Distortionless sound playback system for counter electromotive force signals

A back electromotive force, distortion-free technology, applied in the direction of electrical components, transducer circuits, sensors, etc., can solve problems such as blindness and failure to meet expectations, and achieve the effect of no distortion of sound, wide frequency response, and distortion elimination

Inactive Publication Date: 2012-11-28

方炳钧

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AI-Extracted Technical Summary

Problems solved by technology

However, whether it is a "dynamic feedback system" or a "dynamic feedback speaker", they are all implemented with the concept of adding a microphone. Influence...

Abstract

The invention discloses a distortionless sound playback system for counter electromotive force signals. The distortionless sound playback system is characterized by comprising a counter electromotive force signal loudspeaker and a counter electromotive force signal amplifier, wherein when the loudspeaker body is distorted, and the motion speed of a paper disk is deviated from a desired value under the pressure of air in a sound box or the influence of sound reflection, resonance, standing waves and harmonic factors, a sound coil in the counter electromotive force signal loudspeaker, which is connected with the paper disk, can instantly detect the generated deviation and feed back the deviation to the counter electromotive force signal amplifier; and the counter electromotive force signal amplifier instantly makes a response to rectify the deviation until the deviation completely disappears. The distortionless sound playback system is rational in design; the loudspeaker is changed into a standard four-end network provided with an input and an output; and moreover, an output signal can really reflect an electric signal of the motion of the loudspeaker, so that a power amplifier and the loudspeaker belong to a real electronic network system. The frequency response is wide and flat, and the sound is not subjected to distortion and phase shift; the counter electromotive force signal loudspeaker can replace all treble, alto and bass loudspeakers in the sound box; and therefore, the step of adjusting the troublesome frequency divider is omitted, and the manufacturing cost of the sound box is greatly reduced.

Application Domain

Transducer circuits

Technology Topic

Signal amplifierStanding wave +12

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Examples

Experimental program(3)

Example Embodiment

[0026] Example one

[0027] Reference figure 2 , Regard the speaker voice coil as the (K+1) segment of equal effective length, starting from the hot end of the voice coil (the end of the same name) to the first segment, until K-1, K, K+1 segments and then to the cold end of the voice coil (Non-name end) End. The tap is drawn between the K-1 section and the K section as the output terminal. For a conventional loudspeaker, the output end (between the cold end of the voice coil) should be Uo=2E+2I(ZL+R), where E, ZL, and R are the parameters of a section of coil, and I is the voice coil current.

[0028] Two changes are made to the back-EMF signal speaker: First, separate the K+1 section from the moving voice coil, and place it in the magnetically conductive soft iron in the speaker, which means that the K+1 section does not participate in the movement of the voice coil. Uo=E+2I(Z L +R), one E is reduced. Then connect it in reverse, according to the self-inductance principle K, K+1 section gets IZ L The magnitudes are equal, but they are offset due to the opposite direction, so Uo=E+2IR at this time. So far we can see that the output successfully captures the K segment back-EMF signal E, which is what we desire! Its E value is one K of the total E value of the voice coil. As for the 2RI attached to E, since R is a constant that does not change with frequency (the inductance in the voice coil is different, it is a function of frequency, and it is also affected by many complex factors in the speaker), so the E signal It is easy to deduct it in the amplifier (using "2RI deduction circuit").

Example Embodiment

[0029] Example two

[0030] Reference image 3 , Using two resistors R1 and R2 to divide the total Uo value as a part of K instead of the movable K section in the first embodiment, Uo=E+I(Z L +R), and after canceling the K segment in the voice coil, K-1 and K+1 are connected and the tap is taken out. Here, a negative I(Z L +R), and then E+I(Z L +R) mix and add, just cancel out I(Z L +R) item, the remaining back-EMF E signal is output to the back-EMF signal amplifier. This method is simpler than the first embodiment, but the disadvantage is that the voltage divider resistance adjustment needs to be accurate.

Example Embodiment

[0031] Example three

[0032] Reference Figure 4 , Divide the speaker voice coil into two groups in parallel (the actual speaker voice coil is usually double-wired in parallel), the two groups are from the first section to the K section, and the winding directions of the two groups are exactly the same, each group K-1 , K output lines are led out between the two segments, for conventional speakers, the two output lines (between the cold end of the voice coil) have voltage values: Uo = E + I (Z L +R).

[0033] The back-EMF signal speaker has only one modification: the K-segment of one group is changed to be fixed in the magnetic soft iron in the speaker, and does not participate in the motion of the voice coil. At this time, the voltages obtained on the two sets of output lines are U1=E+I(Z L +R) and U2=I(Z L +R), at this time, U1 and U2 are sent to the back-EMF signal amplifier and subtracted to obtain the back-EMF E signal, the value is one K of the total E value of the voice coil. Compared with the previous two methods, this method has the advantage of fewer reverse windings, thus reducing the loss of magnetic flux, so the voice coil efficiency is high. The disadvantage is to add an output line, so it is more suitable for active speakers.

[0034] Because the speaker can output the back-EMF signal, it is called "back-EMF signal speaker". It is a standard four-terminal network that we expect to get. It can be seen that the structure of the "back-EMF signal speaker" is simple, and the material cost is the same as that of a conventional speaker (only the winding process is slightly more complicated).

[0035] The back-EMF signal amplifier is essentially different from the conventional amplifier (referring to the pure rear stage of the power amplifier). The signal amplifier uses the speaker as an element of its own (the back-EMF signal speaker output terminal is connected to the back-EMF signal amplifier input negative terminal), which is sound (Ie, the back-EMF signal) and amplify to ensure that the sound is not distorted; and the conventional amplifier does not use the speaker as an element of its own (the amplifier output K is connected to the negative end of the input), only to ensure that it is not distorted and amplified .

[0036] When the two positive inputs are the same Ui, but the output E is different:

[0037] For the back-EMF signal amplifier, the total E value E=KUi, that is, the sound (E) is proportional to the input voltage (Ui).

[0038] For a conventional amplifier, the total E value E=KUi-ZI, that is, the sound (E) is not proportional to the input voltage (Ui).

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Distortionless sound playback system for counter electromotive force signals

AI-Extracted Technical Summary

Problems solved by technology

Abstract

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Examples

Example Embodiment

Example Embodiment

Example Embodiment

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Description & Claims & Application Information

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