SU385388A1 - ULTRASONIC DELAY LINE - Google Patents

Description

one

The invention relates to radio engineering. The delay line can be used in color television receivers and color video monitoring devices according to the SECAM and PAL system.

An ultrasonic delay line is known, which contains a two-transducer sump.

The purpose of the invention is to provide a time delay of two independent signals.

The proposed ultrasonic delay line is characterized in that piezotransducers are fixed on the sound conduit so that their acoustic axes do not coincide, and the edges of the sound guide lines spaced from the piezoelectric transducers at a distance of half the nominal delay are perpendicular to the direction of ultrasonic wave propagation.

FIG. 1 shows the simplest embodiment of the proposed delay line; on fi1g. 2 variant of the proposed showers with additional internal reflections in the sump.

Consider first the construction shown in FIG. one.

Opposite working faces / and 2 sound ducts are plane-parallel. The acoustic length of the sound duct from one face to the other corresponds to half the line length. On one of the faces, for example, on the verge /, two piezotransformers 3 and 4 are fixed.

The electrical signals applied to the piezoelectric transducers create mechanical vibrations in the duct, which propagate along the acoustic axes of the piezoelectric transducers perpendicular to the faces of the piezoelectric transducers. Waves of oscillation income m to the edge 2 and, reflected from it, return to the edge /. Insofar as

face 2 is perpendicular to the direction of propagation of direct waves, each reflected wave returns to the piezoelectric transducer that created it, and is converted into an electrical signal in it. Because

the acoustic axes of the piezo transducers do not coincide, the signals from one piezo transducer to another do not fall. Thus, the proposed line delays two independent signals as two shortened lines. At the same time, the number of machined faces is halved, which reduces the cost of fabricating the sound duct.

FIG. 2 shows the second option of the proposed delay line. In this version

The rectangular acoustic duct has two diagonally located bevels 5 and 5. The piezo transducers are mounted on the opposing faces of the acoustic duct. Each ultrasonic wave comes from a piezoelectric transducer to

the oblique face of the sound duct, is reflected from it and at a right angle reaches the side face. Due to the fact that the forward wave falls on the lateral face at an angle, the reflected wave follows the same path as the forward one and returns to the piezoelectric transducer that created it, which ensures a separate delay of two independent signals.

Subject invention

An ultrasonic delay line containing a sound conductor with two transducers, characterized in that, in order to delay the time of two independent signals, piezo transducers are fixed on the duct so that their acoustic axes do not coincide, and the faces of the sound conductor spaced apart from the piezo transducers corresponding to half of the nominal delay, are lerindicular to the direction of propagation of ultrasonic waves.

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