SU1437829A2 - Digital meter of time intervals - Google Patents

Abstract

The invention relates to electronics and can be used in digital measurement technology. The purpose of the invention is to improve accuracy by synchronizing the generator 1 of the counting sequence and reducing the range of elements used. To do this, a trigger 14 is inserted into the device, and the generator 1 of the counting sequence is implemented as a shock excitation generator, which is similar in design to the Vernier 2 generator 2. In this case, the operation of the generator depends on the state of the trigger 14, the inputs of which are connected to the Start bus and to the output of the depressor 12 zero. With the npsixoAOM pulse, the generator of a 1-digit sequence is transferred to the oscillation mode, and its first pulse coincides with the beginning of the measured interval. The generation is stopped after the trigger 14 is transferred to the 1-loop state by a signal from the decoder 12 zero, whose input is connected to the output of the reversible counter 11, which determines the instant of coincidence of the pulses of the counting and vernier sequences according to the phase attribute. 2il. i (L

Description

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The invention relates to radio electronics n can be used in digital measurement technology, in particular for the construction of n, ifro-; time meters (timers), as well as in automation, computing, radar and experimental physics.

The aim of the invention is to increase the accuracy of the measurement.

FIG. 1 depicts a structural

Scheme SCHFASO time interval meter; Fig. 2 shows time diagrams of signals at the inputs and outputs of individual elements of the meter.

The digital time interval meter contains the generator 1 and my in the counting and the generator 2 pulses of noni. Sequences, elements I 3 - 5, counters 6, 7, triggers 8, 9, elements I-lTO-i 10, reversible counter 11 ,, digital decoder 12 zero

indicator 13, trigger 14, and start and stop input buses. The generator 1 through the element And 3 is connected to the counter 6, and through the element And 4, the element OR 10, trigger 9 and generator 2 - to the counter 7. Element And 5 inputs connected respectively to the output of the generator 1 and trigger 9, and the output connected to the input adding a reversible counter 11, a subtraction input connected to the output of the generator 2, and an installation input connected to the input

installation house counters 6 and 7 and Start bus “Reversible counter 11 outputs are connected to 12 zero decoder, output connected to the second input of the element OR 10. Trigger 8 output is connected to the second input of the IZ element, and its single and zero input are connected to Start buses, respectively and Stop, Bus Stop is also connected to a single

the trigger input 9 and the second input element And 4, Triggers | 4 output

connected to generator 1, and its single and zero inputs are connected respectively to the Start bus and to the output of the decoder 12 zero. The outputs of the counters 6 are connected to the inputs of the indicator 13, the reversible counter 11 is made two-stage, so that it must have three different states: j two states, periodically replacing one another up to the moment с: ш, value of the vernier pulses and countable sequence in classic vernier

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method, and the third cocToRirne, corresponding to the moment. It is co-owned and different from the previous two.

The functionally reversible counter 11 contains two binary bits set before the start of measurements with the Start signal in the +2 position.

The decoder 12 zeroes can be performed on the elements And, triggered by the transition of both triggers reversible counter 11a in the zero position,.

Counters 6, 7 operate in the binary-decimal code.

The number of decimal digits of counter 6 is selected based on the maximum duration of the measuring interval and the duration of the generator period 1 o The number of binary-decimal digits of counter 7 must coincide with the minimum value of m.

The generators 1 and 2 produce pulse sequences with the smallest possible from the point of view of the operation of the counters 6 and 11 duration.

Feed over the bus Start of the pulse to the inputs of the installation of counters b and 7 to the position -1 provides a normal reading of the digital indicator 13 when measuring time intervals smaller than T, 10 (for counter 5, Start

since the position of the pulse must match

the generator pulse 1) j and when changing time intervals equal to the whole of the number of periods Tp (for counter 7). Connection nmn Start with the input of the installation of the reversible counter 1 1 in position i-2 allows periodically changing the code of this counter in the interval of +2 and provides a third position, different from the ngth, Zero when two vertices appear in the interval between the fronts neighboring pulses counting pos. impairment.

The meter works as follows.

In the initial position, the triggers 8, 9 to 1 h are ri ri the zero state n-i, and the generators 1, 2 do not generate.

The Start signal (FIG. 2a) of counter 6 and 7 is switched to the -1 state, and the reversal schRT chik 11 is switched to the +2 state (Fig. 2m.1).

triggers 8 and 14 are set to state 1 (FIG. 2d and b, respectively). The generator 1 pulses the counting sequence, and the signal from the single output of the trigger 8 is fed to the input element And 3. The pulses from the output of the generator 1 through the element 3 arrive at the input of the counter 6, where the number of incoming pulses is counted.

By the Stop signal, the trigger 8 is transferred to the state O (Fig. 2d) and the arrival of time stamps from the generator 1 on the counter. 6 is terminated (FIG. 2d). Simultaneously, the trigger 9 is transferred to state 1 (Fig. 2e) and starts the generator 2 of the pulses of the nano sequence, the pulses from the output of which are fed to the input of counter 7 and to the subtracting input of the reversing counter 11 (Fig. 2g), and to the summing input of the counter 11 begin to receive pulses from the generator 1 pulses of the counting sequence through the element And 5 (Fig. 2c).

The ratio between the pulse repetition period TO of the pulse generator 1 (a counting sequence) and the pulse repetition period Tj, the generator of the 2 pulses of the Vernier sequence is chosen from the condition Tn (T-Yu).

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The number of pulses in the counter 6 corresponds to an integer number of periods T o in the interval between the Start and Stop pulses, and the code in the counter 7 corresponds to the number

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between the last pulse Tp, passing to the main counter 6, and the Stop signal.

The result from counters 6 and 7 up, steps on the digital indicator 13.

In the case when the pulse Stop coincides with the pulse of the generator 1 of the pulses of the counting sequence, a signal appears at the output of the element K 4, which triggers the trigger 9 to the state O, and the device stops working. Since the triggering of the element AND 4 ji of the trigger 9 does not occur instantaneously, the generator 2 has time to generate one pulse, which translates the counter 7 into the state O.

The result from the outputs of the counter 6 is fed to the inputs of the digital indicator 13.

Claims (1)

30 claims The iFlash time interval meter by aut. St. № 1177793, about t At the time t J. the conversion of the reversible counter 11 to the state O, the decoder 12 zero generates a signal that trigger 9 through the element OR-10 and trigger-14 set to the zero state and disrupt the generation of generators 1 and 2. FIG. 2 shows the change of the Nc4 code in a two-stage reversible counter 11. Led by the fact that, with a 2g goal, to improve measurement accuracy, a third trigger is additionally introduced into it, and the generator is controlled, the input of which is connected to the forward output of the third trigger, in which 40 inputs of the unit are set to one and to zero state respectively, to the start-pulse bus and the de-encoder output. Ofrrapm / -, Stop pi / s. i