SU1411819A1 - Device for measuring signal mismatch - Google Patents

Description

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The invention relates to instrumentation, namely, devices for measuring signal error.

The purpose of the invention is to reduce the measurement measurement accuracy by decreasing the effect of a change in the speed of two-way magnetic recording media. The drawing shows the functional diagram of the device for measuring the error of signals about

The device for measuring the error of the signals contains the first and second comparators 1 and 2 connected by outputs to the inputs of the first and 15 second multivibrators 3 and 45 of the adder 5 and the input and output pshnk 6 and 7. In addition, the device for measuring the error of the signals contains the first and second band-pass filters 8 and 9, connected by inputs to the same input bus b, the third and fourth band-pass filters 10 and i1J, connected by inputs to another input bus 6, the inverting amplifier - 25, tel 2, first, second and the third switches 13s i and 15, - the third computer rator 16, pulse generator 17, IS trigger, NE-NE element 19, counter 20 11 pulses, setpoint master 21 codes, register 30 and 22 and first and second elements 23 and 24, and adder 5 made in the form of a reversible counter 5 And; the first switch 13 is connected by an output to the input of the first comparator 1, es by the first input to the output of the second band-pass filter 9 and the second input through an inverting amplifier 12 to the output of the first band-pass filter 8o

The second switch 14 is connected by output to the input of the second comparator 2, the inputs to the outputs of the third and fourth band filters 10 and 11 - and the control input to the interconnected control input of the first switch 13 and the third comparator 16, connected by one group of inputs to the outputs of the master 21 codes and another group of inputs to the group of output buses 7 and with the outputs of the third switch 15 connected to the control LIAUSH. The input to one of the output buses 7 and to the output of the trigger 18 and inputs to the outputs of the register 22, Register 22 podso union of a control input to the control input of the reversible counter 5 and the output of the pulse counter 20 and the inputs to the outputs of the down counter 5 connected sum50

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the second input And the second element And 24 and the subtractive input with the output of the second element And 24, The second element And 24 is connected by the first input to the interconnected output of the generator 17 pulses and the first input of the first element And, the second input to the interconnected output of the element I- NOT 19, the input of the counter 20 pulses and the second input of the first element I 23 and the third input to the inverted trigger trigger 18 "Trigger 18 is connected by an output to the third input of the first element And 23 and inputs to the outputs of the first and second waiting multivibrators 3 4, the AND-NO element 19 is connected to the inputs to the outputs of the first and second comparators 1 and 2a

The device works as follows.

When playing a test signal from the left and right channels of a stereo recorder, input signals 6 are sent to the input buses 6 to monitor the amplitude-frequency characteristics of the tape recorder and to control the tilt angle of the working gaps of the magnetic heads (meaning the standard measuring tape ZLIT2. CHN.4)., Bandpass filters, 8-11, select a burst of pulses of corresponding frequencies. With large mismatch values, the upper frequencies are not reproduced, and therefore the first and second switches 13 and 14 are switched on to transmit bursts of lower-frequency pulses. The comparators and 2 of the pulses coming from the outputs of the first and second switches 13 and 14 form rectangular pulses whose durations are equal to the time intervals between the instantaneous amplitudes of the input signals equal to the reference voltage levels supplied to the second switches of the Pr switch. Coal pulses from the outputs of Comparators 1 and 2 are fed to the inputs of the AND-NE element 19, which forms at its output. Right-angle pulses, the duration of which corresponds to the magnitude of the signal mismatch, and For each positive half-wave of the input signal, two mismatch pulses are generated, respectively, between the leading and trailing edges of the rectangular pulses

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 multivibrators 3 and 4 produce single short pulses on each front of the input pulse that control the trigger 18 In case the input signal on one of the input buses 6 is ahead of the input signal on the other input bus 6, then the output of the trigger 18 is present logical unit and thus the operation of the first element AND 23 returns. Otherwise, the operation of the second element AND 24, rectangular impulses from the output of the element, is permitted. AND-NOT 19 is fed to the inputs of the first and second elements And 23 and 24, where the clock pulses from the output of the generator 17 pulses. At the output of element 23 and element 24, depending on the state of the outputs of trigger 18, there are clock bursts, the number of which corresponds to the duration of the error signals. Reverse counter 5 accumulates them and a binary digital code corresponding to twice the value is generated at its output for one period of the input signal mismatch of the signals, respectively, for n periods of the input signal at the output of the reversing counter 5 a doubled sum of the values of the error of the signals is formed, and in the counter 30 , the counting input of which also receives pulses from the N 19 element, the specified number about Counter 20 generates a transfer signal through a specified number of input pulses, and: it zeroes itself. According to the transfer signal from the counter 20 to the register 22, a digital code is recorded, and in such a way that the high-order bit arrives at the zero-bit of the register 22 Has has been provided with these actions; the accumulation of mismatch values and their averaging over a given number n of periods of the input signal O Reverse counter 5 by the second rectangular impulse coming from the output of the element IS-HE 19 work to subtract, while the result remains equal to two. The work of the reversible counter 5 on the subtraction takes place in the presence of a logical unit at the inverse output of par 18. This takes place under the control of single pulses, developed

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first wait multivibrator 3, i.e. pulses corresponding to the signals received on one bus 6 o

Depending on the order of the signals on the input buses 6, at the forward output of the trigger 18, either a logical one or a logical zero is present at the end of the measurement, which are the control signals for the third switch 16, the Third switch 16 according to the logic level of the signal present its control input transmits direct or inverse digital codes from the corresponding outputs of register 22 to the output information bus 7, so that regardless of the code at the output of the reversing counter 5, the output information bus 7 received only a direct numeric code. The control signal. The third switch 15 is also transmitted to the output bus 7, the logical value of its level determines the sign of the result. The output digital code from the output of the third switch 15 is compared by the third comparator 16 with a digital code corresponding to the value of the lower limit of the measurement of the magnitude of the error of the signals that can be achieved when conducting measurements at a lower frequency. This is due to the fact that standard tapes on the frequency do not guarantee high measurement accuracy. High measurement accuracy is guaranteed at the upper frequencies of the standard signal graph. Therefore, when a digital code is received at the first input, corresponding to the magnitude of the mismatch of signals If the signal is switched in the form of a digital code on the second codes of the third comparator 16, then a signal is generated at its output that switches the first: And the second analog switches 13 and JA pass the signals from 8 and 10 upper band pass filter outputs. At the top frequency device. works in a similar way

Claims (1)

Using the device, it is possible to measure the in-phase electrical output of stereo channels of tape recorders. A device for measuring the error of the signals, containing five 0 five 0 five 514118 The second and second comparators are connected. outputs to the inputs of the first and second standby multivibrators, the adder and the input and output buses, it is due to the fact that, in order to reduce the measurement error by reducing the effect of changes in the speed of movement of the magnetic recording media, the first Yu and second band filters were introduced into it connected to the same input bus by the inputs, the third and fourth band-pass filters connected to the other input bus, Inverting amplifier, the first, the second J5 and the third switches, the third comparator, a pulse generator, a trigger, an element AND NOT , pulse counter, code setter, register, and the first and second elements AND, and the adder are out-. 20 is not in the form of a reversible counter, with the first switch connected to the input of the first comparator, the first input to the code of the second bandpass filter 25 and the second input through an inverting amplifier to the output of the first bandpass filter, the second switch connected to the output of the second comparator, inputs to outputs o the third and fourth bandpass: filters and control input to the co-; 9 . 6 between the control input of the first switch and the code of the third comparator connected by one group of inputs to the code sensor outputs and another group of inputs to the group of output buses and from the outputs of the third switch connected by the control input to one of the output buses and to the trigger output and inputs to the register outputs connected by a control input to the control input of the reversible counter and the output of the pulse counter and inputs to the outputs of the reversing counter connected by summing them with the output p of the second element And connected by the subtracting input with the output of the second element And connected by the first input to the interconnected output of the pulse generator and the first input of the first element And, the second input to the interconnected output of the element IS NOT the input of the counter I1-1 pulses and the second input of the first element AND and the third input to the inverse output of the trigger connected by the output to the third input of the first element AND and the inputs to the outputs of the first and second waiting multivibrators, and the element AND NOT connected to the inputs of the first and second Some comparators,