SU107390A1 - Synchronization of phototelegraph apparatus with variable sweep speed - Google Patents

Description

The invention relates to the field of phototelegraphic communication.

With a variable sweep speed in photo-telegraph devices, it is necessary to get equal reference frequencies at the receiving end by supplying correction pulses to the line, which follow an unequal sequence, but the time interval between which is a multiple of a reference value, for example, the synchronization frequency.

For this purpose, a high-stable reference frequency generator is usually used in transmission, from the oscillations of which auxiliary signals are formed, one of which is a correction pulse, which differs from other signals transmitted into a line by some parameter, for example amplitude. At the reception with the help of a correction pulse, the same onor frequency should be formed as in the transmission. The oscillation phase of the received frequency must be very stable and be in a certain constant relationship with the oscillation phase in the transmission.

Solving this problem usually leads to the construction of complex devices that do not have sufficient stability, or the use of autonomous synchronization systems with highly stable generators for transmitting and receiving, while difficult to adjust the phase is difficult.

The proposed device, the circuit of which is shown in the figure, has: stunen / extraction of the correction pulse coming from the line; multiply. frequency - multivibrator 2, synchronized by selected correction pulses; oscillatory circuit 5, tuned to the main synchronization frequency; developing stage.

The device operates according to the method of synchronization of devices with variable sweep speed, in which, for the purpose of synchronizing the devices of the receiving and transmitting parts of the phototelegraphic communication, the main message is sent from the image emulsions (1) sent during the transmission of the image clock frequency using frequency multiplier for example

l ultivibrator, with a variable multiplication factor. The multivibrator, in order to stabilize its operation in the time intervals between incoming correction pulses, is loaded on an oscillating circuit, which is tuned to the main synchronization frequency.

Here, the multiplicity of the time intervals between the pulses is assumed.

Subject and title

The synchronization device of phototelegraphic apparatuses with variable sweep speed with the help of correction pulses or pulses having any distinguishing feature, such as amplitude, given

from transmission through different but multiples of time intervals, characterized in that, in order to synchronize the receiving and transmitting apparatuses with variable sweep speed, the simplest amplitude selector is turned on at the receiving end, which extracts the horizontal correction pulses from the signal and captures multiple harmonics of these pulses a vibrated multivibrator at the synchronization frequency, moreover, to achieve the necessary stability of the oscillation frequency of the multivibrator in the intervals between the horizontal correction pulses applied oscillatory circuit, which is the load of the multivibrator and tuned to the synchronization frequency.

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