SU566405A1 - Circuit for measuring the minimum duration of the fronts of videosignals - Google Patents

Description

gaseous pulse generator 2, the inputs of which are supplied with a video signal, converter 3 is a differential signal — amplitude and a display unit 4, a comparison unit 5, a controlled voltage divider 6, a control unit 7, an AND 8 element connected to the first input of the former shaper pulses 2, the second output of which is connected to the first input of the control unit 7, and the second input — simultaneously to the output of the converter I, the steepness of the front — the amplitude and the first input of the control unit 5, and the output of the And 8 element are connected to the second input of the comparison unit 5,through which converter through signal converter 3 is a differential signal - the amplitude is connected to the output of the controlled voltage divider 6, and the output of the comparison unit 5 is connected to the second input of the control unit 7 connected by the control outputs, and the display outputs, respectively, to the Ahrda of the controlled divider voltage 6 and the inputs of the display unit 4, the input of the converter 1 is the steepness of the front — the amplitude is connected to the signal input of the controlled voltage divider 6. The control unit 7 contains the pulse distributor 9, code registers 1O and display 11, and the display unit 4, the decoder 12 and digital indicators 13. The meter works as follows: the video signal enters the shaper of 2 X pulses, the transducer 1 is the front slope - amplitude. and through the controlled voltage divider 6 - into the converter 3 Signal difference - amplitude. The pulses formed in the converters 1, 3, whose span is proportional to the steepness of the video signal fronts and the steady-state values of the video signal drops, arrive at the comparison block 5. In the initial state, the distributor. pulses 9 is set so that the voltage divider 6 used has the maximum attenuation coefficient. In those cases, when 17 V., the overcompensation signal from the output of the comparison unit 5 enters the register 10, allowing overwriting of information from it pulse distributor 9. Clock pulses, in which quality:; staffing; The sync pulses targeted in the extinguished pulse shaper 2 are inserted into the pulse distributor 9, switching it and, accordingly, the controlled voltage divider 6 to the next position. In this case, the comparison and rewriting into the register 10 is performed again. This process continues as many times as the bits B of the controlled divider 6. Consequently, by the end of the measurement cycle in the register 10, the recorded information on those attenuation coefficients where at least for one frontage; the signal is valid as U ,, j. At the end of the measurement cycle, the pulses from the pulse distributor 9 are sent to the registers of code 10 and display 11, the information is overwritten in the display register 11 and the register is reset and code 10. The decoder 12 is designed so that at its output there is a decimal code corresponding to the minimum attenuation coefficient recorded in the display register 11. The control signal from the decoder 12 is fed to the digital indicators 13. To prevent measuring the duration of the edges of the dimming and synchronizing impulses that do not carry information. : the sharpness of the reproduced images, the comparison block 5 is interrogated by a signal coming from the output of the element And 8, when the inverted extended damping pulses and pulses at the output of the transducer 1 coincide in time, and the front is amplitude. The proposed device provides high measurement accuracy by eliminating measurement errors. Formula from a scanner Measuring instrument of the minimum duration of the video signal fronts, containing the front slope converter. - amplitude, driver of damping pulses, at the inputs of which a video signal is fed, converter differential signal - amplitude and display unit, characterized in that, in order to improve the measurement accuracy, a comparison block, a controlled voltage divider, an control unit and an element are entered into it And, connected by the first input to the first output of the quenching pulse generator, the second output of which is connected to the first input of the control unit, and the second input — simultaneously to the output of the converter — the slope of the front — the amplitude and the first input Comparison unit, automatic input of element I is connected to the second input of the comparator unit, the third input of which through a converter is the differential signal amplitude connected to the output of the controlled voltage divider, and the output of the comparator unit connected to the second input of the control unit connected to the control outputs and display outputs respectively to the inputs of the controlled voltage divider and the inputs of the display unit, the input of the converter being steep to the front; It is connected to the signal input of a controlled voltage divider.

Sources of information taken into account in the examination of the invention

1 .. USSR Author's Certificate No. 314326, M.cl. H 04 N 7/02, 15.05. 1970.

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