Volume control system and device of hearing protection earphone

Abstract

The invention discloses a volume control system and device of a hearing protection earphone. The volume control system comprises a microprocessor, a touch input unit, a key input unit, a voltage detection unit, an execution unit, a prompt tone unit and a loudspeaker module. The microprocessor is used for detecting a key or touch state; touch input: sensing a human body touch signal; the voltage detector is used for monitoring the voltage of the connected battery in real time, and feeding back the voltage to the microprocessor in time to make a response when the voltage is too low or overheated during charging; the execution unit is used for outputting a corresponding voltage signal according to an instruction of the microprocessor so as to change the volume; and the prompt tone unit is used for outputting prompt tones when key pressing or touch operation exists or the sound is maximum or minimum, so that the man-machine interaction capability is enhanced. According to the invention, a domestic microprocessor scheme is adopted to replace an imported high-performance digital processing chip or a special chip, the cost is low, the volume control range is large, the use is flexible, and uncontrollable factors of a supply chain are greatly reduced.

Description

Technical Field

[0001] The invention belongs to the technical field of audio equipment, and in particular relates to a volume control system and a device for hearing protection earphones. Background Art

[0002] With the rapid development of modern society, many people who are engaged in heavy physical labor or work in high-noise environments easily ignore the issue of hearing protection. Any sound generated in an industrial environment may affect the hearing health of people in the workplace, such as rotating mechanical equipment and gear transmission friction, cutting and welding, etc. These noises are not only high-frequency but also long-lasting, and the risk of causing damage to the human ear is relatively high. In addition, explosive sound waves often occur during military training or engineering construction. Such sound waves are stronger than general mechanical vibrations and frictions, and may cause sudden hearing loss. Therefore, it is particularly important to protect people's hearing health.

[0003] There are many different devices on the market to reduce the damage caused by noise to the ears. The most commonly used are noise-reducing earmuffs, which can filter out most of the noise and industrial noise in the environment. There are also some customized earplugs, noise-reducing helmets, and sound wave barriers. These devices reduce the sound in the environment that is transmitted to the human auditory system by absorbing or reflecting sound waves. This is passive noise reduction. With the development of technology, some products that use technical means to actively reduce noise have also appeared on the market. They rely on high-performance imported chips and combine intelligent algorithms to achieve noise reduction functions to achieve the purpose of hearing protection.

[0004] For the hearing protection earphone products on the market, such as noise reduction earmuffs, they use physical properties to isolate the external noise from the ears. They are mainly designed to be tighter in the headphone head, to perform acoustic optimization in the cavity connected to the ear, and to put sound-absorbing materials inside the earmuffs to achieve physical sound insulation of the earphones, so as to achieve the effect of noise reduction and sound insulation. This kind of product belongs to passive noise reduction. Active noise reduction products use digital technology processing principles. First, they are designed to be physically isolated or in-ear, tightly fit the ear canal to block external sounds, select external noise source signals through the pickup, and generate reverse pulses inside the product to offset the noise, so as to achieve the effect of noise reduction.

[0005] From the analysis of hearing protection earphones currently on the market, passive noise reduction products are generally large in size and inconvenient to carry around. Wearing them for a long time will make the human ear feel uncomfortable, especially in hot weather. In addition, the outside sound is basically inaudible when worn, which poses some safety hazards when used in certain industrial environments. With this type of noise reduction, the noise reduction volume cannot be adjusted or controlled.

[0006] Active noise reduction hearing protection earphones use imported high-performance digital processing chips or dedicated chips, combined with external circuits, to achieve active noise reduction effects. They are expensive, have a relatively narrow noise reduction depth, and a small volume control range. Due to the use of imported or dedicated chips, when the supply chain is tight, it is difficult to supply, and the product launch will be affected. Therefore, we propose a volume control system and device for hearing protection earphones. Summary of the invention

[0007] The purpose of the present invention is to provide a volume control system and device for hearing protection headphones to solve the existing problems.

[0008] In order to solve the above technical problems, the present invention is achieved through the following technical solutions:

[0009] The present invention is a volume control system for a hearing protection headset, comprising a microprocessor, a touch input, a key input, a voltage detection, an execution unit, a prompt sound unit and a speaker module;

[0010] A microprocessor is used to detect the key or touch status, output the corresponding signal to be executed by the execution unit and set the corresponding volume level, and output the prompt sound signal at the same time;

[0011] Key input, consisting of a single or multiple keys;

[0012] Touch input, by sensing human touch signals, single click, multiple clicks or long press operations, output signals to the microprocessor to perform corresponding actions;

[0013] Voltage detection is used to monitor the connected battery voltage in real time. When the voltage is too low or overheated during charging, it will be fed back to the microprocessor in time for response;

[0014] The execution unit outputs a corresponding voltage signal according to the microprocessor instruction to change the volume;

[0015] The prompt sound unit outputs a prompt sound when there is a key or touch operation, or when the sound is at the maximum or minimum, to enhance the human-computer interaction capability;

[0016] The speaker module is used to convert electrical energy into sound energy. By receiving the analog signal from the sound source, the vibrating element is vibrated under the power drive, thereby generating sound.

[0017] A hearing protection headset comprises a sound input module, a preamplifier module, an AGC circuit module, a balance circuit module, a volume control module, a power amplifier module, a speaker module and a power circuit module; the output end of the sound input module is electrically connected to the input end of the preamplifier module and the input end of the AGC circuit module respectively; the output end of the preamplifier module is electrically connected to the output end of the AGC circuit module, the connection port is electrically connected to the input end of the balance circuit module, and the output end of the balance circuit module is electrically connected to the port of the volume control module; the port of the volume control module is electrically connected to the input end of the power amplifier module, and the output end of the power amplifier module is electrically connected to the positive end of the speaker;

[0018] The sound input module is connected to an external microphone to convert external noise into an audio signal, including various microphones such as an electret microphone and a MEMS microphone.

[0019] The preamplifier module amplifies weak audio signals for subsequent processing;

[0020] The AGC circuit is an automatic gain control circuit, which automatically adjusts the gain of the preamplifier circuit when the received signal exceeds the designed value, so that the output signal is limited to the rated range;

[0021] The preamplifier module, AGC circuit module, an amplifier or detector circuit composed of discrete transistor components, or a circuit with the same function composed of an integrated circuit chip as the core;

[0022] The purpose of the balance circuit module is to ensure that the left and right balance of two speakers is maintained within a reasonable range when the two speakers are used at the same time;

[0023] The volume control module controls the volume of the signal output by the balancing circuit and sets the corresponding volume level according to the state of the external button or touch to meet different application occasions;

[0024] The power amplifier module amplifies the signal to meet the needs of driving the speaker;

[0025] The speaker module is used to restore the input signal and includes the application of multiple speakers;

[0026] In one of the embodiments, the volume control module includes an execution unit, a control signal unit, a prompt sound unit, a voltage detection unit and headphone volume control software;

[0027] The execution unit includes a transistor Q1 and a resistor R3, the control signal unit includes a microprocessor, a resistor R1, a resistor R2, a resistor RA, a resistor RB, a resistor RC, a resistor RD, a resistor RE, a resistor RF, a resistor RG, a resistor RS1, a resistor RS2, a capacitor C1, a button S1, a button S2 and a touch button J1, the prompt sound unit includes a resistor R20 and a capacitor C15, and the voltage detection unit includes R1 and R2;

[0028] By detecting the button or touch status and cooperating with the hardware circuit, the volume can be adjusted. The microprocessor needs to do software design. The button S1 is connected to the UP pin of the microprocessor and the ground, the button S2 is connected to the DOWN pin of the microprocessor and the ground, and the touch button J1 is connected to the TOUCH pin of the microprocessor. You can choose to adjust the volume by pressing the button or touching the button; one end of the capacitor C15 is connected to the K8 pin of the microprocessor, and the other end is connected to the positive pole of the speaker 11 after being connected in series with the resistor R20 to output the prompt tone;

[0029] The signal output end of the control signal unit is connected in series with the resistor R3 in the execution unit to the base of the transistor Q1, the emitter of the transistor Q3 is grounded, and the collector is connected to the output end of the balance circuit module to control the sound level; wherein the resistors RA, RB, RC, RD, RE, RF, and RG in the control signal unit are volume gear resistors, one end of which is respectively connected to the corresponding K1, K2, K3, K4, K5, K6, and K7 pins of the microprocessor, and the other end is connected to the signal output end of the control signal unit, the resistor RS1 connects the signal output end of the control signal unit with the reference power supply, and the resistor RS2 connects the signal output end of the control signal unit with the ground, that is, by clicking the buttons S1 and S2 or touching the button J1 to control the working states of the corresponding K1, K2, K3, K4, K5, K6, and K7 pins of the microprocessor 32 to realize the function of volume adjustment, and a prompt tone is given when the volume is at the lowest or highest level;

[0030] When the volume needs to be adjusted, the microprocessor will calculate the current output pin (K1 / K2 / K3 / K4 / K5 / K6 / K7) according to the number of button clicks and output it. Due to the different resistance values ​​of the volume gear resistors (RA / RB / RC / RD / RE / RF / RG), the voltage value at the VF end changes according to the different output pins. When different voltage values ​​are output to the execution unit, the execution unit will control the sound volume according to the received VF voltage value, thus realizing the volume adjustment function;

[0031] The voltage at the VF terminal can be calculated using the following formula:

[0032]

[0033] RS2′=RS2 / R

[0034] Where: VF is the voltage at point F, VREF is the reference voltage, RS2 is the lower resistor, RS1 is the upper resistor, R is the resistance value when the gear is switched, such as RA / RB / RC / RD / RE / RF / RG, and RS2' is the resistance value after R and RS2 are connected in parallel.

[0035] In one of the embodiments, the headphone volume control software is composed of a key detection module, a low voltage detection module, a volume gear switch, a communication module, a timer module, a watchdog module and an interrupt module. The key detection module detects the key or touch status and cooperates with the hardware circuit to adjust the volume.

[0036] In one embodiment, the sound input module includes a microphone, a resistor R5, a resistor R6, and a capacitor C7. The positive electrode of the microphone is connected in series with the resistors R5 and R6 and then connected to a voltage-stabilized power supply, and the negative electrode is connected to ensure the normal operation of the microphone.

[0037] In one embodiment, the preamplifier module includes a transistor Q2, a transistor Q3, a resistor R7, a resistor R8, a resistor R12, a capacitor C6, and a capacitor C2. The emitters of the transistors Q2 and Q3 are grounded, the resistor R7 is connected to the collector of the transistor Q2 and the regulated power supply, the resistor R12 is connected to the collector of the transistor Q3 and the regulated power supply, the resistor R8 is connected to the collector and the base of the transistor Q3, the capacitor C6 is connected to the collector of the transistor Q2 and the base of the transistor Q3, and the capacitor C2 is connected to the collector of the transistor Q3 and the output end of the AGC circuit module to ensure the normal operation of the preamplifier module, so that the audio signal converted by the sound input module is amplified by the preamplifier module and output to the balanced circuit module.

[0038] In one embodiment, the AGC circuit module includes a transistor Q4, a diode D1, a resistor R10, a resistor R17, a resistor R18, and a capacitor C12. The cathode of the diode D1 is connected to the base of the transistor Q4 and the output end of the preamplifier module, the anode of the diode D1 is connected to the emitter of the transistor Q4, one end of the capacitor C12 and grounded, the other end of the capacitor C12 is connected in series with the resistor R18 and connected to the collector of the transistor, the connection port of the capacitor C12 and the resistor R18 is connected to the resistor R10 and one end of the resistor R17, the other end of the resistor R10 is connected to the voltage-stabilized power supply, and the other end of the resistor R17 is connected to the base of the transistor Q2 to ensure the normal operation of the AGC circuit module.

[0039] In one embodiment, the balancing circuit module includes an adjustable resistor R14, which is connected in series between the preamplifier module and the volume control module; the speaker module includes a speaker, the negative pole of the speaker is grounded, and the positive pole is connected to the resistor R16.

[0040] The power amplifier module includes a power amplifier chip, a resistor R4, a resistor R9, a resistor R11, a resistor R15, a resistor R16, a capacitor C4, a capacitor C9, a capacitor C10, and a capacitor C11. The INB-pin of the power amplifier chip is connected in series with the capacitor C4 and the resistor R4 and then connected to the output end of the volume control module. The OUTB pin of the power amplifier chip is connected in series with the capacitor C11 and the resistor R16 and then connected to the positive electrode of the speaker. The INB+ and INA+ pins of the power amplifier chip are connected to one end of the resistor R11 and the capacitor C9 and then connected in series with the resistor R9 to the positive electrode of the battery. The other ends of the resistor R11 and the capacitor C9 are connected in parallel and then grounded. The INB- and OUTB pins of the power amplifier chip are connected in parallel with the resistor R15 and the capacitor C10 to ensure the normal operation of the power amplifier module.

[0041] The present invention has the following beneficial effects:

[0042] The present invention adopts a domestically produced microprocessor solution to replace imported high-performance digital processing chips or dedicated chips, has the advantages of low cost, large volume control range, flexible use, and greatly reduces uncontrollable factors in the supply chain.

[0043] Of course, any product implementing the present invention does not necessarily need to achieve all of the advantages described above at the same time. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings required for describing the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other accompanying drawings can be obtained based on these accompanying drawings without paying creative work.

[0045] Figure 1 A schematic diagram of the volume control structure of the hearing protection earphone in the present invention;

[0046] Figure 2 A schematic diagram of the structure of a hearing protection earphone according to an embodiment of the present invention;

[0047] Figure 3 A schematic structural diagram of a hearing protection headset according to another embodiment of the present invention;

[0048] Figure 4 It is a schematic diagram of the volume control circuit structure of the hearing protection earphone in the present invention;

[0049] Figure 5 It is a flow chart of the volume control software system of the hearing protection earphone in the present invention;

[0050] Figure 6 The present invention is a schematic diagram of the circuit structure of a hearing protection headset. DETAILED DESCRIPTION

[0051] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0052] In the description of the present invention, it should be understood that the terms "upper", "middle", "outer", "inner" and the like indicating directions or positional relationships are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the components or elements referred to must have a specific direction, be constructed and operated in a specific direction, and therefore should not be understood as limiting the present invention.

[0053] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "provided with", "connected", etc. should be understood in a broad sense. For example, "connected" can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0054] See also Figure 1-Figure 6 As shown, the volume control system of the hearing protection headset of this embodiment includes a microprocessor 32, a touch input 33, a key input 30, a voltage detection 31, an execution unit 34, a prompt sound unit 35 and a speaker module 11;

[0055] The microprocessor 32 is used to detect the key or touch state, output the corresponding signal to be executed by the execution unit 34 and set the corresponding volume level, and output the prompt sound signal;

[0056] Key input 30, consisting of a single key or multiple keys;

[0057] Touch input 33, by sensing human touch signals, single click, multiple clicks or long press operations, outputs signals to the microprocessor 32 to perform corresponding actions;

[0058] Voltage detection 31 is used to monitor the connected battery voltage in real time, and when it is too low or overheated during charging, timely feedback is given to the microprocessor 32 for response;

[0059] The execution unit 34 outputs a corresponding voltage signal according to the instruction of the microprocessor 32 to change the volume;

[0060] The prompt sound unit 35 outputs a prompt sound when there is a key or touch operation, or when the sound is at the maximum or minimum, thereby enhancing the human-computer interaction capability;

[0061] The speaker module 11 is used to convert electrical energy into sound energy. By receiving an analog signal from a sound source, the vibrating element is vibrated under the drive of electricity, thereby generating sound.

[0062] The hearing protection earphone of this embodiment includes a sound input module 1 / 5, a preamplifier module 2 / 6, an AGC circuit module 3 / 7, a balanced circuit module 4 / 8, a volume control module 9, a power amplifier module 10, a speaker module 11 / 12 and a power circuit module 13; the output end of the sound input module 1 / 5 is electrically connected to the input end of the preamplifier module 2 / 6 and the input end of the AGC circuit module 3 / 7 respectively; the output end of the preamplifier module 2 / 6 is electrically connected to the output end of the AGC circuit module 3 / 7, the connection port is electrically connected to the input end of the balanced circuit module 4 / 8, and the output end of the balanced circuit module 4 / 8 is electrically connected to the port of the volume control module 9; the port of the volume control module 9 is electrically connected to the input end of the power amplifier module 10, and the output end of the power amplifier module 10 is electrically connected to the positive end of the speaker;

[0063] The sound input module 1 / 5 is connected to an external pickup to convert external noise into an audio signal, including various pickups such as an electret microphone and a MEMS microphone;

[0064] The preamplifier module 2 / 6 amplifies weak audio signals for subsequent processing;

[0065] The AGC circuit is an automatic gain control circuit. When the received signal exceeds the design value, it automatically adjusts the gain of the preamplifier circuit to limit the output signal to the rated range.

[0066] Preamplifier module 2 / 6, AGC circuit module 3 / 7, an amplifier or detector circuit composed of discrete transistor components, or a circuit with the same function composed of an integrated circuit chip as the core;

[0067] Balanced circuit module 4 / 8, its purpose is to ensure that the left and right balance of two speakers is maintained within a reasonable range when they are used at the same time;

[0068] The volume control module 9 controls the volume of the signal output by the balance circuit and sets the corresponding volume level according to the state of the external button or touch to meet different application occasions;

[0069] The power amplifier module 10 is used to amplify the power of the signal to meet the needs of driving the speaker;

[0070] The speaker module 11 / 12 is used to restore the input signal, including the application of multiple speakers;

[0071] The volume control module 9 includes an execution unit 34, a control signal unit 38, a prompt sound unit 35, a voltage detection unit 31 and a headphone volume control software;

[0072] The execution unit 34 includes a transistor Q1 and a resistor R3, the control signal unit 38 includes a microprocessor 32, a resistor R1, a resistor R2, a resistor RA, a resistor RB, a resistor RC, a resistor RD, a resistor RE, a resistor RF, a resistor RG, a resistor RS1, a resistor RS2, a capacitor C1, a button S1, a button S2 and a touch button J1, the prompt sound unit 35 includes a resistor R20 and a capacitor C15, and the voltage detection unit 31 includes R1 and R2;

[0073] By detecting the button or touch state and cooperating with the hardware circuit, the volume can be adjusted. The microprocessor 32 needs to be designed with software. The button S1 is connected to the UP pin of the microprocessor 32 and the ground, the button S2 is connected to the DOWN pin of the microprocessor 32 and the ground, and the touch button J1 is connected to the TOUCH pin of the microprocessor 32. The volume can be adjusted by pressing the button or touching the button. One end of the capacitor C15 is connected to the K8 pin of the microprocessor 32, and the other end is connected to the positive pole of the speaker 11 after being connected in series with the resistor R20 to output the prompt tone.

[0074] The signal output end of the control signal unit 38 is connected in series with the resistor R3 in the execution unit 34 to the base of the transistor Q1, the emitter of the transistor Q3 is grounded, and the collector is connected to the output end of the balance circuit module 4 / 8 to control the sound level; wherein the resistors RA, RB, RC, RD, RE, RF, and RG in the control signal unit are volume gear resistors, one end of which is respectively connected to the corresponding K1, K2, K3, K4, K5, K6, and K7 pins of the microprocessor 32, and the other end is connected to the signal output end of the control signal unit, the resistor RS1 connects the signal output end of the control signal unit with the reference power supply, and the resistor RS2 connects the signal output end of the control signal unit with the ground, that is, by clicking the buttons S1 and S2 or touching the button J1 to control the working states of the corresponding K1, K2, K3, K4, K5, K6, and K7 pins of the microprocessor 32 to realize the function of volume adjustment, and a prompt tone is given when the volume is at the lowest or highest level;

[0075] When the volume needs to be adjusted, the microprocessor 32 calculates the current output pin (K1 / K2 / K3 / K4 / K5 / K6 / K7) according to the number of button clicks and outputs it.

[0076] / RF / RG) The different resistance values ​​cause the voltage value at the VF end to change according to the different output pins. When different voltage values ​​are output to the execution unit 34, the execution unit 34 will control the sound volume according to the received VF voltage value, thus realizing the volume adjustment function.

[0077] The voltage at the VF terminal can be calculated using the following formula:

[0078]

[0079] RS2′=RS2 / R

[0080] Where: VF is the voltage at point F, VREF is the reference voltage, RS2 is the lower resistor, RS1 is the upper resistor, R is the resistance value when the gear is switched, such as RA / RB / RC / RD / RE / RF / RG, and RS2' is the resistance value after R and RS2 are connected in parallel.

[0081] Among them, the headphone volume control software is composed of a button detection module, a low voltage detection module, a volume gear switch, a communication module, a timer module, a watchdog module and an interrupt module. The button detection module detects the button or touch status and cooperates with the hardware circuit to adjust the volume.

[0082] The sound input module 1 includes a microphone, a resistor R5, a resistor R6, and a capacitor C7. The positive electrode of the microphone is connected in series with the resistors R5 and R6 and then connected to a voltage-stabilized power supply, and the negative electrode is connected to ensure the normal operation of the microphone.

[0083] Among them, the preamplifier module 2 includes transistor Q2, transistor Q3, resistor R7, resistor R8, resistor R12, capacitor C6, and capacitor C2. The emitters of transistors Q2 and Q3 are grounded, resistor R7 connects the collector of transistor Q2 and the regulated power supply, resistor R12 connects the collector of transistor Q3 and the regulated power supply, resistor R8 connects the collector and base of transistor Q3, capacitor C6 connects the collector of transistor Q2 and the base of transistor Q3, and capacitor C2 connects the collector of transistor Q3 and the output end of AGC circuit module 3 to ensure the normal operation of preamplifier module 2, so that the audio signal converted by sound input module 1 is amplified by preamplifier module 2 and output to balance circuit module 4.

[0084] Among them, the AGC circuit module 3 includes a transistor Q4, a diode D1, a resistor R10, a resistor R17, a resistor R18, and a capacitor C12. The cathode of the diode D1 is connected to the base of the transistor Q4 and the output end of the preamplifier module 2, the anode of the diode D1 is connected to the emitter of the transistor Q4, one end of the capacitor C12 and grounded, the other end of the capacitor C12 is connected in series with the resistor R18 and connected to the collector of the transistor, the connection port of the capacitor C12 and the resistor R18 is connected to the resistor R10 and one end of the resistor R17, the other end of the resistor R10 is connected to the voltage-stabilized power supply, and the other end of the resistor R17 is connected to the base of the transistor Q2 to ensure the normal operation of the AGC circuit module 3.

[0085] The balance circuit module 4 includes an adjustable resistor R14, which is connected in series between the preamplifier module 2 and the volume control module 9; the speaker module 11 includes a speaker, the negative pole of the speaker is grounded, and the positive pole is connected to the resistor R16.

[0086] Among them, the power amplifier 10 module includes a power amplifier chip, resistor R4, resistor R9, resistor R11, resistor R15, resistor R16, capacitor C4, capacitor C9, capacitor C10, and capacitor C11. The INB- pin of the power amplifier chip is connected in series with capacitor C4 and resistor R4 and then connected to the output end of the volume control module 9. The OUTB pin of the power amplifier chip is connected in series with capacitor C11 and resistor R16 and then connected to the positive pole of the speaker. The INB+ and INA+ pins of the power amplifier chip are connected to one end of the resistor R11 and capacitor C9 and then connected in series with resistor R9 to the positive pole of the battery. The other ends of the resistor R11 and capacitor C9 are connected in parallel and then grounded. The INB- and OUTB pins of the power amplifier chip are connected in parallel with resistor R15 and capacitor C10 to ensure the normal operation of the power amplifier module 10.

[0087] In the description of this specification, the description with reference to the terms "one embodiment", "example", "specific example", etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.

[0088] The preferred embodiments of the present invention disclosed above are only used to help explain the present invention. The preferred embodiments do not describe all the details in detail, nor do they limit the invention to the specific implementation methods described. Obviously, many modifications and changes can be made according to the content of this specification. This specification selects and specifically describes these embodiments in order to better explain the principles and practical applications of the present invention, so that those skilled in the art can understand and use the present invention well. The present invention is limited only by the claims and their full scope and equivalents.

Claims

1. A volume control system for hearing protection headphones, Features: It includes a microprocessor, a touch input, a key input, a voltage detection, an execution unit, a prompt sound unit and a speaker module; A microprocessor is used to detect the key or touch status, output the corresponding signal to be executed by the execution unit and set the corresponding volume level, and output the prompt sound signal at the same time; Key input, consisting of a single or multiple keys; Touch input, by sensing human touch signals, single click, multiple clicks or long press operations, output signals to the microprocessor to perform corresponding actions; Voltage detection is used to monitor the connected battery voltage in real time. When the voltage is too low or overheated during charging, it will be fed back to the microprocessor in time for response; The execution unit outputs a corresponding voltage signal according to the microprocessor instruction to change the volume; The prompt sound unit outputs a prompt sound when there is a key or touch operation, or when the sound is at the maximum or minimum, to enhance the human-computer interaction capability; The speaker module is used to convert electrical energy into sound energy. By receiving the analog signal from the sound source, the vibrating element is vibrated under the power drive, thereby generating sound.

2. A hearing protection headset, using the volume control system as claimed in claim 1, It is characterized in that It includes a sound input module, a preamplifier module, an AGC circuit module, a balance circuit module, a volume control module, a power amplifier module, a speaker module and a power circuit module; the output end of the sound input module is electrically connected to the input end of the preamplifier module and the input end of the AGC circuit module respectively; the output end of the preamplifier module is electrically connected to the output end of the AGC circuit module, the connection port is electrically connected to the input end of the balance circuit module, and the output end of the balance circuit module is electrically connected to the port of the volume control module; the port of the volume control module is electrically connected to the input end of the power amplifier module, and the output end of the power amplifier module is electrically connected to the positive end of the speaker; The sound input module is connected to an external pickup to convert external noise into an audio signal, including various pickups such as an electret microphone and a MEMS microphone; The preamplifier module amplifies weak audio signals for subsequent processing; The AGC circuit is an automatic gain control circuit, which automatically adjusts the gain of the preamplifier circuit when the received signal exceeds the designed value, so that the output signal is limited to the rated range; The preamplifier module, AGC circuit module, an amplifier or detector circuit composed of discrete transistor components, or a circuit with the same function composed of an integrated circuit chip as the core; The purpose of the balance circuit module is to ensure that the left and right balance of two speakers is maintained within a reasonable range when the two speakers are used at the same time; The volume control module controls the volume of the signal output by the balancing circuit and sets the corresponding volume level according to the state of the external button or touch to meet different application occasions; The power amplifier module amplifies the signal to meet the needs of driving the speaker; The speaker module restores the input signal and includes the application of multiple speakers.

3. A hearing protection headset according to claim 2, It is characterized in that The volume control module includes an execution unit, a control signal unit, a prompt sound unit, a voltage detection unit and headphone volume control software; The execution unit includes a transistor Q1 and a resistor R3, the control signal unit includes a microprocessor, a resistor R1, a resistor R2, a resistor RA, a resistor RB, a resistor RC, a resistor RD, a resistor RE, a resistor RF, a resistor RG, a resistor RS1, a resistor RS2, a capacitor C1, a button S1, a button S2 and a touch button J1, the prompt sound unit includes a resistor R20 and a capacitor C15, and the voltage detection unit includes R1 and R2; By detecting the button or touch status and cooperating with the hardware circuit, the volume can be adjusted. The microprocessor needs to do software design. The button S1 is connected to the UP pin of the microprocessor and the ground, the button S2 is connected to the DOWN pin of the microprocessor and the ground, and the touch button J1 is connected to the TOUCH pin of the microprocessor. You can choose to adjust the volume by pressing the button or touching the button; one end of the capacitor C15 is connected to the K8 pin of the microprocessor, and the other end is connected to the positive pole of the speaker 11 after being connected in series with the resistor R20 to output the prompt tone; The signal output end of the control signal unit is connected in series with the resistor R3 in the execution unit to the base of the transistor Q1, the emitter of the transistor Q3 is grounded, and the collector is connected to the output end of the balance circuit module to control the sound level; wherein the resistors RA, RB, RC, RD, RE, RF, and RG in the control signal unit are volume gear resistors, one end of which is respectively connected to the corresponding K1, K2, K3, K4, K5, K6, and K7 pins of the microprocessor, and the other end is connected to the signal output end of the control signal unit, the resistor RS1 connects the signal output end of the control signal unit with the reference power supply, and the resistor RS2 connects the signal output end of the control signal unit with the ground, that is, by clicking the buttons S1 and S2 or touching the button J1 to control the working states of the corresponding K1, K2, K3, K4, K5, K6, and K7 pins of the microprocessor 32 to realize the function of volume adjustment, and a prompt tone is given when the volume is at the lowest or highest level; When the volume needs to be adjusted, the microprocessor will calculate the current output pin (K1 / K2 / K3 / K4 / K5 / K6 / K7) according to the number of button clicks and output it. (RA / RB / RC / RD / RE / RF / RG) The different resistance values ​​cause the voltage value at the VF end to change according to the different output pins. When different voltage values ​​are output to the execution unit, the execution unit will control the sound volume according to the received VF voltage value, thus realizing the volume adjustment function; The voltage at the VF terminal can be calculated using the following formula: RS2′=RS2 / R Where: VF is the voltage at point F, VREF is the reference voltage, RS2 is the lower resistor, RS1 is the upper resistor, R is the resistance value when the gear is switched, such as RA / RB / RC / RD / RE / RF / RG, and RS2' is the resistance value after R and RS2 are connected in parallel.

4. A hearing protection headset according to claim 3, It is characterized in that The headphone volume control software consists of a key detection module, a low voltage detection module, a volume gear switch, a communication module, a timer module, a watchdog module and an interrupt module. The key detection module detects the key or touch status and cooperates with the hardware circuit to adjust the volume.

5. A hearing protection headset according to claim 4, It is characterized in that The sound input module includes a microphone, a resistor R5, a resistor R6, and a capacitor C7. The positive electrode of the microphone is connected in series with the resistors R5 and R6 and then connected to a voltage-stabilized power supply, and the negative electrode is connected to the ground to ensure the normal operation of the microphone.

6. A hearing protection earphone according to claim 5, It is characterized in that The preamplifier module includes transistor Q2, transistor Q3, resistor R7, resistor R8, resistor R12, capacitor C6, and capacitor C2. The emitters of transistors Q2 and Q3 are grounded, resistor R7 is connected to the collector of transistor Q2 and the voltage-stabilized power supply, resistor R12 is connected to the collector of transistor Q3 and the voltage-stabilized power supply, resistor R8 is connected to the collector and base of transistor Q3, capacitor C6 is connected to the collector of transistor Q2 and the base of transistor Q3, and capacitor C2 is connected to the collector of transistor Q3 and the output end of the AGC circuit module to ensure the normal operation of the preamplifier module, so that the audio signal converted by the sound input module is amplified by the preamplifier module and output to the balanced circuit module.

7. The hearing protection earphone according to claim 6, It is characterized in that The AGC circuit module includes a transistor Q4, a diode D1, a resistor R10, a resistor R17, a resistor R18, and a capacitor C12. The cathode of the diode D1 is connected to the base of the transistor Q4 and the output end of the preamplifier module, the anode of the diode D1 is connected to the emitter of the transistor Q4, one end of the capacitor C12 and grounded, the other end of the capacitor C12 is connected in series with the resistor R18 and connected to the collector of the transistor, the connection port of the capacitor C12 and the resistor R18 is connected to the resistor R10 and one end of the resistor R17, the other end of the resistor R10 is connected to the voltage-stabilized power supply, and the other end of the resistor R17 is connected to the base of the transistor Q2 to ensure the normal operation of the AGC circuit module.

8. The hearing protection earphone according to claim 7, It is characterized in that The balance circuit module includes an adjustable resistor R14, which is connected in series between the preamplifier module and the volume control module; the speaker module includes a speaker, the negative pole of the speaker is grounded, and the positive pole is connected to the resistor R16.

9. The hearing protection earphone according to claim 8, It is characterized in that The power amplifier module includes a power amplifier chip, a resistor R4, a resistor R9, a resistor R11, a resistor R15, a resistor R16, a capacitor C4, a capacitor C9, a capacitor C10, and a capacitor C11. The INB-pin of the power amplifier chip is connected in series with the capacitor C4 and the resistor R4 and then connected to the output end of the volume control module. The OUTB pin of the power amplifier chip is connected in series with the capacitor C11 and the resistor R16 and then connected to the positive electrode of the speaker. The INB+ and INA+ pins of the power amplifier chip are connected to one end of the resistor R11 and the capacitor C9 and then connected in series with the resistor R9 to the positive electrode of the battery. The other ends of the resistor R11 and the capacitor C9 are connected in parallel and then grounded. The INB- and OUTB pins of the power amplifier chip are connected in parallel with the resistor R15 and the capacitor C10 to ensure the normal operation of the power amplifier module.

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