RU1778915C - Electroacoustic converter - Google Patents

Abstract

The invention relates to electroacoustics and, in particular, to designs of differential electromagnetic transducers with a moving core. The anchor is made in cross section in the shape of an isosceles trapezoid with an optimum angle of 120 °; between its lateral sides, which form two uniform thicknesses of the air gap with the beveled pole ends of the electromagnetic circuit, and the larger base of the core is located along the direction of its oscillatory motion and is attached to a double-sided spring mounted on the pole tip of the permanent magnet, and the end of the tip with the base of the core forms an air gap. The end of the pole tip of the permanent magnet facing the core is made with a thickening in the shape of a trapezoid. 3 ill.

Description

The invention relates to electroacoustics and, in particular, to designs of differential electromagnetic transducers with a moving core.

The purpose of the invention is to increase sensitivity and expand the frequency range.

Figure 1 presents a longitudinal section of the Converter; figure 2 is a perspective view of a core with a double-sided spring; in Fig.Z is an enlarged section of the core with pole tips.

The electro-acoustic transducer contains a permanent magnet 1, pole pieces 2 and 3 attached to the magnet, an electromagnetic coil 4, a core 5, an upper core 6, a core 7, its larger base 8, which is attached to a double-sided spring 9, and a rod 10 made for integral with the core and connected to the diaphragm 11. A rectangular window 13 is made in the pole piece 3, into which the core 5 is pressed

and the upper core 6 of the electromagnetic circuit is attached to its bent edge with a screw. The cross section of the core 7 is made in the form of an isosceles trapezoid with an optimum angle of 120 ° between its lateral sides, which with the beveled ends of the cores 5 and 6 form the same thickness of the air gaps 13 and 14. The larger base 8 of the core 7 with the pole tip 2 forms an air gap 15, moreover, the pole tip is made with a thickening in the shape of a trapezoid. The thickness of the air gaps 13 and 14 in the direction of passage of the magnetic flux through them, indicated by the value m, is associated with the size of the gap Y in the direction of the vibrational movement of the core by the ratio of Y 2m determined by the optimal angle of 120 ° section of the core 7. The design of core 7 with a trapezoid cross-section provides it with the smallest mass, reduces the return force of the spring, and two-sided execution at xI

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In the case of the grain, it contributes to the directional oscillation of the core together with the diaphragm 11. The tapered ends of the cores 5 and 6 and the thickened end of the pole piece 2 achieve an increase in the area of the air gaps coming to them, and, consequently, an increase in their magnetic conductivity.

Electro-acoustic transducer operates as follows. An anchor 7 in the absence of a sound frequency current in the coil 4 of the electromagnetic circuit is affected by the resultant of two equal forces of magnetic attraction from the side of the beveled ends of the cores 5 and 6, which is compensated by the tensile reaction of the bilateral spring 9, and on the opposite side, the core 7 is under the influence of the magnetic force of the pole piece 2, which is compensated by the longitudinal compression of the spring 9, as a result of which the measles is balanced on two opposite sides by acting on about the forces of attraction of a permanent magnet 1. If there is an audio frequency current in coil 4, the alternating magnetic flux generated by it in one of the air gaps, for example, at 13, is added to the flux of the permanent magnet, and in the other, for example, at 14, it is subtracted from it, as a result of which the balance of core 7 is disturbed and it moves towards that gap, where both magnetic fluxes, in the same direction, are folded and vibrate the measles in the Y direction of air gaps 13 and 14. A double-sided spring 9 fastened to the core 7 and the pole tip 2, bending, provides a directional oscillatory movement of the diaphragm 11. Attached to the rod 10 core 7.

The converter can also work in the reception mode, i.e. in microphone mode. The sound waves that act in this case on the diaphragm 11 cause it to oscillate, which through the rod 10 is transmitted to the core 7, which changes the magnetic flux crossing the coils of the coil 4 with the excitation of a variable emf in them.

Claims (1)

SUMMARY OF THE INVENTION An electro-acoustic transducer comprising a housing with a permanent magnet mounted therein with pole tips, a core with a coil and a core, one of the ends of which is attached to the center of the diaphragm mounted on the housing with a rod, characterized in that In order to increase the sensitivity and expand the frequency range, the measles in the cross section is made in the form of an isosceles trapezoid with an angle of 120 ° between its lateral sides and is fixed on the introduced bilateral spring installed and the pole tip, the end of which is facing the larger base of the core, is made with a thickening in the shape of a trapezoid, the end of the pole tip with the base of the core forming an air gap, and the air gaps m formed by the lateral sides of the core and the ends of the pole tips of the cores made tapered, and the air gap I in the direction of vibrational movement of the core is related by the relation I 2m. Figure 1 /ABOUT Fig.Z