Microphone output control circuit of subway train cab and microphone

Abstract

The utility model relates to a microphone output control circuit of a subway train cab, which comprises a wiring connector, a voltage conversion module, an adjustable resistor and a power amplifier, the wiring connector is provided with a power supply port, a microphone signal input port and a microphone signal output port, and the voltage conversion module is provided with a power supply input port and a power supply output port. The power supply input port is connected with the power supply port, the fixed end of the adjustable resistor is respectively connected with the output port of the voltage conversion module and the grounding port of the voltage conversion module, and the microphone signal input port is connected into a connecting line of the adjustable resistor and the output port; a signal input port of the power amplifier is connected with an adjustable end of the adjustable resistor, a power port is connected with an output port of the voltage conversion module, and a signal output port is connected with a microphone signal output port. Compared with the prior art, the utility model has the advantages that the circuit board and the microphone are separated, the replacement is convenient, the later maintenance cost is low, the output signal is stable, and the quality is high.

Description

Technical Field

[0001] The utility model relates to the technical field of microphones, in particular to a microphone output control circuit and a microphone in a subway train driver's cab. Background Art

[0002] Early subway cab microphones used imported ALSTOM equipment, with an operating voltage of 24V and a sensitivity of 775mV / Pa (±3dB).

[0003] Most of the above microphones use electret condenser microphones, which include electret condenser acoustic circuit and output control circuit. Figure 1 As shown, the existing solution integrates the two circuits into an integrated structure. Once damaged, the entire structure can only be replaced. In addition, it is difficult to purchase the same model product on the market. The procurement cycle of original products is long and the price is expensive.

[0004] Therefore, there is an urgent need for a low-cost alternative with electrical parameters that can meet the original product parameters. Utility Model Content

[0005] The purpose of the present utility model is to provide a microphone output control circuit and microphone for a subway train driver's cab in order to overcome the defects of the above-mentioned prior art that the microphone electret condenser acoustic circuit and the output control circuit are an integral structure. Once damaged, they can only be replaced as a whole, which is inconvenient to maintain and has a high cost of the overall structure.

[0006] The purpose of the utility model can be achieved through the following technical solutions:

[0007] A microphone output control circuit for a subway train driver's cab includes a wiring connector, a voltage conversion module, an adjustable resistor, and a power amplifier. The wiring connector is provided with a power supply port, a microphone signal input port, a microphone signal output port, and a first ground port. The voltage conversion module is provided with a power input port, an output port, and a second ground port. The power input port is connected to the power supply port. The two fixed ends of the adjustable resistor are respectively connected to the output port and the second ground port of the voltage conversion module. The microphone signal input port is also connected to the connection line between the adjustable resistor and the output port of the voltage conversion module.

[0008] The power amplifier is provided with a signal input port, a third ground port GND, a gain port, a power port and a signal output port. The signal input port is connected to the adjustable end of the adjustable resistor, the power port is connected to the output port of the voltage conversion module, and the signal output port is connected to the microphone signal output port of the wiring connector.

[0009] Furthermore, a first capacitor and a third resistor are connected in series in the connection line between the adjustable resistor and the output port of the voltage conversion module, and the microphone signal input port is connected to the connection line between the first capacitor and the third resistor.

[0010] Furthermore, the microphone signal output port includes a microphone signal positive output port and a microphone signal negative output port, and the signal output port of the power amplifier is connected to the seventh capacitor and then connected to the microphone signal positive output port; the connection line between the adjustable resistor and the second ground port of the voltage conversion module also branches out a branch connected to the eighth capacitor and then connected to the microphone signal negative output port.

[0011] Furthermore, a branch is branched from the connection line between the adjustable resistor and the second ground port of the voltage conversion module, which is connected to a second capacitor and then connected to the output port of the voltage conversion module.

[0012] Furthermore, the wiring connector is further provided with an LED power supply interface, which is connected to a second resistor and then connected to the output port of the voltage conversion module.

[0013] Furthermore, the LED power supply interface is used to connect to the ring indicator light on the microphone. The ring indicator light is a ring structure and is embedded in the housing of the microphone.

[0014] Furthermore, a third capacitor is connected in series in the connection line between the adjustable end of the adjustable resistor and the signal input port of the power amplifier.

[0015] Furthermore, the power amplifier has two gain ports, the two gain ports are connected to each other, and a sixth capacitor is connected in series in the connection line.

[0016] Furthermore, an audio filter signal is also connected to the connection line between the power supply port of the wiring connector and the power input port of the voltage conversion module.

[0017] The utility model also provides a microphone for a subway train driver's cab, comprising an electret condenser acoustic circuit and a microphone output control circuit for a subway train driver's cab as described above, wherein the output end of the electret condenser acoustic circuit is connected to the microphone signal input port of the wiring connector.

[0018] Compared with the prior art, the utility model has the following advantages:

[0019] (1) The utility model realizes the external connection of the overall microphone output control circuit through a wiring connector, and can convert the DC 24V powering the microphone into DC 12V to power the control circuit board through a voltage conversion module. The voltage conversion module can be adjusted according to actual conditions to achieve wide voltage input; the signal of the microphone input signal is amplified by a power amplifier, and the output sensitivity of the power amplifier can be adjusted by an adjustable resistor;

[0020] Overall, the microphone output control circuit is separated from the microphone's electret condenser acoustic circuit, which facilitates replacement and reduces subsequent maintenance costs.

[0021] (2) The utility model sets a first capacitor and a third resistor on the microphone signal input port side of the adjustable resistor, which can achieve anti-hysteresis and low-pass filtering to eliminate the influence of high-frequency noise and interference on the power amplifier; the third capacitor is set in the connection line between the adjustable end of the adjustable resistor and the signal input port of the power amplifier to prevent hysteresis, filter out high-frequency resonance and noise in the circuit, improve the quality and stability of the signal, and make the output signal of the power amplifier purer and more stable; as a whole, the input and output are completely isolated, which plays an anti-interference role.

[0022] (3) The structural cost of the utility model is low, only about one tenth of the original cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 This is a schematic structural diagram of an electret capacitor acoustic circuit provided in the background technology of the present utility model;

[0024] Figure 2 The present invention is a schematic structural diagram of a microphone output control circuit for a subway train driver's cab provided in an embodiment of the present invention. DETAILED DESCRIPTION

[0025] To make the purpose, technical solutions, and advantages of the embodiments of the present invention more clear, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Generally, the components of the embodiments of the present invention described and shown in the drawings herein can be arranged and designed in various different configurations.

[0026] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but rather merely represents selected embodiments of the present invention. All other embodiments derived by persons of ordinary skill in the art based on the embodiments of the present invention without creative effort are also within the scope of protection of the present invention.

[0027] It should be noted that similar reference numerals and letters denote similar items in the following drawings, and therefore, once an item is defined in one drawing, it does not need to be further defined or explained in subsequent drawings.

[0028] In the description of this utility model, it should be noted that the terms "first" and "second" are used for descriptive purposes only and should not be understood to indicate or imply relative importance or implicitly specify the number of the technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of this application, "plurality" means two or more, unless otherwise specifically defined.

[0029] Example 1

[0030] like Figure 2 As shown, this embodiment provides a microphone output control circuit for a subway train driver's cab, including a wiring connector CN1, a voltage conversion module U2, an adjustable resistor R1, and a power amplifier U6. The wiring connector CN1 is provided with a power supply port, a microphone signal input port, a microphone signal output port, and a first ground port. The voltage conversion module U2 is provided with a power input port VIN, an output port +VO, and a second ground port 0V. The power input port VIN is connected to the power supply port. The two fixed ends of the adjustable resistor R1 are respectively connected to the output port +VO and the second ground port 0V of the voltage conversion module U2. The microphone signal input port is also connected to the connection line between the adjustable resistor R1 and the output port +VO of the voltage conversion module U2.

[0031] The power amplifier U6 is provided with a signal input port INPUT+, a third ground port GND, a gain port GAIN, a power port VCC and a signal output port VOUT. The signal input port INPUT+ is connected to the adjustable end of the adjustable resistor R1, the power port VCC is connected to the output port +VO of the voltage conversion module U2, and the signal output port VOUT is connected to the microphone signal output port VOUT of the wiring connector CN1.

[0032] The utility model can convert the DC 24V powering the microphone into DC 12V to power the control circuit board through the voltage conversion module U2. The voltage conversion module U2 can be adjusted according to actual conditions to achieve a wide voltage input: DC 9-36V, which is suitable for products from multiple manufacturers.

[0033] The microphone input signal is amplified by the power amplifier U6, and the output sensitivity of the power amplifier U6 can be adjusted by the adjustable resistor R1.

[0034] Overall, the microphone output control circuit is separated from the microphone's electret condenser acoustic circuit, which facilitates replacement and reduces subsequent maintenance costs.

[0035] Specifically, the connection line between the adjustable resistor R1 and the output port +VO of the voltage conversion module U2 is further connected in series with a first capacitor C1 and a third resistor R3, and the microphone signal input port INPUT+ is connected to the connection line between the first capacitor C1 and the third resistor R3.

[0036] The first capacitor C1 can resist hysteresis and reduce the influence of the voltage pulse of the input port INPUT+ on the power amplifier U6, thereby ensuring the stable operation of the power amplifier U6;

[0037] The third resistor R3 works together with the first capacitor C1 to implement low-pass filtering, eliminate the influence of high-frequency noise and interference on the power amplifier U6, and resist current resonance.

[0038] A third capacitor C3 is further connected in series in the connection line between the adjustable end of the adjustable resistor R1 and the signal input port INPUT+ of the power amplifier U6.

[0039] The third capacitor C3 can be provided to resist hysteresis, filter out high-frequency resonance and noise in the circuit, improve the quality and stability of the signal, and make the output signal of the power amplifier U6 purer and more stable.

[0040] The microphone signal output port includes a microphone signal positive output port MIC1+ and a microphone signal negative output port MIC1-. The signal output port VOUT of the power amplifier U6 is connected to the seventh capacitor C7 and then connected to the microphone signal positive output port MIC1+; a branch is also branched out in the connection line between the adjustable resistor R1 and the second ground port 0V of the voltage conversion module U2, which is connected to the eighth capacitor C8 and then connected to the microphone signal negative output port MIC1-.

[0041] A branch is further branched from the connection line between the adjustable resistor R1 and the second ground port 0V of the voltage conversion module U2 , which is connected to the second capacitor C2 and then connected to the output port +VO of the voltage conversion module U2 .

[0042] The wiring connector CN1 is further provided with an LED power supply interface, which is connected to a second resistor R2 and then connected to an output port +VO of the voltage conversion module U2.

[0043] The LED power supply interface is used to connect to the ring indicator light on the microphone. The ring indicator light is a ring structure and is embedded in the shell of the microphone.

[0044] The power amplifier U6 has two gain ports GAIN, which are connected to each other, and a sixth capacitor C6 is connected in series in the connection line.

[0045] Preferably, the power amplifier U6 is also provided with a BYPASS interface, and the BYPASS interface and the power port VCC are respectively connected to the fourth capacitor C4 and the fifth capacitor C5 and then connected to each other, and the connection line between the fourth capacitor C4 and the fifth capacitor C5 is connected to the second ground port 0V, and the connection line between the power port VCC and the fifth capacitor C5 is connected to the output port +VO.

[0046] Preferably, an audio filter signal VF is further connected to the connection line between the power supply port of the wiring connector CN1 and the power input port VIN of the voltage conversion module U2.

[0047] In this embodiment, the model of the wiring connector CN1 is KF2EDGR-3.5-8P, the model of the voltage conversion module U2 is URB2412YMD-6WR3, and the model of the power amplifier U6 is LM386M-1;

[0048] The output port +VO of the voltage conversion module U2 outputs a +12V voltage. The resistance of the adjustable resistor R1 is 50kΩ, the resistance of the second resistor R2 is 1.8kΩ, and the resistance of the third resistor R3 is 10kΩ. The capacitance of the first capacitor C1 is 100nF, the capacitance of the second capacitor C2 is 100uF, the capacitance of the third capacitor C3 is 1uF, the capacitance of the fourth capacitor C4 is 100nF, the capacitance of the fifth capacitor C5 is 100nF, the capacitance of the sixth capacitor C6 is 10uF, the capacitance of the seventh capacitor C7 is 100uF, and the capacitance of the eighth capacitor C8 is 100uF.

[0049] This embodiment also provides a microphone for a subway train driver's cab, including an electret condenser acoustic circuit and the above-mentioned microphone output control circuit for a subway train driver's cab. The output end of the electret condenser acoustic circuit is connected to the microphone signal input port INPUT+ of the wiring connector CN1.

[0050] The above describes in detail the preferred embodiments of the present invention. It should be understood that those skilled in the art can make numerous modifications and variations based on the concepts of the present invention without inventive effort. Therefore, any technical solutions that can be derived by those skilled in the art based on the concepts of the present invention through logical analysis, reasoning, or limited experimentation based on the existing technology should be within the scope of protection defined by the claims.

Claims

1. A microphone output control circuit for a subway train driver's cab, characterized in that: It includes a wiring connector, a voltage conversion module, an adjustable resistor and a power amplifier. The wiring connector is provided with a power supply port, a microphone signal input port, a microphone signal output port and a first ground port. The voltage conversion module is provided with a power input port, an output port and a second ground port. The power input port is connected to the power supply port. The two fixed ends of the adjustable resistor are respectively connected to the output port and the second ground port of the voltage conversion module. The microphone signal input port is also connected to the connection line between the adjustable resistor and the output port of the voltage conversion module. The power amplifier is provided with a signal input port, a third ground port GND, a gain port, a power port and a signal output port. The signal input port is connected to the adjustable end of the adjustable resistor, the power port is connected to the output port of the voltage conversion module, and the signal output port is connected to the microphone signal output port of the wiring connector. The microphone signal input port of the wiring connector cooperates with the electret condenser acoustic circuit of the subway train driver's cab.

2. The microphone output control circuit for a subway train driver's cab according to claim 1, characterized in that: A first capacitor and a third resistor are connected in series in the connection line between the adjustable resistor and the output port of the voltage conversion module, and the microphone signal input port is connected to the connection line between the first capacitor and the third resistor.

3. The microphone output control circuit for a subway train driver's cab according to claim 1, characterized in that: The microphone signal output port includes a microphone signal positive output port and a microphone signal negative output port. The signal output port of the power amplifier is connected to a seventh capacitor and then connected to the microphone signal positive output port; a branch is also branched out from the connection line between the adjustable resistor and the second ground port of the voltage conversion module and is connected to an eighth capacitor and then connected to the microphone signal negative output port.

4. The microphone output control circuit for a subway train driver's cab according to claim 1, characterized in that: A branch is formed in the connection line between the adjustable resistor and the second ground port of the voltage conversion module, which is connected to a second capacitor and then connected to the output port of the voltage conversion module.

5. The microphone output control circuit for a subway train driver's cab according to claim 1, characterized in that: The wiring connector is further provided with an LED power supply interface, which is connected to a second resistor and then connected to the output port of the voltage conversion module.

6. The microphone output control circuit for a subway train driver's cab according to claim 5, characterized in that: The LED power supply interface is used to connect to the ring indicator light on the microphone. The ring indicator light is a ring structure and is embedded in the shell of the microphone.

7. The microphone output control circuit for a subway train driver's cab according to claim 1, characterized in that: A third capacitor is connected in series in the connection line between the adjustable end of the adjustable resistor and the signal input port of the power amplifier.

8. The microphone output control circuit for a subway train driver's cab according to claim 1, characterized in that: The power amplifier has two gain ports, which are connected to each other, and a sixth capacitor is connected in series in the connection line.

9. The microphone output control circuit for a subway train driver's cab according to claim 1, characterized in that: An audio filter signal is also connected to the connection line between the power supply port of the wiring connector and the power input port of the voltage conversion module.

10. A microphone for a subway train driver's cab, characterized in that: It comprises an electret condenser acoustic circuit of a subway train driver's cab and a microphone output control circuit of a subway train driver's cab as described in any one of claims 1-9, wherein the output end of the electret condenser acoustic circuit is connected to the microphone signal input port of the wiring connector.

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