SU1506587A1 - Sync generator - Google Patents

Abstract

The invention relates to radio engineering and can be used in broadcast television and in applied television installations. The purpose of the invention is to simplify the synchronous generator by simplifying software and downloading programs. The synchronous generator contains a phase detector 1, a low-pass filter 2, a controlled oscillator 3, a driver of 4 pulse signals. The goal is achieved by introducing into the synchro-generator eight single-oscillators 5-12 and three dividers 13-15 frequencies, moreover, the single-oscillators and frequency dividers are made in the form of programmable timers. 1 hp f-ly, 3 ill.

Description

SP

SP

00

1

3 150 AND: the invention relates to the equipment and can be used in broadcast television and in applied television installations.

The aim of the invention is to simplify the clock generator by simplifying software and downloading programs.

Figs 1 and 2 respectively show the structural spectroscopic scheme of the synchro-generator and the pulse generator; in fig. 3 - time diagrams of signals, explaining the operation of the synchronous generator,

The synchronous generator contains a phase detector (PD) 1, a low-pass filter 2 (FR), a controlled oscillator (UG) 3, a driver of 4 pulse signals, the first 5, the second 6 and the third 7 single vibrators, the fourth 8, the fifth 9, the sixth 10, the seventh 11 and the eighth 12 one-shot, the first 13, the second 14 and the third 15 frequency dividers.

Shaper 4 pulse signals contains an inverter 16, a multiplexer 17 and the element And 18.

The clock generator works in the following way.

; An external synchronization signal arrives at the first input of PD 1 (Fig. 1) (when operating in the slave mode), and from the output of PD 1 through the LPF 2, the control signal enters the UG 3 input, adjusting its frequency to the external synchronization frequency.

The signal with a clock frequency (fig.Z) from the output of UG 3 is fed to the inputs of the first 13, second 14 and third 15 dividers and clock inputs of the first 5, second 6, third 7, fourth 8, fifth 9, sixth 10, seventh 11 and the eighth 12 one-shot.

The first divider 13 divides the frequency of the clock signal to the frequency of vertical scanning (Fig. 3, b). From the output of the first divider 13, the frame frequency signal arrives at the start-up input of the first one-vibrator 5, thereby restarting it each time. With the positive-edge drive, the first one-shot 5 produces a single pulse (FIG. 3, c) with a duration equal to the length of the first sequence of equalizing pulses (1 UI).

From the output of the first one-cycle 5,1; 1 otor 5, a single pulse arrives at the triggering input of the second one-vibration 6, the positive front triggers its start (Fig. 3B, c). From the output of the second one-shot 6, a single pulse (Fig. 3, d), according to the length of the equal duration of the personnel cIj signal, is fed to the third (control) input of the multiplexer 17 of the imaging unit 3 (Fig. 2-). At the second (control) input of the multiplexer 17 comes a single pulse from the output of the third one-oscillator 7 with a duration of Tu (Fig. 3, e) equal to

m-h-m

 V VH i KSK

+ t

yw I

0 5

0

five

0 5

0

five

where Tui, Tui of the duration of the first, second sequence of equalizing pulses (1UI and 2UI) and the frame sync pulse, respectively.

Under the action of signals acting on the control inputs of multiplexer 17, one of three sequences of signals is switched at its output: a sequence of equalizing pulses (Fig. 3, m) taken from the output of the seventh one-oscillator 11, an inverted sequence of equalizing pulses (Fig. 3 , n), taken from the output of the inverter 16 (Fig. 2), and a sequence of horizontal sync pulses (FID), taken from the output of the fifth one-oscillator 9 (Fig. 3, k), as a result of which the syncro signal is removed from the output of the multiplexer 17 mixture (fig.Z, o).

The sequence of equalizing pulses of a given duration is formed by the seventh single vibrator 11.

The frequency of the horizontal pulses with respect to the frequency of the equalizing pulses is determined by the third divider 15,

A sequence of horizontal sync pulses of a predetermined duration, removed from the output of the fifth one-shot one-shot 9, is obtained by restarting it on the front of the horizontal line signal of the horizontal frequency (Fig. 3,) coming from the delay line of the horizontal sync pulses relative to the horizontal damping pulses implemented on the fourth one-shot 8 , which the

in turn, it is triggered by a signal having the form of a meander and the horizontal scanning frequency (Fig. 3, g) and taken from the output of the second divider 14 of the clock frequency to the line frequency (Fig. 3, l). The same signal triggers the sixth one-shot 10, a horizontal lowering damping pulse (Fig. 3, h) on each positive edge at its triggering input. The sequence of these pulses arrives at the first input of an element 18, the second input of which receives a sequence of frame extinguishing pulses (fig. 3, e) from the output of the eighth one-vibrator 12 and a frame frequency signal triggered on the front of the frame (fig. 3, rf ). From the output of the element And 18, the quenching signal is removed (Fig. 3, i).

All timing parameters of the synchro mix and extinguishing mix are set programmatically during initialization of programmable timers, on the basis of which the first 5, second 6 and third 7 single vibrators, quarter 8, fifth 5, sixth 10, seventh 11 and eighth 12 single vibrators and the first 13, the second 14, the third 15 dividers, which allows to obtain arbitrary sync signals in an arbitrary decomposition standard.

Claims (2)

1. A synchronous generator containing a series-connected phase detector, a low-pass filter and a controlled oscillator, as well as a pulse shaper, the first input of the phase detector and the pulse shaper generator outputs are respectively the input and outputs of the clock generator, characterized in that, in order to simplify sync generator for q q five - five 0 five by simplifying the software and loading the programs, serially connected first and second single vibrators, serially connected first frequency divider and third single vibrator, serially connected second frequency divider, fourth single vibrator, third frequency divider and fifth single vibrator, and also the sixth , the seventh and eighth one-shot, while the triggering inputs of the sixth and seventh one-shot are connected respectively to the outputs of the second frequency divider and the fourth one-shot, run The tactile inputs of the first and eighth mono vibrators are combined with the second input of the phase detector and connected to the output of the first frequency divider, the input of which is combined with the input of the second frequency divider and the clock inputs of all single vibrators and connected to the output of the controlled oscillator, and the outputs from the second to the eighth one-vibrator are connected to the first - the sixth inputs of the pulse former, all the switches and the first, second and third frequency dividers are made in the form of programmable timers. 2. A synchronous generator according to claim 1, characterized in that the pulse driver comprises a series-connected inverter and a multiplexer, as well as an element, the second, third and fourth inputs of the multiplexer, the input of the inverter and the first and second inputs of the element AND, respectively The second, fifth, fourth, third, and sixth inputs of the pulse former, and the outputs of the multiplexer, inverter, and element And are the outputs of the pulse former.