A condenser microphone

Abstract

This application relates to the field of audio equipment technology and discloses a condenser microphone, including a power conversion module comprising a power supply module and a voltage regulator module. The output terminal of the power supply module is connected to the input terminal of the voltage regulator module. The power conversion module is used for preliminary processing of input power supply voltage conversion and adaptation. A gain enhancement module is also included, with the output terminal of the voltage regulator module connected to its input terminal. A high-impedance signal pre-adjustment module has its input terminal connected to the output terminal of the gain enhancement module. An OTL power module has its input terminal connected to the output terminal of the high-impedance signal pre-adjustment module, and its output terminal is connected to the input terminal of the power supply module. A bias module has its input terminal connected to the output terminal of the voltage regulator module, and the output terminals of the bias module are connected to both the high-impedance signal pre-adjustment module and the OTL power module. This application has the advantages of improving signal processing stability, reducing nonlinear distortion, and enhancing power supply voltage adaptation capability.

Description

Technical Field

[0001] This application belongs to the field of audio equipment technology, specifically relating to a condenser microphone. Background Technology

[0002] With the continuous innovation of audio recording technology, condenser microphones have become core components in the professional audio recording field due to their high sensitivity and wide frequency response. In particular, condenser microphones based on microelectromechanical systems (MEMS) technology occupy an important position in recording equipment and professional audio acquisition equipment due to their excellent sound quality, stable performance output, and ultra-high sensitivity.

[0003] However, in the traditional condenser microphone technology system, most products using transformer-coupled output still have significant technical bottlenecks. When encountering high-intensity sound pressure input, the transformer coupling structure is prone to nonlinear distortion, leading to severe audio signal distortion and even complete equipment failure. At the same time, the electromagnetic characteristics of the transformer itself introduce parasitic parameter interference, which restricts key indicators such as sound quality purity, electromagnetic interference resistance, and frequency response flatness, making it difficult to meet the stringent requirements of modern audio acquisition for high fidelity and high reliability. Utility Model Content

[0004] To address the shortcomings of the prior art, this application provides a condenser microphone that offers advantages such as improved signal processing stability, reduced nonlinear distortion, high fidelity, and high reliability.

[0005] The technical effects to be achieved in this application are realized through the following aspects:

[0006] This application provides a condenser microphone, including

[0007] A power conversion module includes a power module and a voltage regulator module. The output terminal of the power module is connected to the input terminal of the voltage regulator module. The power conversion module is used to perform preliminary processing for the conversion and adaptation of the input power supply voltage.

[0008] A gain enhancement module, wherein the output terminal of the voltage regulator module is connected to the input terminal of the gain enhancement module;

[0009] A high-impedance signal pre-tuning module, the input of which is connected to the output of the gain enhancement module;

[0010] An OTL power module, the input of which is connected to the output of the high-impedance signal pre-tuning module, and the output of the OTL power module is connected to the input of the power supply module; and

[0011] The bias module has its input terminal connected to the output terminal of the voltage regulator module, and the output terminals of the bias module are all connected to the high-impedance signal pre-adjustment module and the OTL power module.

[0012] In some implementations, the high-impedance signal pre-tuning module includes a microphone MK1, a capacitor C8, and an amplification module. The capacitor C8 is connected to the output terminal of the microphone MK1 and the input terminal of the amplification module. The input terminal of the microphone MK1 is connected to the output terminal of the gain enhancement module, and the output terminal of the amplification module is connected to the OTL power module.

[0013] In some implementations, the amplification module includes transistors Q7, Q6, and Q8 connected in parallel. The gate of transistor Q7 is connected to the output terminal of capacitor C8, and the sources of transistors Q8, Q6, and Q7 are all connected to the input terminal of the OTL power module.

[0014] In some implementations, the OTL power module includes:

[0015] An input differential amplifier unit is provided, the input of which is connected to the output of the voltage regulator module, in order to reduce the impact on the preceding signal source.

[0016] A voltage amplification unit, whose input is connected to the high-impedance signal pre-tuning module, is used to amplify the voltage amplitude of the differential signal; and

[0017] The output unit is driven, with its input terminal connected to the output terminal of the voltage amplification unit and its output terminal connected to the output terminal of the power supply module, for further amplifying the signal power.

[0018] In some implementations, the input differential amplifier unit includes transistor Q4, transistor Q5, resistor R11, and resistor R12; the gate of transistor Q4 is connected to resistor R11, the gate of transistor Q5 is connected to resistor R12, and the drains of transistors Q4 and Q5 are both connected to the voltage amplifier unit.

[0019] In some implementations, the voltage amplification unit includes transistor Q9A and transistor Q9B. The bases of transistors Q9A and Q9B are both connected to the high-impedance signal pre-tuning module. The emitter of transistor Q9A is connected to the emitter of transistor Q9B. The collector of transistor Q9A is connected to the collector of transistor Q9B through capacitor C17, and the collector of transistor Q9B is connected to the drive output unit.

[0020] In some implementations, the drive output unit includes transistors Q11A, Q2A, Q2B, and Q11B;

[0021] The base of transistor Q11A and the base of transistor Q2A are both connected to the collector of transistor Q9B.

[0022] The emitter of transistor Q2A is connected to the base of transistor Q11B through resistor R20, and the collector of transistor Q2A is connected to the collector of transistor Q2B.

[0023] The emitter of transistor Q2B is connected to the output terminal of the power module through resistor R14;

[0024] The emitter of transistor Q11B is connected to the output terminal of the power module through resistor R18, and the collector of transistor Q11B is grounded.

[0025] In some implementations, the gain enhancement module includes an oscillation module and a voltage multiplier module. The input terminal of the oscillation module is connected to the output terminal of the voltage regulator module, the output terminal of the oscillation module is connected to the input terminal of the voltage multiplier module, and the output terminal of the voltage multiplier module is connected to the high-impedance signal pre-tuning module.

[0026] In some implementations, the oscillation module includes a transistor Q17, a capacitor C24, a resistor R32, and a transformer T2;

[0027] The emitter of transistor Q17 is connected to the output terminal of the voltage regulator module through resistor R26, the collector of transistor Q17 is connected to the input terminal of transformer T2, and the base of transformer T2 is connected to transformer T2 through capacitor C24 and resistor R32.

[0028] In some implementations, the voltage multiplier module includes diodes D2, D3, and D4, capacitors C23, C28, C26, and C29, resistors R30 and R31, switch S3, a 60V output terminal, and a 120V output terminal.

[0029] Diodes D2, D3, and D4 are connected in series. The cathodes of diodes D4 are connected to the output terminals of capacitor C28 and transformer T2. The anode of diode D2 is connected to one end of resistor R31, and the other end of resistor R31 is connected to resistor R30.

[0030] The capacitor C23 is connected in parallel with the diodes D3 and D4, which are connected in series.

[0031] The capacitor C26 is connected in parallel with the diodes D3 and D2, which are connected in series.

[0032] One end of capacitor C29 is connected to capacitor C26, and the other end of capacitor C29 is connected to ground.

[0033] The switch S3 is connected to the resistor R30 via resistor R34, or to the resistor R30 via resistor R36;

[0034] One end of the 60V output terminal is connected between diode D3 and diode D4; the other end of the 60V output terminal is connected to the high-impedance signal pre-adjustment module.

[0035] One end of the 120V output terminal is connected to the capacitor C26, and the other end of the 120V output terminal is connected between the diode D2 and the resistor R31.

[0036] In summary, this application has at least the following advantages:

[0037] The condenser microphone provided in this application achieves voltage adaptation optimization through a power conversion module. Combined with the collaborative work of a gain enhancement module and an OTL power module, it effectively reduces nonlinear distortion and improves system stability. It has the advantages of improving signal processing stability, reducing nonlinear distortion, and enhancing power supply voltage adaptation capability. Attached Figure Description

[0038] Figure 1 This is a schematic diagram of the structure of the condenser microphone in Embodiment 1 of this application.

[0039] Figure 2 This is another structural schematic diagram of the condenser microphone in Embodiment 1 of this application.

[0040] Figure 3 This is a schematic diagram of the OTL power module in Embodiment 2 of this application.

[0041] Figure 4 This is a schematic diagram of the gain enhancement module in Embodiment 3 of this application.

[0042] Marked in the image:

[0043] 12. Voltage Regulator Module; 2. Gain Enhancement Module; 3. High Impedance Signal Pre-tuning Module; 4. OTL Power Module; 41. Input Differential Amplifier Unit; 42. Voltage Amplifier Unit; 43. Driver Output Unit; 5. Bias Module; 21. Oscillation Module; 22. Voltage Multiplier Module. Detailed Implementation

[0044] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. The described embodiments are only some embodiments of this application, not all embodiments.

[0045] Therefore, the following detailed description of the embodiments of this application provided in the accompanying drawings is not intended to limit the scope of the claimed application, but merely to illustrate selected embodiments of the application. All other embodiments obtained by those skilled in the art based on the embodiments in this application without inventive effort are within the scope of protection of this application.

[0046] Example 1:

[0047] Please see the appendix Figure 1-2 This application proposes a condenser microphone comprising a power conversion module, a gain enhancement module 2, a high-impedance signal pre-tuning module 3, an OTL power module 4, and a bias module 5. The power conversion module includes a power supply module and a voltage regulator module 12, with the output of the power supply module connected to the input of the voltage regulator module 12. The input of the gain enhancement module 2 is connected to the output of the voltage regulator module 12, and the input of the high-impedance signal pre-tuning module 3 is connected to the output of the gain enhancement module 2. The input of the OTL power module 4 is connected to the output of the high-impedance signal pre-tuning module 3, and its output is connected to the input of the power supply module. The input of the bias module 5 is connected to the output of the voltage regulator module 12, and its output is connected to both the high-impedance signal pre-tuning module 3 and the OTL power module 4.

[0048] The power conversion module refers to the circuit unit that performs voltage conversion and regulation of the input power supply. It can be implemented by cascading a switching power supply and a linear regulator. Its function is to provide stable power supply for the subsequent circuits and eliminate the impact of voltage fluctuations on signal processing.

[0049] Gain enhancement module 2 refers to a functional unit that amplifies the signal amplitude. It can be implemented through an operational amplifier and a feedback network. Its function is to increase the signal strength and provide sufficient driving capability for high impedance transmission.

[0050] The high-impedance signal pre-conditioning module 3 refers to a signal conditioning circuit that uses high input impedance characteristics. It can be implemented using a field-effect transistor and a capacitive coupling structure. Its function is to suppress parasitic interference during signal transmission through impedance matching and to complete signal waveform shaping.

[0051] OTL power module 4 refers to a power amplifier circuit without an output transformer. It can be implemented using a complementary symmetrical push-pull circuit. Its function is to eliminate the nonlinear distortion introduced by the transformer through a closed-loop feedback mechanism and expand the frequency response range.

[0052] Bias module 5 refers to the voltage source that provides the static operating point for the amplifier circuit. It can be implemented using a voltage divider resistor and filter capacitor network. Its function is to stabilize the DC bias voltage of each functional module and improve the system's anti-interference capability.

[0053] Specifically, the power supply module converts the external input power to the target voltage value, and the voltage regulator module 12 eliminates ripple interference and outputs stable DC power. The gain enhancement module 2 receives the regulated power and amplifies the input audio signal. The high-impedance signal pre-adjustment module 3 suppresses parasitic capacitance effects during signal transmission through its high input impedance characteristics, while simultaneously using capacitive coupling to filter out DC components. The OTL power module 4 amplifies the pre-processed signal and then enhances the power output through a complementary push-pull circuit. Its output and the power supply module input form a closed-loop feedback path, correcting the power stage's operating state in real time. The bias module 5 provides a reference voltage to the high-impedance signal pre-adjustment module 3 and the OTL power module 4, ensuring the transistors operate in the linear amplification region. When all modules work together, there are no electromagnetic coupling devices involved in the entire signal link, fundamentally eliminating distortion and interference caused by transformers.

[0054] This embodiment replaces transformer coupling with the closed-loop feedback structure of the OTL power module 4, eliminating nonlinear distortion caused by core saturation. The high-impedance signal pre-tuning module 3 uses capacitive coupling to avoid introducing parasitic inductance from electromagnetic components. The power conversion module and the bias module 5 form a dual voltage regulation mechanism to overcome the interference of power supply fluctuations on the signal link in traditional solutions.

[0055] The above settings effectively reduce waveform distortion of audio signals during transmission and suppress the impact of electromagnetic interference on sound quality. The system's frequency response flatness is significantly improved, and the dynamic range is extended to the level required by professional recording equipment. The equipment maintains stable signal output characteristics even under high sound pressure levels, enhancing the accuracy and reliability of acquiring complex sound fields.

[0056] Example 2:

[0057] The difference between this embodiment and Embodiment 1 is that, please refer to... Figure 3 The high-impedance signal pre-tuning module 3 in this embodiment includes a microphone MK1, a capacitor C8, and an amplification module. The capacitor C8 is connected to the output terminal of the microphone MK1 and the input terminal of the amplification module. The input terminal of the microphone MK1 is connected to the output terminal of the gain enhancement module 2, and the output terminal of the amplification module is connected to the OTL power module 4.

[0058] The MK1 transducer is the core component for sound-to-electric conversion, which can be implemented using an electret condenser or a microelectromechanical system (MEMS) transducer structure. Its function is to convert sound wave vibrations into an initial electrical signal. The capacitor C8 is an AC coupling element, which can be implemented using a polyester film or ceramic dielectric capacitor. It is used to block DC components and establish a high-frequency signal path. The amplification module is a multi-stage signal processing unit, which can be implemented using a parallel transistor array. It improves the signal-to-noise ratio of weak signals through multi-stage amplification.

[0059] Specifically, after the acoustic signal is converted into an electrical signal by the microphone MK1, the DC offset component is filtered out by capacitor C8, retaining the AC audio signal before entering the amplification module. The parallel transistor array in the amplification module performs staged amplification of the signal, reducing thermal noise interference while maintaining linear gain characteristics. The pre-processed signal is directly input to the OTL power module 4 through a low-impedance path, avoiding hysteresis losses caused by traditional transformer coupling. The impedance matching network formed between the microphone MK1 and the input of the amplification module ensures minimal energy loss during signal transmission.

[0060] This solution completely eliminates the source of nonlinear distortion from magnetic components through capacitive coupling and a transistor array. The direct connection of the microphone MK1 to the amplification module shortens the signal transmission path and reduces the probability of external electromagnetic interference. The parallel structure of the amplification module, compared to a single-stage amplifier, expands the dynamic range and improves transient response speed. These features enable high-fidelity preprocessing of the acoustic signal, preventing baseline drift and electromagnetic interference during signal transmission. AC coupling capacitors effectively isolate DC components, preventing operating point shifts in subsequent circuits due to abnormal bias voltage. The multi-stage transistor array maintains linear amplification characteristics over a wide frequency range, ensuring distortion-free transmission of high sound pressure levels to the power amplification stage. This design fundamentally avoids the magnetic saturation risk of traditional transformer-coupled structures, improving the system's operational stability under high sound pressure levels.

[0061] This application further proposes an amplification module including transistors Q7, Q6, and Q8 connected in parallel. The gate of transistor Q7 is connected to the output terminal of capacitor C8, and the sources of transistors Q8, Q6, and Q7 are all connected to the input terminal of OTL power module 4.

[0062] Parallel configuration refers to multiple transistors being connected to the circuit in parallel, which can be achieved by connecting the collector or drain in parallel, in order to distribute the input signal load.

[0063] The connection between the gate of transistor Q7 and the output terminal of capacitor C8 indicates that a signal input path has been established. This can be achieved using metal wires or printed circuit board traces, and is used to receive the audio signal processed by the pre-amplifier.

[0064] The connection of the source terminals to the input terminals of the OTL power module 4 means that the output terminals of multiple transistors are combined to the same node. This can be achieved by using a common connection point or a star topology to reduce the equivalent impedance of the signal transmission path.

[0065] Specifically, transistor Q7 serves as the main signal channel, receiving the audio signal from capacitor C8. Transistors Q6 and Q8 form an auxiliary current path through a parallel connection. The sources of all three transistors are connected to the input terminal of the OTL power module 4, allowing each transistor to automatically distribute the load current under dynamic operating conditions. When the input signal amplitude changes abruptly, transistor Q8 is preferentially turned on to provide additional current compensation, while transistor Q6 maintains its linear operating range through its conduction characteristics. The parameter differences between the transistors caused by process variations are balanced by the multi-point connection structure, thereby avoiding cutoff distortion caused by overload of a single device.

[0066] Compared to existing technologies, traditional solutions typically use a single transistor to process high-voltage signals, which is prone to nonlinear distortion due to uneven load. This solution achieves automatic current distribution through a multi-transistor parallel structure, utilizes device redundancy to suppress transient signal distortion, and forms a low-impedance path at the common connection point to improve signal integrity. This effectively solves the distortion problem caused by uneven transistor load in high-voltage signal processing, significantly improving the linearity of the amplification module and the stability of signal transmission.

[0067] This application further proposes an OTL power module 4 including an input differential amplifier unit 41, a voltage amplifier unit 42, and a driver output unit 43. The input terminal of the input differential amplifier unit 41 is connected to the output terminal of the voltage regulator module 12 to reduce the impact on the pre-amplifier signal source; the input terminal of the voltage amplifier unit 42 is connected to the high-impedance signal pre-adjustment module 3 to amplify the voltage amplitude of the differential signal; the input terminal of the driver output unit 43 is connected to the output terminal of the voltage amplifier unit 42, and its output terminal is connected to the output terminal of the power supply module to further amplify the signal power.

[0068] Among them, the input differential amplifier unit 41 refers to a signal processing unit composed of a symmetrical differential circuit. Specifically, it can be implemented by using a transistor pair structure in conjunction with a balanced resistor network. It cancels common-mode interference and reduces the load effect on the preceding circuit through dual-channel input.

[0069] The voltage amplification unit 42 refers to the amplitude enhancement module composed of multi-stage amplifier circuits. Specifically, it can be implemented by cascading bipolar transistors or complementary field-effect transistor structures. It expands the voltage gain of the differential signal to match the input requirements of the power stage.

[0070] The output unit 43 refers to a transformerless power amplifier circuit, which can be implemented by combining a complementary symmetrical output stage with a power supply feedback loop. A closed-loop control path is formed by directly feeding the signal back to the power supply output terminal.

[0071] Specifically, the input differential amplifier unit 41 receives the stable voltage signal from the voltage regulator module 12 through a balanced input structure, suppressing common-mode interference and reducing the signal source load effect; the voltage amplifier unit 42 expands the amplitude of the differential signal from the high-impedance signal pre-tuning module 3, using multi-stage amplification to maintain the linearity of the signal waveform; the drive output unit 43 transmits the amplified signal to the output of the power module through a complementary symmetrical output stage, forming a power feedback path to eliminate the traditional transformer coupling structure. The three units achieve inter-stage coordination through impedance matching and power adaptation. The input differential amplifier unit 41 is directly connected to the front-stage voltage regulator module 12 to form an isolation barrier, the voltage amplifier unit 42 uses dual-channel amplification to maintain signal balance, and the drive output unit 43 establishes a self-stabilized operating point through the power feedback path.

[0072] Compared with existing technologies, traditional solutions rely on transformer coupling output, which leads to magnetic saturation distortion and parasitic parameter interference. In this embodiment, an OTL transformerless structure is adopted. The input differential amplifier unit 41 reduces the load effect of the front stage, the voltage amplifier unit 42 increases the signal amplitude, and the output unit 43 drives the signal to be directly fed back to the power supply. This eliminates the nonlinear distortion and electromagnetic interference introduced by the transformer, and avoids the power extraction effect of the front stage signal source.

[0073] With the above settings, the input differential amplifier unit 41 reduces the power extraction from the previous signal source, the voltage amplifier unit 42 ensures the amplitude stability of the signal transmission, and the output unit 43 achieves closed-loop control of power output through the power feedback path, thereby improving signal processing stability and power conversion efficiency.

[0074] This application further proposes an input differential amplifier unit 41 including transistor Q4, transistor Q5, resistor R11 and resistor R12; the gate of transistor Q4 is connected to resistor R11, the gate of transistor Q5 is connected to resistor R12, and the drains of transistors Q4 and Q5 are both connected to voltage amplifier unit 42.

[0075] Among them, the input differential amplifier unit 41 refers to a symmetrical circuit composed of two transistors, which can be implemented using bipolar transistors or field-effect transistors, and cancels common-mode interference through differential input signals.

[0076] Specifically, when the audio signal is transmitted to the differential amplifier unit, resistors R11 and R12 distribute the signal to the gates of transistors Q4 and Q5, respectively. The two transistors, based on a symmetrical circuit structure, generate amplified signals with opposite phases, which are output to the voltage amplifier unit 42 through their drains. Due to the high common-mode rejection ratio of the differential amplifier structure, external electromagnetic interference generates equal-amplitude and in-phase noise signals in the two transistors, which cancel each other out after differential processing. Simultaneously, the impedance network formed by resistors R11 and R12 makes the input circuit exhibit high impedance characteristics, reducing the load effect on the pre-amplification module 2 and preventing energy loss from the signal source due to impedance mismatch. The drains of transistors Q4 and Q5 are directly coupled to the voltage amplifier unit 42, utilizing the complementary characteristics of the differential outputs to maintain the stability of the circuit's static operating point.

[0077] This solution employs a symmetrical differential circuit design, constructing an impedance matching network at the input end. This improves signal transmission efficiency and effectively suppresses electromagnetic interference, enabling low-load access to the pre-amplifier and significantly reducing energy loss during signal transmission. Simultaneously, the dual-ended output characteristics of the differential amplifier unit avoid signal distortion caused by power supply fluctuations in single-ended structures, eliminate common-mode interference, enhance system anti-interference capabilities, and improve the purity of the audio signal. The combination of symmetrical transistors and matching resistors maintains circuit operating point stability, ensuring that the amplified signal is transmitted to the subsequent processing unit without distortion.

[0078] This application further proposes a voltage amplification unit 42 including transistor Q9A and transistor Q9B. The base of transistor Q9A and the base of transistor Q9B are both connected to the high-impedance signal pre-tuning module 3. The emitter of transistor Q9A is connected to the emitter of transistor Q9B. The collector of transistor Q9A is connected to the collector of transistor Q9B through capacitor C17. The collector of transistor Q9B is connected to the drive output unit 43.

[0079] In this embodiment, the output signal of the high-impedance signal pre-tuning module 3 is simultaneously input to the bases of transistors Q9A and Q9B, forming a symmetrical differential signal input. The emitters of the two transistors are directly connected, causing common-mode interference signals to cancel each other out at the emitter node, thereby suppressing the influence of external electromagnetic interference on the differential signal. The collector of transistor Q9A is coupled to the collector of transistor Q9B through capacitor C17. Capacitor C17 performs phase adjustment of the AC signal, compensating for harmonic distortion generated in the nonlinear operating region of the transistor, while blocking the DC component to avoid bias voltage offset. The collector of transistor Q9B is directly connected to drive the output unit 43, shortening the signal transmission path to a single-stage amplification structure and reducing parasitic capacitance attenuation of high-frequency signals in the transmission path.

[0080] This solution replaces the transformer with a transistor differential structure and capacitive coupling, effectively suppressing signal distortion under high-intensity sound pressure input, reducing high-frequency signal attenuation, and improving the linearity and stability of the differential amplifier circuit. Common-mode interference signals are actively canceled, ensuring the audio signal remains pure during amplification. Simultaneously, the capacitive coupling and direct output structure avoid the hysteresis and parasitic effects associated with traditional transformers.

[0081] This application further proposes a drive output unit 43 including transistors Q11A, Q2A, Q2B, and Q11B; the bases of transistors Q11A and Q2A are both connected to the collector of transistor Q9B; the emitter of transistor Q2A is connected to the base of transistor Q11B through resistor R20, and the collector of transistor Q2A is connected to the collector of transistor Q2B; the emitter of transistor Q2B is connected to the output terminal of the power module through resistor R14; the emitter of transistor Q11B is connected to the output terminal of the power module through resistor R18, and the collector of transistor Q11B is grounded.

[0082] The bases of transistors Q11A and Q2A are connected to the output of the preamplifier unit 42, forming a dual-signal drive mechanism, which can reduce the risk of single-signal overload.

[0083] Resistor R20 is connected between the emitter of transistor Q2A and the base of transistor Q11B to establish a negative feedback path to suppress thermal noise interference.

[0084] The collector interconnect of transistors Q2A and Q2B forms a push-pull output core, which, together with resistor R14, connects to the power module, thereby increasing the output power and stabilizing the operating point.

[0085] The emitter of transistor Q11B is connected to the power supply through resistor R18 to form a current discharge path, and its collector is grounded to build a complete signal loop, reducing the probability of crossover distortion and parasitic oscillation.

[0086] In this embodiment, the dual-path drive structure of transistors Q11A and Q2A can synchronously receive the voltage amplification signal from the pre-amplified stage, forming a dynamic balance during signal transmission and avoiding nonlinear distortion caused by excessive amplitude of a single signal. The negative feedback path of resistor R20 can adjust the base voltage of transistor Q11B in real time, suppressing signal drift caused by transistor temperature changes. The collectors of transistors Q2A and Q2B are directly connected to form a complementary push-pull output, which is connected to the stable voltage of the power module through resistor R14, ensuring that the operating point of the output stage is not affected by load fluctuations. The grounded collector of transistor Q11B and resistor R18 together form a low-impedance loop, which can quickly discharge residual charge and reduce signal delay and phase distortion.

[0087] Compared to existing technologies, traditional condenser microphones using transformer-coupled outputs are prone to signal distortion under high sound pressure levels due to the core saturation characteristics, and the parasitic capacitance of the transformer windings introduces high-frequency interference. This solution replaces the transformer with a complementary transistor push-pull structure. The symmetrical complementary transistor push-pull structure reduces output stage crossover distortion, the resistive feedback network suppresses thermal noise interference in the signal link, and the optimized layout of the power connection points enhances operating point stability, ultimately achieving an overall improvement in the anti-interference capability of the signal amplification stage.

[0088] Example 3:

[0089] The difference between this embodiment and Embodiment 2 is that, please refer to... Figure 4 In this embodiment, the gain enhancement module 2 includes an oscillation module 21 and a voltage multiplier module 22. The input terminal of the oscillation module 21 is connected to the output terminal of the voltage regulator module 12, the output terminal of the oscillation module 21 is connected to the input terminal of the voltage multiplier module 22, and the output terminal of the voltage multiplier module 22 is connected to the high-impedance signal pre-tuning module 3.

[0090] The oscillation module 21 is a circuit that converts direct current into high-frequency alternating current signals. It can be implemented using a combination of transistors and transformers, generating a high-frequency alternating magnetic field through electromagnetic induction. This module replaces traditional linear transformer coupling in the design, avoiding nonlinear distortion caused by magnetic saturation.

[0091] The voltage multiplier module 22 refers to a circuit that superimposes voltage based on the charge pump principle. Specifically, it can be implemented using a diode and capacitor series structure, achieving voltage multiplication through multi-stage capacitor charging and discharging. This module is used in the scheme to generate a high-amplitude bias voltage, addressing the stability issue of high-voltage power supply.

[0092] In this design, switch S3 is a control device used to switch between voltage multiplication modes. It can be implemented using mechanical contacts or a semiconductor switch, and the output voltage level is adjusted by changing the resistor network connection. This device is used in the solution to dynamically adjust the voltage amplitude to adapt to signal processing requirements at different sound pressure levels.

[0093] Specifically, the transistor in the oscillation module 21 conducts under the DC voltage output from the voltage regulator module 12, driving the primary winding of the transformer to generate an alternating current, which in turn induces a high-frequency AC signal in the secondary winding. The voltage multiplier module 22 receives this AC signal and performs multi-stage voltage superposition through a charge pump circuit composed of diodes and capacitors. For example, a first-stage voltage boost is performed between capacitor C23 and diode D3, and a second-stage voltage boost is performed between capacitor C26 and diode D2, ultimately forming two output voltage levels: 60V and 120V. Switch S3 changes the load characteristics of the voltage multiplier module 22 by switching the connection path of resistors R34 and R36, allowing the output voltage to automatically adjust according to the sound pressure level. This process completely eliminates the traditional transformer coupling method; the high-frequency AC signal is transmitted through capacitive components, avoiding parasitic parameters introduced by electromagnetic interference.

[0094] This solution employs an active boost method combining high-frequency oscillation and capacitor voltage multiplication. This not only eliminates the risk of magnetic saturation but also blocks reverse interference signals through the unidirectional conductivity of diodes. Furthermore, the DC bias voltage output by the voltage multiplier module 22 blocks the electromagnetic interference conduction path, and the switch-controlled resistor network enables dynamic adjustment of the output voltage, thereby improving the linearity of audio signal transmission and the system's anti-interference capability.

[0095] This application further proposes an oscillation module 21 including a transistor Q17, a capacitor C24, a resistor R32, and a transformer T2; the emitter of transistor Q17 is connected to the output terminal of the voltage regulator module 12 through a resistor R26, the collector of transistor Q17 is connected to the input terminal of transformer T2, and the base of transformer T2 is connected to transformer T2 through a capacitor C24 and a resistor R32.

[0096] Among them, transistor Q17 is the core component that constitutes the oscillation circuit. Specifically, it can be implemented using a bipolar transistor or a field-effect transistor. Its emitter is connected to the output terminal of the voltage regulator module 12 through resistor R26 to form current negative feedback, which is used to stabilize the operating point and control the oscillation amplitude.

[0097] Capacitor C24 refers to a high-frequency filtering element, which can be implemented using a ceramic capacitor or a film capacitor. It is connected in parallel between the base terminal of transformer T2 and ground to absorb high-frequency parasitic oscillations caused by the distributed capacitance of the transformer winding.

[0098] Resistor R32 refers to the bias resistor, which can be implemented using a metal film resistor or a carbon film resistor. It is connected in series in the base circuit of transformer T2 to establish the DC operating path of transistor Q17 and limit the base current.

[0099] Transformer T2 refers to an electromagnetic energy conversion device, which can be implemented using a ferrite core or a nanocrystalline core. Its input terminal receives the collector output signal of transistor Q17 and generates a high-frequency oscillation signal through electromagnetic induction.

[0100] Specifically, the emitter of transistor Q17 is connected to the DC voltage output by voltage regulator module 12 through resistor R26, forming a stable base bias current. The collector output signal undergoes energy conversion through the primary winding of transformer T2, generating a high-frequency carrier wave in the secondary winding. Capacitor C24 and the base winding of transformer T2 form a parallel resonant circuit. By adjusting the capacitance value to match the distributed inductance of the transformer winding, high-order harmonics exceeding the set frequency are suppressed. Resistor R32 is connected in series in the base circuit, forming an RC time constant with capacitor C24, limiting the rate of change of magnetic flux in the transformer core and preventing waveform clipping distortion caused by core saturation. The base terminal of transformer T2 is simultaneously connected to capacitor C24 and resistor R32, forming a dual feedback path: the capacitor path filters out high-frequency interference, and the resistor path maintains DC balance. The synergistic effect of the two allows the transformer to operate in the non-saturated linear region.

[0101] This solution eliminates high-frequency self-excited oscillations caused by distributed winding parameters by setting a capacitor and resistor in parallel at the transformer base terminals. Furthermore, the DC negative feedback established by the resistor suppresses residual magnetism accumulation in the core, effectively reducing harmonic distortion caused by transformer core saturation and suppressing interference from high-frequency parasitic oscillations on the audio signal. This allows the condenser microphone to maintain signal waveform integrity even under high-intensity sound pressure input. Simultaneously, the emitter resistor R26 of transistor Q17 forms current negative feedback, ensuring that the oscillation amplitude remains constant regardless of input voltage fluctuations, maintaining the linearity of signal conversion, reducing electromagnetic leakage crosstalk to surrounding circuits, and improving the signal-to-noise ratio and frequency response flatness of the audio signal.

[0102] This application further proposes a voltage multiplier module 22 comprising diodes D2, D3, and D4; capacitors C23, C28, C26, and C29; resistors R30 and R31; a switch S3; a 60V output terminal; and a 120V output terminal. Diodes D2, D3, and D4 are connected in series. The cathode of diode D4 is connected to capacitor C28 and the output terminal of transformer T2. The anode of diode D2 is connected to one end of resistor R31, and the other end of resistor R31 is connected to resistor R30. Capacitor C23 is connected in parallel with the series connection of diodes D3 and D4, and capacitor C26 is connected in parallel with the series connection of diodes D3 and D2. One end of capacitor C29 is connected to capacitor C26, and the other end is grounded. Switch S3 is connected to resistor R30 through either resistor R34 or resistor R36. The 60V output terminal is connected between diodes D3 and D4, and the other end is connected to the high-impedance signal pre-adjustment module 3; the 120V output terminal is connected between capacitor C26, diode D2, and resistor R31.

[0103] In this embodiment, the AC signal output from transformer T2 undergoes multi-stage rectification via a series path of diodes D2-D4. Capacitor C23 absorbs high-frequency interference across diodes D3-D4, while capacitor C26 smooths low-to-mid-frequency fluctuations across diodes D2-D3. Capacitor C28, in conjunction with diode D4, completes the first-stage voltage multiplication, and capacitor C26, in conjunction with diodes D2 and D3, completes the second-stage voltage multiplication. When switch S3 selects resistor R34, the circuit resistance decreases, and the current-limiting network formed by capacitor C29 and resistors R30 and R31 controls the charging speed, resulting in a 60V output voltage. When switching to resistor R36, the circuit resistance increases, capacitor C26 stores a higher potential, and a 120V output voltage is generated. Capacitor C29 forms a filter circuit through grounding, eliminating residual ripple. The 60V output terminal extracts a half-multiplied voltage signal from the intermediate node of diodes D3-D4, and the 120V output terminal obtains a full-multiplied voltage signal from capacitor C26, achieving graded output.

[0104] This solution employs a transformerless multi-stage diode-capacitor voltage multiplier architecture, directly boosting the voltage through semiconductor devices to avoid signal distortion caused by core material saturation. Furthermore, by switching resistors to change the voltage multiplication path, it achieves two adjustable output levels. This tiered output structure provides precisely matched voltages for different signal processing modules, and the adjustable resistor network enables dynamic voltage adaptation. Simultaneously, the segmented filtering design of the capacitor network replaces the traditional LC filter circuit, reducing component size and electromagnetic interference, effectively suppressing high-frequency noise, and lowering output voltage ripple, thereby improving the purity and anti-interference capability of the audio signal.

[0105] In this application, unless otherwise expressly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0106] In the description of this application, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship commonly used when the product of this application is in use. They are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation on this application. In addition, the terms "first," "second," and "third," etc., are only used to distinguish descriptions and should not be construed as indicating or implying relative importance.

[0107] Furthermore, terms such as "horizontal," "vertical," and "sag" do not imply that components must be absolutely horizontal or suspended, but rather that they can be slightly tilted. For example, "horizontal" simply means that its direction is more horizontal relative to "vertical," and does not mean that the structure must be completely horizontal, but can be slightly tilted.

[0108] In this application, unless otherwise expressly specified and limited, "above or below" a first feature may include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on" a first feature includes the first feature directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" a first feature includes the first feature directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0109] Although the description of this application has been made in conjunction with the specific embodiments described above, it is obvious to those skilled in the art that many substitutions, modifications, and variations can be made based on the above description. Therefore, all such substitutions, modifications, and variations are included within the spirit and scope of the appended claims.

Claims

1. A condenser microphone characterized by comprising: include The power conversion module includes a power module and a voltage regulator module (12). The output terminal of the power module is connected to the input terminal of the voltage regulator module (12). The power conversion module is used to perform preliminary processing for the conversion and adaptation of the input power supply voltage. Gain enhancement module (2), the output terminal of the voltage regulator module (12) is connected to the input terminal of the gain enhancement module (2); The input terminal of the high-impedance signal pre-adjustment module (3) is connected to the output terminal of the gain enhancement module (2); The input terminal of the OTL power module (4) is connected to the output terminal of the high-impedance signal pre-tuning module (3), and the output terminal of the OTL power module (4) is connected to the input terminal of the power supply module. as well as The input terminal of the bias module (5) is connected to the output terminal of the voltage regulator module (12), and the output terminal of the bias module (5) is connected to the high impedance signal pre-adjustment module (3) and the OTL power module (4).

2. The condenser microphone according to claim 1, characterized in that, The high impedance signal pre-tuning module (3) includes a microphone MK1, a capacitor C8 and an amplification module. The capacitor C8 is connected to the output terminal of the microphone MK1 and the input terminal of the amplification module. The input terminal of the microphone MK1 is connected to the output terminal of the gain enhancement module (2), and the output terminal of the amplification module is connected to the OTL power module (4).

3. The condenser microphone according to claim 2, characterized in that The amplification module includes transistors Q7, Q6 and Q8 connected in parallel. The gate of transistor Q7 is connected to the output terminal of capacitor C8. The source of transistor Q8, the source of transistor Q6 and the source of transistor Q7 are all connected to the input terminal of the OTL power module (4).

4. The condenser microphone according to claim 1, wherein The OTL power module (4) includes: The input differential amplifier unit (41) is connected to the output of the voltage regulator module (12) to reduce the impact on the previous signal source; A voltage amplification unit (42), whose input terminal is connected to the high-impedance signal pre-tuning module (3), is used to amplify the voltage amplitude of the differential signal; and The output unit (43) is driven, its input terminal is connected to the output terminal of the voltage amplification unit (42), and its output terminal is connected to the output terminal of the power supply module, for further amplifying the signal power.

5. The condenser microphone according to claim 4, characterized in that The input differential amplifier unit (41) includes transistor Q4, transistor Q5, resistor R11 and resistor R12; the gate of transistor Q4 is connected to resistor R11, the gate of transistor Q5 is connected to resistor R12, and the drains of transistor Q4 and transistor Q5 are both connected to the voltage amplifier unit (42).

6. The condenser microphone according to claim 4, wherein The voltage amplification unit (42) includes transistor Q9A and transistor Q9B. The base of transistor Q9A and the base of transistor Q9B are both connected to the high-impedance signal pre-tuning module (3). The emitter of transistor Q9A is connected to the emitter of transistor Q9B. The collector of transistor Q9A is connected to the collector of transistor Q9B through capacitor C17. The collector of transistor Q9B is connected to the drive output unit (43).

7. The condenser microphone according to claim 5, characterized in that, The drive output unit (43) includes transistor Q11A, transistor Q2A, transistor Q2B and transistor Q11B; The base of transistor Q11A and the base of transistor Q2A are both connected to the collector of transistor Q9B. The emitter of transistor Q2A is connected to the base of transistor Q11B through resistor R20, and the collector of transistor Q2A is connected to the collector of transistor Q2B. The emitter of transistor Q2B is connected to the output terminal of the power module through resistor R14; The emitter of transistor Q11B is connected to the output terminal of the power module through resistor R18, and the collector of transistor Q11B is grounded.

8. The condenser microphone according to claim 1, characterized in that, The gain enhancement module (2) includes an oscillation module (21) and a voltage multiplier module (22). The input terminal of the oscillation module (21) is connected to the output terminal of the voltage regulator module (12). The output terminal of the oscillation module (21) is connected to the input terminal of the voltage multiplier module (22). The output terminal of the voltage multiplier module (22) is connected to the high impedance signal pre-tuning module (3).

9. The condenser microphone according to claim 8, characterized in that, The oscillation module (21) includes transistor Q17, capacitor C24, resistor R32 and transformer T2; The emitter of transistor Q17 is connected to the output terminal of the voltage regulator module (12) through resistor R26, the collector of transistor Q17 is connected to the input terminal of transformer T2, and the base of transformer T2 is connected to transformer T2 through capacitor C24 and resistor R32 respectively.

10. The condenser microphone according to claim 9, characterized in that, The voltage multiplier module (22) includes diodes D2, D3, and D4, capacitors C23, C28, C26, and C29, resistors R30 and R31, switch S3, a 60V output terminal, and a 120V output terminal. Diodes D2, D3, and D4 are connected in series. The cathodes of diodes D4 are connected to the output terminals of capacitor C28 and transformer T2. The anode of diode D2 is connected to one end of resistor R31, and the other end of resistor R31 is connected to resistor R30. The capacitor C23 is connected in parallel with the diodes D3 and D4, which are connected in series. The capacitor C26 is connected in parallel with the diodes D3 and D2, which are connected in series. One end of capacitor C29 is connected to capacitor C26, and the other end of capacitor C29 is connected to ground. The switch S3 is connected to the resistor R30 via resistor R34, or to the resistor R30 via resistor R36; One end of the 60V output terminal is connected between diode D3 and diode D4; the other end of the 60V output terminal is connected to the high-impedance signal pre-adjustment module (3); One end of the 120V output terminal is connected to the capacitor C26, and the other end of the 120V output terminal is connected between the diode D2 and the resistor R31.

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