SU911717A1 - Pulse recurrence period discriminator - Google Patents

Description

: The invention relates to a pulse technique and 8 different radio devices can be used.

The pulse selector is known, which contains a pulse former, a pulse counter, triggers, equivalence blocks, AND, OR elements and a counting unit {ll The disadvantage of this device is low noise immunity.

The closest to the proposed one is a pulse selector according to the following period, containing two input matching elements, one of the inputs of which is connected to the input bus, the other inputs are connected to the inverse output of the counter 1pulses. directly and via an inverter, and the outputs - to the inputs of the first trigger, the direct output of which is connected to the control input of the-mentioned impulse counter: the counting input of which is connected via a frequency divider to the clock pulse generator, two additional pulse counters whose outputs are connected with the first inputs of blocks of equivalence, the second inputs of which are connected.

The main inputs of the pulse counter are connected to the output of the clock pulse generator through the corresponding frequency dividers, while the outputs of the equivalence blocks are connected to the trigger inputs of the strobe formation, the output of which is connected to the control

10 to the input of the second additional counter and to one short-circuit input of the output element I, the second input of which is connected to the input bus, the inverse output of the second additional

15 pulse counter is connected to the first input of the second trigger, the output of which is connected to the control INPUT; the first additional pulse counter, and the second input to the output of the matching element, two inputs of which are connected to the inputs of one of the input matching elements, and the third input with the inverse output of the first trigger 23

25 The disadvantage of the known device is low noise immunity.

The purpose of the invention is to improve noise immunity.

The goal is achieved

30 in that - that in the pulse selector by the following period, containing the first pulse counter, the output of which is connected to the first input of the equivalence block, the second input is connected to the output of the second pulse counter and the first input of the second equivalence block, the trigger, the output of which is connected to the first input And, the second input of which is connected to the input bus and the clock pulse generator, is introduced a code converter, a delay element, a pulse generator and OR elements, the first input of the first of which is connected to the second control input of the clock generator, the second input with the pulse driver output and the first trigger input, and the output with the output terminal of the second pulse counter, the counting input of which is connected to the output of the clock generator, the second control input of which is connected to the output of the second a block of equivalence and the first input of the second OR element, the second input of which is connected to the output of the delay element, whose input is connected to the output of the AND element, and the output is connected to the trigger input, while the input of the first counter The pulses are connected to the installation bus, and the output is connected to the input of the code converter, the output of which is connected to the second input of the second equivalence block. The drawing shows the structure of the device. The device contains counters 1 and 2 pulses, blocks 3 and 4 of equivalence, converter 5 codes generator 6 clock pulses, elements 7 and 8 OR, pulse shaper, trigger 10, delay element 11, element 12 I. Digits 13 - 15 denote respectively input , installation and output bus device. The device works as follows. Before the start of the selection, the code 1 on the bus 14 records the period code of the pulse sequence to be extracted from the signal applied to the input of the selector. The period code from the output of counter 1 is fed to the inputs of block 3 and converter 5. Transducer 5 performs conversion (scaling) of the period code, i.e., is proportional to its reduction to the value required to set the duration of the selection gate. From the output of converter 5, the strobe code is transmitted to the first inputs of block 4. The second inputs of block 2 and 4 are supplied with current values from counter 2, which counts the generator b pulses. At the moment of equality of the codes of counter 2 and converter 5, block 4 generates a pulse that enters one of the control inputs of the generator 6, and also, having passed element 8, triggers trigger 10, which closes element 12. Generator b, supplemented by an internal switch (in the drawing not shown, T has two stable states. When applying control pulses to one of its inputs, it generates pulses of the main frequency, to the second one, pulses of double frequency, and alternately applying control pulses to various inputs gives out Therefore, the pulse of the block 4 either switches the frequency of the generator 6 or leaves it unchanged if this pulse is not preceded by a pulse through another input of the generator 6. Continuing to count the clock pulses of the generator b, meter 2 equal to the period of the selected pulses, generates a code equal to the counter code 1, i.e. the code that determines the set period of the selected pulses. Block 3 generates a pulse of equality of codes, which is extended by shaper 9 and transmitted through element 7 to zero the input of counter 5, as well as to the first input of trigger 8, which forms the beginning of the strobe, opening element 12. Counter 2 after zeroing, first read and at the second equality of the codes of the counter 2 and the converter 5 block. 4 is again triggered and through element 8, flip-flop 10, which forms the end, closing element 12. Continuing to work without input signals, the selector periodically generates selector gates, the frequency of which is determined by the code recorded in counter 1, and the duration by converter code 5. The duty cycle of strobe pulses is kept constant, regardless of the period they follow. If the first input pulse of the signal does not enter the strobe / it does not pass through the element 12. This pulse through the element 7 zeroes the counter 2 and, acting on the second input of the generator 6, translates the latter into the mode of generating the doubled frequency of the clock pulses and, therefore, Counter 2 starts counting twice as fast. After a time determined by the converter code 5. and the generator frequency b, the block 4 will operate, which

will transfer the generator 6 to the main mode, the position of the trigger 10 does not change, and the counter 2 switches to the counting mode with a normal and not doubled tempo. By switching the generator 6 to the mode of generating pulses of doubled frequency at the moment of arrival of the input pulse, the selector forms a anticipating system whose middle coincides with the expected time of the leading edge of the next pulse. In case of equality of the counter codes 1 and 2, the block 3 is triggered, the output impulse of which through the driver 9 has zeroed the counter 2, triggers the trigger 10, which, in turn, opens element 12.

The second input pulse enters the strobe and passes through element 12 if the time interval between the input pulses corresponds to the code recorded in counter 1, with a tolerance on the width of the strobe. The pulse from the output of the element 12, which is the output of the selector, enters the input of the element 11, is delayed therein by the amount of the required output pulse duration and through the element 8 the trigger 10, the locking element 12, overturns. On the other hand, the second input pulse of the signal has turned the counter 2 and switches the generator 6 which begins to generate clock pulses with doubled frequency until the moment when block 4 again triggers, etc.

If the second input pulse arrives earlier or later than the time specified by counter 1, then it cannot pass through element 12, and the rest of the process in the selector proceeds as described.

If there is a gap in the input sequence of selectable pulses for an integer number of periods, the selector continues to form selector gates while preserving the phase relationships, so that the pulse coming after the break falls into the middle of the gate and passes to the selector output, ensuring that the input information is preserved.

Due to the elements introduced and the connections between them, the interference immunity of the device is affected.

Claims (2)

1. USSR author's certificate  4,71663, class I 03 K 5/18, 07/17/73. 2. The author's certificate of the USSR JQ 490262, cl. H 03 K 5/18, 1973.