Electromagnetic vibration transduction system

Abstract

The application relates to electromagnetic vibration conversion technology and discloses an electromagnetic vibration conversion system which comprises an electromagnetic vibration conversion electromechanical mechanism and a braking circuit connected in parallel at two input ends of the electromagnetic vibration conversion electromechanical mechanism, and the equivalent resistance of the braking circuit ranges from 0.001R L to 99.9R L , wherein R L is the impedance of the electromagnetic vibration conversion electromechanical mechanism. When the electromagnetic vibration conversion electromechanical mechanism works, the back electromotive force generated by free vibration is more distributed to the internal resistance of the electromagnetic vibration conversion electromechanical mechanism, so that the electromagnetic braking effect of the electromagnetic vibration conversion electromechanical mechanism is increased, the unnecessary free vibration is weakened, and the energy output distortion degree is reduced.

Description

Technical Field

[0001] This application relates to electromagnetic vibration transduction, and in particular to a technique for reducing the free vibration of electromechanical mechanisms using electromagnetic vibration transduction. Background Technology

[0002] Traditional mechanisms that convert electrical energy into kinetic energy through electromagnetic vibration (referring to mechanisms that use electromagnetic effects to drive the vibration of objects with electrical energy), such as moving coil transducers, moving iron transducers, flat panel loudspeakers, ribbon loudspeakers, and moving iron loudspeakers, will continue to vibrate freely due to inertia when the output of the drive circuit suddenly drops to 0 or changes instantaneously. This results in a discrepancy between the displacement and velocity output and the drive signal, thus causing distortion.

[0003] Currently, the main efforts to reduce the free vibration of electromagnetic vibration transducer electromechanical mechanisms are concentrated in two directions: mechanical and electronic. Mechanical measures primarily involve reducing the mass of the vibrating component, increasing its area, and improving its rigidity. However, due to limitations in materials science development, progress has been relatively slow.

[0004] The electronic approach mainly includes the following five solutions: 1. Increase the damping coefficient of the drive circuit to enhance electromagnetic braking capability; 2. Increase output power reserve; 3. Use Class A amplifier circuits as drive circuits; 4. Measure the motion characteristics of the electromagnetic vibration transducer, predict distortion in advance based on the measured motion characteristics and input signal, and then superimpose distortion correction current when outputting drive current; 5. Continuously measure the real-time displacement and velocity of the electromagnetic vibration transducer, and apply negative feedback adjustment current accordingly. Among them, the first solution mainly utilizes the negative feedback mechanism. At that time, transistor amplifiers could achieve damping coefficients of thousands, but in reality, high damping coefficients did not significantly improve the listening experience; instead, they brought about the so-called negative effect of transistor sound. This solution subsequently faded into obscurity. Later, it was generally believed that the problem was caused by insufficient power output from the amplifier, and there was corresponding but unclear feedback in terms of listening experience. The second approach is based on the theory that the drive circuit should minimize distortion under small signals. The goal is to make the actual driving current capability of the drive circuit much greater than the required current, thus minimizing theoretical distortion under small signals. This is a widely accepted view. However, because the current is small under small signals, it cannot influence the free vibration of moving parts. The third approach, in the audio field, currently recognizes high-current Class A transistor and high-current Class A tube drive circuits as having the best sound quality, with higher power Class A amplifiers generally exhibiting better sound quality. However, Class A amplifiers typically have a conversion efficiency of only around 10% because their power dissipation is constant and does not change with output power, resulting in extremely low conversion efficiency, even below 1% when listening at low output power. The fourth approach requires precise instantaneous characteristic measurements of each electromagnetic vibration transducer mechanism and the establishment of corresponding compensation mathematical models for pre-predicting motion compensation. This makes implementation difficult and inconvenient, preventing its widespread adoption. The fifth approach was once used to amplify low-frequency audio, effectively enhancing the bass response. However, due to measurement and phase delay compensation issues, it ultimately led to sound quality degradation, so it is now rarely used.

[0005] How to more effectively reduce the distortion of the transducer system, especially the distortion caused by free vibration, while reducing power consumption has always been a research topic. Summary of the Invention

[0006] The purpose of this application is to provide an electromagnetic vibration transducer system. When the electromagnetic vibration transducer electromechanical mechanism is working, a larger proportion of the back electromotive force generated by free vibration is distributed to the internal resistance of the electromagnetic vibration transducer electromechanical mechanism itself, thereby increasing its electromagnetic braking effect, reducing unnecessary free vibration, and lowering energy output distortion.

[0007] This application discloses an electromagnetic vibration transducer system, including an electromagnetic vibration transducer electromechanical mechanism and a braking circuit connected in parallel to the two input terminals of the electromagnetic vibration transducer electromechanical mechanism. The equivalent resistance of the braking circuit is in the range of 0.001R. L ~99.9R L , where R L The impedance of the electromagnetic vibration transducer electromechanical mechanism is given.

[0008] In a preferred embodiment, the equivalent resistance of the braking circuit is in the range of 0.1R. L ~10R L .

[0009] In a preferred embodiment, the braking circuit is a single braking resistor, or the braking circuit is a parallel circuit of multiple braking resistors.

[0010] In a preferred embodiment, the braking circuit is a filtered braking branch consisting of a first filter and a braking resistor coupled to the output of the first filter, or a circuit consisting of multiple filtered braking branches connected in parallel, wherein the first filter is used to filter a preset frequency band, and the braking resistor is a braking resistor corresponding to the filter circuit.

[0011] The filter braking branch is composed of the first filter and the braking resistor connected in series, or the filter braking branch is composed of a first filter with two input terminals respectively coupled to the two input terminals of the electromagnetic vibration transducer system and a braking resistor with two ends respectively coupled to the two output terminals of the first filter.

[0012] The first filter includes a high-pass filter, a low-pass filter, a band-pass filter, and a band-stop filter.

[0013] In a preferred embodiment, the braking circuit includes a first sub-branch and a second sub-branch connected in parallel with the first sub-branch, wherein the first sub-branch is a single braking resistor or a parallel circuit of multiple braking resistors, and the second sub-branch is the filter braking branch or a circuit composed of multiple filter braking branches connected in parallel.

[0014] In a preferred embodiment, a second filter is further included, the two output terminals of which are coupled to the two ends of the braking circuit, and the two input terminals of which are coupled to the two input terminals of the electromagnetic vibration transducer system.

[0015] In a preferred embodiment, the system further includes a first driving circuit, the two output terminals of which are respectively coupled to the two ends of the braking circuit, and the two input terminals of which are respectively coupled to the two input terminals of the electromagnetic vibration transducer system.

[0016] The first driving circuit is a power amplifier circuit;

[0017] The power amplifier circuit includes at least one or any combination of the following electronic components: vacuum tube, transistor, and integrated circuit.

[0018] In a preferred embodiment, a third filter is further included, wherein the two output terminals of the third filter are respectively coupled to the two input terminals of the first driving circuit, and the two input terminals of the third filter are respectively coupled to the two input terminals of the electromagnetic vibration transducer system.

[0019] In a preferred embodiment, the electromagnetic vibration transducer electromechanical mechanism is a moving coil loudspeaker, a moving iron loudspeaker, a flat panel loudspeaker, a ribbon loudspeaker, a microphone, an earphone, a moving coil linear motor, a moving iron linear motor, or a voice coil motor.

[0020] In a preferred embodiment, the two input terminals of any two sets of electromagnetic vibration transducer systems are coupled in parallel, where M is an integer greater than or equal to 1.

[0021] This application discloses an electromagnetic vibration transducer system, comprising:

[0022] N electromagnetic vibration transducer electromechanical mechanisms, where N is an integer greater than or equal to 2;

[0023] N fourth filters, each with two input terminals coupled to the two input terminals of the electromagnetic vibration transducer system, and the two output terminals of the N fourth filters coupled to the two input terminals of the N electromagnetic vibration transducer electromechanical mechanisms in a one-to-one correspondence.

[0024] A braking circuit, the two ends of which are coupled to the two input terminals of the electromagnetic vibration transducer system, wherein the equivalent resistance of the braking circuit is in the range of 0.001R. L ~99.9R L , where R L The total impedance is the parallel network of N filter branches formed by coupling the two outputs of the N fourth filters to the two inputs of the N electromagnetic vibration transducer electromechanical mechanisms in a one-to-one correspondence.

[0025] In a preferred embodiment, the equivalent resistance of the braking circuit is in the range of 0.1R. L ~10R L .

[0026] In a preferred embodiment, the braking circuit is a single braking resistor, or the braking circuit is a parallel circuit of multiple braking resistors.

[0027] In a preferred embodiment, the braking circuit is a filtered braking circuit consisting of a first filter and a braking resistor connected in series, or a circuit consisting of multiple filtered braking circuits connected in parallel, wherein the first filter is used to filter a preset frequency band, and the braking resistor is a braking resistor corresponding to the filter circuit in which it is located.

[0028] The first filter includes a high-pass filter, a low-pass filter, a band-pass filter, and a band-stop filter.

[0029] In a preferred embodiment, the braking circuit includes a first sub-branch and a second sub-branch connected in parallel with the first sub-branch, wherein the first sub-branch is a single braking resistor or a parallel circuit of multiple braking resistors, and the second sub-branch is the filter braking circuit or a circuit composed of multiple filter braking circuits connected in parallel.

[0030] Compared with the prior art, the embodiments of this application have at least the following advantages:

[0031] Compared to existing electromagnetic vibration transducer systems, this method improves the electromagnetic vibration transducer efficiency to achieve the same low-distortion output effect without significantly increasing power consumption. Based on existing electromagnetic vibration transducer systems (such as speaker systems and audio systems), a braking circuit is incorporated to distribute more of the back electromotive force of the electromagnetic vibration transducer mechanism during operation onto its internal resistance, increasing η and enhancing the electromagnetic braking effect of the mechanism. This effectively reduces unnecessary free vibrations and significantly lowers energy output distortion. Moreover, the braking circuit is low-cost and can be improved upon existing electromagnetic vibration transducer systems or mechanisms at a low cost.

[0032] Furthermore, the electromagnetic vibration transducer system in this application increases the proportion of back electromotive force allocated to electromagnetic braking without significantly increasing power consumption, greatly reducing the kinetic energy output distortion of the electromagnetic vibration transducer electromechanical mechanism, while also not increasing static power consumption. Compared with existing electromagnetic vibration transducer systems, it significantly reduces the cost of drive equipment and saves drive energy while maintaining the same low-distortion electromagnetic vibration transducer effect.

[0033] Meanwhile, the electromagnetic vibration transducer system in the application implementation does not require precise measurement of the motion characteristics of the electromagnetic vibration transducer electromechanical mechanism, nor does it require corresponding correction of the input signal, which greatly reduces the implementation difficulty and cost.

[0034] The specification of this application contains numerous technical features distributed across various technical solutions. Listing all possible combinations of these technical features (i.e., technical solutions) would make the specification excessively lengthy. To avoid this problem, the various technical features disclosed in the above-described invention, the various technical features disclosed in the following embodiments and examples, and the various technical features disclosed in the accompanying drawings can be freely combined to form various new technical solutions (all of which are considered to have been described in this specification), unless such a combination of technical features is technically infeasible. For example, one example discloses feature A+B+C, and another example discloses feature A+B+D+E. Features C and D are equivalent technical means that serve the same function, and technically only one needs to be used; they cannot be used simultaneously. Feature E can technically be combined with feature C. Therefore, the solution A+B+C+D should not be considered as described because it is technically infeasible, while the solution A+B+C+E should be considered as described. Attached Figure Description

[0035] Figure 1 This is a circuit block diagram of an electromagnetic vibration transducer system according to the first embodiment of this application.

[0036] Figure 2 This is a circuit block diagram of an electromagnetic vibration transducer system with an example braking circuit according to an embodiment of the first embodiment of this application.

[0037] Figure 3 This is a circuit block diagram of an electromagnetic vibration transducer system with an example braking circuit according to an embodiment of the first embodiment of this application.

[0038] Figure 4 This is a circuit block diagram of an electromagnetic vibration transducer system according to an embodiment of the first embodiment of this application.

[0039] Figure 5 This is a circuit block diagram of an electromagnetic vibration transducer system according to an embodiment of the first embodiment of this application.

[0040] Figure 6 This is a circuit block diagram of an electromagnetic vibration transducer system according to an embodiment of the first embodiment of this application.

[0041] Figure 7 This is a circuit diagram of an electromagnetic vibration transducer system for a power amplifier circuit that is a driver circuit of a transformer-coupled power amplifier circuit, according to a specific embodiment of the first embodiment of this application.

[0042] Figure 8 This is a circuit diagram of an electromagnetic vibration transducer system for a power amplifier circuit that is a drive circuit of a bridge push-pull power amplifier circuit, according to a specific embodiment of the first embodiment of this application.

[0043] Figure 9 This is a circuit diagram of an electromagnetic vibration transducer system for a power amplifier circuit drive circuit of a power amplifier circuit without an output capacitor, according to a specific embodiment of the first embodiment of this application.

[0044] Figure 10 This is a circuit diagram of an electromagnetic vibration transducer system, which is a power amplifier circuit with an output capacitor and a drive circuit for a power amplifier circuit according to a specific embodiment of the first embodiment of this application.

[0045] Figure 11 This is a circuit diagram of an electromagnetic vibration transducer system for a power amplifier circuit that is a drive circuit of a digital pulse-width modulation power amplifier circuit, according to a specific embodiment of the first embodiment of this application.

[0046] Figure 12 This is a circuit diagram of an electromagnetic vibration transducer system for an H-type drive circuit of a digital pulse-width modulation power amplifier circuit, according to a specific embodiment of the first embodiment of this application.

[0047] Figure 13 This is a multi-unit independent brake speaker system with a passive crossover, according to a specific embodiment of the second embodiment of this application.

[0048] Figure 14 This is an active crossover multi-unit speaker system according to a specific embodiment of the second embodiment of this application.

[0049] Figure 15 This is a multi-unit speaker system with a passive crossover according to a specific embodiment of the third embodiment of this application.

[0050] Figure 16 This is a typical power amplifier circuit driving an electromagnetic loudspeaker. (Equivalent circuit diagram)

[0051] Figure 17 This is an equivalent circuit diagram of an electromagnetic vibration transducer system according to the first embodiment of this application, which has a drive circuit with equal resistance connected across the positive and negative power supplies and the output terminal.

[0052] Figure 18 This is an equivalent circuit diagram of an electromagnetic vibration transducer system according to the first embodiment of this application.

[0053] Figure 19 This is a schematic diagram of the output waveforms of a test headphone according to an example of this application, with and without a braking resistor.

[0054] Figure 20 for Figure 19 Enlarged view of the area marked A Detailed Implementation

[0055] In the following description, many technical details are presented to help the reader better understand this application. However, those skilled in the art will understand that the technical solutions claimed in this application can be implemented even without these technical details and various variations and modifications based on the following embodiments.

[0056] Terminology Explanation:

[0057] Electromagnetic vibration transducer electromechanical mechanism: refers to a mechanism that uses electromagnetic effect to drive a moving object to reciprocate.

[0058] To make the objectives, technical solutions, and advantages of this application clearer, the embodiments of this application will be described in further detail below with reference to the accompanying drawings.

[0059] The first embodiment of this application relates to an electromagnetic vibration transducer system, the circuit block diagram of which is shown below. Figure 1 As shown, the electromagnetic vibration transducer system includes an electromagnetic vibration transducer electromechanical mechanism and a braking circuit connected in parallel to the two input terminals of the electromagnetic vibration transducer electromechanical mechanism. The two ends of the braking circuit are also coupled to the two input terminals of the electromagnetic vibration transducer system, respectively. The equivalent resistance R of the braking circuit... brk The resistance range is 0.001R. L ~99.9R L , where R L Let R be the impedance of the electromagnetic vibration transducer electromechanical mechanism. The equivalent resistance R of the braking circuit is... brk The resistance value can be adjusted based on the inherent braking characteristics of the electromagnetic vibration transducer itself, and the total load impedance (R) of the electromagnetic vibration transducer system also needs to be considered. brk / / R L It is not less than the minimum output impedance that the driving circuit coupled at the input terminal can withstand, where " / / " means parallel connection.

[0060] Preferably, the equivalent resistance R of the braking circuit brk The resistance value can be in the range of (0.1 to 10) times R. L .

[0061] The braking circuit can be composed of various components. Optionally, the braking circuit may consist of a single braking resistor. Optionally, the braking circuit may be a parallel circuit of multiple braking resistors. Optionally, the braking circuit may be a filtered braking branch consisting of a first filter and a braking resistor coupled to the output of the first filter, wherein the first filter is used to filter a preset frequency band, and the braking resistor is a braking resistor corresponding to its respective filter loop. Optionally, the braking circuit may be a circuit composed of multiple such filtered braking branches connected in parallel. The aforementioned first filter may be a high-pass filter, a low-pass filter, a band-pass filter, a band-stop filter, etc.

[0062] The aforementioned filter braking branch has several circuit configurations. Optionally, such as... Figure 2 As shown, the filter braking branch consists of a first filter and a braking resistor connected in series. Optionally, as... Figure 3 As shown, this filter-braking branch consists of a first filter with two input terminals coupled to the two input terminals of the electromagnetic vibration transducer system, and a braking resistor with two ends coupled to the two output terminals of the first filter. In both circuit configurations, each filter-braking sub-branch has its own filter and a braking resistor with a corresponding resistance value. The filter can filter a set frequency band, and in conjunction with the braking resistor with the corresponding resistance value coupled to it, different braking effects can be applied to the set frequency band.

[0063] Optionally, the braking circuit includes a first sub-branch and a second sub-branch connected in parallel with the first sub-branch, wherein the first sub-branch is a single braking resistor or a parallel circuit of multiple braking resistors, and the second sub-branch is the filter braking branch or a circuit composed of multiple filter braking branches connected in parallel.

[0064] Optionally, the electromagnetic vibration transducer system further includes a second filter, the two output terminals of which are coupled to the two ends of the braking circuit, and the two input terminals of which are coupled to the two input terminals of the electromagnetic vibration transducer system. Figure 4 This is a circuit block diagram of an electromagnetic vibration transducer system according to one embodiment.

[0065] Optionally, such as Figure 5 The circuit block diagram shown indicates that the electromagnetic vibration transducer system also includes a first drive circuit. The two output terminals of the first drive circuit are coupled to the two ends of the braking circuit, respectively, and the input terminal of the first drive circuit is the input terminal of the electromagnetic vibration transducer system.

[0066] The first drive circuit can be any drive circuit involving the free vibration of an electromagnetic vibration transducer electromechanical mechanism. Optionally, the first drive circuit can be, but is not limited to, a power amplifier circuit.

[0067] There are many types of power amplifier circuits. These include transformer-coupled power amplifier circuits, power amplifier circuits without output transformers, power amplifier circuits without output capacitors, bridge push-pull power amplifier circuits, digital power drive circuits, etc. Optionally, the amplifier circuit involved in this embodiment may include one or any combination of the following electronic components: vacuum tubes, transistors, and integrated circuits.

[0068] Optionally, the vacuum tube may include, but is not limited to, voltage amplification tubes, transistors, multi-electrode tubes, and composite tubes. Optionally, the transistor may include, but is not limited to, crystal diodes, crystal triodes, silicon controlled rectifiers (SCRs), and field-effect transistors (FETs). Optionally, the integrated circuit may include, but is not limited to, various modules such as integrated power amplification modules, integrated power amplification driver modules, and thick-film integrated amplification modules.

[0069] In one embodiment of the electromagnetic vibration transducer system, such as Figure 6 The circuit block diagram shown indicates that the electromagnetic vibration transducer system includes the electromagnetic vibration transducer electromechanical mechanism, a braking circuit connected in parallel to the two input terminals of the electromagnetic vibration transducer electromechanical mechanism, the first driving circuit, and the third filter. The two output terminals of the first driving circuit are coupled to the two ends of the braking circuit, the two output terminals of the third filter are coupled to the two input terminals of the first driving circuit, and the two input terminals of the third filter are coupled to the two input terminals of the electromagnetic vibration transducer system.

[0070] In one specific embodiment, the power amplifier circuit is a transformer-coupled power amplifier circuit. For example... Figure 7 As shown, the braking resistor R brk Connected in parallel across the secondary winding of the output transformer, the impedance characteristics of the output transformer show that in the low-frequency range (e.g., below 500Hz), the impedance of the transformer coil itself is relatively low, which can already provide a certain braking effect. However, in the mid-to-high frequency range, as the impedance of the transformer coil increases, the braking effect weakens sharply. At this point, the increased braking resistance R... brk However, it can provide excellent braking.

[0071] In another specific embodiment, the power amplifier circuit is a bridge push-pull power amplifier circuit. For example... Figure 8 The input terminal of the electromagnetic vibration transducer electromechanical mechanism is connected to the braking resistor R. brk Parallel coupling, braking resistor R brk Both ends are coupled in parallel to the two output poles of the two sets of bridge drive circuits.

[0072] In another specific embodiment, the power amplifier circuit is a power amplifier circuit without an output capacitor. For example... Figure 9 As shown, the input terminal of the electromagnetic vibration transducer electromechanical mechanism is connected to the braking resistor R. brk Parallel coupling, braking resistor Rbrk Both ends are coupled to the push-pull output of the drive circuit and the ground line.

[0073] In another specific embodiment, the power amplifier circuit is a power amplifier circuit with an output capacitor. For example... Figure 10 As shown, the input terminal of the electromagnetic vibration transducer electromechanical mechanism is connected to the braking resistor R. brk Parallel coupling, braking resistor R brk Both ends are coupled to the output of the drive circuit.

[0074] In another specific embodiment, the power amplifier circuit is a digital driver circuit. For example... Figure 11 As shown, the input terminal of the electromagnetic vibration transducer electromechanical mechanism is connected to the braking resistor R. brk Parallel coupling, braking resistor R brk Both ends are coupled to the output terminal after LC output filtering of the drive circuit.

[0075] In another specific embodiment, the power amplifier circuit is an H-type drive circuit of a digital pulse-width modulation power amplifier circuit. For example... Figure 12 As shown, this circuit diagram represents the output section of a widely used low-voltage Class D amplifier circuit. The input terminal of the electromagnetic vibration transducer electromechanical mechanism is connected to the braking resistor R. brk Parallel coupling, braking resistor R brk Both ends are coupled to the output terminals of the left and right drive circuits.

[0076] It should be noted that: in the appendix Figure 7 To be continued Figure 11 The part within the dashed box in the image is the specific composition of the drive circuit. (See attached image.) Figure 12 The part outside the dashed box is the specific composition of the drive circuit.

[0077] This electromagnetic vibration transducer electromechanical mechanism refers to a mechanism that uses electromagnetic effect to drive moving parts to reciprocate. Optionally, this electromagnetic vibration transducer electromechanical mechanism can be, but is not limited to, a moving-coil loudspeaker, a moving-iron loudspeaker, a flat panel loudspeaker, a ribbon loudspeaker, a microphone, an earphone, a moving-coil linear motor, a moving-iron linear motor, a voice coil motor, etc.

[0078] It should be noted that the coupling between two elements, devices and components involved in this application should satisfy the following: positive terminals are coupled to positive terminals, and negative terminals are coupled to negative terminals.

[0079] The second embodiment of this application relates to an electromagnetic vibration transducer system, comprising M groups of electromagnetic vibration transducers as described in the first embodiment of this specification. The input terminals of any two groups of these M groups are coupled in parallel, where M is an integer greater than or equal to 1. The electromagnetic vibration transducer system of this embodiment includes all the technical details of the electromagnetic vibration transducer system of the first embodiment, as well as the beneficial effects resulting from including all the technical details.

[0080] Optionally, when the electromagnetic vibration transducer system of this embodiment does not include a first driving circuit, the second filter can be a passive filter; when the electromagnetic vibration transducer system of this embodiment includes a first driving circuit, the third filter can be a passive filter, an active filter, or a digital filter, etc.

[0081] Figure 13 This is a specific embodiment of a multi-unit independent braking speaker system with a passive crossover implemented according to this embodiment. The speaker system includes multiple loudspeakers (SPK1, SPK2...SPK...). m (where m≥2), and multiple corresponding braking resistors (Rbrk1, Rbrk2...Rbrk). m ), and corresponding multiple second filters (Filter1, Filter2...Filter) m (where m≥2). Each speaker unit has an independent parallel braking resistor. The braking effect of each unit is less affected by its respective filter and can be adjusted independently. This second filter is a passive filter. Optionally, these multiple second filters can be m-channel filters.

[0082] Figure 14 This is a specific embodiment of an active crossover multi-unit audio system implemented according to this method. The audio system includes multiple third filters (Filter1, Filter2...Filter...). y A frequency divider (where y≥2) and corresponding multiple braking resistors (Rbrk1, Rbrk2, ..., Rbrk) y Where y≥2), corresponding to multiple speaker units (SPK1, SPK2, ..., SPK). y The power amplifiers (AMP1, AMP2, ..., AMP) with a total of y channels, where y ≥ 2, are y channels in total. y (where y≥2). That is, the frequency divider has only one output that divides into y frequency bands. The output of each frequency band is coupled to an independent transducer, and each transducer can be independently connected in parallel with a braking circuit. The third filter can be a digital filter, an active filter, or a passive filter.

[0083] The third embodiment of this application relates to an electromagnetic vibration transducer system, comprising: N electromagnetic vibration transducer electromechanical mechanisms, where N is an integer greater than or equal to 2; N fourth filters, each fourth filter having two input terminals coupled to two input terminals of the electromagnetic vibration transducer system, and the two output terminals of the N fourth filters being coupled one-to-one to the two input terminals of the N electromagnetic vibration transducer electromechanical mechanisms; and a braking circuit, the two ends of which are coupled to the two input terminals of the electromagnetic vibration transducer system, the equivalent resistance of which is in the range of 0.001R. L ~99.9R L , where R L This is the total impedance of the parallel network of N filter branches formed by coupling the two outputs of the N fourth filters one-to-one with the two inputs of the N electromagnetic vibration transducer electromechanical mechanisms. Optionally, the equivalent resistance of the braking circuit is in the range of 0.1R. L ~10R L .

[0084] Optionally, the braking circuit is a single braking resistor, or the braking circuit is a parallel circuit of multiple braking resistors.

[0085] Optionally, the braking circuit is a filtered braking circuit consisting of a first filter and a braking resistor connected in series, or a circuit consisting of multiple such filtered braking circuits connected in parallel. The first filter is used to filter a preset frequency band, and the braking resistor is a braking resistor corresponding to its respective filtering loop. The first filter may include a high-pass filter, a low-pass filter, a band-pass filter, or a band-stop filter.

[0086] Optionally, the braking circuit includes a first sub-branch and a second sub-branch connected in parallel with the first sub-branch, wherein the first sub-branch is a single braking resistor or a parallel circuit of multiple braking resistors, and the second sub-branch is the filter braking circuit or a circuit composed of multiple filter braking circuits connected in parallel.

[0087] The electromagnetic vibration transducer electromechanical mechanism and braking circuit involved in this embodiment can be the electromagnetic vibration transducer electromechanical mechanism and braking circuit involved in the first embodiment of this application, and includes all the technical details of the electromagnetic vibration transducer electromechanical mechanism and braking circuit involved in the first embodiment, as well as the beneficial effects resulting from including all the technical details.

[0088] Figure 15 This is a specific embodiment of a multi-unit speaker system with a passive crossover implemented according to this embodiment. The speaker system includes a braking resistor R. brk A filter with multiple sets of fourth filters (Filter1, Filter2, ... Filter) nA crossover network with n≥2) and corresponding multiple loudspeakers (SPK1, SPK2, ..., SPK). n (where n≥2). The fourth filter is a passive filter. This system is simple to implement, but because the frequency divider is connected in series in the braking circuit, it will have different effects on the braking effect of signals of different frequencies.

[0089] To better understand the technical solution of this application, specific examples are provided below. The details listed in the examples are mainly for ease of understanding and are not intended to limit the scope of protection of this application.

[0090] To evaluate the electromagnetic braking effect of the electromagnetic vibration transducer system, firstly, an index value η is defined, where η is the back electromotive force voltage distributed within the electromagnetic vibration transducer electromechanical mechanism itself (R). L The ratio of the back electromotive force voltage to the electromagnetic braking effect is called the electromagnetic braking percentage.

[0091] Taking a typical power amplifier circuit driving an electromagnetic loudspeaker as an example, it can be seen as follows: Figure 16 The equivalent circuit shown, where U out R0 is the output electromotive force (i.e., voltage source) of the drive circuit, and R0 is the equivalent internal resistance of the drive circuit; R0 tr The impedance is the transmission line impedance; the electromagnetic vibration transducer electromechanical mechanism shown by the dashed line on the right side of the diagram can be considered as a purely resistive load R. L and a back electromotive force voltage source U an A series circuit. From the back electromotive force voltage source U an In terms of direction, the closed loop of the current is R. L +R tr +R0(U out and U an The theoretical internal resistance of the voltage source is 0 ohms. Here, the back electromotive force U... an The proportion of the generated electromagnetic braking voltage distributed within the electromagnetic vibration transducer electromechanical mechanism itself is defined as η. If the back electromotive force U... an The internal resistance R of the electromagnetic vibration transducer electromechanical mechanism itself L If we consider them together as a driving circuit, then the driven load is R. tr +R0, in this way Because of R L and R tr At a single frequency, all values ​​are fixed and their impact on η is predictable. The only unpredictable factor is the internal resistance R0 of the drive circuit. We will discuss the patterns of R0 and its impact on η using three examples (Example 1, Example 2, and Example 3).

[0092] Example 1: Taking a typical AB-class OCL driver circuit as an example, assume V cc =40V, quiescent current I a0 =I b0 =0.050A, R L =8Ω, transmission line resistance R tr =0.5Ω, which can be regarded as... Figure 17 The equivalent circuit shown, where I a and I b It can be considered a current source. Since the drive circuit controls the output stage I based on the voltage of the input signal... a and I b The current, thereby controlling the output voltage U out Its internal resistance R0 is a variable, and it is equal to the input signal voltage during the positive half-cycle. During the negative half-cycle of the input signal voltage, it equals In the simplest static state U out For example, if the value is 0, then at this time...

[0093] When the output voltage U out When the voltage is +0.1V, the current flows through R. L Current I L The current is 0.1 ÷ (8 + 0.5) = 0.018 A. Based on the characteristics of Class AB circuits, I... L =I a -I b ,at this time Equivalent internal resistance η + ≈1.2%; η - ≈0.8%.

[0094] When the output voltage U out When the voltage is +10V, the current flows through R. L Current I L The value is 10V ÷ (8 + 0.5) = 1.17A. Based on the characteristics of Class AB circuits, the output has now entered the Class B range. b It has already dropped to 0, therefore I a =1.17A, equivalent positive half-cycle internal resistance Positive half-cycle η + ≈20.3%; I b =0A, equivalent negative half-cycle internal resistance R 0- For ∞, negative half-cycle η - =0%. This indicates that there is only a certain braking effect on the positive half-cycle of the back EMF, and no braking effect on the negative half-cycle of the back EMF.

[0095] It can be seen that the internal resistance R0 of the drive circuit exhibits a relationship related to the static current I0 of the drive circuit, and changes with U. out An impedance whose amplitude changes in opposite directions, and whose positive and negative currents have inconsistent directions. Because... R L and R tr Since all values ​​are fixed at a single frequency, it can be seen that the instantaneous braking ratio η in this case is only related to R0, and is related to the instantaneous amplitude of the drive circuit output. It is a strange state that mostly only works on the back electromotive force for half a cycle (even in Class A state, because R0 is large in both positive and negative cycles, it cannot play a braking role).

[0096] Example 2: Taking a traditional pure Class A power amplifier driving an electromagnetic resonant transducer with a nominal impedance of 8Ω as an example, other conditions remain the same as in Example 1, except that the static current is increased by 100 times, i.e., I a0 =I b0 =5A. At this time, the static power consumption P0 of a single channel of the drive circuit is V. cc ×2×I a =400W, static internal resistance Therefore, in the static case, η = 8 ÷ (8 + 0.5 + 8) = 48.5%.

[0097] When the output voltage U out When the voltage is +0.1V, the current flows through R. L Current I L The current is 0.1 ÷ (8 + 0.5) = 0.018 A. Based on the characteristics of the circuit, I... L =I a -I b ,at this time Equivalent internal resistance η + ≈48.5%; η - ≈48.5%.

[0098] When the output voltage U out When the voltage is +10V, the current flows through R. L Current I L The current is 10 ÷ (8 + 0.5) = 1.17 A. Based on the characteristics of the circuit, I... L =I a -I b ,at this time Equivalent internal resistance R 0+ =(V cc -U out ) / I a ≈5.4Ω, η + ≈57.5%; η -≈40.6%. It can be seen that when the output voltage is high, η can still be maintained above 40%, which has a good braking effect.

[0099] The sound quality of "Example 2" in actual use is generally considered to be much better than that of "Example 1". However, the static power consumption of 400W per channel is indeed very large. This power consumption is mainly converted into heat, so the heat generation is also very large. The huge heat generation leads to a sharp increase in material costs, design costs and heat dissipation costs.

[0100] The key question is how to increase the η of the electromagnetic vibration transducer and reduce the output distortion rate without significantly increasing power consumption.

[0101] This invention connects a braking resistor R in parallel across the input terminals of the electromagnetic vibration transducer electromechanical mechanism. brk (like Figure 18 (within the dashed box on the right), thereby directly reducing the back electromotive force U. an The load circuit impedance is reduced, thereby distributing more back electromotive force to the internal resistance R of the electromagnetic vibration transducer electromechanical mechanism itself. L This increases η, thereby enhancing its electromagnetic braking effect, reducing unnecessary free vibrations, and lowering energy output distortion.

[0102] When a braking resistor R is connected in parallel across the input terminals of the electromagnetic vibration transducer electromechanical mechanism brk Then, the back electromotive force U an R connected in series via R0 tr After and R brk Parallel connection, then with R L The concatenated network consumes resources, which are then allocated to R. L Back EMF voltage ratio ( / / means resistors in parallel), it can be seen that even if R0 is infinite, it will not significantly affect the value of η. The calculation formula can be simplified to

[0103] Example 3: All conditions are the same as in Example 1, except that a resistor R is connected in parallel across the input terminals of the electromagnetic vibration transducer electromechanical mechanism. brk = 4Ω. At this time, the steady-state power consumption P0 of the single channel of the drive circuit is V. cc ×2×I a =4W, and Since R0+R tr Much larger than R brk Calculate (R0+R tr ) / / R brk The value at which the position can be ignored can be obtained when the position is static. Since R0 no longer affects the value of η, the output voltage of the drive circuit that affects R0 no longer affects η, and η remains basically unchanged.

[0104] This result indicates that the back electromotive force accounts for 66.7% of the electromagnetic braking. From the perspective of the original drive circuit, the corresponding load impedance decreases from 8.5Ω to R. tr +R brk / / R L =3.16Ω. If the original drive circuit can still guarantee the output quality under this load, then it can work normally.

[0105] Without significantly increasing power consumption, the proportion of back electromotive force allocated to electromagnetic braking increases from 1% to 66.7%, which is higher than that of typical high-power Class A drive circuits. At the same time, the electromagnetic vibration transducer system as a whole has lower static power consumption, saving about 100 times the energy consumption compared to the Class A drive circuit in Example 2, while also saving costs in various aspects.

[0106] In practical applications, R can be adjusted based on the braking characteristics of the electromagnetic vibration transducer electromechanical mechanism itself and the desired braking ratio η. brk The resistance value is adjusted to achieve different effects in suppressing free vibration. The braking ratio η ranges from 0.1% to 99.9%. (Note: The static internal resistance R0 of the drive circuit is ignored here, so R brk The value range of R is (0.001~99.9). L At the same time, it is also necessary to consider that the total load impedance is not less than the minimum output impedance that the drive circuit can withstand.

[0107] The following is a further explanation of the braking effect achieved by this embodiment based on an audio experiment, which uses a simulated human head containing a standard IEC711 artificial ear and an external professional sound card to measure the sound emitted by headphones.

[0108] The test headphones used in this audio experiment were AKG K701 (open-back over-ear headphones) with an impedance of 62Ω and a sensitivity of 105dB / Vrms. The audio signal used was a standard square wave at 30Hz. The sound emitted by the test headphones was measured both with and without a braking resistor (16Ω braking resistor). Waveforms of the sound signal output from the test headphones under these two conditions were acquired using a condenser microphone in the artificial ear, as shown in the figure. Figure 19 As shown in the figure. The condenser microphone in the artificial ear is used to convert sound signals into electrical signals.

[0109] from Figure 19As can be seen, compared with the test headphones without a braking resistor, the test headphones with a braking resistor (e.g., with a 16Ω braking resistor, η≈77.6%) have a smaller amplitude of free vibration and a shorter time to stop vibration after the diaphragm moves to the target position. This effectively reduces the uncontrolled vibration of the diaphragm and thus reduces distortion.

[0110] Figure 20 for Figure 19 The magnified diagram (approximately 1:5) of the area marked A shows that, compared to the test headphone with a braking resistor (e.g., with a 16Ω braking resistor), the process of the diaphragm returning to the equilibrium position also changes to some extent, with the return time being significantly shorter.

[0111] The above experiments show that after setting the braking resistor, the braking effect of the headphone diaphragm is enhanced. Compared with the diaphragm movement without the braking resistor, it can more quickly reduce free vibration, reduce sound coloration, and produce better sound effects.

[0112] Furthermore, the inventors of this application have practically applied the braking circuit involved in this embodiment to improve a common audio amplifier system. The improved audio amplifier system significantly enhances the realism of the reproduced sound. Tests using both headphones and speakers show that the change in listening experience is across the entire frequency range. Specifically, the low-frequency response is faster, with drum sounds and electronic instruments appearing tighter and less muddy, and the perceived low-frequency component is also enhanced. The mid-frequency range is more powerful, especially in reproducing sounds like gunshots, cannons, and lightning with more concentrated energy. The high-frequency range improves upon the harshness and unpleasantness of traditional transistor amplifiers in the high-frequency range; the overtones of instruments are more refined, clearer, and easier to distinguish, especially in large-scale environments like symphonies where the resolution is higher, allowing for clear instrument differentiation. The violin part is no longer muddy but rather possesses a sweet musicality with rich overtones.

[0113] Compared with the prior art, the implementation method of the application has produced unexpected technical effects and has made significant progress.

[0114] It should be noted that in this patent application, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one" does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element. In this patent application, if it refers to performing an action according to an element, it means performing the action at least according to that element, including two cases: performing the action only according to that element, and performing the action according to that element and other elements. Expressions such as "multiple," "repeatedly," and "various" include two, two times, two kinds, and more than two, more than two times, and more than two kinds.

[0115] All documents mentioned in this application are considered to be incorporated integrally into the disclosure of this application so that they can serve as the basis for modifications if necessary. Furthermore, it should be understood that the above descriptions are merely preferred embodiments of this specification and are not intended to limit the scope of protection of this specification. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of one or more embodiments of this specification should be included within the scope of protection of one or more embodiments of this specification.

Claims

1. An electromagnetic vibration transducer system, characterized in that, include: There are N electromagnetic vibration transducer electromechanical mechanisms, where N is an integer greater than or equal to 2; N fourth filters, each with two input terminals coupled to the two input terminals of the electromagnetic vibration transducer system, and the two output terminals of the N fourth filters coupled to the two input terminals of the N electromagnetic vibration transducer electromechanical mechanisms in a one-to-one correspondence. A braking circuit is provided, the two ends of which are coupled to the two input terminals of the electromagnetic vibration transducer system. The two ends of the braking circuit are also directly connected to the two input terminals of each of the fourth filters. The equivalent resistance of the braking circuit has an impedance range of 0.001 R. L ~99.9 R L , where R L The total impedance is the parallel network of N filter branches formed by coupling the two outputs of the N fourth filters to the two inputs of the N electromagnetic vibration transducer electromechanical mechanisms in a one-to-one correspondence.

2. The electromagnetic vibration transducer system as described in claim 1, characterized in that, The equivalent resistance of the braking circuit has an impedance range of 0.1 R. L ~10 R L .

3. The electromagnetic vibration transducer system as described in claim 1, characterized in that, The braking circuit is a single braking resistor, or the braking circuit is a parallel circuit of multiple braking resistors.

4. The electromagnetic vibration transducer system as described in claim 1, characterized in that, The braking circuit is a filter braking branch consisting of a first filter and a braking resistor coupled to the output of the first filter, or a circuit consisting of multiple filter braking branches connected in parallel. The first filter is used to filter a preset frequency band, and the braking resistor is a braking resistor corresponding to the filter circuit. The filter braking branch is composed of the first filter and the braking resistor connected in series, or the filter braking branch is composed of the first filter with two input terminals respectively coupled to the two input terminals of the electromagnetic vibration transducer system and a braking resistor with two ends respectively coupled to the two output terminals of the first filter. The first filter includes a high-pass filter, a low-pass filter, a band-pass filter, or a band-stop filter.

5. The electromagnetic vibration transducer system as described in claim 4, characterized in that, The braking circuit includes a first sub-branch and a second sub-branch connected in parallel with the first sub-branch. The first sub-branch is a single braking resistor or a parallel circuit of multiple braking resistors. The second sub-branch is a circuit composed of one of the filter braking branches or multiple filter braking branches connected in parallel.

6. The electromagnetic vibration transducer system as described in claim 1, characterized in that, It also includes one or more second filters, the two input terminals of which are coupled to the two input terminals of the electromagnetic vibration transducer system, and the two output terminals of which are coupled to the two ends of the braking circuit.

7. The electromagnetic vibration transducer system as described in claim 1, characterized in that, The electromagnetic vibration transducer system further includes a first drive circuit, the two input terminals of the first drive circuit are respectively coupled to the two input terminals of the electromagnetic vibration transducer system, and the two output terminals of the first drive circuit are respectively directly connected to the two ends of the braking circuit. The first driving circuit is a power amplifier circuit; The power amplifier circuit includes at least one or any combination of the following electronic components: vacuum tubes and transistors.

8. The electromagnetic vibration transducer system as described in claim 7, characterized in that, It also includes one or more third filters, each third filter having two input terminals coupled to the two input terminals of the electromagnetic vibration transducer system, and each third filter having two output terminals coupled to the two input terminals of the first drive circuit. The third filter includes a digital filter, an active filter, or a passive filter.

9. The electromagnetic vibration transducer system according to any one of claims 1-8, characterized in that, The electromagnetic vibration transducer electromechanical mechanism is a moving coil loudspeaker or a moving iron loudspeaker.

10. The electromagnetic vibration transducer system according to any one of claims 1-8, characterized in that, The electromagnetic vibration transducer electromechanical mechanism is a flat panel loudspeaker.

11. The electromagnetic vibration transducer system according to any one of claims 1-8, characterized in that, The electromagnetic vibration transducer electromechanical mechanism is a belt loudspeaker.

12. The electromagnetic vibration transducer system according to any one of claims 1-8, characterized in that, The electromagnetic vibration transducer electromechanical mechanism is a moving coil linear motor or a moving iron linear motor.

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