RU1780046C - Automatic instrument for measuring frequency characteristics of group delay time of four-terminal network - Google Patents

Abstract

Usage: in the electrical engineering control phase-frequency characteristics of the four-terminal network. SUMMARY OF THE INVENTION: The well-known four-terminal group-delay automatic time delay frequency response (TWT) frequency meter is improved by the introduction of a peripheral synchronization detector and generator, with the help of which the meter receives additional functionality: the ability to measure the delay time for signals recorded on a tape drive. 1 ill.

Description

The invention relates to measuring technique and can be used to automatically study the group delay time of signals recorded on magnetic tape.

A device is known for automatically measuring the frequency characteristics of group delay time, comprising a generator, a modulator, a phase meter, an amplifier with automatic gain control, a crystal oscillator, a synchronous detector, a phasemeter-computer communication unit, a decoder, a frequency control unit, and the generator output is connected to the input of the studied four-terminal network and simultaneously with the reference input of the phase meter, the input of the studied four-terminal network is connected to the signal input of the modulator, the output of which is connected through an amplifier an amplifier with automatic gain control (AGC) with a signal input of a synchronous detector, the control inputs of a modulator and a synchronous detector are connected to a crystal oscillator, the output of a synchronous detector is connected to the measuring input of a phase meter. The information output of the phase meter through the communication unit, the computer phase meter is connected to the input computer bus, the control bus computer is connected to the first control input of the communication unit, the second control input of which is connected to the output of the computer input device, and the control output to the output of the computer SIP, bus The computer Upr is connected through a decoder to the first control input of the frequency control unit, the second input of which is connected to terminal BB, the information input of the frequency control unit is connected to the computer bus Output, and the information output to the control input of the generator. The disadvantage of this device is the inability to measure the parameters of the signals recorded on the magnetic tape, due to the inability to synchronously fix the moment of coincidence of the signals of the reference and measuring channels.

The purpose of the invention is to expand the functionality by providing measurement of group delay time (DT) of signals recorded on magnetic tape.

This goal is achieved by the fact that in the automatic meter of the frequency characteristics of the GVZ, containing a generator, a modulator, a phase meter, an amplifier with AGC, a crystal oscillator, a synchronous detector, a phasemeter-computer communication unit, a decoder, a frequency control unit, a detector and an SIP pulse generator are introduced . In this case, the input of the detector is connected to the output of the synchronous detector, and its output is connected via the SIP pulse shaper to the input of the SIP computer.

The drawing shows a structural diagram of the proposed meter.

Generator 1 is a standard generator having a digital frequency control input, e.g. GZ113 or frequency synthesizer 46-31, modulator 4 is a standard node. an amplifier with automatic gain control 6, a synchronous detector 7 are standard units, a crystal oscillator 5 is a self-contained oscillator; standard unit, the phase meter 3 is a standard meter having a digital output, for example Ф2-16 or Ф228, the communication unit is a computer phase meter 8, the frequency control unit 10 is standard blocks, the decoder 9 is a standard block, detector 11 is a standard AM a signal detector, an SIP pulse generator 12 is a standard unit.

The meter contains a generator 1, the output of which is connected to the input of the tape recorder 2 and simultaneously with the reference input of the phase meter 3, the output of the tape recorder 2 is connected to the signal input m of the modulator 4, the output of which is connected through the amplifier with AGC 6 to the signal input of the synchronous detector 7, controlling the inputs of the modulator 4 and the synchronous detector 7 are connected to the crystal oscillator 5, the output of the synchronous detector 7 is connected to the measuring input of the phase meter 3, the information output of the phase meter 3 is connected to the computer bus via the phasemeter-computer 8 communication unit. Input, buses The control unit is connected to the control input of the communication unit 8, the second control input of which is connected to the output of the computer BB, and the control output is connected to the output of the SIP computer, the control bus of the control unit is connected via decoder 9 to the first control input of the frequency control unit 10, the second the input of which is connected to the output of BB, the information input of the frequency control unit is connected to the computer bus. The output, and the information output to the control input of the generator 1, the synchronous detector 7 through the detector 11 and the SIP driver is connected to the input of the SIP computer.

The principle of operation of the device is:

two steps: the first is the step of recording a sample signal: the second is the measurement step,

At the recording stage, the signal of the generator 1 is fed to the recording input of the tape recorder 2 ::

is recorded. The recorder output is turned off. The recorded signal has the following initial parameters: Rmii minimum frequency range F. ex maximum frequency range; sh-aizg.;.:

rhenium F F2-Pi; and the step of viewing the chag of the relative AF range. However, initially at the output of generator 1, a tag signal with a frequency of 1 kHz is set, which fixes; it records the moment the recording starts. Then the sip -, -; arriving at the input of the tape recorder, bend-5 is as follows: after the signal is set, the frequency is set. Meanwhile FMHH + §, these two frequencies fPi and form luar measurements nz .le ..

torogs measures the GVZ fr; c, this process will be slowed down by 3T,: i: 1 / Zmere, ii).

Then set the hourgog::. DgiRmin + R. followed by Rmin + PL g

IRmin + pAP + P. Thus, the process of measuring the frequency is repeated until the condition Pmin- - pA P Pmax is satisfied, where

, 1,2,3 followed by a stop.

The initial parameters of the signal are recorded in a computer, where in accordance with the program:.:

produced by CHIPSN TSi-vll i i ori:;

Scientific research institute of frequency recognized by genezgor 1.

At the measurement stage, the output signal

tape recorder 2, passed through a modulator 4, an amplifier with AGC 6 and a synchronous detector 7, is fed to the input of the detector 11. The appearance of a signal at the output of the detector 11 leads to the operation of the driver 12. The pulse

SIP at the output of the shaper 12, in turn, leads to the launch of the computer program. The duration of the pre-marked mark 1 kHz and the duration of the preparatory stage of the computer to

the settings by the generator 1 of the desired frequency of the RMI coincide. According to the SIP signal with the required delay, the generator 1. controlled by the frequency control unit 10, is set to the Rmiya frequency, which

arrives at the input of the phasemeter 3, to the second input of which the signal of the tape recorder is received, thus, at the inputs of the phasemeter 3 there are simultaneously two signals with a frequency that play with oi opi-tofo

output, i.e. generator 1 and measuring, i.e. from the output of tape recorder 2. This is caused by the tight coupling of the moment of the beginning of counting in the meter and the moment of the appearance of the required signal at the output of the tape recorder. The readings of phaseometer 1 are recorded at this frequency. Then, in the same way, the measurements are repeated at the frequency Pmin +. F rg and tpi readings are recorded. The group delay time is determined from the expression

(9 - f

360 (2-Fi)

Then the measurements are repeated at the frequency Gmin + D F and FMHH + D F + F, etc.

The use of a detector and a sync pulse shaper (SIP) allows; to provide a fixation of the moment of the beginning of the measurement type, the reproduction accuracy of which determines, in turn, the measurement error. Introducing the detector; -: formM1 roggs; 1Я Ci / iij allows .... ir, b (in hd4a; ia of the M3MepenVifi stage and also o6pa3oivi it is possible to measure i C3 from the panel. Previously recorded. tape

, ai..i .. U: uujJdoOiV., GfvDLyGdSMOb yCipvJH

CT8G allows you to expand the functionality compared to the prototype, as pozalet provide the ability to measure the delay of the signals previously recorded Hc5 magnetic tape,

and about (V - i у; i d inventions. Automatic meter of frequency characteristics of group delay time of a four-terminal device, containing a generator, series-connected modulator, amplifier with automatic gain control, synchronous detector

and a phase meter, the second input of which is connected to the output of the generator, input and output terminals for connecting a four-pole connected respectively to the output 5 of the generator and the input of the modulator, as well as a crystal oscillator connected to the second inputs of the modulator and synchronous detector, a calculator and a block computer controls connected

0 between each other by a main bus, a frequency control unit, a decoder and a communication unit, moreover, the control input of the generator is connected to the output of the frequency control unit, the first input of which is connected to the output of the decoder, and the second and third inputs are connected to the corresponding outputs Bv and Vyv of the calculator control unit whose digital output control is connected to the inputs of the decoder and the first input

0 communication unit, the second input of which is connected to the output of the input layer of the computer; the input is connected to the digital output of the phase meter, the sync output; igzii bo;.: slugs connected to bXwAuivi

5 c; nxpOv n;: - ac; and g; gr -1phery (SIP) cvnoicd control of the computer, the bus input of which is connected to the cformation output of the unit, which means that, with the whole. functional expansion

0 possibilities by providing the possibility of measuring the group delay time of the signals recorded on the magnetic tape of the drive, a series-connected detector is introduced into it

5 and a peripheral-H synchronization driver, the output of which is connected to the input of the SIP of the control unit of the calculator, and the input of the detector is connected to the output of the synchronous detector, the input and output

0 meter terminals are connected respectively to the input and output of the magnetic storage.