of the selector directly, and the other through a delay element . The output of the AND element is the output of the selector.

The input bus 1 is connected to the first input element AND 5, the input element NOT 3, the first inputs of the elements AND 9 OR 10 and the input of the shaper 14 of the rear edge of the impulse. The output of the element NO 3 is connected to the first input of the element AND 6, the second input of which is connected to the input bus 2, to the input of the element NO 4, to the second inputs of the elements AND 9, OR 10 and the input of the rear edge generator 13. The output of the NOT 4 element is connected to the second input of the AND 5 element. The output of the AND 9 element is connected to the input of the front-edge pulse generator 15, the output of which is connected to the first input of the OR 12 element and the first input of the trigger 17, whose direct output is connected to the first input of the AND element 7. The output element OR 10

connected to the input of the backplane of the pulse front edge 16, the output of which is connected to the second input of the elec. ment And 7 and the second input of the trigger 17, the inverse input of which is connected to the first input of the element And 8 and to the third inputs of the elements And 5 and 6. The fourth inputs: the elements And 5 and 6 are connected respectively to the inverse

and direct outputs of the trigger 18, the input of which is connected to the output of the element OR 12, the second input of which is connected to the output of the element And 7, and the third input - to the output of the element And 8, the second

5 input of which is connected to the output of the element OR 11 connected by inputs with codes of drivers of 13 and 14 pulses,. The outputs of the elements And 5 and 6 are connected through selectors 21 and 22

0 pulses of minimum duration to the first inputs of flip-flops 19 and 20, respectively. The second inputs of the flip-flops 19 and 20 are combined and connected to the output of the driver 16 pulses.

5 The inverse output of the trigger 19 is connected to the third inputs of the elements 7 and 8, the fourth inputs of which are connected to the inverse output of the trigger 20. The direct outputs (first and second) of the triggers 19. and 20 are respectively the buses 23 and 24,

The state of the triggers, in which at the direct output the resolving (high) potential, is taken as a single one, and the state in which, at the inverse output, the resolving potential, is zero.

The device works in the following way.

In the initial state, the triggers 17, 19 and 20 are reset to a zero state by a signal (not shown). Trigger state 18 is arbitrary, Element I 5 is closed at the first input of LOW (forbidden) bus potential 1 and is opened at the second and third inputs with high output potentials of the element HE 4 and inverse output trigger 17, Element I 6 is closed at the second input low potential of the tire 2 and is open on the first and third inputs with high output potentials of the HE 3 element and inverse trigger output 17 "At the fourth inputs of the AND 5 and 6 elements, the potentials depend on the condition of the trigger 18, the AND 9 and OR 10 elements are closed at both inputs by low sweats ntsialami input buses 1 and 2, an OR gate 11 is closed

0

five

0

S

0

3

Both inputs have low output potentials of the formers of 13 and 14 pulses. Element And 7 is closed at the first and second inputs by low potentials of the direct output of the trigger 17 and the output of the pulse shaper 16, respectively, and is open at the third and fourth inputs by the high potentials of the inverse outputs of the flip-flops 19 and 20, respectively. Element And 8 is open at the first, third and fourth inputs of the high potentials of the inverse outputs of the trigger 17, 19 and 20, respectively, and is closed at the second input of the low output potential of the element OR 11.

Consider the operation of the device for a slash when, of two compared pulse frequency sequences that are close together, the frequency of the second sequence slightly exceeds the frequency of the first sequence. If at the time of the occurrence of the first positive pulse on the input bus 1, the trigger 18 was in the unit state (see the diagram of voltages And 1, And 18 in Fig. 2), then the element And 5 remains closed at the fourth input with a low potential of the inverse output of the trigger 18 for the duration of the input pulse. At the same time, the element OR 10 is opened, the output signal of which is fed to the input of the driver 16 pulses. At the end of the input pulse on bus 1 (along the trailing edge of the pulse), positive pulses are generated at the outputs of the formers 14 and 16. The impulse from the output of the imaging unit 16 is supplied to the second input of the element I 7, which is closed at the first input by a low potential of the direct output of the trigger 17, and to the second inputs of the trigger 17, 19 and 20, confirming their zero state. The pulse from the output of the shaper 14 through the element OR 11 enters the second input element AND 8 and opens it. The signal from the output of the element And 8 enters through the element OR 12 at the input of the trigger 18 and switches it on the leading edge to the zero state (see the voltage diagram of And 14, And 8, And 18 in figure 2).

With the occurrence of the first positive impulse on the input bus 2 (see diagram AND 2 by 4 d.2), the element 6 remains closed at the fourth input by the low potential of the trigger output 18 for the duration

282524

input pulse. At the end of the input pulse on the bus 2 (at the trailing edge of the pulse), pulses are generated at the outputs of the formers 13 and 16.

5 The impulse from the output of the imaging unit 16 again confirms the zero state of the triggers 17, 19 and 20, and the impulse from the output of the imaging device 13 through the elements OR 11, AND 8, OR 12 goes to

o trigger input 18 and switches it to a single state (see voltage diagram of And 13, And 8, And 18 in figure 2).

Similarly, at the end of the second pulse on the input bus 1 trigger 18

5 switches to the zero state, and at the end of the second pulse on the input bus 2, to the single state. Thus, at the end of each input pulse on bus 1 (by

Q trailing edge) a pulse is formed at the output of shaper 14, and at the end of each input pulse on bus 2 a pulse is formed at the shaper 13 output. At the end

5 each pulse (at the falling edge) at the output of the element OR 10 a pulse is formed at the output of the imaging unit 16.

If the input signals are received separately (not overlapping in time), the pulse from the outputs of the formers 13 or 14 through the OR 11 element opens the AND 8 element, the output signals of which are fed through the OR element 12 to the input of the trigger 18 and switch it to opposite states . In this case, the pulses from the output of the imaging unit 16 arrive at the second input of the element And 7, closed at the first input, and confirm the zero (initial) state of the triggers 17, 19 and 20. The elements And 5 and 6 remain closed at the corresponding time moments fourth low potential inputs from trigger outputs 18.

If by the time the first positive pulse appears on the input bus 1, the trigger 18 was in the zero state, then the input pulse opens element 5, the output signal of which goes through the pulse selector 21 of the minimum duration to the first input of the trigger 19 and switches it to one the In this case, the low potential of the inverse output of the flip-flop 19 closes the elements I 7 and 8 on the third inputs, therefore on the end. Institute of input pulse output name- 5

0

five

0

the pulse of the shaper 14 will not pass to the output of the element 8, and the output pulse will form 16 will not pass to the exit of the element of the 7. 7. At the end of the pulse at the output of the shaper 16 (on the falling edge) will switch to the zero (initial) state trigger 19 and the zero state will be confirmed triggering triggers 17 and 20,

Thus, the first pulse from the input bus 1 will pass to the first output of the device, and the trigger .18 will remain in the zero state.

With the appearance of the first pulse on the input bus 2, the element And 6 remains closed by the low potential of the direct output of the trigger 18, and at the end of the input pulse, the pulse formed at the output of the imaging unit 13 switches the trigger 18 to one state.

Similarly to the indicated power supply, at the end of the second pulse on bus 1, the trigger 18 switches to the zero state, and at the end of the second pulse on bus 2 - to the unit one. In this case, elements 5 and 6 for the duration of the input pulses will be closed due to the presence at appropriate fourth time inputs of low potentials from the outputs of the trigger 18. Subsequently, with alternate, separate input pulses, the device will work in a similar way.

If, before the end of the pulse on bus 1, there is a pulse on bus 2 (in the diagram of FIG. 4, one third of the pair of input pulses), then element 9 opens, the output of which triggers the front edge pulse generator 15. At the same time, on the leading edge of the pulse from the output of the imaging unit 15, the trigger 17 and the trigger state 18 are switched to one state (see voltage diagram I1, I2, I9, I15, I17, and 19 in Fig. 2). When switching to one state, the trigger 17 opens element 7 and the first input element 7 and closes the third input elements AND 5, 6 and the first input element AND 8. At the end of the pulse, bus 1 starts the driver 14, the output of which does not pass at the output of the element And 8, and at the end of the impulse on the bus 2, the former 13 and 16 will work. The pulse from the output of the former 13 also

passes to the output of the element AND 8. A pulse from the output of the imaging device 16 opens the element AND 7, the output signal of which switches the trigger 18 to the unit state.

At the end of the pulse at the output of the imager 16 (on the falling edge), the trigger state 17 switches to the zero (initial) state and confirms the zero state of the flip-flops 19 and 20. At the time of the input pulses, the elements And 5 and 6 remain closed. the corresponding points in time at their fourth inputs of low potentials from the outputs of the trigger 18, and due to the presence of low potential at the third inputs from the inverse output of the trigger 17.

Thus, when the input pulses overlap in time, the control trigger 18 is switched twice. The first switching occurs when element 9 opens at the moment the input pulses begin to cross and the pulse generator 15 is started. trigger 18 and into a single state trigger 17. With this, the high potential of the forward code of the trigger 17 opens at the first input of the element And 7, low the potential of the inverse output of the trigger 17 is closed at the first input of the element And 8 and at the third inputs of the elements of the And 5 and 6. The second is switched. Trigger 18 is activated at the end of a pulse at the output of the element OR 10, when pulse shaper AND 16 is started, the output of which opens element And 7 and switches the trigger. On the falling edge of the pulse from the output of the former 16, the trigger 17 switches to the zero (initial) state and the zero status of the triggers 19 and 20 is confirmed. During the pulse on tires 1 and 2, elements 5 and 6 remain closed by low potentials arriving at the corresponding points in time from the outputs of the trigger 18 to their fourth inputs with a low potential of the inverse output of the trigger 17, arriving at the third inputs. In addition, for the duration of the input pulse on bus 1, the AND 6 element is closed at the first input

element 3, -a input pulse AND 5 is closed on the second input signal from the output element 4.

With further partial coincidence in time of the input pulses up to their complete coincidence, the circuit operates in the same way.

After the complete coincidence in time of the input pulses on buses 1 and 2, the pulses with a higher frequency in the second sequence begin to gradually outpace the pulses with a lower frequency in the first sequence. Since after the input pulses coincide completely, the trigger 18 is in the unit state and opens the 6th element at the fourth input and the appearance of the lead pulse on the bus2 opens for the time of the 6th input element, the output of which is fed to the input of the pulse selector 22 of the minimum duration. If the pulse duration at the input of the selector 22 is less than the selection threshold, then the pulse to the output selector will not pass (see the diagram of voltages I 1, I 2, I 6, I 22. on 4IG.2). With the appearance of a pulse (lagging in time), on bus 1, element 9 opens and shaper 15 starts, the output of which switches the trigger 18 to the zero state and the trigger 17 which opens to the first state. the input element is AND 7. At the end of the pulse on bus 1 and, accordingly, at the output of the element OR 10, a driver 16 is started, the output of which switches the trigger 18 to the unit state and the trigger 17 to the zero state.

Upon receipt of subsequent pairs of input pulses overlapping in time and a gradual increase in the advancing of the pulses of the first sequence of pulses of the first sequence, the device will work in the same way until the pulse width of element 6 does not exceed the selection threshold of the selector 22. After exceeding the selection threshold by the output of the selector 22 is driven by a pulse that will go to the first input of the trigger 20 and switch it on the leading edge to one, at the direct output the trigger EPA and 20 respectively

ten

15

20

25

2282528

at the second output of the device, the leading edge of the difference frequency pulse is formed (see diagrams AND 1, AND 2, And 6, And 22, and 20 in FIG. 2). When opening element 9 and 9, the trigger 15 starts, the output signal of which switches the trigger 18 to the zero state and the trigger 17 to one. When the trigger 20 switches to the single state, the low potential of its inverse output closes the elements 7 and 8 at quarter inputs, therefore the impulse from the output of the imaging unit 16 will not pass to the output of the element AND 7, as a result of which the trigger 18 at the end of the overlapping-from input pulses remains in the zero state. On the falling edge of the pulse from the output of the imager 16, the trigger 17 and the trigger 20 switch to the zero state, while the rear edge of the difference frequency pulse is formed at the output of the trigger 20 and at the second output of the device

When the next pair of input pulses arrives, if there is a pulse advance on bus 2, element 6 will be closed at the fourth input by a low potential of the direct output of trigger 18, as a result of which the differential frequency pulse at the second output of the device will be absent.

In the future, the scheme will work in a similar way until the next full coincidence of the input pulses, after which the beginning of the pulses of the second sequence of pulses of the first sequence begins and the element 6 begins to open, the duration of the output pulses will gradually increase to the value exceeding the selector selection threshold 22 pulses of the minimum duration. After the pulse duration from the output of the AND 6 element is exceeded, the selection threshold of the selector 22 again switches to one state the trigger 20, and a differential frequency pulse will again be generated at the second output of the device.

Thus, at the second output of the device, a differential frequency pulse is formed after exceeding the pulse duration from the output of the element AND 6 of the selection threshold of the pulse selector 22. In this case, the opening of the element 6 begins when

35

40

45

50

five

For the arrival of advanced pulses on bus 2 (after the preceding full time coincidence of the input pulses), the trigger 18 is in a single state. Similarly, at the first output of the device, a differential frequency pulse is formed after the pulse duration from the output of the element 5 is exceeded by the selection threshold of the pulse selector 21. In this case, the opening of the element 5 begins when, at the time of arrival of the leading pulses on bus 1 (after the preceding full time coincidence of the input pulses) trigger 18 is in the zero state.

Thus, when opening the AND 6 or 5 elements, as long as the signals from their outputs do not exceed the selection threshold of the selectors 22 or 21, the trigger 18 switches twice. This feature improves the accuracy of forming differential frequency pulses when comparing two pulse frequency sequences that are close to each other. in the presence of mutual oscillations (shifts) of the fronts of the input pulses, due to the frequency deviation in both one and the other sequences. Obviously, the mutual oscillations of the fronts of the input pulses are most significant at the instants of time when, after the complete coincidence of the input pulses, the pulses begin to gradually graduate at a higher frequency in the sequence of pulses by a smaller frequency in the sequence, and when due to the shifts of the pulses fronts A for some time, pulses of one or another sequence may be leading.

The operation diagram of the device for such a case is shown in FIG. 3, where T1 T2. From the diagram (Fig. 3) it can be seen that the trigger 18, being in the single state, after the end of the input pulses completely intersecting in time (in the diagram, the first pair of input pulses) as a result of the double switching, again appears in the single state, opening high potential of the direct output on the fourth input element And 6. Therefore, with the arrival of the second pair of input pulses, of which

825210

the pulse on bus 2 is advanced, the AND 6 element opens for an idle time. The short pulse c, the output of the element AND 6, is shorter in duration,. the selection threshold does not pass to the output of the selector 22, with the result that trigger 20 remains in the zero (initial) state (see voltage diagram I1, I2, I6, I22, I20

.JQ (in FIG. 3). Therefore, after the end of the second pair of overlapping input yoibCOBs as a result of a twofold switching, the trigger 18 again remains in the one state. If, with the stroke of the third pair of overlapping input pulses, the pulse on bus 1 turns out to be leading due to the shift of the pulse fronts due to the deviation of the first frequencies of the input sequences, then for the lead time the And 5 element remains closed at the fourth input of the low potential of the inverse output of the trigger 18, When finished the third pair of overlap

25 shchx input pulses, due to the double switching trigger 18 will again appear in a single state.

five

0

So, if, with the arrival of the fourth par 5 overlapping input pulses, the impulse through bus 2 leads, the I-6 element is disconnected, the output signal duration of which is equal to the advance one. If the lead (the duration of the output pulse of the AND 6 element) is less than the selection threshold of the selector 22, then at the end of the overlapping input pulses, the trigger 18 will again be in the same state. The device will work in the same way until the output signal of the And 6 element (the advance value) exceeds the threshold of the salekdia of the selector 22.

The selection threshold of the selectors 21 and 22 is chosen to be less than the duration of the input signals on buses 1 and 2 and more than the maximum possible data for the pulse sequence generators of the total pulse shift to different directions due to frequency deviation.

With the arrival of a pair of overlapping input pulses in advance (shift-g timing), exceeding the selection threshold (in the diagram of FIG. 3 of the first pair of input pulses), the output impulse of element And 6 passes through the selector 22, the signal of which switches over

five

0

five

eleven

the leading edge into a single state is the trigger 20, at the forward output of which the leading edge of the differential frequency pulse is formed, and the low potential of the inverse output blunts the fourth inputs of elements And 7 and 8 (see diagram And 1, And 2, And 6, And 22, and 20 in FIG. 3), wherein on the leading edge the pulse from the output of the former 15 triggers 17 to be switched to one, and the trigger 18 to the zero state, and to the falling edge of the pulse from the output of the former 16 triggers 17 and 20 in the initial state. At the output of the trigger 20, the leading edge of the differential frequency pulse will be formed. With the occurrence of a leading pulse on bus 2, element 6 will be closed with a low potential of direct output of trigger 18, etc.

Thus, after a complete coincidence in time of the input pulses, the trigger 18 will be at the time of arrival of each subsequent pair of overlapping pulses in a single state if the frequency of the second sequence exceeds the frequency of the first sequence, and in the zero state if the frequency of the first sequence exceeds the frequency of the second sequence. The change in the specified switching regularity of the trigger 18 occurs after the separation of the differential frequency pulse at one of the device outputs and a single switching of the trigger.

Claims (1)

Invention Formula A device for generating differential frequency pulses containing a trigger, five AND elements, an OR element and two NOT elements, the first input bus is connected to the first input of the first AND element and through the first element to the first input of the second And element, the second input of which is connected to the second the input pshne and through the second element NOT to the second input of the first element I, the trigger input is connected to the output of the element OR, the first and second inputs of which are connected to the outputs of the third and fourth elements I, O tl and - 2825212 In order to increase the resolution and accuracy of forming differential frequency pulses, three triggers, four pulse makers, two pulse selectors of the minimum duration and two OR elements were additionally introduced, the first inputs of the fifth AND element, the first additional element OR and the input of the first pulse generator are combined and connected to the second input bus, the second inputs of the fifth element AND, the first additional 15 element OR and the input of the second pulse generator bedineny and connected to the first input bus, the output of the fifth AND gate is connected to the input of the third pulse shaper 20 whose output is connected to the third input of the OR gate and to the first input of the first further flip-flop, a first output connected to a first input of the third AND gate, 5 and the second output - with the first input of the fourth element I and with the fourth inputs of the first and second elements I, the outputs of which are connected respectively via the first and second pulse selectors of the minimum duration to the first inputs of the second and third additional triggers, the first outputs are connected to the first and the second output buses, and the second inputs - with the output of the fourth pulse shaper, with the second input of the first additional trigger and with the second input of the third element I, the input of the fourth form the pulse former is connected to the output of the first additional element OR, the outputs of the first and second pulse formers are connected via the second additional 5 element OR to the second input of the fourth element AND, whose third input is connected to the third input of the third element AND and to the second output of the second additional trigger, the fourth outputs of the third and fourth elements AND are connected to the second output of the third additional trigger, while the third inputs of the first and The second elements And are connected respectively to the second and first outputs five trigger 2. U1 IL „r,, Tr FIG. 3 Compiled by V.Gerasimov Editor M.Tovtin Tehred I.Veres Corrector M.Demchik Order 2296/57 Circulation 816 Capital VNIIPI USSR State Committee for inventions and discoveries 113035, Moscow, Zh-35, Raushsk nab., 4/5 Production and printing company, Uzhgorod, st. Project, 4