SU1478383A1 - Broadcast television radio signal parameter tolerance check - Google Patents

Abstract

The invention relates to television technology and can be used in automated television transmitters. The purpose of the invention is to improve the accuracy of the tolerance control while simultaneously increasing the number of monitored parameters. To achieve the goal, two peak detectors 4, 5, four peak detectors 6–9 with gating, frequency converter 10, local oscillator 11, low-pass filter 15, frequency predistortion circuit 16, six scale amplifiers 17–22, block 23 , three subtractor 24-26, voltage follower 27, and two blocks 31, 32 of controlled reference voltages. Since the tolerance voltage depends on the voltage of the carrier sound, the tolerance control removes the dependence of the voltage at the output of the repeater 27 on the voltage of the sound carrier. Because Tolerance voltage depends on the voltage of the radio signal of the image, the tolerance control of the voltage of the radio signal of the image, proportional to the white signal level of the image, is carried out in relative units. 1 il.

Description

14, the bandwidth of which is 200 - 50 Noise frequency deviation of the carrier sound 250 kHz. Of the accompaniment, removed from the part

From the second output of the bandpass filter, the signal goes to the signal

The input of the peak detector 9 with gating, to the control input of which receives a sequence of pulses that open the peak detector 9 for a duration of 1}, 12 μs. Output is generated

loads of the peak detector 5, through the voltage follower 27 is supplied to the fifth signal input of the block 55 33. To the third and fourth reference inputs of the block 33 from the outputs of the second block 32 the tolerance voltages are received. Since these tolerance voltages depend on the magnitude of the direct frequency deviation of the sound carrier, removed from

loads of the peak detector 5, through the voltage follower 27 is supplied to the fifth signal input of the block 33. To the third and fourth reference inputs of the block 33 from the outputs of the second lock 32 the tolerance voltages are received. Since these tolerances depend on the voltage of the carrier sound, the tolerance control removes the dependence of the voltage at the output of the repeater 27 on the voltage of the sound carrier.

The 6.5 MHz difference frequency signal from the output of video detector 2 is separated by a band-pass filter 13, the transmission band of which is in the order of 1 MHz. This signal has the highest amplitude.

3B enters the video detector 3, the output of which highlights the envelope signal from the output of the video detector 3,

(passage through block 23 is tied by the vertexes of the pulses to zero. Next, the pulses are detected by the peak detector 8 with strobing with a constant time of 20 to 30-30 this part of its load a constant positive voltage of approximately 0.8 V enters to the scale amplifier 20 and further to the input of the subtractor 26, to the other input of which a voltage is applied equal to 1.58 V. As a result, the output of the subtractor 26 produces a constant voltage corresponding to the white signal level of the image Uf 0.75 V that pic upaet the fourth signal input of the block 33 comparators.

To the fifth and sixth reference inputs of the block 33, tolerance voltages are supplied from the corresponding outputs of the first block 31. Since these tolerances of the new voltages depend on the voltage of the image radio signal, the starting voltage control, proportional to the white level of the image radio signal, is carried out in relative units.

Constant positive voltage from peak detector output

4 is fed to the input of the scale amplifier 19. This constant voltage is fed to the input of the subtractor 25, to the other input of which a constant voltage is supplied equal to U m Je

 1.58 V. The differential voltage enters the third signal input of block 33, and the seventh and eighth reference inputs receive tolerance voltages from the corresponding outputs of block 29 of the reference voltages.

The control input of the peak detector 7 with gating receives a sequence of pulses from

,

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Coverage detector for a C2 duration of 7 µs. Since the duration 2 coincides with the rear part of the line damping pulse, a constant positive voltage is generated at the output of the peak detector 7, which is proportional to the sum of the voltages. This voltage is fed to the scale amplifier 18 and then to one of the inputs of the subtractor 24, to the other input of which a constant voltage is applied. As a result, the output of the subtractor 24 produces a constant voltage equal to the needle 3.75 V, which is fed to the second signal input of the block 33, and the ninth and tenth inputs are the tolerance voltages from the corresponding outputs of the first block 31. Since the output voltages are Unit 31 depends on the magnitude of the image radio voltage, the tolerance control of the voltage corresponding to the level of quenching is carried out, in relative units.

The color burst signal in the red line, present at the output of video detector 2, is separated by a band-pass filter 12 with a center frequency of 4.75 MHz and a passband of about 50 kHz, and as a sequence of packets of radio pulses it arrives at the signal input of the peak detector 6 with gating, constant the discharge time is of the order of 1 min. From the load part of the peak detector 6, this voltage, approximately 1.5 V, is fed to the input of the scale amplifier 17, the output voltage of which is set (when adjusted) to the amplitude of the color burst signal in the red line 1.35 V. To the first signal input of block 33. To the eleventh and twelfth reference inputs of block 33, tolerance voltages are received from the corresponding outputs of block 31, making tolerant control of the color synchronization signal voltage in relative units.

If the voltage at any of the signal inputs of block 33 is greater and less than the corresponding voltages at the lower and upper reference inputs, then the measured voltage (monitored parameter) is within

set tolerance and the corresponding output of the block 33 produces a voltage - logical zero. Otherwise, a voltage is generated - a logical unit.

If the voltages at all measuring inputs of block 33 are within the tolerance, then all the outputs of this block produce voltages - a logical zero, under the influence of which a voltage - a logical zero appears at the output of the block WE. This means that all parameters controlled by the device are within tolerance. If at least one of the voltages at the measuring inputs of block 33 is out of tolerance, at one of the outputs of this block, the voltage is a logical unit, as a result of which the output of block 34 produces a voltage of logical unit. This means that one or more of the monitored parameters are out of tolerance. If there is no color synchronization signal (image in black and white) when other controlled parameters are within the tolerance, there will be no constant voltage at the output of the scale amplifier 17, as well as at the first signal input of block 33 and at the seventh input of block 34, and the sixth output of block 33 according to Vits is the voltage of a logical unit. In this case, under the influence of these voltages, a voltage is generated at the input of the unit 34 at its output — a logical zero, which means that all monitored parameters are within tolerance.

Formula of the invention

. A device for controlling the parameters of a broadcast television signal containing three video detectors, three bandpass filters, a comparators unit, six outputs of which are connected to the corresponding six inputs of a control signal generating unit, the seventh input of which is connected to the first signal input of the comparators unit, connected in series to a stabilized constant source stress

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and the reference voltage block, the first, second, third and fourth outputs of which are connected respectively to the first, second, seventh and eighth inputs of the reference signal of the comparators block, and the inputs of the first and second video detectors are combined and are the radio signal of the broadcast television, and the output of the first video detector connected to the input of a gating pulse unit, characterized in that, in order to improve the accuracy of the tolerance

5 controls while simultaneously increasing the number of monitored parameters, two peak detectors, four peak detectors with strobing, a frequency converter, a local oscillator, a lowpass filter, a frequency filter, a frequency predistortion circuit, six scale amplifiers, an anchor block, three subtractors, a voltage follower and two controllable support blocks

5 voltages, the first bandpass filter, a peak detector with gating and a scale amplifier are connected in series between the output of the second video detector and the first signal input of the comparators unit, the second peak detector with gating, the second scale amplifier and the first subtractor are connected in series between the input of the first vi (Deodetrator and the second signal input of the comparator unit, the first peak detector, the third large-scale amplifier and the second finisher are connected in series between the input of the first video detector and the third signal input of the comparators block, the second bandpass filter, the third video detector, the anchor block, the second peak detector with gating, the fourth scale amplifier and the third compiler are connected in series between the output of the second video detector and the fourth signal inputs of the comparator block, a frequency converter, a low-pass filter, a frequency distortion circuit, a fifth scale amplifier, a second peak detector, and a voltage follower are connected in series between the first Odom block strobe pulses and a fifth signal, the input comparator unit, the third bandpass filter, a peak detector with the fourth and sixth gating

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five

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71478383

the scale amplifier includes the fourth, fifth and sixth outputs in series between the output of the first one and the sixth, sixth, tenth, input of the comparators block, the building of the eleventh and the twelfth inputs, respectively; The inputs of the third and fourth-5 reference signal of the comparators block, that of the peak detectors from the gates-output of the sixth scale amplification are connected to the second output connected to the input of the second block of the gating unit, the first x reference voltages, the first and second outputs of which are connected ... the second and second outputs of which are connected to the gate inputs corresponding to the third and even first and second peak detector inputs of the reference signal of the block of tori with gating, the output wto-comparators, the output of the heterodyne of the subtractor is connected to the input of the switches to the second input of the converter of the first block, controlled by the reference | 5 l of frequency, the third input of which is voltage, the first, second, third

bandpass filter.

Claims (1)

Claim An admittance control device for parameters of a broadcast television radio signal, comprising three video detectors, three bandpass filters, a comparator unit, six outputs of which are connected to the corresponding six inputs of the control signal generating unit, the seventh input of which is connected to the first signal input of the comparators unit, a stabilized constant voltage source and reference voltage unit, the first, second, third and fourth outputs of which are connected respectively to the first, second y, the seventh and eighth inputs of the reference signal of the block of comparators, and the inputs of the first and second video detectors are combined and are the input of the radio signal of broadcast television, and the output of the first video detector is connected to the input of the block of strobe pulses, characterized in that, In order to increase the accuracy of the tolerance 15 control while increasing the number of monitored parameters, two peak detectors, four peak detectors with gating, a frequency converter, a ₂₀ oscillator, a low-pass filter, a frequency predistortion circuit, six scale amplifiers, a reference unit, three subtractors, a repeater were introduced voltage and two blocks of controlled reference voltage 25, and the first band-pass filter, a peak detector with gating and a scale amplifier are connected in series between the output of the second about the video detector and the first signal input of the comparator unit, the second peak detector with gating, the second large-scale amplifier and the first subtractor are connected in series between the input of the first video detector and the second signal input OOS '' the house of the comparator unit, the first peak detector, the third large-scale amplifier and the second subtractor are connected in series between the 4Q input of the first video detector and the third signal input of the comparator unit, the second bandpass filter, the third video detector, the binding unit, the second peak det a gated projector, a fourth scale amplifier and a third subtractor are connected in series between the output of the second video detector and the fourth signal input of the comparator unit, a frequency converter, a low-pass filter, a frequency predistortion circuit, a fifth scale amplifier, a second peak detector and a voltage follower are connected in series between the first output of the unit gating pulses and the fifth signal, the input of the comparator unit, the third bandpass filter, the fourth peak detector with gating sixth ' Ί a scale amplifier is connected in series between the output of the first video detector and the sixth signal input of the comparator unit, the gating inputs of the third and fourth peak detectors with gating are connected to the second output of the gating pulse unit, the first and second outputs of which are connected to the gating inputs of the first and second peak detectors with gating , the output of the second subtractor is connected to the input of the first block, controlled reference voltages, the first, second, third, fourth, fifth and w the net outputs of which are connected respectively to the fifth, sixth, ninth, tenth, eleventh and twelfth inputs ^{5 of the} reference signal of the comparator unit, the output of the sixth large-scale amplifier is connected to the input of the second block of controlled reference voltages, the first and second outputs of which are connected respectively to the third and fourth the inputs of the reference signal of the comparator unit, the local oscillator output is connected to the second input of the frequency converter, the third input of which is connected to the second output of the third band-pass filter.