Pre-amplification circuit of gooseneck microphone

Abstract

The utility model relates to the technical field of microphone circuits, and discloses a gooseneck microphone pre-amplification circuit, which enhances the signal intensity through multistage amplification, forms an adjustable compensation filter circuit based on elements such as a potentiometer R78, protects elements based on elements such as an amplitude limiter D35, and forms a feedback compensation circuit based on a triode Q24 and a field tube Q12, so that the circuit is stable in different environments. And the gooseneck microphone can continuously and reliably output high-quality audio.

Description

Technical Field

[0001] This application relates to the field of microphone circuit technology, and in particular to a gooseneck microphone preamplifier circuit. Background Technology

[0002] In the field of modern communication and audio equipment, gooseneck microphones are widely used in conferences, speeches, and other similar scenarios. Traditional gooseneck microphone preamplifier circuits have several shortcomings in signal processing, specifically:

[0003] 1. The signal input and processing structure of the existing circuit is relatively simple. It cannot efficiently acquire and initially amplify weak microphone audio signals, making the signal susceptible to external interference and resulting in noise in the output sound, which seriously affects the audio quality.

[0004] 2. Regarding the gain adjustment function, the existing circuit lacks a flexible and precise adjustment mechanism. It can usually only perform fixed gain amplification, making it difficult to accurately adjust the microphone volume according to the actual usage scenario and needs.

[0005] 3. The stability of the existing circuit is also poor. Under different ambient temperature, humidity and other conditions, the circuit performance fluctuates greatly and cannot guarantee stable and reliable audio output.

[0006] In summary, these problems greatly limit the effectiveness of gooseneck microphones in practical applications, and there is an urgent need for a new preamplifier circuit for gooseneck microphones to solve these technical challenges. Utility Model Content

[0007] The purpose of this application is to provide a gooseneck microphone preamplifier circuit to solve the technical problems mentioned in the background art.

[0008] To achieve the above objectives, this application discloses the following technical solution: a gooseneck microphone preamplifier circuit, comprising capacitors C35, C56, C137, C52, C108, C34, C54, polarized capacitors C48, C38, C49, C53, C102, and C47, resistors R69, R70, R62, R67, R56, R202, R170, R71, R44, R45, R43, R79, R58, R46, R144, and R64, a socket J5, a selection channel ESWS4, a limiter D35, a limiter D34, a chip U1B, a chip U2B, a transistor Q24, a field-effect transistor Q12, and a potentiometer R78;

[0009] Pin 1 of capacitor C35, pin 1 of resistor R69, and pin 1 of capacitor C56 are all connected to pin 3 of socket J5. Pin 2 of socket J5 is floating, pin 1 of socket J5 is grounded, pin 2 of capacitor C35 is grounded, the positive terminal of polarized capacitor C48, pin 1 of resistor R70, and pin 1 of resistor R62 are all connected to pin 2 of resistor R69, the negative terminal of polarized capacitor C48 and pin 2 of resistor R70 are both grounded, pin 2 of resistor R62 is connected to GNDA, pins 1 and 2 of limiter D35, pin 2 of resistor R67, and pin 5 of chip U2B are all connected to pin 2 of capacitor C56. Pin 3 of the resistor R67, pin 1 of the resistor R67, the positive terminal of the polarized capacitor C38, pin 1 of the resistor R56, and pin 3 of the limiter D34 are all connected to pin 5 of the chip U1B. The negative terminal of the polarized capacitor C38 is grounded. Pin 2 of the resistor R56 is grounded. Pin 2 of the limiter D34 is connected to VCC. Pin 1 of the limiter D34 and pin 1 of the resistor R202 are both connected to GNDA. Pin 2 of the resistor R202 and pin 1 of the capacitor C137 are both connected to pin 6 of the chip U1B. Pin 2 of the capacitor C137 and pin 7 of the chip U1B are both connected to pin 1 of the resistor R170. Pin 2 of the resistor R170 is connected to GNDA. The emitter of transistor Q24 and pin 1 of resistor R71 are both connected to VCC. Pins 2 of resistor R71 and R44 are both connected to the base of transistor Q24. Pin 1 of resistor R44 is connected to pin 2 of capacitor C52. Pin 1 of resistor R45 and the positive terminal of polarized capacitor C49 are both connected to the collector of transistor Q24. The negative terminal of polarized capacitor C49 is grounded. Pins 2 of resistor R43 and pin 3 of MOSFET Q12 are both connected to pin 2 of resistor R45. Pin 2 of MOSFET Q12 is connected to the positive terminal of polarized capacitor C53. The negative terminal of polarized capacitor C53 is grounded. Pin 1 of MOSFET Q12 and the... Pin 1 of resistor R43 is connected to pin 1 of resistor R79. Pin 2 of resistor R79, pin 1 of resistor R58, and pin 1 of capacitor C34 are all connected to pin 6 of chip U2B. Pin 2 of resistor R58 and pin 1 of resistor R46 are both connected to pin 1 of capacitor C108. Pin 2 of resistor R46, pin 2 of capacitor C34, and pin 1 of capacitor C54 are all connected to pin 3 of potentiometer R78. Pin 2 of capacitor C108 and the negative terminal of polarized capacitor C102 are both grounded. The positive terminal of polarized capacitor C102 is connected to pin 1 of resistor R144. Pin 2 of resistor R144 is connected to pin 2 of potentiometer R78.Pin 2 of capacitor C54, pin 1 of potentiometer R78, pin 1 of capacitor C52, and pin 7 of chip U2B are all connected to the negative terminal of polarized capacitor C47. The positive terminal of polarized capacitor C47 and pin 1 of resistor R64 are both connected to the selection channel ESWS4. Pin 2 of resistor R64 is connected to GNDA.

[0010] Beneficial effects: The gooseneck microphone preamplifier circuit of this application, in terms of signal processing, uses an input circuit composed of capacitors C35 and C56 to efficiently acquire the gooseneck microphone signal, and then amplifies the signal strength through multiple stages of chips U1B and U2B, effectively reducing external interference, significantly reducing noise in the output audio signal, and greatly improving sound quality. In terms of gain adjustment, the adjustable compensation filter circuit composed of potentiometer R78 and surrounding resistors and capacitors achieves flexible and precise gain adjustment, allowing users to conveniently adjust the microphone volume according to actual scenarios to meet diverse needs. In terms of circuit stability, the limiters D35 and D34 limit the signal amplitude protection element, and the feedback compensation circuit composed of transistor Q24 and MOSFET Q12 dynamically adjusts according to the signal, so that the circuit can remain stable in different environments, ensuring that the gooseneck microphone continuously and reliably outputs high-quality audio, making it highly practical and valuable for application. Attached Figure Description

[0011] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0012] Figure 1 The circuit diagram of the gooseneck microphone preamplifier circuit provided in the embodiments of this application. Detailed Implementation

[0013] The technical solutions in the embodiments of this application will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments in this application, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of this application.

[0014] In this document, the term "comprising" is intended to cover a 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 limitation, an element defined by the phrase "comprising..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0015] This embodiment discloses, as follows: Figure 1 The gooseneck microphone preamplifier circuit shown includes capacitors C35, C56, C137, C52, C108, C34, C54, polarized capacitors C48, C38, C49, C53, C102, and C47; resistors R69, R70, R62, R67, R56, R202, R170, R71, R44, R45, R43, R79, R58, R46, R144, and R64; socket J5; selection channel ESWS4; limiter D35; limiter D34; chip U1B; chip U2B; transistor Q24; MOSFET Q12; and potentiometer R78.

[0016] Pin 1 of capacitor C35, pin 1 of resistor R69, and pin 1 of capacitor C56 are all connected to pin 3 of socket J5. Pin 2 of socket J5 is left floating, pin 1 of socket J5 is grounded, pin 2 of capacitor C35 is grounded, the positive terminal of polarized capacitor C48, pin 1 of resistor R70, and pin 1 of resistor R62 are all connected to pin 2 of resistor R69. The negative terminal of polarized capacitor C48 and pin 2 of resistor R70 are both grounded. Pin 2 of resistor R62 is connected to GNDA. Pins 1 and 2 of limiter D35, pin 2 of resistor R67, and pin 5 of chip U2B are all connected to pin 2 of capacitor C56. Pin 3 of limiter D35, pin 1 of resistor R67, the positive terminal of polarized capacitor C38, and resistor R... Pin 1 of R56 and pin 3 of limiter D34 are both connected to pin 5 of chip U1B. The negative terminal of polarized capacitor C38 is grounded. Pin 2 of resistor R56 is grounded. Pin 2 of limiter D34 is connected to VCC. Pin 1 of limiter D34 and pin 1 of resistor R202 are both connected to GNDA. Pin 2 of resistor R202 and pin 1 of capacitor C137 are both connected to pin 6 of chip U1B. Pin 2 of capacitor C137 and pin 7 of chip U1B are both connected to pin 1 of resistor R170. Pin 2 of resistor R170 is connected to GNDA. The emitter of transistor Q24 and pin 1 of resistor R71 are both connected to VCC. Pin 2 of resistor R71 and pin 2 of resistor R44 are both connected to the transistor... The base of transistor Q24 is connected to the ground. Pin 1 of resistor R44 is connected to pin 2 of capacitor C52. Pin 1 of resistor R45 and the positive terminal of polarized capacitor C49 are both connected to the collector of transistor Q24. The negative terminal of polarized capacitor C49 is grounded. Pin 2 of resistor R43 and pin 3 of MOSFET Q12 are both connected to pin 2 of resistor R45. Pin 2 of MOSFET Q12 is connected to the positive terminal of polarized capacitor C53. The negative terminal of polarized capacitor C53 is grounded. Pin 1 of MOSFET Q12 and pin 1 of resistor R43 are both connected to pin 1 of resistor R79. Pin 2 of resistor R79, pin 1 of resistor R58, and pin 1 of capacitor C34 are all connected to pin 6 of chip U2B. Pin 2 of resistor R58 and pin 1 of resistor R46 are both connected to the collector of transistor Q24. All pins are connected to pin 1 of capacitor C108. Pins 2 of resistor R46, pins 2 of capacitor C34, and pin 1 of capacitor C54 are all connected to pin 3 of potentiometer R78. Pin 2 of capacitor C108 and the negative terminal of polarized capacitor C102 are grounded. The positive terminal of polarized capacitor C102 is connected to pin 1 of resistor R144. Pin 2 of resistor R144 is connected to pin 2 of potentiometer R78. Pins 2 of capacitor C54, pin 1 of potentiometer R78, pin 1 of capacitor C52, and pin 7 of chip U2B are all connected to the negative terminal of polarized capacitor C47. The positive terminal of polarized capacitor C47 and pin 1 of resistor R64 are both connected to the selection channel ESWS4. Pin 2 of resistor R64 is connected to GNDA.

[0017] In the specific application of this embodiment, the external gooseneck microphone (MIC) is connected to capacitor C56 via pin 3 of connector J5, and then connected in series to limiter D35. The signal is sent to pin 5 of chip U1B (model LM833 in this embodiment) via limiter D35. After being filtered by polarized capacitor C38 and resistor R56, the signal is output from pin 7 of chip U1B and connected to ground GNDA via resistor R170. Pin 7 of chip U1B is fed back to pin 6 of chip U1B via resistor C137. Another path is amplified by non-inverting input of pin 5 of chip U2B (model LM833 in this embodiment) and then output from pin 7 of chip U2B. At this point, the output signal splits into two paths. One path is coupled to the selection channel ESWS4 via polarized capacitor C47, and the other path is limited to ground GNDA via resistor R64. A feedback compensation signal is output from pin 7 of chip U2B, connected in series with capacitor C52 to resistor R44, and supplied to the base of transistor Q24. After being amplified by the collector of transistor Q24, it is current-limited by resistor R45 and input to the gate of MOSFET Q12 (pin 3 of MOSFET Q12 in this embodiment). The signal then enters the drain of MOSFET Q12 and is output, and then connected to the core via resistor R79. The U2B chip's pin 6 is an inverting input amplifier. The components surrounding pin 6 of the U2B chip, including capacitors C54 and C34, resistors R78 and R144, polarized capacitors C102 and C108, and resistor R58, form an adjustable signal compensation filter circuit. Adjusting the resistance of potentiometer R78 changes the microphone gain. Finally, after internal compensation and amplification, the signal is preamplified and output from the U2B chip's output pin, coupled to the selection channel ESWS4 via capacitor C47, and partially connected to ground GNDA via resistor R64 (the balancing resistor).

[0018] In summary, the gooseneck microphone preamplifier circuit of this embodiment efficiently acquires the gooseneck microphone signal through the input circuit composed of capacitors C35 and C56, and enhances the signal strength through multi-stage amplification by chips U1B and U2B, effectively reducing external interference, significantly reducing noise in the output audio signal, and greatly improving sound quality. Regarding gain adjustment, the adjustable compensation filter circuit composed of potentiometer R78 and surrounding resistors and capacitors achieves flexible and precise gain adjustment, allowing users to conveniently adjust the microphone volume according to actual scenarios and meet diverse needs. In terms of circuit stability, limiters D35 and D34 limit the signal amplitude protection element, and the feedback compensation circuit composed of transistor Q24 and MOSFET Q12 dynamically adjusts according to the signal, ensuring the circuit remains stable under different environments and guaranteeing the gooseneck microphone's continuous and reliable output of high-quality audio, demonstrating high practicality and application value.

[0019] Finally, it should be noted that the above description is only a preferred embodiment of this application and is not intended to limit this application. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A gooseneck microphone preamplifier circuit, characterized in that, Includes capacitors C35, C56, C137, C52, C108, C34, C54, polarized capacitors C48, C38, C49, C53, C102, and C47; resistors R69, R70, R62, R67, R56, R202, R170, R71, R44, R45, R43, R79, R58, R46, R144, and R64; socket J5; channel selector ESWS4; limiter D35; limiter D34; chip U1B; chip U2B; transistor Q24; MOSFET Q12; and potentiometer R78. Pin 1 of capacitor C35, pin 1 of resistor R69, and pin 1 of capacitor C56 are all connected to pin 3 of socket J5. Pin 2 of socket J5 is floating, pin 1 of socket J5 is grounded, pin 2 of capacitor C35 is grounded, the positive terminal of polarized capacitor C48, pin 1 of resistor R70, and pin 1 of resistor R62 are all connected to pin 2 of resistor R69, the negative terminal of polarized capacitor C48 and pin 2 of resistor R70 are both grounded, pin 2 of resistor R62 is connected to GNDA, pins 1 and 2 of limiter D35, pin 2 of resistor R67, and pin 5 of chip U2B are all connected to pin 2 of capacitor C56. Pin 3 of the resistor R67, pin 1 of the resistor R67, the positive terminal of the polarized capacitor C38, pin 1 of the resistor R56, and pin 3 of the limiter D34 are all connected to pin 5 of the chip U1B. The negative terminal of the polarized capacitor C38 is grounded. Pin 2 of the resistor R56 is grounded. Pin 2 of the limiter D34 is connected to VCC. Pin 1 of the limiter D34 and pin 1 of the resistor R202 are both connected to GNDA. Pin 2 of the resistor R202 and pin 1 of the capacitor C137 are both connected to pin 6 of the chip U1B. Pin 2 of the capacitor C137 and pin 7 of the chip U1B are both connected to pin 1 of the resistor R170. Pin 2 of the resistor R170 is connected to GNDA. The emitter of transistor Q24 and pin 1 of resistor R71 are both connected to VCC. Pins 2 of resistor R71 and R44 are both connected to the base of transistor Q24. Pin 1 of resistor R44 is connected to pin 2 of capacitor C52. Pin 1 of resistor R45 and the positive terminal of polarized capacitor C49 are both connected to the collector of transistor Q24. The negative terminal of polarized capacitor C49 is grounded. Pins 2 of resistor R43 and pin 3 of MOSFET Q12 are both connected to pin 2 of resistor R45. Pin 2 of MOSFET Q12 is connected to the positive terminal of polarized capacitor C53. The negative terminal of polarized capacitor C53 is grounded. Pin 1 of MOSFET Q12 and the... Pin 1 of resistor R43 is connected to pin 1 of resistor R79. Pin 2 of resistor R79, pin 1 of resistor R58, and pin 1 of capacitor C34 are all connected to pin 6 of chip U2B. Pin 2 of resistor R58 and pin 1 of resistor R46 are both connected to pin 1 of capacitor C108. Pin 2 of resistor R46, pin 2 of capacitor C34, and pin 1 of capacitor C54 are all connected to pin 3 of potentiometer R78. Pin 2 of capacitor C108 and the negative terminal of polarized capacitor C102 are both grounded. The positive terminal of polarized capacitor C102 is connected to pin 1 of resistor R144. Pin 2 of resistor R144 is connected to pin 2 of potentiometer R78.Pin 2 of capacitor C54, pin 1 of potentiometer R78, pin 1 of capacitor C52, and pin 7 of chip U2B are all connected to the negative terminal of polarized capacitor C47. The positive terminal of polarized capacitor C47 and pin 1 of resistor R64 are both connected to the selection channel ESWS4. Pin 2 of resistor R64 is connected to GNDA.

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