SU1314483A1 - Device for converting peak-to-peak amplitude of colour subcarrier signal to d.c.voltage - Google Patents

Abstract

The invention m, b, is used in systems for monitoring and measuring the quality indicators of a television channel. The purpose of the invention is to expand the dynamic, range of transformable stresses. The device contains a band-pass filter I, comparators 2 and 8, D-flip-flop 3, integrator 4, adder 6, noise generator 7. Amplitude detector 5 is introduced, the introduction of delay line 10, multiplexer 11 and counter 9 allows oscillations to be formed at a frequency close to but not equal to the signal frequency of the color subcarrier, which allows the dynamic range to be expanded, the range of measured voltages. 1 il. hS

Description

The invention relates to television technology and can be used in systems for monitoring and measuring the quality indicators of a television channel.

The purpose of the invention is to expand the dynamic range of the voltages being transformed.

The drawing shows a functional electrical circuit of the device converting the magnitude of the color carrier to a constant voltage.

The device contains a band-pass filter 1, the first comparator 2, D- trigger 3, integrator 4, amplitude detector 5, adder 6, noise generator 7, second comparator 8, counter 9, delay line 10 and multiplexer 1 1.

The input signal filtered by the bandpass filter 1 is fed to the first input of the first comparator 2, where it is compared with the reference voltage supplied to the second input of the comparator 2 from the output of the adder 6. The output of the comparator 2 is connected to the D input of the D-trigger 3. To the second input Adder 6 is connected to the output of noise generator 7, and to the first input is the output of integrator 4, whose input is connected to the output of D-flip-flop 3. The output of TQpa 4 is connected to the input of amplitude detector 5, the output of which is the output of the device. The output signal of the bandpass filter 1 is also connected to the first input of the second comparator 8, the second input of which is grounded, and the output is connected to the counting input of the counter 9 and to the input of the delay line 10, the N outputs of which are connected respectively to the N information inputs of the multiplexer 11, controlling the inputs of which are connected to the corresponding outputs of the counter 9 and the output connected to the C-input of the D-flip-flop 3.

The signal-to-voltage-to-voltage-signal spreading device operates as follows.

The input signal of the color subcarrier through the bandpass filter 1 is fed to the first input of the comparator 8, where it is compared with the Earth potential and converted at the output of the comparator 8 into a pulse sequence with a frequency and phase corresponding to the frequency and phase of the input signal. This pulse is a follower.

In this way, the state at its outputs, which are controlled by a multiplexer 11, to the information inputs of which are connected N output lines of the delay line 10, to the input of which pulses are output from the comparator 8. The difference in the delays of two the adjacent outputs of the delay line 10 is, / N, where TC is the period of the color subcarrier. Since, when the state of the outputs of the counter 9 changes, the next input of the multiplexer 11 is connected to its next input, then the C input of the D flip-flop 3 is affected by pulses whose following frequency

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Consequently, at the output of the integrator 4, a voltage will be formed, the amplitude of which is equal to the amplitude of the chromaticity subcarrier and frequency. This alternating low-frequency voltage is detected by an amplitude detector 5, the output of which produces a constant voltage equal to the amplitude of the color subcarrier signal input to the input device of the color subcarrier signal's conversion to constant voltage.

Thus, the introduction of a delay line, a multiplexer and a counter into the device makes it possible to form; oscillations with a frequency close to, but not equal to, the frequency of the signal of the color subcarrier, which allows the dynamic range of the measured voltages to be expanded.

Claims (1)

Invention Formula A device for converting a signal span of a color subcarrier into a constant voltage containing series-connected band-pass filter, the input of which is the device input, the first comparator, the P-flip-flop, the integrator and the adder, the second input. which is connected to the output of the noise generator, and the output is connected to the second input of the first comparator, the first input of which is combined with the first input of the second kompar.ator, about t l and. 313144834 This is due to the fact that, with the purpose, whose outputs are connected to the N expansion of the dynamic range, the information inputs of the multiplexer, the transformed voltages, the control inputs of which are connected are the amplitude detector, the delay lines are connected to the outputs of the counter, and the output sub multiplexer and counter, counting 5 is connected to the C input of the D flip-flop, and the input of which is connected to the output of the BTO number N is equal to the ratio of the Rogo comparator, the second input of which subcarrier frequency to the upper boundary. euder frequency mplitudnogo detector.