Sound generation and sound pickup dual-purpose circuit applied to speaker unit

Abstract

The present invention relates to the technical field of speakers. Disclosed is a sound generation and sound pickup dual-purpose circuit applied to a speaker unit. The apparatus comprises a microphone interface unit, an electronic power switch module, a signal gain module and a double-pole double-throw switch module that are connected, wherein NC1 and NC2, and COM1 and COM2 of the double-pole double-throw switch module are respectively connected to the signal gain module and a sound generation unit end module; positive and negative poles of a speaker interface unit are respectively connected to NO2 and NO1 of the double-pole double-throw switch module; a positive pole of a signal receiving state switching interface unit is connected to an EN terminal of the double-pole double-throw switch module and an EN terminal of the electronic power switch module; and the sound generation unit end module is configured to connect to a low-impedance sound generation unit. Controlled by the signal receiving state switching interface unit, the low-impedance sound generation unit is switched to sound pickup or sound generation, such that an earphone realizes the dual purposes of sound generation and sound pickup only by connecting to one low-impedance sound generation unit, thus solving the problem of excessively high costs of existing earphones having sound generation and sound pickup functions.

Description

A sound emitting and sound picking dual-purpose circuit applied to a loudspeaker unit

[0001] Cross-reference to Related Applications

[0002] The present application claims priority to the Chinese patent application No. 202410436159.1 entitled "A sound emitting and sound picking dual-purpose circuit applied to a loudspeaker unit" and filed with the China Patent Office on April 11, 2024, the content of which is incorporated herein by reference in its entirety. TECHNICAL FIELD

[0003] The present application relates to the technical field of loudspeakers, and in particular to a sound emitting and sound picking dual-purpose circuit applied to a loudspeaker unit. BACKGROUND

[0004] To realize a separate loudspeaker sound emitting unit and a sound picking microphone unit, a conventional wired communication earphone needs a loudspeaker with at least 2-core connecting wires, a 2-core connecting wire microphone, and a 1-core or 2-core PTT control connecting cable, which are then connected to a intercom through an adapter plug, so as to realize the combination of the sound emitting and sound picking functions of the communication earphone.

[0005] In order to enhance the sound picking performance of the microphone sound picking function, a rod type adjustable angle or length microphone structure is usually used, and the microphone is set as close to the mouth as possible; or the sound picking sensitivity is enhanced under the condition that the sensitivity of the single microphone is unchanged; wherein a single directional noise reduction microphone is used; that is, the single directional noise reduction function of the single microphone is used to reduce the pickup range of environmental noise, so as to reduce the pickup of environmental noise, and the sound of the main sound source that needs to be picked up will be relatively clearer.

[0006] In view of the labor protection scenes such as construction sites, heavy industrial factories, or machining workshops, and various scenes with complex environments such as cabin operations, airport ground operations, and police and military operations; due to the work, the workers often need to communicate in real time to ensure smooth operation, but the workers will inevitably encounter various noises in this environment, and these noisy environmental noises have a great interference on the communication quality of the workers; in order to solve the problem of the noisy environmental noise affecting the communication quality, a good earphone needs to be used, and the common points of these earphones are that the quality of the built-in microphone and the structural cavity is very good, and the earphone has an excellent and high-end communication circuit design, so that the sound can be reduced in the receiving process. Distortion to restore the true sound of the sound source, and the corresponding software noise reduction algorithm is also used to make the picked-up sound can be intelligently processed, further filter out part of the noise, thereby enhancing the effect of receiving sound, but this undoubtedly has high requirements for the design of the earphone, resulting in great difficulty in the design and manufacture of the earphone, and the cost will also rise sharply, and the cost performance is low, so the price of these earphones is usually very high. These earphones can only be used in some high-end industries; for some industries that need to obtain high-definition communication quality in a noisy environment and need high-cost-performance earphones, the complex structure design (cavity design and connecting rod or connecting cable) of the sound pickup unit of this type of earphone makes the cost of this type of earphone high, and the high-priced earphone is difficult to popularize and use.

[0007] In summary, the applicant finds that the prior art at least has the following technical problems:

[0008] The existing earphones with sound emission and sound pickup all adopt complex structure design to ensure that the earphones have good noise reduction and sound pickup effect, so that the earphones with sound emission and sound pickup have high cost. SUMMARY

[0009] The purpose of the present application is to provide a sound emission and sound pickup dual-purpose circuit applied to a loudspeaker monomer, to solve the problem that the existing earphones with sound emission and sound pickup all adopt complex structure design to ensure that the earphones have good noise reduction and sound pickup effect, so that the earphones with sound emission and sound pickup have high cost.

[0010] The preferred technical solutions in the many technical solutions provided by the present application can produce many technical effects, which are described in detail below.

[0011] In order to solve the above technical problems, the present application provides the following technical solutions:

[0012] The application provides a sound emitting and pickup dual-purpose circuit applied to a loudspeaker monomer, which comprises a communication interface module, an electronic power switch module, a filter, a signal gain module, a double-pole double-throw switch module and a sound emitting unit end module; the communication interface module comprises a microphone interface unit, a loudspeaker interface unit and a receiving state switching interface unit; the positive electrode of the microphone interface unit is connected with the electronic power switch module, the signal gain module and the double-pole double-throw switch module; the electronic power switch module, the filter and the signal gain module are sequentially connected, and the ground end of the signal gain module is grounded; NC1 and NC2 of the double-pole double-throw switch module are connected with the signal gain module respectively, COM1 and COM2 of the double-pole double-throw switch module are connected with the sound emitting unit end module respectively, and the ground end of the double-pole double-throw switch module is grounded; the negative electrode of the microphone interface unit is grounded; the positive electrode of the loudspeaker interface unit is connected with NO2 of the double-pole double-throw switch module; the negative electrode of the loudspeaker interface unit is connected with NO1 of the loudspeaker interface unit; the positive electrode of the receiving state switching interface unit is connected with the EN end of the double-pole double-throw switch module and the EN end of the electronic power switch module; the negative electrode of the receiving state switching interface unit is grounded; the sound emitting unit end module is used for connecting with a low-impedance sound emitting unit; the receiving state switching interface unit controls the electronic power switch module and the double-pole double-throw switch module to switch the working state of the low-impedance sound emitting unit as pickup or sound emission.

[0013] In one of the embodiments, the receiving state switching interface unit is used for connecting with a PTT switch.

[0014] S1: the PTT switch controls the electronic power switch module to be turned on, the signal gain module is connected, and the EN end of the double-pole double-throw switch module is synchronously pulled down, so that COM1 and COM2 of the double-pole double-throw switch module are connected with NC1 and NC2 of the double-pole double-throw switch module, and the working state of the low-impedance sound emitting unit is switched to a pickup state.

[0015] S2: the PTT switch controls the electronic power switch module to be turned off, the signal gain module is disconnected, and the EN end of the double-pole double-throw switch module is synchronously pulled up, so that COM1 and COM2 of the double-pole double-throw switch module are connected with NO1 and NO2 of the double-pole double-throw switch module, and the working state of the low-impedance sound emitting unit is switched to a sound emission state.

[0016] In one of the embodiments, the PTT switch is a PTT-Switch mechanical switch.

[0017] In one of the embodiments, a clock signal module is further included, and the trusted state switching interface unit is contained in the clock signal module; the clock signal module enables the control of the electronic power switch module and the double-pole double-throw switch module.

[0018] S1: the negative pulse width of the clock signal module controls the turn-on of the electronic power switch module, the signal gain module is turned on, and at the same time, the EN end of the double-pole double-throw switch module is synchronously pulled down, so that COM1 and COM2 of the double-pole double-throw switch module are connected with NC1 and NC2 of the double-pole double-throw switch module, and the working state of the low-impedance sound unit is switched to a pickup state.

[0019] S2: the positive pulse width of the clock signal module controls the turn-off of the electronic power switch module, the signal gain module is turned off, and at the same time, the EN end of the double-pole double-throw switch module is synchronously pulled up, so that COM1 and COM2 of the double-pole double-throw switch module are connected with NO1 and NO2 of the double-pole double-throw switch module, and the working state of the low-impedance sound unit is switched to a sound emission state.

[0020] In one of the embodiments, when the low-impedance sound unit is installed in an earphone in the form of an earplug, the pickup state of the sound unit end module serves as an ear canal pickup state.

[0021] In one of the embodiments, the double-pole double-throw switch module includes a double-pole double-throw electronic analog switch or a double-pole double-throw mechanical switch.

[0022] In one of the embodiments, the type of the low-impedance sound unit includes a moving coil unit, a moving iron unit, an electrostatic diaphragm sound unit or a planar diaphragm unit; and the impedance of the low-impedance sound unit is 4Ω-2.2KΩ.

[0023] In one of the embodiments, the signal gain module includes an operational amplifier; and the input of the operational amplifier includes a differential input, a single-ended same-direction input, a single-ended reverse input or a discrete device input.

[0024] In one of the embodiments, the signal frequency of the chip kernel generator of the clock signal module is 8KHz-48KHz.

[0025] The beneficial effects of the present application are as follows:

[0026] The sound emitting and pickup dual-purpose circuit is provided with a communication interface module, an electronic power switch module, a filter, a signal gain module, a double-pole double-throw switch module and a sound emitting unit terminal module; in order to realize the two working states of sound emitting and pickup, the communication interface module is provided with a microphone interface unit, a loudspeaker interface unit and a receiving state switching interface unit, and the signal given by the receiving state switching interface unit controls the circuit to switch on the microphone interface unit or the loudspeaker interface unit, so as to realize the switching of sound emitting and pickup.

[0027] The positive pole of the microphone interface unit is connected with the electronic power switch module, the signal gain module and the double-pole double-throw switch module; the electronic power switch module, the filter and the signal gain module are connected in sequence, and the ground end of the signal gain module is grounded; the NC1 and the NC2 of the double-pole double-throw switch module are connected with the signal gain module respectively, the COM1 and the COM2 of the double-pole double-throw switch module are connected with the sound emitting unit terminal module respectively, and the ground end of the double-pole double-throw switch module is grounded; the negative pole of the microphone interface unit is grounded; a conversation pickup bypass is formed by the microphone interface unit, the filter, the signal gain module and the sound emitting unit terminal module, so as to realize the function of pickup through the sound emitting unit terminal module; and the sound emitting unit terminal module is used for connecting a low-impedance sound emitting unit, and the pickup principle is that if the low-impedance sound emitting unit is a moving coil unit, the sound pressure of the outside world will drive the moving coil to move to generate an alternating signal, which is used as a pickup input to provide a signal source for the signal gain module, and the audio signal is output to the microphone interface unit after entering the filter, so as to realize the function of using the moving coil unit as a pickup unit.

[0028] The positive pole of the loudspeaker interface unit is connected with the NO2 of the double-pole double-throw switch module; the negative pole of the loudspeaker interface unit is connected with the NO1 of the loudspeaker interface unit; the positive pole of the receiving state switching interface unit is connected with the EN end of the double-pole double-throw switch module and the EN end of the electronic power switch module; the negative pole of the receiving state switching interface unit is grounded; a conversation sound emitting bypass is formed by the loudspeaker interface unit and the sound emitting unit terminal module, so as to realize the function of sound emitting through the sound emitting unit terminal module.

[0029] And the mechanism of switching the sound emitting and pickup circuit by using a single loudspeaker is realized by controlling the electronic power switch module and the double-pole double-throw switch module through the receiving state switching interface unit, so that the working state of the low-impedance sound emitting unit is switched as pickup or sound emitting, thereby realizing the functions of pickup and sound emitting by using a single loudspeaker and an integrated circuit. Compared with the prior art, the structure design and cavity design of the pickup unit, the use of connecting rods or connecting cables, and the cost are greatly reduced. When the low-impedance sound emitting unit is installed in the earphone in the form of earplug, the pickup state of the sound emitting unit end module is the ear canal pickup state, and the earplug can effectively filter environmental noise, thereby obtaining a low-noise high-definition pickup signal. BRIEF DESCRIPTION OF DRAWINGS

[0030] In order to more clearly illustrate the technical solutions of the present application, the following will briefly introduce the drawings needed in the embodiments. Obviously, the drawings described below are only some embodiments of the present application, and those skilled in the art can obtain other drawings according to these drawings without creative labor.

[0031] Fig. 1 is a block diagram of the first embodiment of the present application;

[0032] Fig. 2 is a schematic diagram of the first embodiment of the present application;

[0033] Fig. 3 is a block diagram of the second embodiment of the present application. DETAILED DESCRIPTION

[0034] The technical solutions in the embodiments of the present application will be described in detail below with reference to the drawings in the embodiments of the present application.

[0035] Obviously, the described embodiments are only some embodiments of the present application, not all embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor are within the scope of protection of the present application.

[0036] The specific embodiment provides a sound emitting and pickup dual-purpose circuit applied to a single loudspeaker, which effectively solves the problem that the earphones with sound emitting and pickup function have a complex structure design to ensure good noise reduction pickup effect, and the cost of the earphones with sound emitting and pickup function is too high.

[0037] The following describes the embodiments with reference to the drawings. In addition, the entire content of the following embodiments is not limited to the solutions necessary for the invention described in the claims.

[0038] The first embodiment of the sound emitting and pickup dual-purpose circuit applied to the loudspeaker monomer is shown in FIG. 1 and FIG. 2, which comprises a communication interface module (CN1), an electronic power switch module module (Q1), a filter (F1), a signal gain module (U1), a double-pole double-throw switch module (U2) and a sound emitting unit end module (SPK-Unit). The communication interface module comprises a microphone interface unit (MIC), a loudspeaker interface unit (SPK) and a receiving state switching interface unit (PTT). The positive pole of the microphone interface unit is connected with the electronic power switch module module, the signal gain module and the double-pole double-throw switch module. The electronic power switch module module, the filter and the signal gain module are connected in sequence, and the ground end of the signal gain module is grounded. The NC1 and NC2 of the double-pole double-throw switch module are connected with the signal gain module respectively, the COM1 and COM2 of the double-pole double-throw switch module are connected with the sound emitting unit end module respectively, and the ground end of the double-pole double-throw switch module is grounded. The negative pole of the microphone interface unit is grounded. The positive pole of the loudspeaker interface unit is connected with the NO2 of the double-pole double-throw switch module. The negative pole of the loudspeaker interface unit is connected with the NO1 of the loudspeaker interface unit. The positive pole of the receiving state switching interface unit is connected with the EN end of the double-pole double-throw switch module and the EN end of the electronic power switch module module. The negative pole of the receiving state switching interface unit is grounded. The sound emitting unit end module is used for connecting with a low impedance sound emitting unit (JK1 Speaker-Unit). The receiving state switching interface unit controls the electronic power switch module module and the double-pole double-throw switch module to switch the working state of the low impedance sound emitting unit as pickup or as sound emitting.

[0039] In the application, the sound emitting and pickup dual-purpose circuit is provided with the communication interface module, the electronic power switch module module, the filter, the signal gain module, the double-pole double-throw switch module and the sound emitting unit end module. In order to realize the two working states of pickup and sound emitting, the communication interface module is provided with the microphone interface unit, the loudspeaker interface unit and the receiving state switching interface unit. The signal given by the receiving state switching interface unit controls the circuit to switch on the microphone interface unit or the loudspeaker interface unit, so as to realize the switching of pickup and sound emitting.

[0040] The positive pole of the microphone interface unit is connected with the electronic power switch module, the signal gain module and the double-pole double-throw switch module; the electronic power switch module, the filter and the signal gain module are connected in sequence, and the grounding end of the signal gain module is grounded; NC1 and NC2 of the double-pole double-throw switch module are connected with the signal gain module respectively, COM1 and COM2 of the double-pole double-throw switch module are connected with the sound unit end module respectively, and the grounding end of the double-pole double-throw switch module is grounded; the negative pole of the microphone interface unit is grounded; a conversation sound pickup bypass is formed through the microphone interface unit, the filter, the signal gain module and the sound unit end module, so that the function of sound pickup through the sound unit end module is realized; and the sound unit end module is used for connecting a low-impedance sound unit, the sound pickup principle is that if the low-impedance sound unit is a moving coil unit, the sound pressure in the external environment drives the moving coil to move to generate an alternating signal, which is used as a sound pickup input to provide a signal source for the signal gain module, and the audio signal is output to the microphone interface unit after entering the filter, so that the function of using the moving coil unit as a sound pickup unit is realized.

[0041] The positive pole of the loudspeaker interface unit is connected with NO2 of the double-pole double-throw switch module; the negative pole of the loudspeaker interface unit is connected with NO1 of the loudspeaker interface unit; the positive pole of the receiving state switching interface unit is connected with the EN end of the double-pole double-throw switch module and the EN end of the electronic power switch module; and the negative pole of the receiving state switching interface unit is grounded; a conversation sound production bypass is formed through the loudspeaker interface unit and the sound unit end module, so that the function of sound production through the sound unit end module is realized.

[0042] The mechanism for realizing sound pickup and sound production circuit switching through one single loudspeaker is that the receiving state switching interface unit controls the electronic power switch module and the double-pole double-throw switch module to realize switching of the working state of the low-impedance sound unit as sound pickup or as sound production, so that the two functions of sound pickup and sound production can be realized through one single loudspeaker and one integrated circuit. Compared with the prior art which needs to realize clear sound pickup in a complex noise environment and needs a complex cavity, a single loudspeaker, multiple microphones and a cable, the structure design and cavity design of the sound pickup unit and the use of connecting rods or connecting cables can be greatly reduced, and the cost is obviously reduced.

[0043] As one of the optional embodiments,

[0044] The connection of the receiving state switching interface unit is shown in FIGS. 1 and 2, and the receiving state switching interface unit is used for connecting a PTT switch (PTT-Switch).

[0045] After the PTT switch is applied, the working state switching steps of the low-impedance sound unit are as follows:

[0046] S1: PTT switch control electronic power switch module module conduction, signal gain module connected, while the EN end of the double-pole double-throw switch module is synchronized to pull low, COM1 and COM2 of the double-pole double-throw switch module are connected with NC1 and NC2 of the double-pole double-throw switch module, and the working state of the low-impedance sound unit is switched to the pickup state.

[0047] S2: PTT switch control electronic power switch module module is disconnected, signal gain module is disconnected, while the EN end of the double-pole double-throw switch module is synchronized to pull high, COM1 and COM2 of the double-pole double-throw switch module are connected with NO1 and NO2 of the double-pole double-throw switch module, and the working state of the low-impedance sound unit is switched to the sound state.

[0048] Regarding the type of specific device used in the above PTT switch, the PTT switch is a PTT-Switch mechanical switch.

[0049] Regarding the specific type of double-pole double-throw switch used in the above double-pole double-throw switch module, the double-pole double-throw switch module includes a double-pole double-throw electronic analog switch or a double-pole double-throw mechanical switch.

[0050] Regarding the type of specific device used in the above low-impedance sound unit, the type of low-impedance sound unit includes a moving coil unit, or a moving iron unit, or an electrostatic diaphragm sound unit, or a planar diaphragm unit; the impedance range of the low-impedance sound unit is 4Ω-2.2KΩ.

[0051] Regarding the type of specific gain device used in the above signal gain module, the signal gain module includes an operational amplifier; wherein the input of the operational amplifier includes differential input, or single-ended same direction input, or single-ended reverse input, or discrete device input.

[0052] In application, as shown in the schematic diagram 2, the operational amplifier uses differential input to form a differential amplifier circuit.

[0053] Specifically, in the principle application, as shown in Figure 2, Q1 is a P-Mos tube; when PTT-Switch is pressed, PTT is connected to ground, Q1 is turned on to supply power to U1, and at the same time U2-EN is synchronized to pull low, U2-COM1 and COM2 are connected with U2-NC1 and NC2; JK1Speaker-Unit selects a moving coil unit to access SPK-Unit, the sound pressure will drive the voice coil to move to generate an alternating signal, which is used as a pickup input to provide a differential signal source to U1, and the audio signal is amplified by U1 signal gain and then input to R2, C3, and finally output to the MIC of the intercom interface, realizing the working principle of moving coil speaker as a pickup unit.

[0054] When the PTT-Switch is not pressed, Q1 is off and U1 power is off, U1 loses the signal gain amplification function, at the same time, U2-EN is pulled high by R9, U2-COM1 and COM2 are connected to U2-NO1 and NO2, U2-COM1 and COM2 are disconnected from U2-NC1 and NC2, that is, JK1Speaker-Unit is connected to U2-COM1 and COM2 and U2-NO1 and NO2, the signal is output to the intercom interface SPK through R12, realizing the working principle of the moving coil loudspeaker as a sound unit.

[0055] Take 20dB as an example, use a balanced input operational amplifier (Pre-Amp) to build a 20dB gain amplifier circuit, and use a differential amplifier configuration. In this configuration, the gain is determined by the ratio of peripheral components.

[0056] The relationship between gain A, (in voltage ratio) and decibels (dB) is given by the following formula: Av(dB) = 20log10(Av);

[0057] For a 20dB gain, we have: 20 = 20log10(Av); solving this equation gives Av, the numerical ratio of voltage gain.

[0058] The gain calculation formula of the differential amplifier assumes that an ideal operational amplifier is used and all resistors are accurate, and the gain can be expressed as: Av = Vout / Vin = Rf / Rin; where Rf is the feedback resistor and Rin is the input resistor. To achieve a 20dB gain, the numerical ratio of Av needs to be calculated first, and then appropriate Rf and Rin values are selected based on this ratio. Then calculate the specific Av numerical ratio, and give a specific resistance value to realize this gain.

[0059] The signal strength of the low-impedance sound unit is relatively weak compared to the output electrical signal of the conventional microphone pickup unit, so it needs to be assisted by U1 to provide a gain of about 20dB or more to the intercom MIC input to meet the required sensitivity of the electrical signal.

[0060] The second embodiment of the sound and pickup dual-purpose circuit applied to the loudspeaker unit is shown in Figure 3. The difference between this embodiment and the first embodiment is that it also includes a clock signal module (Clock), which contains a received state switching interface unit; the clock signal module enables the control of the electronic power switch module and the double-pole double-throw switch module.

[0061] After applying the clock signal module, the working state switching steps of the low-impedance sound unit are shown in Figure 2 combined with the clock signal module of Figure 3:

[0062] S1: the negative pulse width of the clock signal module controls the electronic power switch module to be turned on, the signal gain module is connected, the EN end of the double-pole double-throw switch module is synchronously pulled down, COM1 and COM2 of the double-pole double-throw switch module are connected with NC1 and NC2 of the double-pole double-throw switch module, and the working state of the low-impedance sound unit is switched to a pickup state;

[0063] S2: the positive pulse width of the clock signal module controls the electronic power switch module to be turned off, the signal gain module is disconnected, the EN end of the double-pole double-throw switch module is synchronously pulled up, COM1 and COM2 of the double-pole double-throw switch module are connected with NO1 and NO2 of the double-pole double-throw switch module, and the working state of the low-impedance sound unit is switched to a sound emitting state.

[0064] The signal frequency of the chip kernel generator of the clock signal module is 8KHz-48KHz.

[0065] In application, the 8KHz-48KHz signal generated by the chip kernel generator of the clock signal module can make the circuit realize full-duplex signal transceiving, and be further applied to ordinary consumer products, mobile phones and other audio communication devices. Since the signal of the clock signal module is high-speed switching at 8KHz-48KHz, the instantaneous switching of the pickup or sound emitting state is not easy to be found by human ears, so full-duplex transceiving is realized, and the pressing action of PTT-Switch is avoided.

[0066] The third embodiment of the sound emitting and pickup dual-purpose circuit applied to a loudspeaker unit is different from the first and second embodiments in that when the low-impedance sound unit is installed in an earphone in the form of earplugs, the pickup state of the sound unit end module serves as the ear canal pickup state.

[0067] In application, when the earphone is in the form of earplugs, the low-impedance sound unit serves as the ear canal pickup unit, and environmental noise can be effectively filtered out through the earplugs attached to the earphone, so that low-noise and high-definition pickup effect is obtained, and the purpose of further noise reduction and pickup is achieved.

[0068] The technical features of the above embodiments can be combined in any manner. To make the description concise, not all possible combinations of the technical features in the above embodiments are described.

[0069] The above describes the preferred embodiments of the present application. It should be noted that those skilled in the art can make several improvements and refinements without departing from the principles of the present application, and these improvements and refinements are also considered within the protection scope of the present application. Therefore, the protection scope of the present application should be subject to the protection scope of the claims.

Claims

1. A sound-generating and sound-pickup dual-purpose circuit applied to a speaker unit, characterized in that: It includes a communication interface module, an electronic power switch module, a filter, a signal gain module, a double-pole double-throw switch module and a sound unit end module; The communication interface module includes a microphone interface unit, a speaker interface unit and a trusted state switching interface unit; The positive electrode of the microphone interface unit is connected to the electronic power switch module, the signal gain module and the double-pole double-throw switch module; the electronic power switch module, the filter and the signal gain module are connected in sequence, and the ground end of the signal gain module is grounded; NC1 and NC2 of the double-pole double-throw switch module are respectively connected to the signal gain module, COM1 and COM2 of the double-pole double-throw switch module are respectively connected to the sound unit end module, and the ground end of the double-pole double-throw switch module is grounded; the negative electrode of the microphone interface unit is grounded; The positive pole of the speaker interface unit is connected to NO2 of the double-pole double-throw switch module; the negative pole of the speaker interface unit is connected to NO1 of the speaker interface unit; The positive electrode of the trusted state switching interface unit is connected to the EN end of the double-pole double-throw switch module and the EN end of the electronic power switch module; the negative electrode of the trusted state switching interface unit is grounded; The sound unit end module is used to connect to the low-impedance sound unit; the trusted state switching interface unit controls the electronic power switch module and the double-pole double-throw switch module to switch the working state of the low-impedance sound unit as a sound pickup or as a sound generator; The trusted state switching interface unit is used to access the PTT switch; the PTT switch is a PTT-Switch mechanical switch; S1: The PTT switch controls the electronic power switch module to be turned on, the signal gain module to be turned on, and at the same time, the EN end of the double-pole double-throw switch module is synchronously pulled low, so that COM1 and COM2 of the double-pole double-throw switch module are connected to NC1 and NC2 of the double-pole double-throw switch module, so that the working state of the low-impedance sounding unit is switched to the sound pickup state; S2: The PTT switch controls the electronic power switch module to be cut off and disconnected, and the signal gain module is disconnected. At the same time, the EN terminal of the double-pole double-throw switch module is synchronously pulled high, so that COM1 and COM2 of the double-pole double-throw switch module are connected to NO1 and NO2 of the double-pole double-throw switch module, so that the working state of the low-impedance sounding unit is switched to the sounding state; Specifically, when applying the principle, Q1 is a P-Mos tube; when the PTT-Switch is pressed, the PTT is connected to the ground, Q1 is turned on to power U1, and at the same time U2-EN is synchronously pulled low, U2-COM1 and COM2 are connected to U2-NC1 and NC2; JK1 Speaker-Unit uses a dynamic unit to connect to the SPK-Unit, and the sound pressure will drive the voice coil activity to generate an alternating signal, and provide a differential signal source to U1 as the pickup input. The audio signal enters U1 and is amplified by the signal gain, then enters R2 and C3, and finally outputs to the MIC of the intercom interface, realizing the working principle of the dynamic speaker as a pickup unit; When the PTT-Switch is not pressed, Q1 is cut off and the power supply of U1 is disconnected. U1 loses its signal gain amplification function. At the same time, U2-EN is pulled high by R9, U2-COM1 and COM2 are connected to U2-NO1 and NO2, and U2-COM1 and COM2 are disconnected from U2-NC1 and NC2. That is, JK1Speaker-Unit is connected to U2-NO1 and NO2 via U2-COM1 and COM2, and the signal is output to the intercom interface SPK via R12, realizing the working principle of the dynamic speaker as the sound unit.

2. The sound emitting and picking up dual-purpose circuit according to claim 1, characterized in that: When the low-impedance sound-emitting unit is installed in an earphone in an earplug-wearing style, the sound pickup state of the sound-emitting unit end module serves as the ear canal sound pickup state.

3. The sound emitting and picking up dual-purpose circuit according to claim 1, characterized in that: The double-pole double-throw switch module includes a double-pole double-throw electronic analog switch or a double-pole double-throw mechanical switch.

4. The sound emitting and picking up dual-purpose circuit according to claim 1, characterized in that: The type of the low-impedance sound unit includes a dynamic unit, a moving iron unit, an electrostatic diaphragm sound unit, or a planar diaphragm unit; The impedance of the low-impedance sounding unit is 4Ω~2.2KΩ.

5. The sound emitting and picking up dual-purpose circuit according to claim 1, characterized in that: The signal gain module includes an operational amplifier; The input of the operational amplifier includes a differential input, a single-ended non-inverting input, a single-ended inverting input, or a discrete device input.

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