RU2030844C1 - Sound reproducing device with electromechanical feedback - Google Patents

Abstract

FIELD: electroacoustics. SUBSTANCE: device has electrodynamic head with sound coil and diaphragm, negative feedback coil, input adder, and low-frequency amplifier. In addition, it is provided with resistor and two magnetically coupled coils; first of these coils is connected in series with sound coil of electrodynamic head and in parallel with resistor; second coil is connected in series opposition to negative feedback coil which is fixed in position on sound coil of electrodynamic head. EFFECT: improved design. 1 dwg

Description

 The invention relates to radio engineering and can be used in the development of high-precision sound reproducing devices.

 For high-fidelity sound reproduction, devices are used that include either multi-channel amplifiers or single-channel low-frequency amplifiers with isolation filters and multiband speakers. Multiband speakers in turn contain low-, medium- and high-frequency electrodynamic heads [1]. Also known are sound reproducing devices with electromechanical feedback. To generate a negative feedback signal, they contain bridge EMF sensors of the voice coil of the electrodynamic head and high-speed sensors with a negative feedback coil.

 The main source of frequency and non-linear distortions in acoustic systems are electrodynamic sound-emitting heads. The introduction of negative feedback reduces the distortion in their work in proportion to the gain in the feedback circuit. A common drawback of known sound reproducing devices is that the electrodynamic sound-emitting heads in them are either not covered by negative feedback at all, only low-frequency electrodynamic heads, reproducing about 2% of the spectrum of sound frequencies, are covered. Coverage of the mid-frequency and high-frequency electrodynamic heads with negative feedback is not feasible due to mechanical resonances of the known sensors and phase shifts of their output signals, and also because of the impossibility of a complete balance of bridge circuits.

 The closest in technical essence of the known sound reproducing devices is a device with a high-speed type electromechanical sensor, consisting of an additional magnetic system and a negative feedback coil, rigidly connected to the diaphragm of the loudspeaker head [2].

 However, this device has a complex mechanical design and effectively reproduces only a narrow frequency band from 20 to 500 Hz.

 The purpose of the invention is to improve the quality of sound reproduction by expanding the frequency range. A sound reproducing device made according to the invention has minimal non-linear distortion and does not have phase distortion of the acoustic signal associated with the presence of several spatially separated narrow-band electrodynamic heads and separation filters in front of known acoustic systems, and can be successfully used in digital sound equipment .

 This is achieved by the fact that an electromechanical feedback reproducing device containing an electrodynamic head with a voice coil and a diaphragm, a negative feedback coil, an input adder and a low-frequency amplifier, additionally introduces a resistor and two magnetically coupled coils, the first of which is connected in series with the voice coil the electrodynamic head and in parallel with the resistor, and the second - sequentially and counter to the negative feedback coil, which is tightly closed It is insulated on the voice coil of an electrodynamic head.

 The drawing shows a diagram of a sound reproducing device with electromechanical feedback.

 A sound reproducing device with electromechanical feedback includes an input adder 1, a low-frequency amplifier 2, an electrodynamic head with a voice coil and diaphragm 3, a negative feedback coil 4, a resistor 5, and two magnetically connected coils 6, 7.

 Sound reproducing device operates as follows. The input signal is summed with the feedback signal at the input adder 1. The resulting total signal is amplified by the power of the amplifier 2 and fed to the voice coil of the electrodynamic head 3 and the coil 6 connected in series with it, shunted by the resistor 5. In the feedback negative coil 4, which is rigidly fixed on the voice coil of the electrodynamic head 3, the induced EMF is induced from a change in the clutch flux of the coil and the mutual induction EMF. Equal currents flow through series coils 3 and 6. Coil 7 is magnetically coupled to coil 6 and both coils are fixedly fixed. Therefore, in the coil 7, the induced EMF from the change in the cohesion flow of the coil is not induced, but the mutual induction EMF (interference signal proportional to the frequency) is induced. Since the coils 4 and 7 are turned on in opposite directions, the mutual inductions induced by the EMF are compensated and only the EMF induced in the coil 4, which carries information about the movement of the voice coil of the electrodynamic head 3, is fed to the input adder 1 as a feedback negative signal. To correlate the frequency response of the negative negative In this connection, a resistor 5 is used, which forms a frequency-dependent chain with coil 6. The EMF induced in coil 4 is a negative feedback signal, and the EMF induced in coil 7 is a positive feedback signal. Therefore, a decrease in the value of the resistor 5 leads to an increase in the depth of negative feedback in proportion to the frequency of the reproduced signal.

Claims (1)

 SOUND PLAYER WITH ELECTROMECHANICAL FEEDBACK, containing an electrodynamic head with a voice coil and a diaphragm, a negative feedback coil, an input adder and a low frequency amplifier, characterized in that, in order to improve the quality of sound reproduction by expanding the frequency resistor, two magnets are introduced into it coils, the first of which is connected in series with the voice coil of the electrodynamic head and in parallel with the resistor, and the second is followed flax and counter with negative feedback coil, which is rigidly secured to a voice coil electrodynamic driver.

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