SU44583A1 - Speaker - Google Patents

Description

The main disadvantage of conventional electromagnetic loudspeakers is the presence of significant non-linear distortion, which is the result of the non-linearity of their static response (the relationship between current and force acting on measles).

The electromagnetic loudspeaker system described below gives a practically completely linear response and, therefore, is free from non-linear distortion.

In FIG. 1 schematically depicts the magnetic system of a loudspeaker; FIG. 2-part last; FIG. 3-picture of the distribution of the magnetic field in the proposed loudspeaker.

The mobile system consists of a non-magnetic core A, equipped with several thin extensions -y (Fig. 2) made of a ferromagnetic material (it is good to use annealed iron or the corresponding alloys). These extensions are included in the gaps DD of the mm magnetic circuit formed by bonding with the last fixed plates MM. The mm magnetic core is assembled from transformer steel and is provided with a winding consisting of a pair of two

(2-6)

coils 5 and to whose terminals the alternating voltage from the receiver is applied. The mobile system is mounted on flexible beams a and a, connected to a diffuser and can oscillate in the direction of the arrows. The upper and lower parts of the magnetic circuit are tightly applied to the N, S poles of the permanent magnet, i.e. there is a four-pole symmetric system with a separation of constant and alternating magnetic fluxes. When current flows through the winding of the magnetic circuit, the forces that pull in the extension t, t into the gaps D, increase in those gaps (in the drawing on the right side) where the constant and alternating currents are currently collapsing and weaken in that part ( in the drawing in the left), where the streams are subtracted. Then, as the alternating current flows, the system will begin to oscillate in accordance with the number of alternating current periods.

Ecv7H designate:

In the induction of a constant flow in the gap D

B - the amplitude of the induction of alternating current in the gap D

D - main clearance

the gap between the extensions - / and Ui 25

-D

bD - the cross-sectional area of the gap D perpendicular to the drawing plane

the width of the gap D (perpendicular to the plane of the drawing), then, based on the general laws on ponderomotive forces acting in a magnetic field, assuming that the measles and the magnetic core are far from saturation, you can find for this system the amplitude of the resulting force acting on the measles

1 aBQ Wu

k

n.s din

2ira

where n is the number of supers.

Beli to put 5 - | - and В „i GDb

At the highest admissible value of induction in the gap is about, which is not yet saturated in the core and magnetic core, those assumed / const, and the values

and 5d variables, it can be found that the force k depends on «and 5 and, has a maximum at

  , D

 .

where is the thickness of the extension

) (

D,

a gap of D. At

i.e. the force is equal

WoW

n.s din

2, in the system described here, the value is taken somewhat away from the maximum, namely: Y-, since this

In this case, it is easier to obtain the required amplitude of AC induction In the proposed loudspeaker, the magnetic system of the system has several gaps (in this case, l 3), due to which it became possible, leaving the force k unchanged (since n.s const), respectively, reduce the size of the gaps D.

The ratio of the σ-length of the gap / to the very gap D is large, so that uniform magnetic fields form in the gaps and S (Fig. 3). Therefore, the pulling force almost does not change over 80% of the length /. The gap n can practically be considered constant.

The resulting characteristic is linear and has such a small slope that in the absence of current in the winding, the force acting on the measles can be considered equal to zero at any position of the core within 80% of the gap length.

Thus, in the proposed loudspeaker, the principle of a “constant gap” is fully implemented, so that it should have, as already noted, a linear characteristic, i.e., the absence of linear distortion.

The subject matter of the invention.

A loudspeaker with several magnetic gaps and a crust moving along the poles, characterized in that the same measles is provided with several y-extensions located in different magnetic gaps. to the authorship of V.M. 44583 Goitan Bikov