SU811496A1 - Selector of pulses by duration - Google Patents

Description

the second logic element is NOT, two delay elements and two / 5 flip-flops, R-Bxofl, are introduced, the first of which is connected through the first delay element to the first output of the input pulse shaper and the 5-input of the second 5-flip-flop, which is input through the second delay element connected to the second output of the input pulse generator and the 5-input of the first 5-flip-flop, the outputs of the first and second U-5-flip-flops are connected respectively to the inputs of the first and second logical elements NOT, the output of the first of which is connected to the fourth input of one output and the output of the second logic element is NOT connected to the third input of the first output four-input logic element AND-NOT, and the fifth inputs of the second, third five-input element AND-NOT and the fourth input of the first four-input element AND-NOT connected to the first output of the input pulse generator, the second output of which is connected to the fifth input of the first five-input I-NE element and to the fourth input of the second four-input AND-NOT element.

The drawing shows a block diagram of the selector pulse duration.

The pulse selector contains the pulse former 1, the AND – NE logic gates 2–8, the HE 9, 10, // logic gates (- triggers 11–14, forming the first pulse counter, // (- triggers 15–17, forming the second pulse counter , RS triggers 18, 19, delay elements 20, 21, multivibrator 22, amplifiers-formers 23-27.

The pulse selector works as follows.

The input of the imaging unit 1 receives a sequence of pulses modulated in duration. The pauses between pulses are also modulated in duration and are used to transmit information.

At the direct output of the imaging device 1, the phase pulses coincide with the input ones, and at the inverse - they have the opposite polarity. With a zero signal at the control input, the driver is blocked and there are no pulses at its output. When a permissive single signal is applied, pulses are emitted from its output.

The pulses from the direct output of the imager 1 at the time of the appearance of single signals at its information input remove the blocking from the input of the element AND-NOT 2. The second input of the element AND-NOT 2 receives the pulses from the multivibrator 22, which switch from a given frequency triggers 11-14 the first counter.

The selector performs a selection of pulses of three types: short, long, and extra long. The frequency of the multivibrator 22 is set in such a way that when a short pulse arrives at the information input of the shaper 1, only the first two I and 12 triggers of the first counter are switched, after which the shaper 11-14 of the first counter stops switching. The NAND element 3 triggers and generates a signal — a short pulse that is normalized in duration and amplified by the driver former 23.

The duration of the signal at the output of the NAND 3 element is determined by the delay value of the element 20.

When switching to the information input of the imager 1 of a long pulse, which is eight times longer than a short pulse, the triggers AND -14 of the first counter are switched in the same way. However, during a long pulse, they have time to switch a greater number of times, and on the seventh cycle of the multivibrator 22

the coincidence of the single signals at all inputs of the NAND 4. Element at the output of the NAND 4 element appears a zero signal, indicating that a long pulse is applied to the selector input. This signal has a duration equal to one oscillation period of the multivibrator 22.

Upon arrival at the information input, the former of a 1-ultra long pulse, which is approximately twice as long

the long pulse, the I-14 triggers of the first counter are switched 16 times, and the NAND element 5 is triggered, signaling the arrival of an extra-long pulse. Specified Duration Ratios

The pulses were selected according to the conditions of operation of the telemechanical systems with a time separation of signals.

In these systems, short and long pulses alternate in a clock information series, and a superlong pulse is used as a phasing (marker) pulse. For the purpose of compaction of informational packages, a temporary sign is assigned not only to impulses, but also to pauses.

The duration of the pauses is selected by the second counter, which is configured for the selection of short and long pauses, which operates similarly to the first, except for the third impulse sign

(extra long), which is not used for pauses.

One of the principal differences of this selector is the selection of short pulses and pauses, which is significantly different from the selection of long and super long pulses.

When selecting long and super long pulses, the corresponding AND-NOT elements do not work until the end of the selected pulse. At the same time the element is NOT-4

triggered on a superlong pulse, but this does not lead to a false operation of the telemechanical system using this selector, since a superlong (marker) pulse is transmitted once per cycle and at this moment information is not received. For selection of short pulses, this method is unacceptable, since the sensor of short pulses (pauses) should not operate on long pulses (pauses). Therefore, a delay element 20 and 21 and / 5-triggers 18 and 19 are introduced into the device, due to which the signal about the arrival of a short pulse is transmitted to the output at the beginning of the next pause.

Triggers 15-17 constitute a second counter, which is a pause selector. It works independently of the first, providing a separate selection of pulses and pauses.

The use of this pulse selector makes it possible to increase the functionality of telemechanical systems, to increase the reliability of signal reception, especially under the influence of powerful pulse interference in the communication channel, which leads to the splitting of pulses and distortion of the running series. Under these conditions, a more accurate selection of pulses in duration provides reliable control of signal distortion.

Claims (2)

Invention Formula Pulse selector but of duration, containing the first counter of pulses on four // C-flip-flops, the outputs of which are connected to the inputs of the corresponding output I-NOT logic elements, the second pulse counter of three // C-flip-flops, the outputs of which are connected to the inputs of the corresponding output four-input logic elements AND-NOT, input pulse shaper, the input of which is connected to the input bus, the first output - with the first input of the first input logic element AND-NOT, and the second output connected to the first input in the second input logic element AND- NOT, the second input of which is connected to the second input of the first input logic element AND-NOT and the output of the multivibrator, and the counting input of the first pulse counter is connected to the output of the first input logic element AND-NOT, and the reset input of this counter is connected to the output of the first logic element is NOT, the counting input of the second pulse counter is connected to the output of the second input logic element NAND, and the reset input of this counter is connected to the output of the second logic element E, characterized in that in order to improve the accuracy of selection, two delay elements and two / 5 flip-flops are introduced into it, the R-input of the first of which is connected through the first delay element to the first output of the input pulse shaper and the S-input of the second / 5- a trigger whose / -input is connected to the second output of the pulse generator and the S-input of the first 5-flip-flop via the second delay element, the outputs of the first and second 5-flip-flops are connected respectively to the inputs of the first and second logic elements, the output of the first of which They are connected to the fourth input of one output NI logic input element, and the output of the second logic element is NOT connected to the third input of the first output NI 4E input logic element, the fifth inputs of the second, third, and input NI elements and the fourth input the first four-input element AND-NOT is connected to the first output of the input pulse shaper, the second output of which is connected to the fifth input of the first five-input element AND-NOT and to the fourth input of the second four-input element It is the AND-NOT. Sources of information taken into account in the examination 1. USSR author's certificate No. 451186, cl. H 03 K 5/20, 04.14.72. 2. Besheshevich I. I. Automation and remote control of power supply devices of electric railways, 1963, p. 236 (prototype). 12./J /