SU1220140A1 - Frequency-selective splitter of low-frequency signals - Google Patents

Description

I1

The invention relates to general-purpose electronic devices and can be used in systems for analyzing and synthesizing low-frequency signals of various nature, in particular speech.

The purpose of the invention is to increase the frequency selectivity and expand the range of operating frequencies.

FIG. 1 shows a frequency selective splitter of low-frequency signals, a general view; in fig. 2 shows section A-A in FIG. one; in fig. 3 - the node T in FIG. 2

The frequency-selective splitter includes a housing with a cavity 1 with a decreasing inner section along the length of the device, filled with a liquid, such as water 2, fixed in an expanding slot on the side surface of a pre-transversely tensioned membrane 3 that is located at the end pipes input electromagnetic electromechanical transducer 4 with a moving system 5 in contact with a liquid, a set of electrodes 6 arranged perpendicular to the longitudinal axis with a constant pitch along the entire length on the outer surface of the membrane and connected by their taps 7 through a set of matching amplifiers 8 to the outputs of the device 9, a gasket made in the form of, for example, two strips 10 connected in the membrane over the electrodes, an elastic plate 11 made from a material with electret properties, mounted above the set of electrodes and connected to an elastic gasket, and a common grounded electrode 12 located across the entire outer surface of the elastic plate.

The device works as follows.

When an electric signal is applied to the input electromechanical transducer 4, a set of traveling waves propagating along the membrane with frequency-dependent peaks is excited in the splitter, and there is an unambiguous relationship between the spatial position of the oscillation maxima and the spectral composition of the input signal. The presence of an elastic bond 10 between the membrane 3 and the elastic plate 1I concludes

vibrations associated with the membrane in the region of large wavelengths, however, as one approaches the resonance by decreasing the wavelength

the oscillation increases due to an increase in the longitudinal rigidity of the elastic plate 11 mismatch in its oscillations with respect to the membrane 3. The oscillations arising in this case

The capacitances of the elementary capacitors formed by the electrodes 6 and the common electrode 12, in the presence of a constant electric field determined by the electret properties of the plate 9, cause potentials on the electrodes that are proportional to the displacement of the elastic plate relative to the membrane, which are outputted to the device. So

Thus, the selective splitting of the input signal to the frequency components is carried out, and due to the separation of the difference vibrations of the membrane and the elastic plate, proportional to the fourth spatial derivative of the vibrations of the membrane, the selectivity of the coupler is significantly increased while maintaining the temporal characteristics,

inherent in the process of propagation of vibrations along the membrane.

When changing the geometry of the hull. the slot, the thickness of the membrane and the material used for it are possible both by varying the magnitude of the operating frequency range and shifting it to lower or higher frequencies; the upper limit of the operating frequencies of the proposed branch is limited by the speed of sound in the liquid.

Claims (2)

1. The frequency-selective splitter low-frequency signals, comprising a housing with a cavity filled with a liquid, such as water, and with a slot on the side surface. as well as longitudinally fixed above a slotted flat membrane of variable width, an elastic plate located above the membrane, and an electromechanical transducer installed at the end of the body, characterized in that, in order to increase frequency selectivity and extend the working hours: the elastic strip is inserted between membrane and elastic plate, and sensors displacing the surface of the membrane dispersed along the length of the membrane, while the cavity in the housing is filled with decreasing length along the cross section, and the membrane is made with variable transverse tension. 2201404 2. Splitter according to claim 1, which is tactile because the sensors are made in the form of a series of transverse electrodes located on the surface of the membrane, and a common grounding electrode located on the outer surface of the elastic plate, while the plate is made of a material with electret properties. .f and 2 12 P VNIIPI Order 1334/61 Circulation 624 Subscription Branch of PPP Patent, Uzhgorod, ul. Design, D FIG.