SU439068A1 - - Google Patents

Description

(54) METHOD FOR SELECTION OF PULSE BY DURATION

I

There is a method for selecting pulses in terms of duration, which lies within the limits of the selected time interval-selection interval, an arbitrary frequency of filling with packs of pulses, based on the logical processing of pulses.

When selecting a burst of pulses in a known manner, preliminary demodulation is carried out to convert it into a video pulse.

The purpose of the invention is to increase the resolution of a selector of a burst of pulses regardless of the frequency of filling with pulses of a burst - which is achieved by remembering the signal in two finite time intervals: in the selection interval and immediately after it. If the signal hits in the corresponding time interval, it is remembered as a unit, but if it does not fall within this interval, as zero. With further logical processing of the memory results, the duration of the selected pulse train is estimated.

FIG. 1 is a block diagram of a device for selecting pulses of the proposed method; in fig. 2 is a timing diagram explaining the block diagram operation.

The device contains a driver 1, one-shot 2-5, triggers 6-8, the circuit "And 9, the circuit" OR 10, differentiating

circuit 11. The selectable signal is fed to the driver 1, the output signal is removed from the circuit "And 9.

In the initial state, there is no signal at the input, triggers 6–8 are blocked by voltages of 4, 3, and 5, respectively, and the output potential of the AND 9 circuit is removed by a low potential constant voltage.

At the initial moment, when a burst of arbitrary waveforms and a filling frequency arrives at the circuit, driver 1 standardizes the input signal in amplitude and a pulse is removed from its output, the duration of which is equal to the duration of the incoming signal.

Consider three cases:

a) the duration of the signal t exceeds the time interval composed of a certain time interval ii, the duration of which is equal to the lower limit of the time selection, and the time interval t equal to the time interval

,

b)

c) ti ti + t2.

In the timing diagram of FIG. 2 shown

what is the output pulse (diagram X)

appears only when the duration

the selectable signal lies in the t-z selection interval, case c.

The timing diagrams of FIG. 2 are denoted by the same numbers as the corresponding blocks, the signal from the output of which is represented in these diagrams, and in the diagram denoted by zero, the signal arriving at the input of the circuit is shown.

The flowchart works as follows. In case a, the first pulse of the imaging unit 1 triggers one-shot 2 and 3, at the outputs of which pulses of duration ti and / h appear, respectively. The falling edge of a 1vibratora 2 pulse triggers the odiovibrator 4, a pulse from which with a duration of / 2 removes the lock from trigger 6, and a pulse from the one-vibrator 3 through the OR 10 circuit removes the lock from trigger 7. The pulse from shaper 1 changes the state of trigger 6 and impulse from trigger 6 — state of trigger 7; Signals appear at the outputs of flip-flops 6 and 7.

The falling edge of the one-shot pulse 4 triggers the one-shot 5, at the output of which a pulse of length 4 is formed, which is determined by the pulse frequency in the packet. The impulse from the one-shot 5 removes the blocking from the trigger 8, which changes its state, since during this time interval it receives a selectable pulse with a duration of + / 2. The impulse from the trigger 8 through the scheme "OR 10 blocks the trigger 7 and returns it to the initial state, the trigger 6 also returns to the initial state upon termination of the pulse from the single vibrator 4. The pulse of the trigger 8 is differentiated by the AND circuit, and its positive part goes to the" And 9, momentum on

the output of which can occur only in the case of coincidence of the pulse from trigger 7 and differentiating circuit 11, i.e. in this case there is no pulse at the output of the circuit.

In case b, the state of the flip-flops 6-8 changes, since the duration of the input signal lies in the interval t and does not fall within the intervals of / 2 and 4. Therefore, the pulse at the output of the & 9 circuit also appears.

In case triggers 6 and 7 are triggered. Trigger 8 does not block through OR circuit 10 trigger 7, therefore the AND 9 circuit receives a pulse from trigger 7 and from differentiating circuit 11, and a signal appears at the circuit output (diagram X, Fig. 2 c), indicating that the duration of the selectable signal lies in the selection interval.

Subject invention

A method for selecting pulses by duration, lying in a given time interval, at an arbitrary pulse filling frequency of a packet, based on a logical

processing of pulses, characterized in that, in order to increase the resolution of the selection, regardless of the frequency of filling the packet with pulses, the signal is memorized in the selection interval

and directly carry it, and the signal is remembered as a logical unit if its duration is equal to the duration of the selection interval or exceeds it, and a logical zero if the duration of the pulses

less than the duration of the selection interval, and with further logical processing estimate the duration of the selected pulse train.

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