SU1427602A1 - Device for investigating parameters of television receivers - Google Patents

Abstract

The invention relates to television. The purpose of the invention is to improve the accuracy and reliability of the control of television sets. The device contains an analog signal processing unit 1, switches 2, 4 and 8, low-pass filter 3, A / D converter 5, adder 6, television receiver 7, multiplier 9, control unit 10, code converter 11, print unit 12, display unit 13, memory blocks 14, 15 and 16, comparators 17 and 18, block 19 RF signal processing, sync selector 20, start-stop gr. 21, counter 22, control unit 23 of decoder 24, and shaper of 25 pages of pulses. To reduce the random component of the measurement error, independent unit measurements are repeated K times. With repeated measurements of the same magnitude and subsequent averaging by summing the K independent results and dividing the resulting amount by K, the rms measurement error is reduced, and the reliability of the control increases. The control unit 10 issues a command to repeat every single measurement of this parameter K times. The device monitors all parameters of the receiver 7. .1 il.

Description

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The invention relates to television technology and can be used in test and measurement systems for the operational testing and control of television receivers.

The purpose of the invention is to improve the accuracy and reliability of the control.

The drawing shows the structural electrical circuit of the device for monitoring the parameters of television receivers.

Device for monitoring parameters of television receivers containing block 1 analog signal processing first switch 2 low pass filter 3, second switch 4, analog-to-digital converter (ADC) 5, adder 6, television receiver 7, third switching 8, multiplier 9 control unit 10, converter 11 codes, printing block 12, block 13 in dication, three memory blocks 14-16, two comparators 17 and 18, high frequency signal processing block 19, sync selector 20, start-stop generator 21, counter 22, block 23 control decoder, decoder 24 gating generator 25 pulses.

The device works as follows.

Block 1 analog signal processing connects the television receiver to the input of the first switch 2 and normalizes the monitored signals in amplitude ..

The second switch 4 connects the output of the analog signal conditioning unit 1 through the first switch 2 and the filter 3 to the input of the ADC 5. Switching switches 2 and 4 is performed by the command of the control unit 10.

The determination of the point in time for performing the analog-digital conversion is as follows. The input high-frequency test signal is fed to the input of block 19 from the output of which the full video signal enters the sync-selective

torus 20 where short

synchronous and in-phase pulses with horizontal synchronizing pulses. The generated short pulses control the operation of the start-stop generator 21 and the counter 22,

A start-stop generator 21 is a self-oscillating multivibrator.

and having a control input to which short pulses are fed from the output of the sync selector 20. The pulse frequency at the output of the start-stop generator 21 is nfcTp, and the initial phase is set by a short pulse coming from the output of the sync selector 20.

The sequence of pulses with a frequency of nfcTp. enters the counting input of counter 22, with each pulse of the sequence changing the code at the output of counter 22, and a short pulse arriving at the reset input of counter 22 from the sync output of the selector 20 sets a zero code at the output of counter 22, which corresponds to the beginning of the line.

From the output of the counter 22, its code enters the decoder control unit 23 and the decoder 24, at the output of the latter a set of unitary codes are generated, each of which represents a sequence of pulses with a frequency fpage. The resulting set of codes is a time interval scale. One of the pulses of this scale, corresponding to the temporal position of the parameter being monitored, is fed to the input of the generator of 25 gating pulses. The selection of a specific pulse from the time scale is made by Koi-iaH, coming from the control unit 10. From the output of the shaper pulse generator 25, the signal is fed to the trigger input of the ADC 5, and at this moment the analog-to-digital conversion process takes place. The signal for its termination arrives at the input of the control unit 10, and the monitored signal is digitally fed to the inputs of the adder 6 and the third switch 8..

To reduce the random component of the measurement error, independent single measurements are repeated. With multiple measurements of the same magnitude and subsequent averaging by summing the K independent results and dividing the resulting amount by K, the root mean square measurement error is reduced according to the formula

S b x | g

where 6 is the standard error of the individual measurement.

For example, at K 16, the reliability of the control is increased by A times. The control unit 10 issues a command to repeat every single measurement of this parameter K times. The monitoring of all parameters of the television receiver 7 is carried out in this way.

The adder 6 accumulates the results of single measurements necessary for statistical processing.

When the number of measurements is K 2, the division operation required for calculating the arithmetic mean of the result is reduced to m shifts, after which the signal through the third switch 8 is fed to the inputs of the comparator 17, 18. The latter compare the signal obtained as a result of the control with reference values corresponding to the upper and lower tolerance limits. The values of the reference signals are read from the first and second blocks 14 and 15 of the memory. The results of the comparison operation are displayed by the display unit 13,

From the output of the adder, the binary value of the arithmetic mean of the monitored parameter is fed to the first input of multiplier 9, to the second input of which from the third memory block 16 a code of a number equal to the degree of signal normalization performed in block 1 of analog signal processing is read.

From the output of the multiplier 9, the signal is fed to the code converter 11, which generates the codes necessary for the operation of the printing unit 12 and the block. 13 indications.

Claims (1)

 Invention Formula A device for controlling television parameters of television receivers, containing an analog signal processing unit, the input of which is connected to the corresponding TV receiver outputs of an ion receiver, a control unit, the first and second outputs of which are connected respectively to the control input of the analog signal processing unit and to the first input of the former gating pulses, two comparator and the indicator block. V.NIIPI Order 4867/57 0 five about five 0 five 0 five 0 five In order to improve the accuracy and reliability of the control, a low-pass filter, three switches, an analog-digital converter, a high-frequency signal processing unit, a sync selector, a start-stop generator, a counter, a decoder, a decoder control unit, three memory blocks, an adder, a multiplier and a code converter, the first switch, the low-pass filter, the second switch, the analog-to-digital converter, the adder, the multiplier, and the code converter are connected in series between the analog signal processing unit and the first input of the display unit, the second and third inputs of which are connected to the outputs of the first and second comparators, a high frequency signal processing unit, a sync selector, start-stop generator, a counter, a decoder control unit and a decoder are connected in series between the television input the receiver, which is the input of the test signal, and the second input of the gating pulse former, the output of which is connected to the control input of the analogue digit The second converter, the second output of which is connected to the input of the control unit, the outputs of the first and second memory blocks are connected to the first inputs of the first and second comparators, respectively, the second inputs of which are combined and connected to the output of the third switch coder, the first and second inputs of which are connected respectively to the input and the output of the adder, and the control input of the third switch are connected to the third output of the control unit, the fourth output of which is connected to the control inputs of the first and second switches, the second output of the sync selector is connected to the second input of the counter, the second output of which is connected to the second input of the decoder, the output of the third the memory unit is connected to the second input of the multiplier, and the output of the analog signal processing unit is connected to the second the input of the second switch. Irage 660 Lodpisnoe