SU1318988A1 - Device for detecting standard time signal - Google Patents

Abstract

The invention relates to a pulse technique. The purpose of the invention is to increase the reliability of accurate timing signals. The device contains a pre-filter 1 and a period selection block 2, a discrete filter 3, a discrete integrator 4, a block 5 for selection of a given duration, a counter 6 of the number of signals, a block 7 coincidence block and an automatic gain control block 8 for maintaining a constant input level are entered into the device. signal device. 2 Il. § (L Fy

Description

The invention relates to a pulse technique and can be used in devices for extracting accurate time signals transmitted over the broadcasting channels of the State Committee on Broadcasting and Television.

The aim of the invention is to increase the reliability of the allocation of accurate time signals.

FIG. 1 is a block diagram of an apparatus for extracting time signals; in fig. 2 - diagram of the period selector.

A device for extracting accurate time signals comprises (FIG. 1) a pre-filter 1, a period selection block 2, a discrete filter 3, a discrete integrator 4, a block 5

dinene with the first input of the element OR 11, the second input of which is connected to the first input of the expander 15 and the clock pulse bus, and the output is connected to the counting input of the time counter 12, the output of the time counter 12 is connected to the input of the coincidence element 13, the first output of which is connected to the first the input element OR 14, and the second output is connected to the second input of the element OR 14, the output of which is connected to the second input of the expander 15, the first input of which is connected to the bus clock pulses.

A device for extracting time signals is as follows.

From the output of the receiver (not shown) low-frequency signals arrive at

THAT

15

selection of a given duration, counting unit 8, intended for supporter 6 of the number of signals, coincidence unit 7, automatic gain control unit 8, the input of automatic gain control unit 8 connected to the output of a receiving device (not shown), and output 8 connected to the input pre-filter 1, the output of which is connected to the input of the discrete filter 3, the output of which through the discrete integrator 4 is connected to the input of the selection unit 5 of a given length I,

the output of which is connected to the first input of the counter 6 of the number of signals and to the first input of the period selection block 2, the output of which is connected to the second input of the counter 6 of the number of signals whose output is connected to the first input of the coincidence unit 7, the second input of which is connected to the bus current time, and the second input of the period selection block 2 is connected to the clock pulse bus. The period selection block 2 contains (FIG. 2) an OR 9 element, a trigger tO, an OR 11 element, a time counter 12, a coincidence element 13, an OR 14 element, a pulse spreader 15, the first input of the OR 9 element is connected to the output of the selection block 5 duration, the second input of which is connected to the first installation input of the trigger 10 and the output of the expander 15, the output of which is connected

25

thirty

a constant input device level. The stability of the level is maintained by clipping (two-sided limitation) of the signal. The normalized signal from the output of the block 8. arrives at the prefilter 1, which serves to select the main (first) MONICA frequency (1000 Hz) frequency signal. At the same time, pre-filter 1 reduces the level of all signals outside the filter bandwidth, which for the experimental sample was 0.7 from 400 Hz to 1.6 kHz in terms of the level.

A sinusoidal time signal from the output of pre-filter 1 is fed to discrete filter 3, where it is converted into a pack of square pulses that, when the signal frequency corresponds to a specified value, goes to discrete integrator 4. At the output of the latter, a signal appears that represents pulses. The envelope of the exact time signal from the output of the integrator 4 is fed to the block 5 for the selection of a given length, which ensures the verification of the received signals of the exact time by duration. If the duration of the incoming signal is as specified, then the output of block 5 is at 35

40

45

The installation input of the counter 12 is the output signal. If the length of time. The second installation input of the trigger 10 is connected to the output of the block 5 of a given duration, the output soy

189882

dinene with the first input of the element OR 11, the second input of which is connected to the first input of the expander 15 and the clock pulse bus, and the output is connected to the counting input of the time counter 12, the output of the time counter 12 is connected to the input of the coincidence element 13, the first output of which is connected to the first the input element OR 14, and the second output is connected to the second input of the element OR 14, the output of which is connected to the second input of the expander 15, the first input of which is connected to the bus clock pulses.

A device for extracting time signals is as follows.

From the output of the receiver (not shown) low-frequency signals arrive at

THAT

15

 block 8, designed to support5

0

a constant input device level. The stability of the level is maintained by clipping (two-sided limitation) of the signal. The normalized signal from the output of the block 8. arrives at the prefilter 1, which serves to select the main (first) MONICA frequency (1000 Hz) frequency signal. At the same time, pre-filter 1 reduces the level of all signals outside the filter bandwidth, which for the experimental sample was 0.7 from 400 Hz to 1.6 kHz in terms of the level.

A sinusoidal time signal from the output of pre-filter 1 is fed to discrete filter 3, where it is converted into a pack of square pulses that, when the signal frequency corresponds to a specified value, goes to discrete integrator 4. At the output of the latter, a signal appears that represents pulses. The envelope of the exact time signal from the output of the integrator 4 is fed to the block 5 for the selection of a given length, which ensures the verification of the received signals of the exact time by duration. If the duration of the incoming signal corresponds to the specified one, then the output of block 5 is in B5

0

five

 The output signal is. If its duration is more or less than the specified one, then there is no signal at the output. The signal from the output of block 5 of selection of a given duration is fed to the first inputs of block 2 of the period selection and the counter 6 of the number of time signals.

The period selection block 2 is intended for checking the period of incoming signals. Its second input receives pulses from the clock generator (f 1000 Hz). The first signal from the output of the selection unit 5 of a given duration is fed to the counter 6 of the number of time signals and is stored in it. The same signal triggers the period selection block 2, which starts counting the same pulses.

If during the time of 1.06 s, the new time signal does not come from the output of block 5 (the time period of the signals of the exact time is 1 ± 0.05 s), then block 2 causes the signal to be set in O of the counter 6 of the number of time signals. If the time signal arrives earlier, then block 2 is set to O, and the signal of setting the number 6 of the time signals to O is not formed.

The counter 6 of the number of signals of the exact time counts five signals, and the sixth passes to the block 7 the coincidence. The second input of block 7 matches signals from electronic clocks (not shown), which open block 7 of coincidence at a given interval time interval (from 59 minutes 30 seconds to 00 tons 30 seconds). The signal from the output of the counter 6 of the number of time signals after passing through the coincidence unit 7 is used to correct the readings of the electronic clock counters.

Block 2 selection period works as follows.

A signal from the output of block 5 of the selected duration set to the first input of the period selection block 2 sets the trigger 10. To the R input to state 1. As a result, the output of the OR 11 element appears from the second input of a series of tactile frequency signals f, which arrives at the counting input of the counter 12. Simultaneously with setting the trigger 10 to the state 1, the time counter 12 is set to the state O by preparing the counter to start operation. The signals from the output of the counter 12 arrive at the coincidence element 13.

B case counter status

The 12th time (counter code) corresponds to the specified (which is equivalent to the specified time interval after the signal arrives at the first input of the period selection block 2), the element

13 coincidences are triggered and negative signals appear on its outputs, which are combined with the element OR 14. The received signal is normalized in duration (expands in the duration of the signal at the first input of the period selection block 2) using the expander 13. The signal from the expander output sets in О the trigger 10 and the counter 12. Simultaneously with this signal from the output of the period selection block 2, the counter 6 of the number of signals is set to O.

If the period of arrival of the accurate time signals at the first input of block 2 is less than the period of arrival of the signals of exact time, then the counter 12 of block 2 is periodically set to 0 and the output signal is not generated.

Claims (1)

Formula isobteni A device for the selection of accurate time signals containing a prefilter and a selection unit of a p. Period, characterized in that, in order to increase the reliability of the selection of accurate time signals, a discrete filter, a discrete integrator, a selection unit of a specified duration, a signal number counter, a block are entered into it. coincidence and automatic gain control unit, the output of which is connected to the input of the preliminary filter, the output of which is connected to the input of the discrete filter, the output of which is via a discrete integrator connected to the input of a selection unit of a given duration, the output of which is connected to the first input of a signal number counter and to the first input of a period selection unit whose output is connected to a second input of a counter of the number of signals whose output is connected to the first input of a coincidence unit, the second input of which is connected to the bus of the current time, and the second input of the period selection block is connected to the clock pulse bus. Editor A. Vorovich Compiled by E. Chevysin Tehred M. Khodanich Proofreader L. Pilipenko Order 2510/41 Circulation 370 Subscription VNIIPI USSR State Committee for inventions and discoveries 113035, Moscow, Zh-35, Raushsk nab, 4/5 Production and printing company,. Uzhgorod, st. Project, 4