SU438135A1 - Sync generator - Google Patents

Description

The invention relates to radio engineering, in particular to a television device, using synchronous generators, operating in the slave mode and providing accurate phasing across the fields of the master and slave television signals. In the well-known television signal generators with the front-end mode of operation, which contain the receiver synchronization signal selector, one of the output signals is co-connected with the input of field impulses of the Vedam TV signal through the sequentially connected horizontal line unit of the double line frequency and the section block 110 frequency, the second input of which is connected to the output of the key pulse former, the magnitude of the phase phasing error is in the range from 0.5 to 1H, where H is the length the accuracy of the line transition, which does not provide the necessary accuracy of the synchronization system and, processing when playing a color signal. The purpose of the invention is to provide accurate phasing by zeros when processing color information in the master television signal when the synchro-generator operates in the slave mode by reducing the phase phasing error to acceptable limits. This goal is achieved by the fact that the second output of the said selector is connected to one of the inputs of the key and multi-pulse mechanism via the delay line of the field pulses at 1/4 the length of the horizontal frequency period, the second input of which is connected to the output of the pulse-generator unit of the slave television signal through the delay line of the pulses of zeros by 3.4 the length of the horizontal scanning period. The drawing shows a block diagram of the Sihrogenerator. One of the outputs of the selector I of the synchronization signal is connected to the input of the immersioner 2 in the impulses of the fields of the driven television signal through the series-connected phase-locked loop of the horizontal horizontal frequency, the second input of which is connected to the output of the key generator pulse 5. Second output of selector 1 of the receiver synchronization signal through circuit b, delaying the pulses of the fields extracted from the signal by 1/4 of the period of the horizontal hour period tota, connected to one of the inputs of the key 5 pulse generator, to the second input of which the output of the block of the pulse generator of the slave synchronous generator field is connected via delay line 7

field pulses by 3/4 of the horizontal frequency period duration.

The sync denoise signal selector 1 is used to select the signal with the synchronization number of MDS receivers from the master television signal, integrate the MSP, and extract I1M field pulses and rows of the master television signal. The integration of the signal for the admission of naniemiCoV is done by TaiK, which, depending on the duration of the incoming pulse, changes the signal amplitude at the output of the integrating value, with this capacitance charge in the integrating circuit is carried out, according to a law, and practically iMrHoiBeiHwo.

Ta, kim image, maximal “aa; M: at the exit of the sawtooth impulse at the output of the integrating chain will belong to the mullein of fields cut through the sidebars. Shaper I1MpulsO | In the fields of the selector 1 SSP is adjusted so that it starts only maximum, m signal level and the output of the integrating circuit, resulting in a pulse frequency and output of the selector ZN.

With the help of the delay formation circuit 6, this field pulse is delayed by 1/4 of the horizontal frequency period duration (; 16 | Msec) and is formed by a duration TI of -15 microseconds.

The p1 pulse of the frequency of the iolins of cxp01nissar is formed at the output of the 1: 625 divider of the former 2 with a duration of 2.5 N and then delayed by 3/4 of the horizontal frequency period using a delay line and 7. At the output of this circuit, a pulse of fields is formed, the duration of the intersection. The frequency pulses of the fields TI and T2 are compared in phase in the pattern of the formation of a key pulse 5, the output of which is a frequency pulse, which is the duration of the difference between the temporal positions of the master TI and the slave T2 field pulses. The key pulse triggers the arrival of a double frequency line using the switch-off unit 4 to the 1: 625 divider of the pattern of generating pulse fields of the clock generator for a time equal to the duration of the key pulse. In this case, the delayed impulse of the fields of the T2 synchronous generator is shifted by the duration of the key pulse. This leads to the fact that the delayed pulses of the fields of the synchroganizer-torus coincide with the delays of the fields of the driving television signal.

Co1B1 offset ino time of the synchronization signal of the receivers of the synchro-generator with the SSP of the master television signal when phasing over to a fraction is ensured by the following conditions:

delay AND M1pulsov. fields of the synchro generator in relation to j the leading edge of the personnel clock pulse in the ERP of the synchro-generator is equal to the delay of i-pulses

the fields of the leading television signal: on the line from | Wearing to the leading edge of the cadre sync. synchronizing pulse in the MSP of the same signal;

led, the time delays in both channels were chosen such that the leading edges of the delayed pulses of the fields of the synchro-generator and the host television signal are in the middle between two pulses. D1VOY1NOY horizontal frequency;

the delay time of the TI and T2 pulses is chosen so that the phasing-off circuit included in the double horizontal frequency signal deactivation circuit works only with full co-operation of the I1M pulses of the master and slave signal, with the phasing precision lUo line-m .

Subject invention

thirty

The clock signal of the television signal with the slave mode of operation, containing a receiver synchronization signal selector, one of the outputs of which is connected to the input of the pulse former. The fields of the slave television signal through a series-connected double-phase phase-locked loop;

a double horizontal frequency signal, the second input of which is connected to the output of a key pulse pulse former, characterized in that, in order to process color information in a television master signal during

the work of the synchronous generator in the slave. The second output of the selected selector through the delay line of field pulses for 1/4 the duration of the horizontal frequency period is connected to one of the shaper key inputs

im.plyusa, the second input of which is connected to the output of the block of imager of field pulses of the driven television signal through the delay line of field pulses 3/4 of the length of the horizontal frequency period.