SU1144150A1 - Device for checking parameters of magnetic tape recorder - Google Patents

Abstract

A DEVICE FOR MONITORING A MAGNETOPHONE PILOTS, containing a series-connected 1f square pulse generator, a frequency amplifier, a first group of analog keys, a second group of analog keys, the output of which is connected through a control bandwidth through functional and bandwidth filters to the third analog group; the input of the programmer and the control inputs of the first and second groups of analog switches, a serially connected mode setting unit, a switch, a converter - code and memory block and averaging, the first and second outputs of which are connected respectively via a converter code - voltage to the oscilloscope signal input and through an arithmetic device - to one input of the indicator panel, the first and second inputs of the programmer are connected to the output of the third group of analog keys and to the control output of the voltage converter - a code, respectively, the first and second, third, fourth and fifth outputs of the programmer are connected respectively to another input of the indicator board, with the second m input of the memory block and averaging, with control inputs of the voltage converter — code, block, setting modes and third analogue key groups of a clock generator connected by the output to the oscilloscope synchronization input (P fa and the third input of the memory block with and averaging, as well as a tape recorder, the input and output of which are connected respectively to the output of the mode setting unit and to the second input of the second group of analog keys, which is required in order to increase the accuracy of control j in the high frequencies by 1 of spurious amplitude modulation compensation, a chain 01 of a series-connected low-pass filter is introduced into it. an inverter and an analog adder, is connected between the second input of the second group of analog switches and the input of the mode setting block, while the other input of the analog ctl ator is connected to the first input of the programmer.

Description

The invention relates to an instrument structure and can be used to measure and control parameters of tape recorders under conditions of large-scale serial and serial production, as well as to control nodes of a tape recorder and other radio engineering devices. A device for measuring and monitoring the amplitude-frequency characteristics of tape recorders, containing between the tape recorder output and the oscilloscope signal input serially connected analog-to-digital converter, averaging and storage unit and digital-to-digital converter, as well as a synchronization unit connected to the control input of the averaging and storing unit U However, this device can only be used to control the amplitude-frequency characteristics of a tape recorder; in addition, it is characterized by low productivity in monitoring the parameters of a tape recorder. A device for measuring the frequency response is known, comprising a pilot signal generator, band-pass filters, signal converters connected to the outputs of the band-pass filters. as well as the driver of the command signals and electronic keys 2. However, this device has low performance due to the need to record a number of fixed frequency signals for the entire time of monitoring the frequency characteristics of a tape recorder during playback, as well as low monitoring due to the high pulses of rectifiable voltages allocated by bandpass filters. . The closest in technical essence to the proposed device is a device for monitoring parameters of a tape recorder, implementing a method of controlling parameters of a tape recorder, comprising a switch, three groups of analog switches, a generator of square-wave pulses, digital signals and frequencies, band-pass filters, a switch, functional filters , AC voltage amplitude converter in code, 501 memory block and averaging, indicator display, clock pulse generator, code to voltage converter, oscilloscope, ari meticheskoe device programmer and block specifying modes of. A disadvantage of the known device is the low accuracy of the high-frequency control of the soundtracks reproduced by the tape recorder. This is due to the fact that the reproducible waveform is subject to parasitic amplitude modulation, which gives the maximum error of measurements at high frequencies. The aim of the invention is to improve the control accuracy in the high-frequency range due to the compensation of spurious amplitude modulation. The goal is achieved by the fact that the device for monitoring the parameters of a tape recorder, containing successively connected square pulse generator, frequency dividers, the first group of analogue keys, the second group of analog keys, the output of which through bandpass and functional filters is connected to the inputs of the third group analog switches, a switch connected between the control input of the programmer and the control inputs of the first and second groups of analog switches, sequentially connected to the task block 1 mode c, co1Flutator, voltage converter - code and memory block and averaging, the first and second outputs of which are connected respectively via a converter code - voltage to the oscilloscope signal input and through an arithmetic unit with one input to the indicator display, the first and second inputs of the programmer are connected to the output of the third group of analog switches and to the control output of the voltage converter — the code, respectively, the first, second, third, fourth, and fifth outputs of the programmer are connected respectively to another input Indicator display house, with the second input of the memory unit and averaging, with the control inputs of the voltage converter - the code, the mode setting unit and the third group of analog keys, clock generator, connected BY1 into the synchronization input 3 and the third input a memory unit and averaging unit, as well as a tape recorder, the input and output of which are connected respectively to the output of the mode setting unit and to the second input of the second group of analog switches, a circuit from a series connected low-pass filter torus and an analog adder, is connected between the second input of the second group of analog switches and the input of the mode setting block, while another input of the analog adder is connected to the first input of the programmer. FIG. 1-3, structural devices cxeNfij are presented for monitoring and the programmer and mode setting unit included in it, respectively. The device for monitoring the parameters of the tape recorder (Fig. T) consists of the switches 1, the first group of analog keys 2, the second group of analog keys 3, the third group of analog keys 4, the square pulse generator 5, digital dividers 6, connected in a certain way bandpass filters 7, switch 8, functional filters 9, converter voltage - 1O code, block 11 memory and averaging, 12 indicators, generator, 13 clock pulses, converter 14 voltage code, oscilloscope 15. arithmetic device a 16, programmer 17, block 18-setting modes, low pass filter 19, inverter 20, analog adder 21, tape recorder 22. The programmer (Fig. 2) consists of a trigger 23, a comparator 24, counter 25 periods, connected by a certain pattern schemes SHSh 26, counter 27 of the radio signal sequence, decoder 28, counter 29 cycles, AND circuit 30, second OR circuit 31, level trigger 32, first 33, second 34 and third 35 input TTs first 36, second 37, .the third .38 and fourth 39 weekend tires. The mode setting device (Fig. 3) consists of a connected op amp 40, an input resistor 41, a low level resistor 42. 504 load level resistors 43, first 44 and second keys 45, erase key 46, pause key 47. The device worked as follows. Switch 1 is set to Record mode. According to the Recording signal received from switch 1, the analog switches 2 of the first group are closed, the analog switches 3 of the second group are opened, the programmer 17 is set to the Record mode. This is organized generation and supply of radio signals from the generator 5 rectangular pulses through digital dividers 6 frequency, the first group of analog keys 2, the second group of analog keys 3, band-pass filters 7, the third group of analog keys 4, analog adder 21 and block 18 setting modes to the input of the tape recorder 22. The generation of radio signals is produced by band-pass filters 7, to the input of which rectangular pulses are applied, corresponding to their transmission frequencies. Under the control of the programmer 17, analog keys 4 of the third group are sequentially closed, which pass radio signals produced by the band-pass filters 7. These signals through the analog adder 21 are fed to the mode setting unit 18, where, under the control of the programmer 17, they are given a certain amplitude, for example, equal to nominal level or reduced several times. The mode setting unit 18 under the control of the programmer 17 also extracts the Pause and Erase signals, which arrive at the input of the tape recorder 22. In the Recording mode, the first input of the programmer 17 receives radio signals from the third group of analog switches 4. The programmer 17 counts them and after passing through a certain number of them switching analog keys 4 of the third group, changes the mode on the mode setting block 18. In this way, a waveform of radio test sequences for monitoring the recorder parameters is generated. With the passage of the last radio signal of the last sequence, i.e. at the end of the waveform, the programmer 17 cuts in the signal on the board of 12 indicators from its first output and ends with the RECLINE.

When the switch 1 is set to the Playback mode, the analog switches 2 of the first group are disconnected from its output, the analogue keys 1 of the second group are locked, and the programmer 17 is set to the Playback mode.

In Vos1CH mode, the programmer t closes the analog switches 4 of the third group, thereby ensuring that the radio signals from the bandwidth or function (ion filters via analogue 2t, block 18. Setting of the MODES, Kof tytaTop, 8 to the converter 10 are variable amplitude w 8 code. When reproducing a high-frequency signal, a low-frequency filter (19 low-pass filter separates the low-frequency signal representing the parasitic amplitude modulation). The low-frequency signal is inverted and fed to the input of the analog sum. the torus 21, wherein skladgoaets with modulirovanshli vysokochastotnm signal. This analog adder 21 for compensation of stray manufactured amplitude modulations high frequency radio signal..

The radio signals transmitted by the programmer 17 through the analog keys 4 of the third group from the bandpass filters are used to control the amplitude of the frequency response of the tape recorder and the speed of movement of the information carrier. The dvgaseniy speed of the information carrier is made by the amplitude of the radio signal transmitted through the bandwidth fuibTp, whose width bandwidth is equal to the permissible deviation of the speed of movement of the information carrier from the nominal value. Radio signals that are passed through functional filters, such as a weighted relative-level parasitic strain filter, a weighted filter of noise and interference, a third-octave filter with center frequency 1 (SOO Hz, a third-octave filter with center frequency 1200 Hz, respectively) are used to measure the relative level parasitic voltages, relative noise and interference, relative erasure, harmonic coefficient.

When reproducing waveforms, the programmer 17 from the third output generates a signal, according to which the variable voltage amplitude converter 10 converts the amplitude of the alternating voltage into a code 10 and outputs a conversion end signal to the programmer 17, and using this signal, the programmer 17 switches the analog key 4 of the third group and outputs cell address from its second output to block 11 of memory and averaging. When playing the same radio waveform signals, the memory and averaging unit 11 determines the average value between the previous amplitude value and the newly reproduced amplitude and records the average value found in the cell with the address where the previous signal amplitude value was stored.

The clock pulses received at the second input of the storage unit and averaging read out the digital codes of the values of the amplitude of the radio signals.

The read information comes from one part of the memory through the first output of the memory block 11 and averaging to the converter 14 code-voltage, where it is converted into a proportional voltage level and in the form of rectangular pulses is displayed on the oscilloscope screen 15, which is synchronized by the clock pulse generator 13. The read information from another part of the memory of the 1t memory unit and averaging through the second output goes to the arithmetic unit 16, where the relative level of parasitic voltages, relative level of noise and interference, relative erasure level, coefficient of harmonics is calculated. Digital codes from the arithmetic unit come on the display of indicators 12 and are highlighted in the form of numbers.

The programmer 17 operates as follows. The trigger 23 modes from the third input bus 35 receives a Record signal, the trigger of 23 modes closes the AND 30 circuit on this signal and enables the counter for 25 periods, to the input of which rectangular pulses produced by the comparator 24 from the radio signals from the first input bus 33 arrive. Counter 25 periods counts a certain number of pulses, for example sixteen, and generates a transfer signal through the first circuit OR 26 to the input of the counter 27 sequentially of these radio signals. These sixteen pulses indicate the passage of sixteen radio signals to the input of the tape recorder, which constituted the first radio sequence of the test waveform. The transfer signals from the counter of 25 periods are considered to be counter 27 by means of a radio signal. At the output of the sequence counter 27, a code is generated that is fed to the input of the decoder 28. In accordance with the latest code, a signal is generated at its output, which via the fourth output bus goes to the analog keys 4 of the third group and through the second Ida 31 circuit - to the trigger 32 level The signal from the trigger 32 on the fourth output bus 39 post goes to the block 18 setting modes. The counter 27 of the radio signal sequences counts a certain number of pulses, for example eight, which indicates the eight sequences produced that arrived at the input of the tape recorder. When a pulse radio signal sequence passes to the counter 27, the digital code changes at its output and, accordingly, one of the outputs of the fourth output bus 39 is excited at the output of the decoder 28. Different analog keys 4 of the third group are closed by the signals of the fourth output bus 39, thereby forming a sequence various radio pulses. Upon termination of the counting by the sequence counter 27, a transfer signal is produced, which is fed to the counter 29 cycles, which counts a certain number of cycles, for example, eight, the test waveform is formed, consisting of eight identical cycles. At the end of the counting impulse pe-. 29 cycles from the counter are fed to the scoreboard of 12 indicators on the first output bus and flashes the end of record indicator. Counters 25, 27, 29 — cyclical and every other counter, producing a transfer signal, return to the initial state, ensuring that the generated test waveforms are identical. At receipt from the switch 1 on the third input bus signal Replay the trigger 23 modes goes into the initial state and the signal from its output opens the circuit AND 30, prohibits the operation of the counter of 25 periods and, passing through the second circuit OR 31, sets the trigger level 32 and the signal c its output via the fourth output bus 39 enters block 18. setting modes, where the transfer coefficient is set to one. The radio signals on the first output bus are compared by a comparator 24 with a voltage level equal to the tolerance of the amplitudes of the reproducing signals. When the amplitude reproduced radio signal of this level is equal or exceeded, a pulse is generated at the output of the comparator 24, which, passing through the AND circuit 30, enters the tO amplitude of the alternating voltage through the third output bus into the code and starts it. When the conversion is finished, the output of the converter 10 is received from the output of the converter 10 via the second input bus 34 through the first OR circuit 26 to the input of the counter 27 of the radio signal sequences. The conversion end pulses in the Play mode and the transfer pulses of the period counter 25 in the Record mode are identical and the counter 27 of the radio signal sequence, the counter of 29 cycles, the decoder 28 are identical in both modes, thereby ensuring synchronism and identification of the recorded and reproduced radio signals.

9.1

In the event that the above level is not exceeded by the amplitude of the reproduced radkos, the comparator 2A generates a signal on the inadmissibility of the speed of the MOVEMENT of the information carrier, which on the first output indicator 36 arrives on the display of 12 indicators and illuminates the indicator on the inadmissibility of the speed of movement.

The operation of the mode setting unit 18 is based on the dependence of the transmission coefficient of the operational amplifier DL on the ratio of the resistance values of the input resistor 41 and the resistance values of the feedback resistors, i.e. resistors are low 42 and high 43 levels. Their switching in the feedback circuit is produced by the first 44 shsh second 45 key 1 "n. The erase key 46 disables the output of the operational amplifier 40 from the output bus, thereby creating a sharp erasure. Locking key 47 pauses on a common shi with the key off 46

Yiwu

power mode

erase creates

Shl.

This level corresponds to a transmission coefficient equal to one, and to a high ten.

415010

The use of a device to control the parameters of a tape recorder allows one to increase the accuracy of the high-frequency control of the soundtracks reproduced by the tape recorder, which is due to the compensation of parasitic amplitude modulation, which gives the maximum measurement error at high frequencies.

 The proposed device allows an increase in labor productivity in the operation of monitoring the parameters of a tape recorder, since it requires recording and reproducing a certain number of radio signal sequences needed only to obtain an average result, as well as due to the detection of an expanded number of parameters of the tape recorder.

The use of the proposed device for monitoring the parameters of a tape recorder also makes it possible to increase the monitoring accuracy due to recording and reproducing radio signal sequences using the same set of band-pass filters, since measurement error is eliminated.

0 due to temperature drift of the amplitude of the radio signals, in the case of their generation - a separate generator of radio signals.

thirty

Claims (1)

DEVICE FOR CONTROLLING MAGNETOPHONE PARAMETERS containing a rectangular pulse generator, a frequency amplifier, a first group of analog keys, a second group of analog keys, the output of which is connected to the inputs of the third group of analog switches through band and function filters, a switch connected between the control input of the programmer and the control the inputs of the first and second groups of analog keys, connected in series mode setting unit, switch, voltage converter - a code and a memory and averaging unit, the first and second outputs of which are connected respectively through a code converter - voltage with the signal input of the oscilloscope and through an arithmetic device - with one input of the indicator board, the first and second inputs of the programmer are connected to the output of the third group of analog keys and to the control output of the voltage - code converter, respectively, the first and second, third, fourth and fifth outputs of the programmer <'are connected respectively to the other input of the indicator board, to the second input of and the memory and averaging, with the control inputs of the voltage converter - a code, a block, setting modes and the third group of analog keys, a clock pulse generator, connected output - S mn to the oscilloscope synchronization input and to the third input of the memory and averaging block, as well as a tape recorder, input and the output of which is connected, respectively, with the output of the mode setting unit and with the second input of the second group of analog keys, which means that, in order to increase the accuracy of control in the high-frequency region by compensating for spurious a amplitude modulation, a chain of series-connected low-pass filters is introduced into it. an inverter and an analog adder, connected between the second input of the second group of analog keys and the input of the mode unit, while the other input of the analog adder is connected to the first input of the programmer. SU., 1144150