SU1545260A1 - Device for measuring tape recorder parameters - Google Patents

Abstract

The invention relates to the accumulation of information, in particular, to recording control devices, and can be used in setting and monitoring parameters of a tape recorder. The purpose of the invention is to reduce the measurement error of the tape recorder parameters with increasing measurement speed. Using a series-connected multivibrator 1, the first 2 and second 3 pulse distributors, the first group of elements 7 and the first 4 and second 5 groups of keys, the frequency of the controlled multivibrator 30, which is part of the signal generator 8, is changed. At the output of the tape recorder 9, the signal through the first detector 13 and the first key 14 is overwritten in memory block 15, from which the low frequency signals and the main measuring frequency through the third key group 16, the integrator group 17 and the switch 18 arrive at the oscilloscope input 26. The pulse generator 19 is designed for filling video signals. At the same time, using a band-pass filter 12, a second detector 24, a second key 23, and an integrator 22, signals proportional to the level of harmonic distortion are generated, which together with the mid and high frequencies from the output of the first detector 13 also commute through the integrator 22 to the oscilloscope input 26. Synchronization all keys are produced using the first 10 and second 11 pulse shapers, the first 20 and second 21 standby multivibrators, the third distributor 27 pulses of the And 2 element

Description

Signals proportional to max 0 2 or less are detected.

The invention relates to the field of measuring storage media, namely, devices for measuring parameters of a tape recorder.

The aim of the invention is to reduce the measurement error of the parameters of the tape recorder with increasing measurement speed.

Figures 1 and 2 show the block diagram and timing diagrams of the operation of the device for measuring the parameters of a tape recorder.

The device for measuring the parameters of the tape recorder contains a series-connected multivibrator 1, the first and second distributors 2 and 3 pulses, the first of which is connected by outputs to the control inputs of the first group of keys A, whose inputs are connected to the control bus 5 and to the inputs of the second group of keys 6, connected by control inputs with the outputs of the first group of elements And 7 connected by interconnected first inputs with interconnected last output and input of the first and second valves 2 and 3 imp lsov and second inputs connected to the outputs of the second distributor 3 pulses. The device also contains a generator of 8 signals connected by the inputs to the outputs of the first and second groups A and 6 keys and the output to the input of the measured tape recorder H, which is equipped with a snitch. CMM to the inputs of the first and

0

five

0

five

0

five

second shapers 10 and 11 im-. pulses, a band-pass filter 12, and a first detector 13, connected by an output through the first key 1A to an input of the memory unit 15. The memory unit 15 is connected by outputs via serially connected third key group 16 and integrator group 17 to a group of inputs of switch 18 connected by a first input to an output of generator 19, a second input to an output of a first pulse shaper 10 connected via serially connected first and second pending multivibrators 20 and 21 to the control input of the first key 1A, the third input to the output of the first detector 13, the fourth input through the serially connected integrator 22, the second key 23 and the second detector 2A to i dy bandpass filter 12, and the respective outputs to a control input of the memory unit 15 and y. the inputs of the indicator 25 and the oscilloscope 26. The oscillograph 26 is connected by a synchronization input to the output of the second driver 11 pulses. In addition, the device contains the third pulse distributor 27, the AND 28 element and the second group of AND 29 elements connected by the first inputs to the outputs of the third pulse distributor 27, the second inputs to one of the outputs of the switch 18 and the outputs to the third termination control ports

515

keys 16, the third pulse distributor 27 is connected by inputs to the outputs of the first and second drivers 10 and I pulses, and the signal generator 8 comprises a series-connected controlled multivibrator 30, whose inputs are the inputs of a signal generator 8, a pulse counter 31, permanent memory (Memory) 32 and digital-to-analog converter (DAC) 33, the output of which is the output of the signal generator 8, connected by a control input to the output of the last element AND 7 of the first group of elements AND 7. At this The element 28 is connected by the first input to the output of the second standby multivibrator 21, the second input to the corresponding output of the third pulse distributor 27 and the output to the control input of the second switch 23.

The controlled multivibrator 30 cbop-ims pulses, whose frequency changes when one of its inputs is connected using key 4 of the first group of keys 4 to the common bus 5. From the output of the controlled multivibrator 30, the signal is fed to the input of the pulse counter 31. the output of the pulse counter 31 and the address input of the constant memory 32 are fed to a sequentially varying address code. The constant memory 32 stores a discrete series of digital values of a single period of a sinusoidal function. During the full counting cycle of the pulse counter 31, a full interrogation of the addresses of the constant memory 32 is made, the output of which forms a consecutive series of code states corresponding to one period of the SN-function in a discrete-digital representation. With the help of a DAC 33, a discrete series of code sends is converted An analog sinusoidal signal. To generate a signal of the main measuring frequency, the control input of the DAC 33 receives the control signal from one of the elements And 7 of the first circuit at the appropriate time. ups, And 7 elements and the amplitude of the signal is increased, for example, by 20 dB (signal A, FIG. 2a). From the output of NAL 33, the signals are fed to the input of a controlled tape recorder 9,

Frame repetition rate is determined by the output pulse rate.

260

multivibrator 1; The repetition rate is selected from the condition that the image does not flicker on the oscilloscope screen 26 and is 16-18 Hz. These pulses then enter the input of the first distributor 2 pulses, the output of which signals control the operation of the corresponding keys 6 of the second group of keys 6. At the output of the D / A converter 33, sinusoidal signals are generated (Fig. 2a).

Elements And 7 of the first group of elements And 7 form on their outputs

5 pulses shifted relative to each other per frame. These pulses control the inclusion of the corresponding keys 6 of the second group of keys 6. In addition, the frequency of the low-frequency signal

0 within one cycle varies from frame to frame (signals B, FIG. 2a). The number of periods of a low-frequency signal, depending on the frequency, can range from 1 (for a frequency, for example, 40 Hz) to 10 (for a frequency, for example, 400 Hz). The duration of signal B (Fig. 2a) is 3-4 ms. One cycle consists of 4-6 frames. The amplitudes of the signals B and G (Fig 2a) on

0, the output of the D / A converter 33 is equal, since the conditions for the formation of signals of different frequencies are the same and are determined for all frequencies by the common elements of the frequency-controlled generator of 8 signals. Signals B h B (Fig. 2a) at the output of the monitored tape recorder 9, due to the unevenness of the frequency response of the channel, differ from each other in amplitude. These signals come in first and

0 second shapers 10 and 11 pulses. The first of them generates a pulse (Fig. 26) at the time of reproducing one of the signals included in the frame. As such a signal.

5, for example, a signal with a frequency of 4 kHz can be accepted as a compromise between a relatively small amount of spurious amplitude modulation at this frequency and a short time.

0 delay between the leading edges of the radio pulse at the output and the pulse at the output of the first Shaper 10 pulses (the delay time at this frequency is 3-4 periods, i.e.

5 less than 1 is not, which is acceptable for device operation.). At the same time, in the second pulse shaper 11, for example, the second pin is formed according to the frequency and amplitude characteristics.

five

(figv), corresponding to the moment of reproduction of the signal of the main measuring frequency. The pulses from the inputs of the first and second formers 10 and 11 pulses arrive at the input of the third pulse distributor 27, at the outputs of which pulses are formed that are shifted relatively each other in phase (Fig. 2d and e). These pulses arrive at the element 28 and the third group of elements 29. The pulse at the output of the second multivibrator 21 waiting (fig. 2e) is generated at the time the signal A or B is reproduced (fig. 2a) and is fed to the input of a separate element 28 and the first key 14, the signal from the output of the monitored tape recorder 9 through the first detector 13 and the first key 14 is fed to the input of the memory block 15. The first key 14 is opened by the output pulse of the second standby multivibrator 21 (Fig. 2e). In this moment

ten

15

20

the third harmonic of the signal of the main measuring frequency, for example 1200 Hz, and through the second detector 24 enters the second key 23 which is controlled by the signal from the output of the element 28 and opens at the moments of time corresponding to the reproduction of the signal of the main measuring frequency. Filtering the rectified signal, storing its amplitude for the time between two control pulses of the second key 23 and averaging are performed by the integrator 22. Thus, the constant voltage value at the output of the integrator 22 determines the value of the harmonic distortion factor, and at the output of the integrator group 17 - frequency response at low frequencies and the amplitude of the signal at the main measuring frequency. At the same time, the corresponding inputs of the switch 18 receive a signal directly from the output of the first detector 13 and from

time in the memory block 15 memorizes - 25 outputs of the generator of 19 pulses, with a peak value (amplitude) of the clock signal using the first key 14 of the signal A or B (FIG. 2a). Since the peak value is memorized, the requirements for pulse formation time 30 (FIG. 2e) are low, therefore, taking into account the deviation of the transport speed of the carrier, which is important, for example, when playing back a measuring tape recorded in the same way, the pulse duration (Figure 2e) must be less than the duration of the signal A and B (Fig. 2a). Simultaneously from the output of the first shaper 10, the signal arrives at the input 40 of the switch 18. At the output of the switch 18, a pulse is formed (Fig. 2g) arriving at the inputs of the third group of elements And 29, at the exit of each of

which produces a signal, for example, at a frequency of 10 kHz. Switch 18 alternately reads the DC voltages at the outputs of the respective group integrators 17, converts them into a sequence of video pulses, and also fills the video pulses with the frequency of the pulse generator 19, 29 Signals D (Figure 2k) determines the frequency response at low frequencies. The input of the oscilloscope 26 is also switched in real time by the rectified signals of the middle and upper frequencies. Signal E (Fig. 2k) determines the frequency response at mid and high frequencies. The oscilloscope 26 is synchronized by pulses from the output of the second driver 11 pulses. The level of the signals of the output of the integrators of which is formed by a pulse (2h), 45 and 22 degrees CLEAR group integrators 17 at the output of the switch 1b can be measured using the indicator 25. noise operator turns off the output of the DAC 33,

equal to the operation of the corresponding key 16 of the third group of keys 16. This key 16 rewrites the signal from the output of the memory block 15 into

one of the integrators 17. The signal c you-50 records a pause after the next cycle of the multivibrator 1 clears the information in the memory block 15 after rewriting. Each of the integrators 17 averages the information in the course of the operation of the key 16 connected to it of the key 16 of the third group of keys 16. The signal from the output of the controlled tape recorder 9 through the band-pass filter 12 configured by

playback of the received site phonogram. The measurement of the noise level is made by the indicator 25. The non-uniformity of the frequency response of the monitored channel 9 is measured using a stencil printed on the oscilloscope 26. Recurrence of the induced norm body

five

0

the third harmonic of the signal of the main measuring frequency, for example 1200 Hz, and through the second detector 24 hits the second key 23 which is controlled by the signal from the output of the element 28 and opens at the times corresponding to the reproduction of the signal of the main measuring frequency. The rectified signal is filtered, its amplitude is memorized for the time between two control pulses of the second key 23 and averaged by the integrator 22. Thus, the constant voltage at the output of the integrator 22 determines the value of the harmonic distortion factor, and at the output of the group of integrators 17 - frequency response at low frequencies and the amplitude of the signal of the main measuring frequency. At the same time, the corresponding inputs of the switch 18 receive a signal directly from the output of the first detector 13 and

generator output 19 pulses on

which produces a signal, for example, with a frequency of 10 kHz. Switch 18 alternately reads the DC voltages at the outputs of the respective group integrators 17, converts them into a sequence of video pulses, and also fills the video pulses with the frequency of the pulse generator 19, 29; Signals D (FIG. 2k) determine the frequency response at low frequencies. To the input of the oscilloscope 26 is switched also in real time rectified signals of middle and high frequencies. Signal E (Fig. 2k) determines the frequency response at mid and high frequencies. The oscilloscope 26 is synchronized by pulses from the output of the second shaper 11 pulses. The signal level g of the output of the integrator 22 and ° DOWN P3 group integrators 17 at the output of the switch 1b can be measured using the indicator 25, To measure the noise level, the operator turns off the DAC output 33,

records a pause followed by

playback of the received portion of the phonogram. The noise level is measured using the indicator 25. The non-uniformity of the frequency response of the monitored channel of the tape recorder 9 is measured using a stencil printed on the oscilloscope 26. The repetition of the norm induced excludes flickering of the image on the oscilloscope 26, since it is 16-18 Hz.

Claims (1)

Apparatus of the Invention A device for measuring the parameters of a tape recorder, comprising a series-connected multivibrator, first and second pulse distributors, the first of which is connected by outputs to the control inputs of the first group of keys, the inputs of which are connected to the control bus and connected to the inputs of the second group of keys connected for 15 days pulse distributor control inputs to the corresponding outputs of elements AND of the first group, connected by interconnected one inputs to the last output of the first pulse distributor and the input of the second pulse distributor, and also connected by other inputs to the corresponding outputs of the second pulse distributor signal generator connected by inputs to the corresponding outputs the first and second groups of keys and the output to the input terminal of the tape recorder under test, the output terminal of which is connected to the inputs of the two driver pulses, band-pass filter and the first detector, connected via the first key to the input of the memory block and connected by the outputs via the keys of the third group and the group of integrators with the corresponding group of inputs of the switch connected by the first input to the output of the pulse generator, the second input - to the output of the first imager pulses connected by the input through the first and second waiting multivibrators with the control input of the first key, the third the input — with the output of the first detector, the fourth input through the integrator, the second key and the second detector — with the output of the flat filter, as well as the corresponding inputs — with the control input of the memory unit and the inputs of the indicator and oscilloscope connected by a synchronization input to the output of the second pulse shaper, characterized in that, in order to reduce the measurement error of the parameters of the tape recorder with the acceleration of the measurement process, five additional element And and elements AND of the second group, connected by one input to the corresponding outputs of the third pulse distributor, other inputs to the first output of the switch, and outputs to the control inputs of the keys of the third group, the third pulse distributor connected by the corresponding inputs to the outputs of the first and the second one (pulse widther, and the signal generator is designed as a series-connected controlled multivibrator, whose inputs are the corresponding inputs of the generator signals, a pulse counter, a persistent storage device and a digital-analog converter, the output of which is the output of a signal generator connected by a control input to the output of the last element AND of these elements of the first group, and an additional element And connected by one input to the output of the second standby multivibrator , by another input, to the corresponding output of the third pulse distributor and output, to the control input of the second key, five 0 In P to Hiiro Fi.2