SU1377820A1 - Device for measuring time intervals - Google Patents

Abstract

The invention relates to a pulse technique and serves to expand the range of measured intervals. The device contains shock excitation generators 1 and 2, counters 3, 4 and 9, delay block 5, driver 6, element 7 and block 8 of code comparison. The introduction of the delay unit 10 and the formation of new functional connections exclude the dead zones of the device. 2 Il.

Description

with

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FIG. one

11377820

The invention relates to a pulse technique and can be used when measuring time intervals of short duration.

The aim of the invention is to expand the range of measurable time intervals by eliminating the deadband.

FIG. 1 shows the structural unit of block 8 is interrogated by a pulse.

a circuit for measuring time intervals; in fig; 2 - timing charts of the device when measuring t t-.

A device for measuring time intervals, contains generators 1 and 2 of shock excitation, first counter 3, second counter 4, first delay unit 5, driver 6, element 7, code comparison block 8, third counter 9, second delay block 10, input buses 11, 12.

The first input bus 11 is connected to the starting input of the shock excitation generator 1, the output of which is connected to a delayed delay 10, is supplied to the counting input of the counter 3 and through the serially connected delaying unit 5, the driver 6 to the first input of the element 7, the second input which is connected to the output of the code comparison block 8, the first inputs of which are connected to the corresponding outputs of the counter 3, the reset input of which through the second delay unit 10 is connected to the reset input of the generator 1, the output of the counter 9 and the reset input of the generator shock excitation torus 2, the start input of which is connected to the second input bus 12, the generator 2 output is connected to the counting input of the counter 4, whose outputs are connected to the corresponding bit inputs of the code comparison unit 8, you-i element stroke 7 is connected to the counting input counter 9 and reset input of counter 4. I

The device works as follows.

The pulse of the beginning of the measured measurement, which is accurate to the reading of the measurement, zeroed the counter 3 and the device is ready for the next measurement cycle.

At time T, the first equality of the codes in the counters 3 and 4, the code will be written

T T - tx

N,

35

40

where do we find t, TO

T -

45

The pulses with period T are counted by counter 3 during the entire interval T, and counter 4 at time T is zero, therefore the counting of pulses with period Tg continues for a period of time T,. , From the last formula we get

the termination t is triggered by the generator 1, the output of which forms the main pulse sequence with a pulse following period T (Fig. 2a), the number of which is counted by the counter 3. The pulse of the end of the measured start-up interval is: generator 2, the output of which forms the auxiliary pulse sequence with a period

following impulses, (fig. 26). The number of pulses of the auxiliary sequence is counted by counter 4. Counter codes 3 and 4 are constantly compared with each other in block 8 of code comparison, at the OUTPUT of which, when the counter codes of 3.4 coincide, level 1 is formed. unit 5 delay, relative to the pulses of the generator 1. The value of the delay unit 5 should be chosen

  TO - T (figa). When the codes of the counters 3 and 4 coincide, the pulse of the former 6 passes through the element 7 and zeroes the counter 4.

The zero pulse of counter 4 is counted by counter 9 with a capacitance p.

After the counter 9 is filled, the overflow pulse from its output stops the generators 1, 2 and through

to accurately measure the measurement result, zero the counter 3 and the device is ready for the next measurement cycle.

At time T, the first equality of the codes in the counters 3 and 4, the code will be written

T T - tx

N,

zo

35

where do we find t, TO

T -

The pulses with period T are counted by counter 3 during the entire interval T, and counter 4 at time T is zero, therefore the counting of pulses with period Tg continues for a period of time T,. , From the last formula we get

N,

tx-Tc

Tm „- tL

55

On the basis of the N-th cycle, we get the measurement result recorded: in counter 3

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TO

do t

FIG. 2 shows time diagrams illustrating the moments of equality of the codes of the counters 3, 4 when measuring time intervals. FIG. The pulses of the generator 1 are presented behind, which are fed to the input of the counter 3. In FIG. Zb, c, d, d, e show the moments of equality of the codes of counters 3 and 4 with a counter capacity of 9 p 2 when measuring the time intervals t LT (fig.Sv); t, 2 DT (Fig. 3g); t, 3 IT (Fig. Zd); t 4 LT (Fig. Ze).

Claims (1)

Invention Formula A device for measuring time intervals containing two input buses, two shock excitation generators, three counters, a first delay unit, a driver, a code comparison unit, and element, the first input bus connected to the start input of the first shock excitation generator, the output of which connected to the counting input of the first counter and through serially connected the first block of the delay and driver R Go 0 0 5 five the first input of the element I, the second input of which is connected to the output of the code comparison block, the first bit inputs of which are connected with the corresponding outputs of the first counter, the second bit inputs of the code comparison block connected to the corresponding outputs of the second counter, whose counting input through the second generator of shock excitation is connected to the second input bus, the output of the element I is connected to the counting input of the third counter, the overflow output of which is connected to the input of the stop of the first generator of the shock excitation Nor, characterized in that, in order to expand the range of measured time intervals, a second delay unit is inserted into it, the output of which is connected to the reset input of the first counter, the input of the second delay unit is connected to the stop input of the second shock excitation generator, and overflow output of the third counter, the counting input of which is connected to the reset input of the second counter.