A control circuit for a microphone in a cycling helmet

Abstract

This utility model relates to the technical field of microphone / receiver devices, specifically to a microphone / receiver control circuit for a cycling helmet. It includes a circuit board installed in a control box on one side of the helmet. The circuit board houses a main control processing unit, a power amplifier control unit, a main microphone noise reduction / voice enhancement control unit, an LDO 3.3V power supply unit, and a battery charging unit. The main control processing unit is connected to the main microphone noise reduction / voice enhancement control unit, the power amplifier control unit, the LDO 3.3V power supply unit, and the battery charging unit via wires. It features the ability to achieve clear voice transmission and reception, as well as the ability to detect ambient sounds, during both low-speed and high-speed cycling, through an AI voice processing chip and a power amplifier.

Description

Technical Field

[0001] This utility model relates to the field of microphone equipment technology, specifically to a microphone control circuit for a cycling helmet. Background Technology

[0002] Cycling is a popular leisure activity, enjoyed by many. Some cycling enthusiasts consider it a way to de-stress after work. Wearing a helmet is essential for safety while cycling. However, using a mobile phone while cycling poses safety risks. Furthermore, riding against the wind, especially when wind pressure is high, can significantly affect microphone call quality.

[0003] Therefore, a microphone is installed on bicycle helmets with perforations to solve the problem of answering phone calls. However, ensuring clear audio transmission and reception for both normal riding speeds below 50 km / h and high-speed riding speeds above 50 km / h becomes a problem that needs to be solved. Therefore, developing a microphone that guarantees clear audio transmission and reception for different riding speeds is the problem our company aims to solve. Utility Model Content

[0004] The purpose of this invention is to address the shortcomings and deficiencies of existing technologies by providing a microphone control circuit for cycling helmets. This circuit solves the problem of smooth communication for cyclists wearing cycling helmets (especially bicycle helmets with holes) while cycling, particularly when riding against the wind and the wind pressure is high, which affects the microphone's call quality.

[0005] The present invention discloses a control circuit for a microphone in a cycling helmet, comprising a circuit board installed in a control box on one side of the helmet. The circuit board is provided with a main control processing unit, a power amplifier control unit, a main microphone noise reduction / voice enhancement control unit, an LDO 3.3V power supply unit, and a battery charging unit. The main control processing unit is connected to the main microphone noise reduction / voice enhancement control unit, the power amplifier control unit, the LDO 3.3V power supply unit, and the battery charging unit through wires.

[0006] Further, the main control processing unit includes a main control circuit, which includes a U2 chip. Pins 1 and 3 of the U2 chip are connected to the MUTE and ENC_EN terminals, respectively. Pin 2 of the U2 chip is connected to switch SW3, which is connected in series with resistor R6, with the other end of resistor R6 grounded, controlling the volume increase. Switch SW4 is connected in series with resistor R12 and then in parallel across switch SW3 and resistor R6, controlling the volume decrease. Pins 5 and 6 of the U2 chip are connected in series with capacitors C11 and C50, respectively, with the other ends of capacitors C11 and C50 grounded. Pin 7 of the U2 chip is connected in series with resistor R22, with the other end of resistor R22 connected to the V_BAT terminal. Capacitors C9 and C... Pins 10 and 10 are connected in parallel to pin 7 of the U2 chip, and the other ends of capacitors C9 and C10 are grounded. Pin 8 of the U2 chip is connected in series with inductor L3 and capacitor C12, and the other end of capacitor C12 is grounded. Pin 9 of the U2 chip is grounded. Pin 10 of the U2 chip and capacitor C6 are connected in parallel between inductor L3 and pin 16 of the U2 chip. Pin 15 of the U2 chip is connected in series with resistor R5, and the other end of resistor R5 is connected to Bluetooth antenna ANT1. Pin 16 of the U2 chip is connected in series with capacitor C52, and the other end of capacitor C52 is grounded. Switch SW1, used as a power button, is connected in series with pin 13 of the U2 chip, and the other end of switch SW1 is grounded. Inductors L1 and L5 are connected in parallel across resistor R5, and the other ends of inductors L1 and L5 are grounded.

[0007] Pin 17 of the U2 chip is connected to one pin of crystal oscillator X1, and the other pin of crystal oscillator X1 is connected to pin 18 of the U2 chip; pin 20 of the U2 chip is connected to the PB3_AUX terminal; pin 21 of the U2 chip is connected to the MIC_CS terminal for MIC selection output; pin 22 of the U2 chip is connected in series with capacitor C15, and the other end of capacitor C5 is connected to the DT_SPK terminal for walkie-talkie audio signal input; pin 23 of the U2 chip is connected in series with resistor R26 and diode LED3, and the other end of diode LED3 is grounded for power-on indication and power indicator; pin 24 of the U2 chip is connected to switch SW2, and the other end of switch SW2 is grounded for use as a voice enhancement switch and MIC selection.

[0008] In this design, pins 1 and 2 of the CN7 terminal are connected to the V_BAT terminal and the PB3_AUX terminal, respectively. Pin 3 of the common terminal CN7 is grounded and used as the main control program programming port.

[0009] Furthermore, the U2 chip is a Bluetooth audio SoC chip, model BT8892, primarily used in TWS earphones. It adopts a RISC-V architecture, supports DSP instruction sets, and boasts ultra-low power consumption and powerful computing capabilities. In active noise cancellation mode, the chip consumes only 7mA, and its power consumption is as low as 2uA when powered off. In addition, the BT8892 integrates three microphone signal amplifiers and a high-performance Delta-Sigma ADC, providing a noise reduction depth of 30dB, up to a maximum of 40dB. It supports three modes: feedforward (FF), feedback (FB), and hybrid noise cancellation, offering flexible and diverse noise reduction structure options. It features low power consumption, high performance, and flexible noise cancellation capabilities.

[0010] Furthermore, the power amplification control unit includes a power amplification control circuit, which includes a U4 chip. Pin 1 of the U4 chip is connected in series with resistor R7, and the other end of resistor R7 is connected to the V_BAT terminal. Pin 2 of the U4 chip is connected in series with capacitor C34, and the other end of capacitor C34 is connected in parallel with pin 4 of the U4 chip. Pin 3 of the U4 chip is grounded. Pin 5 of the U4 chip is connected in series with capacitor C36, and the other end of capacitor C36 is grounded. Pin 6 of the U4 chip is grounded. Pins 7 and 8 of the U4 chip are connected to the PINR+ and PINR- terminals respectively; pin 9 of the U4 chip is connected in series with capacitor C44, and the other end of capacitor C44 is grounded; pins 10, 12, 14, and 15 of the U4 chip are connected to the SPKR, SPKL, PINL+, and PINL- terminals respectively; pin 11 of the U4 chip is connected in series with capacitor C11, and the other end of capacitor C11 is grounded; resistor R42 and capacitor C42 are connected in parallel between pins 12 and 14 of the U4 chip respectively.

[0011] Resistors R25 and R21 are connected in parallel to pin 16 of the U4 chip. Resistor R25 is connected to the MUTE terminal, and the other end of resistor R21 is grounded. Capacitors C33 and C35 are connected in series, and pins 1 and 9 of the U4 chip are connected in parallel across capacitors C33 and C35. Resistor R39 is connected in parallel to pin 15 of the U4 chip, and the other end of resistor R39 is grounded. Capacitor C41 is connected in parallel across resistor R39.

[0012] One end of resistor R9 is connected in parallel to pin 7 of the U4 chip, and the other end of resistor R9 is grounded. Capacitor C37 is connected in parallel between resistor R19 and pin 7 of the U4 chip. One end of resistor R20 is connected in parallel to pin 8 of the U4 chip, and the other end of resistor R20 is connected in parallel to pin 10 of the U4 chip. Capacitor C40 is connected in parallel between pins 8 and 10 of the U4 chip.

[0013] Furthermore, the U4 chip is a single-channel, Class AB audio power amplifier chip with model number HT97180.

[0014] Furthermore, the main MIC noise reduction / voice enhancement control unit includes a main MIC noise reduction / voice enhancement control circuit. This main MIC noise reduction / voice enhancement control circuit includes a U7 chip. Pin 3 of the U7 chip is connected in series with capacitor C7. Capacitor C7 is connected to pin 4 of the U5 chip. Pin 5 of the U5 chip is connected to a 3.3V power supply. Pin 6 of the U5 chip is connected to the MIC_CS terminal. Pin 2 of the U5 chip is grounded. Pin 4 of the U7 chip is connected in series with capacitor C14. Capacitor C14 is connected to pin 4 of the U6 chip. Pin 5 of the U6 chip is connected to a 3.3V power supply. Pin 6 of the U6 chip is connected to the MIC_CS terminal. Pin 2 of the U6 chip is grounded.

[0015] Pin 3 of the U5 chip and pin 3 of the U6 chip are connected to pins 1 and 2 of the bone conduction MIC1, respectively; pin 1 of the U5 chip and pin 1 of the U6 chip are connected to pins 1 and 2 of the ordinary MIC2, respectively; pins 5 and 6 of the U7 chip are connected in series with capacitors C18 and C19, respectively, and the other ends of capacitors C18 and C19 are connected to pins 1 and 2 of the voice enhancement MIC3, respectively.

[0016] Pins 11-13 of the U7 chip are connected in series with capacitors C24, C25, and C26, respectively. The other ends of capacitors C24, C25, and C26 are connected to the ENC_RP terminal, the ENC_RN terminal, and the DT_MIC terminal, respectively.

[0017] Pins 16 and 17 of the U7 chip are connected to the two pins of crystal oscillator X2, respectively; pin 23 of the U7 chip is connected in series with capacitor C27, and the other end of capacitor C27 is grounded; pin 24 of the U7 chip is connected to the VDD12 terminal; capacitors C45, C38, C29, and C28 are connected in parallel to pins 24-27 of the U7 chip, respectively.

[0018] Pins 29, 31, and 33 of the U7 chip are connected to the VDD33_AON, VDD18_AON, and VDD08 terminals, respectively. Capacitors C53, C51, C49, C48, C47, and C46 are connected in parallel to pins 28-31, 33, and 35 of the U7 chip, respectively. Pin 39 of the U7 chip is grounded, and pins 40-52 are connected in parallel to pin 39. Pin 69 of the U7 chip is grounded, and pins 63-68 are connected in parallel to pin 69. Pin 73 of the U7 chip is connected in series with inductors L2 and L4 and capacitor C56, with the other end of capacitor C56 grounded. Pin 74 of the U7 chip is connected to the VDD12 terminal. Pin 75 of the U7 chip is connected to inductors L6 and L4. A capacitor C57 is connected in series, with the other end of C57 grounded; pin 76 of the U7 chip is connected to the VDD08 terminal; pin 77 of the U7 chip is connected in series with inductors L8 and L9 and capacitor C58, with the other end of capacitor C58 grounded; pin 78 of the U7 chip is connected to the VDD19 terminal; pins 79-84 of the U7 chip are connected to the VDD18_AUX terminal, VDD18_FLASH_LDO terminal, VDD33 / 18_IO terminal, TXD terminal, and RXD terminal, respectively; pin 88 of the U7 chip is connected to the VDD33 / 18_IO terminal, one end of capacitor C62 is connected in parallel with pin 88 of the U7 chip, and the other end of capacitor C62 is grounded; pin 114 of the U7 chip is connected in series with resistor R8, with the other end of resistor R8 connected to the VDD18_AON terminal.

[0019] Furthermore, the U7 chip is an AI voice processing chip.

[0020] Furthermore, the U5 and U6 chips are single-cell lithium battery charging management chips with the model number LN3657.

[0021] Furthermore, the LDO 3.3V power supply unit includes a power control circuit, which includes a U8 chip. Pin 1 of the U8 chip is connected to the V_BAT terminal. One end of capacitor C39 is connected in parallel with pin 1 of the U8 chip, and the other end of capacitor C39 is grounded. Pin 2 of the U8 chip is grounded. Pin 3 of the U8 chip is connected to the ENC_EN terminal. Pin 5 of the U8 chip is connected to the 3.3V power supply. One end of capacitor C21 is connected in parallel with pin 5 of the U8 chip, and the other end of capacitor C21 is grounded.

[0022] Furthermore, the U8 chip is a low dropout linear regulator chip with model number SGM2036-3.3.

[0023] Furthermore, the battery charging unit includes a battery charging circuit, which includes a U1 chip. Pins 1 and 3 of the U1 chip are grounded, pin 2 of the U1 chip is connected in series with resistor R3, and the other end of resistor R3 is grounded. Pin 4 of the U1 chip is connected to pin 2 of terminal CN1. One end of capacitors C1, C2, and C3 is connected in parallel with pin 4 of the U1 chip, and the other ends of capacitors C1, C2, and C3 are grounded.

[0024] Pin 3 of terminal CN1 is connected in series with core inductor RD6, and the other end of core inductor RD6 is connected to the DT_MIC terminal; pin 4 of terminal CN1 is connected in series with resistor R1, and the other end of resistor R1 is grounded; one end of varistor M6 is connected in parallel with pin 3 of terminal CN1, and the other end of varistor M6 is grounded; one end of varistor M4 is connected in parallel with pin 2 of CN1, and the other end of varistor M4 is grounded; one end of varistor M1 is connected in parallel with pin 3 of CN1, and the other end of varistor M1 is grounded; pin 8 of terminal CN1 is connected in series with core inductor RD7 and resistor R31, and the other end of resistor R31 is connected to the DT_SPK terminal; pin 1 of terminal CN1 is grounded, and pins 12-18 of terminal CN1 are connected in parallel with pin 1 of CN1; one end of resistors R30 and R32 is connected in parallel across resistor R31, and the other ends of resistors R30 and R32 are grounded.

[0025] Pin 5 of chip U1 is connected to the V_BAT terminal; pin 6 of chip U1 is connected in series with diode LED1 and resistor R14, and the other end of resistor R14 is connected in parallel with pin 4 of chip U1; pin 6 of chip U1 is connected in series with diode LED2, and the other end of diode LED2 is connected in parallel with diode LED1; capacitors C4 and C5, and pin 1 of terminal CN5 are connected in parallel with pin 5 of chip U1, and the other ends of capacitors C4 and C5, and pin 2 of terminal CN5 are grounded.

[0026] The beneficial effects of this utility model are as follows: The microphone control circuit for a cycling helmet described in this utility model adopts a circuit board installed in the control box on one side of the helmet. The circuit board is equipped with a main control processing unit, a power amplifier control unit, a main microphone noise reduction / voice enhancement control unit, an LDO 3.3V power supply unit, and a battery charging unit. The main control processing unit is connected to the main microphone noise reduction / voice enhancement control unit, the power amplifier control unit, the LDO 3.3V power supply unit, and the battery charging unit through wires. It has the characteristics of being able to achieve clear voice transmission and reception, as well as the ability to listen to ambient sounds, when cycling at both low and high speeds, through the AI ​​voice processing chip and the power amplifier. Attached Figure Description

[0027] The accompanying drawings, which are provided to further illustrate the present invention and form part of this application, do not constitute an undue limitation of the present invention. In the drawings:

[0028] Figure 1 This is a structural schematic diagram of the helmet of this utility model;

[0029] Figure 2 This is a schematic diagram of the control box in this utility model;

[0030] Figure 3 This is a structural schematic diagram of the switch box in this utility model;

[0031] Figure 4 This is a topological diagram of the control circuit in this utility model;

[0032] Figure 5 This is a structural block diagram illustrating the working principle of this utility model;

[0033] Figure 6 This is a schematic diagram of the control circuit of the main control processing unit in this utility model;

[0034] Figure 7 This is a schematic diagram of the control circuit of the main MIC noise reduction / voice enhancement control unit in this utility model;

[0035] Figure 8 yes Figure 7 Enlarged schematic diagram of the upper control circuit;

[0036] Figure 9 yes Figure 7 Enlarged schematic diagram of the lower half of the control circuit;

[0037] Figure 10 This is a schematic diagram of the control circuit of the power amplifier control unit in this utility model;

[0038] Figure 11 This is a circuit schematic diagram of the AUX / ENC audio mixing in the power amplifier control unit of this utility model;

[0039] Figure 12 This is a circuit diagram of the speaker connector in the power amplifier control unit of this utility model.

[0040] Figure 13 This is a schematic diagram of the control circuit of the battery charging unit in this utility model;

[0041] Figure 14 yes Figure 13 An enlarged view of the control circuit for the TYPE-C charging and walkie-talkie interface on the left.

[0042] Figure 15 yes Figure 13 Enlarged view of the battery charging circuit on the right;

[0043] Figure 16 This is the circuit diagram of the LDO 3.3V power supply in this utility model.

[0044] Explanation of reference numerals in the attached figures:

[0045] Helmet 1;

[0046] Control box 2; Control box body 21; Circuit board 22; Lithium battery 23; Speaker 24; Wiring hole 25; Heat dissipation hole 26;

[0047] Switch box 3; switch box body 31; volume down button 32, volume up button 33; power button 34; microphone 35; type-C interface 36. Detailed Implementation

[0048] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments. The illustrative embodiments and descriptions are only used to explain the present invention and are not intended to limit the present invention.

[0049] like Figure 4 As shown in the figure, the control circuit for a microphone in a cycling helmet described in this specific embodiment includes a circuit board installed in a control box 2 on one side of the helmet 1. The circuit board is provided with a main control processing unit, a power amplifier control unit, a main microphone noise reduction / voice enhancement control unit, an LDO 3.3V power supply unit, and a battery charging unit. The main control processing unit is connected to the main microphone noise reduction / voice enhancement control unit, the power amplifier control unit, the LDO 3.3V power supply unit, and the battery charging unit through wires.

[0050] Furthermore, such as Figure 6As shown, the main control processing unit includes a main control circuit, which includes a U2 chip. Pins 1 and 3 of the U2 chip are connected to the MUTE and ENC_EN terminals, respectively. Pin 2 of the U2 chip is connected to switch SW3, which is connected in series with resistor R6. The other end of resistor R6 is grounded, controlling the volume increase. Switch SW4 is connected in series with resistor R12 and then in parallel across switch SW3 and resistor R6, controlling the volume decrease. Pins 5 and 6 of the U2 chip are connected in series with capacitors C11 and C50, respectively, with the other ends of capacitors C11 and C50 grounded. Pin 7 of the U2 chip is connected in series with resistor R22, the other end of which is connected to the V_BAT terminal. Capacitors C9 and C1... Pins 0 and 10 are connected in parallel to pin 7 of the U2 chip, and the other ends of capacitors C9 and C10 are grounded. Pin 8 of the U2 chip is connected in series with inductor L3 and capacitor C12, and the other end of capacitor C12 is grounded. Pin 9 of the U2 chip is grounded. Pin 10 of the U2 chip and capacitor C6 are connected in parallel between inductor L3 and pin 16 of the U2 chip. Pin 15 of the U2 chip is connected in series with resistor R5, and the other end of resistor R5 is connected to Bluetooth antenna ANT1. Pin 16 of the U2 chip is connected in series with capacitor C52, and the other end of capacitor C52 is grounded. Switch SW1, which is used as a power button, is connected in series with pin 13 of the U2 chip, and the other end of switch SW1 is grounded. Inductors L1 and L5 are connected in parallel across resistor R5, and the other ends of inductors L1 and L5 are grounded.

[0051] Pin 17 of the U2 chip is connected to one pin of crystal oscillator X1, and the other pin of crystal oscillator X1 is connected to pin 18 of the U2 chip; pin 20 of the U2 chip is connected to the PB3_AUX terminal; pin 21 of the U2 chip is connected to the MIC_CS terminal for MIC selection output; pin 22 of the U2 chip is connected in series with capacitor C15, and the other end of capacitor C5 is connected to the DT_SPK terminal for walkie-talkie audio signal input; pin 23 of the U2 chip is connected in series with resistor R26 and diode LED3, and the other end of diode LED3 is grounded for power-on indication and power indicator; pin 24 of the U2 chip is connected to switch SW2, and the other end of switch SW2 is grounded for use as a voice enhancement switch and MIC selection.

[0052] In this design, pins 1 and 2 of the CN7 terminal are connected to the V_BAT terminal and the PB3_AUX terminal, respectively. Pin 3 of the common terminal CN7 is grounded and used as the main control program programming port.

[0053] Furthermore, the U2 chip is a Bluetooth audio SoC chip, model BT8892, primarily used in TWS earphones. It adopts a RISC-V architecture, supports DSP instruction sets, and boasts ultra-low power consumption and powerful computing capabilities. In active noise cancellation mode, the chip consumes only 7mA, and its power consumption is as low as 2uA when powered off. In addition, the BT8892 integrates three microphone signal amplifiers and a high-performance Delta-Sigma ADC, providing a noise reduction depth of 30dB, up to a maximum of 40dB. It supports three modes: feedforward (FF), feedback (FB), and hybrid noise cancellation, offering flexible and diverse noise reduction structure options. It features low power consumption, high performance, and flexible noise cancellation capabilities.

[0054] Furthermore, such as Figure 10 As shown, the power amplification control unit includes a power amplification control circuit, which includes a U4 chip. Pin 1 of the U4 chip is connected in series with resistor R7, and the other end of resistor R7 is connected to the V_BAT terminal. Pin 2 of the U4 chip is connected in series with capacitor C34, and the other end of capacitor C34 is connected in parallel with pin 4 of the U4 chip. Pin 3 of the U4 chip is grounded. Pin 5 of the U4 chip is connected in series with capacitor C36, and the other end of capacitor C36 is grounded. Pin 6 of the U4 chip is also grounded. Pins 7 and 8 of the U4 chip are connected to the PINR+ and PINR- terminals, respectively; pin 9 of the U4 chip is connected in series with capacitor C44, and the other end of capacitor C44 is grounded; pins 10, 12, 14, and 15 of the U4 chip are connected to the SPKR, SPKL, PINL+, and PINL- terminals, respectively; pin 11 of the U4 chip is connected in series with capacitor C11, and the other end of capacitor C11 is grounded; resistor R42 and capacitor C42 are connected in parallel between pins 12 and 14 of the U4 chip, respectively.

[0055] Resistors R25 and R21 are connected in parallel to pin 16 of the U4 chip. Resistor R25 is connected to the MUTE terminal, and the other end of resistor R21 is grounded. Capacitors C33 and C35 are connected in series, and pins 1 and 9 of the U4 chip are connected in parallel across capacitors C33 and C35. Resistor R39 is connected in parallel to pin 15 of the U4 chip, and the other end of resistor R39 is grounded. Capacitor C41 is connected in parallel across resistor R39.

[0056] One end of resistor R9 is connected in parallel to pin 7 of the U4 chip, and the other end of resistor R9 is grounded. Capacitor C37 is connected in parallel between resistor R19 and pin 7 of the U4 chip. One end of resistor R20 is connected in parallel to pin 8 of the U4 chip, and the other end of resistor R20 is connected in parallel to pin 10 of the U4 chip. Capacitor C40 is connected in parallel between pins 8 and 10 of the U4 chip.

[0057] like Figure 11As shown, in this design, the AUX and ENC audio mixing unit is configured as follows: one end of resistor R52 is connected to the AUX_RP terminal, the other end of resistor R52 is connected in parallel with resistor R53, one end of resistor R53 is connected to the PINR+ terminal, and the other end of resistor R53 is connected to the ENC_RP terminal; one end of resistor R54 is connected to the AUX_RN terminal, the other end of resistor R54 is connected in parallel with resistor R55, one end of resistor R55 is connected to the PINR- terminal, and the other end of resistor R55 is connected to the PINR- terminal. Connect the ENC_RN terminal; connect one end of resistor R56 to the AUX_LN terminal, connect the other end of resistor R56 in parallel with resistor R57, connect one end of resistor R57 to the PINL- terminal, connect the other end of resistor R55 to the ENC_RN terminal; connect one end of resistor R58 to the AUX_LP terminal, connect the other end of resistor R58 in parallel with resistor R59, connect one end of resistor R59 to the PINL+ terminal, connect the other end of resistor R59 to the ENC_RP terminal.

[0058] like Figure 12 As shown, in this design, pins 1 and 4 of the speaker connector CN4 are connected to the SPKR and SPKL connectors respectively; pin 3 of the common connector CN4 is grounded.

[0059] Furthermore, the U4 chip is a single-channel, Class AB audio power amplifier chip with model number HT97180.

[0060] Furthermore, such as Figures 7-9 As shown, the main MIC noise reduction / voice enhancement control unit includes a main MIC noise reduction / voice enhancement control circuit. This circuit includes a U7 chip, with pin 3 of the U7 chip connected in series with capacitor C7. Capacitor C7 is connected to pin 4 of the U5 chip, pin 5 of the U5 chip is connected to a 3.3V power supply, pin 6 of the U5 chip is connected to the MIC_CS terminal, and pin 2 of the U5 chip is grounded. Pin 4 of the U7 chip is connected in series with capacitor C14, which is connected to pin 4 of the U6 chip. Pin 5 of the U6 chip is connected to a 3.3V power supply, pin 6 of the U6 chip is connected to the MIC_CS terminal, and pin 2 of the U6 chip is grounded.

[0061] Pin 3 of the U5 chip and pin 3 of the U6 chip are connected to pins 1 and 2 of the bone conduction MIC1, respectively; pin 1 of the U5 chip and pin 1 of the U6 chip are connected to pins 1 and 2 of the ordinary MIC2, respectively; pins 5 and 6 of the U7 chip are connected in series with capacitors C18 and C19, respectively, and the other ends of capacitors C18 and C19 are connected to pins 1 and 2 of the voice enhancement MIC3, respectively; the ordinary MIC2 and the bone conduction MIC1 form the main MIC;

[0062] Pins 11-13 of the U7 chip are connected in series with capacitors C24, C25, and C26, respectively. The other ends of capacitors C24, C25, and C26 are connected to the ENC_RP, ENC_RN, and DT_MIC terminals, respectively. The ENC_RN and DT_MIC terminals correspond to the voice enhancement audio signal output and the main MIC audio signal, respectively.

[0063] Pins 16 and 17 of the U7 chip are connected to the two pins of crystal oscillator X2, respectively; pin 23 of the U7 chip is connected in series with capacitor C27, and the other end of capacitor C27 is grounded; pin 24 of the U7 chip is connected to the VDD12 terminal; capacitors C45, C38, C29, and C28 are connected in parallel to pins 24-27 of the U7 chip, respectively.

[0064] Pins 29, 31, and 33 of the U7 chip are connected to the VDD33_AON, VDD18_AON, and VDD08 terminals, respectively. Capacitors C53, C51, C49, C48, C47, and C46 are connected in parallel to pins 28-31, 33, and 35 of the U7 chip, respectively. Pin 39 of the U7 chip is grounded, and pins 40-52 are connected in parallel to pin 39. Pin 69 of the U7 chip is grounded, and pins 63-68 are connected in parallel to pin 69. Pin 73 of the U7 chip is connected in series with inductors L2 and L4 and capacitor C56, with the other end of capacitor C56 grounded. Pin 74 of the U7 chip is connected to the VDD12 terminal. Pin 75 of the U7 chip is connected to inductors L6 and L4. A capacitor C57 is connected in series, with the other end of C57 grounded; pin 76 of the U7 chip is connected to the VDD08 terminal; pin 77 of the U7 chip is connected in series with inductors L8 and L9 and capacitor C58, with the other end of capacitor C58 grounded; pin 78 of the U7 chip is connected to the VDD19 terminal; pins 79-84 of the U7 chip are connected to the VDD18_AUX terminal, VDD18_FLASH_LDO terminal, VDD33 / 18_IO terminal, TXD terminal, and RXD terminal, respectively; pin 88 of the U7 chip is connected to the VDD33 / 18_IO terminal, one end of capacitor C62 is connected in parallel with pin 88 of the U7 chip, and the other end of capacitor C62 is grounded; pin 114 of the U7 chip is connected in series with resistor R8, with the other end of resistor R8 connected to the VDD18_AON terminal.

[0065] In this design, the chip programming port is as follows: pins 1, 2, and 4 of terminal CN2 are connected to the TXD, RXD, and VDD33 / 18_IO terminals respectively, and pin 3 of terminal CN2 is grounded.

[0066] Furthermore, the U7 chip is an AI voice processing chip.

[0067] Furthermore, the U5 and U6 chips are single-cell lithium battery charging management chips with the model number LN3657.

[0068] Furthermore, such as Figure 13-15 As shown, the LDO 3.3V power supply unit includes a power control circuit, which includes a U8 chip. Pin 1 of the U8 chip is connected to the V_BAT terminal. One end of capacitor C39 is connected in parallel with pin 1 of the U8 chip, and the other end of capacitor C39 is grounded. Pin 2 of the U8 chip is grounded. Pin 3 of the U8 chip is connected to the ENC_EN terminal. Pin 5 of the U8 chip is connected to the 3.3V power supply. One end of capacitor C21 is connected in parallel with pin 5 of the U8 chip, and the other end of capacitor C21 is grounded.

[0069] Furthermore, the U8 chip is a low dropout linear regulator chip with model number SGM2036-3.3.

[0070] Furthermore, such as Figure 16 As shown, the battery charging unit includes a battery charging circuit, which includes a U1 chip. Pins 1 and 3 of the U1 chip are grounded, pin 2 of the U1 chip is connected in series with resistor R3, and the other end of resistor R3 is grounded. Pin 4 of the U1 chip is connected to pin 2 of terminal CN1. One end of capacitors C1, C2, and C3 is connected in parallel with pin 4 of the U1 chip, and the other ends of capacitors C1, C2, and C3 are grounded.

[0071] Pin 3 of terminal CN1 is connected in series with core inductor RD6, and the other end of core inductor RD6 is connected to the DT_MIC terminal; pin 4 of terminal CN1 is connected in series with resistor R1, and the other end of resistor R1 is grounded; one end of varistor M6 is connected in parallel with pin 3 of terminal CN1, and the other end of varistor M6 is grounded; one end of varistor M4 is connected in parallel with pin 2 of CN1, and the other end of varistor M4 is grounded; one end of varistor M1 is connected in parallel with pin 3 of CN1, and the other end of varistor M1 is grounded; pin 8 of terminal CN1 is connected in series with core inductor RD7 and resistor R31, and the other end of resistor R31 is connected to the DT_SPK terminal; pin 1 of terminal CN1 is grounded, and pins 12-18 of terminal CN1 are connected in parallel with pin 1 of CN1; one end of resistors R30 and R32 is connected in parallel across resistor R31, and the other ends of resistors R30 and R32 are grounded.

[0072] Pin 5 of chip U1 is connected to the V_BAT terminal; pin 6 of chip U1 is connected in series with diode LED1 and resistor R14, and the other end of resistor R14 is connected in parallel with pin 4 of chip U1; pin 6 of chip U1 is connected in series with diode LED2, and the other end of diode LED2 is connected in parallel with diode LED1; as a charging indicator, diode LED1 is red and diode LED2 is green. Red indicates charging, and green indicates that the battery is fully charged.

[0073] Capacitors C4 and C5, and pin 1 of terminal CN5 are connected in parallel with pin 5 of chip U1. The other ends of capacitors C4 and C5, and pin 2 of terminal CN5 are grounded. Terminal CN5 is connected to the lithium battery.

[0074] The working principle of this utility model is explained in detail below:

[0075] like Figures 1-3 As shown, the helmet 1 of this design has a control box 2 and a switch box 3 on its left and right sides, respectively. A speaker is provided on the left side of the outer surface of the control box 2, a circuit board is provided on the left side inside the control box 2, a circuit board 22 is provided at the bottom inside the control box body 21 of the control box 2, a battery compartment is provided on the right side inside the control box body 21, a lithium battery 23 is provided in the battery compartment, a speaker 24 is provided on the left side of the outer side of the control box body 21, a wire hole 25 is provided in the middle of the outer side of the control box body 21 for easy wiring, and several heat dissipation holes 26 are provided on the right side of the outer side of the control box body 21.

[0076] The switch box 3 includes a switch box body 31. A type-C interface 36 is provided on one side of the switch box body 31. A volume down button 32 and a volume up button 33 are respectively installed on the left and right sides of the outer side of the switch box 3. A microphone 35 and a power button 34 are respectively provided on the upper and lower parts of the outer side of the switch box 3.

[0077] like Figure 5 The diagram shown is a block diagram illustrating the principle of this invention, which is described in detail below: Chip U2 is a Bluetooth audio SoC chip, model BT8892, used as a processor. Chips U5 and U6 control MIC1 and MIC2, respectively, which are then processed by chip U7. The processed sound is amplified by chip U4 and then transmitted to the listener's ear via the speaker's SPL and SPR. The MIC-OUT terminal of chip U7 outputs to a mobile phone or walkie-talkie. During a call, the user's mobile phone or walkie-talkie transmits audio information through chip U2, with SW2 acting as the microphone. Volume can be adjusted via SW3 and SW4. The descriptions of the various control components of this invention are as follows:

[0078] (1) MIC2: Standard microphone. Choose a high-performance omnidirectional microphone. This will allow it to be used normally in normal noise environments at cycling speeds below 50 km / h.

[0079] (2) MIC1: Bone conduction microphone. Select a bone conduction microphone, install it on the back of your head, and adjust the size and position of the headband to avoid wind pressure interference from the front of your face. This way, it can be used normally even in high-noise environments.

[0080] (3) U6 chip and U5 chip: electronic switch, which is used to select the output of MIC2 ordinary microphone or MIC1 bone conduction microphone according to the ambient noise level.

[0081] (4) The U2 chip is a processor, which is used to process logic control relationships, power switch control, control of ordinary microphone and bone conduction microphone selection switch, SPK sound effect processing of external audio devices, volume control and adjustment, and switch impact sound control and processing.

[0082] (5) U7 chip: AI voice processing chip, its function is to separate the voice with environmental noise through algorithms, filter out the noise signal, and output the remaining voice signal to the terminal device, such as the MIC input interface of a mobile phone or walkie-talkie.

[0083] (6) U4 chip: power amplifier. Its functions are: first, to amplify the voice sent out by oneself after processing by the U3AI voice processing chip, and then to drive the SPL / SPR speaker output, so that one can listen to one's own voice. Second, to amplify the voice signal received from the mobile phone or walkie-talkie and drive the speaker output.

[0084] (7) SPL / SPR: These are the left and right channel speaker outputs. These two speaker styles are not limited to in-ear type; they can also be over-ear type, helmet-embedded type, or bone conduction type vibration speaker.

[0085] (8) Power supply section: The battery V-BAT is charged through the TYPE-C socket CN1 and the charging chip U1. V-BAT provides voltage regulation output to the LDO regulator U8 to supply power to each unit chip.

[0086] The working principle of this utility model is explained in detail below:

[0087] (1) If the connection to a mobile phone or walkie-talkie is wired, first connect the control box connected to the helmet to the mobile phone or walkie-talkie via the TYPE-C interface on the control box using the audio cable with MIC and SPK. If the connection is via Bluetooth, the device will enter standby mode after successful pairing.

[0088] (2) Press the power button SW1 on the main control box to start the circuit working;

[0089] (3) By default, the MIC2 ordinary microphone is used when powered on. When riding at a speed less than 50 km / h, use the ordinary microphone to transmit the voice. When the speed is greater than 50 km / h, press and hold the SW2 switch to select the bone conduction microphone to transmit the voice. When speaking, the helmet headset speaker can hear your own voice to judge whether the transmitted voice is clear. Signal working path: When speaking, the voice signal of MIC1 or MIC2 is selected by the electronic switch to output the voice signal of MIC1 or MIC2 to pins 3 and 4 of the U7 voice processing chip. The noise is filtered out and attenuated. Then, the clear voice signal is sent to the connected walkie-talkie MIC-IN through the DT_MIC output (MIC-OUT) of pin 13 of U7 to transmit the voice to the walkie-talkie. At the same time, the voice signal of MIC1 or MIC2 is sent to the U4-ENC input through the DT_MIC output (MIC-OUT) of pins 7 and 13 for listening. After amplification, it is output to the SPL and SPR speakers to achieve the effect of listening to your own voice. If the bone conduction microphone is not loud enough or clear enough, you can adjust the clarity of the voice by adjusting the headband size adjustment device and the tightness of the bone conduction microphone fixed in the adjuster.

[0090] (4) Listening to ambient sounds: Since the speaker of this utility model is not limited to an open-back speaker, it may also be a binaural in-ear speaker. If the in-ear speaker blocks the ears, it will reduce or prevent the hearing of ambient sounds, such as car horns or shouts from other people, during cycling. In order to listen to the ambient sounds, a voice enhancement listening microphone is added. After receiving the ambient sound, the listening microphone MIC3 enters U7 through pins U7-5 and U7-6 to filter and attenuate the noise. Then, the clear signal is output from U7-11 and U7-12 and input to the power amplifier chip U4-ENC. After amplification, the signal is output to the SPL and SPR speakers to achieve the effect of listening to ambient sound signals.

[0091] (5) Speaker listening: You can hear sounds from your mobile phone or walkie-talkie, listen to your own voice, and listen to ambient sounds through the helmet headset speaker. The volume can be adjusted using the SW3 / SW4 volume + / volume - switches on the helmet control box.

[0092] The functional description of this utility model is as follows:

[0093] (1) The travel speed of this design is within 50 km / h, and a regular microphone is selected for communication. You can listen to the clarity of your own voice through the helmet headset speaker to judge the clarity of the voice sent out by the microphone, and then select to use a regular microphone or a bone conduction microphone.

[0094] (2) In this design, when the cycling speed is greater than 50 km / h, the bone conduction microphone is selected for communication. You can use the helmet headset speaker to listen to the clarity of your own voice to judge the clarity of the microphone's output and choose to use a regular microphone or a bone conduction microphone. Alternatively, you can always use the bone conduction microphone at all speeds throughout the entire journey.

[0095] (3) In this design, the voice that you send out when you speak must be heard by the helmet headset speaker.

[0096] (4) In this design, the sound of the outside environment can be detected during the cycling process.

[0097] The circuit design of this utility model does not limit the main processing chip to U2 (model BT8892), and chips with equivalent processing capabilities are all within the protection scope; the circuit design of this utility model does not limit the voice processing chip to U7 (model WQ7036A), and chips with equivalent processing capabilities are all within the protection scope; the circuit design of this utility model, the performance and functional modules, chips, and components are not limited to the above chips and components, and chips and components with the same performance and functions are all within the protection scope.

[0098] The above description is only a preferred embodiment of the present utility model. Therefore, all equivalent changes or modifications made in accordance with the features and principles described in the claims of the present utility model patent application are included in the scope of the present utility model patent application.

Claims

1. A control circuit for a microphone / receiver receiver on a cycling helmet, characterized in that: The system includes a circuit board installed in a control box on one side of the helmet. This circuit board is equipped with a main control processing unit, a power amplifier control unit, a main microphone noise reduction / voice enhancement control unit, an LDO 3.3V power supply unit, and a battery charging unit. The main control processing unit is connected to the main microphone noise reduction / voice enhancement control unit, the power amplifier control unit, the LDO 3.3V power supply unit, and the battery charging unit via wires. The main control processing unit includes a main control circuit, which includes a U2 chip. Pins 1 and 3 of the U2 chip are connected to the MUTE and ENC_EN terminals, respectively. Pin 2 of the U2 chip is connected to switch SW3, which is connected in series with resistor R6. The other end of resistor R6 is grounded, thus increasing the volume. Switch SW4 is connected in series with resistor R12 and then in parallel across switch SW3 and resistor R6, thus decreasing the volume. Pins 5 and 6 of the U2 chip are connected in series with capacitors C11 and C50, respectively. The other end is grounded; pin 7 of the U2 chip is connected in series with resistor R22, and the other end of resistor R22 is connected to the V_BAT terminal; capacitors C9 and C10 are connected in parallel with pin 7 of the U2 chip, and the other ends of capacitors C9 and C10 are grounded respectively; pin 8 of the U2 chip is connected in series with inductor L3 and capacitor C12, and the other end of capacitor C12 is grounded; pin 9 of the U2 chip is grounded; pin 10 of the U2 chip and capacitor C6 are connected in parallel between inductor L3 and pin 16 of the U2 chip; pin 15 of the U2 chip is connected in series with resistor R5, and the other end of resistor R5 is connected to the Bluetooth antenna ANT1. The following connections are made: pin 16 of the U2 chip is connected in series with capacitor C52, and the other end of capacitor C52 is grounded; switch SW1, used as a power button, is connected in series with pin 13 of the U2 chip, and the other end of switch SW1 is grounded; inductors L1 and L5 are connected in parallel across resistor R5, and the other ends of inductors L1 and L5 are grounded; pin 17 of the U2 chip is connected to one pin of crystal oscillator X1, and the other pin of crystal oscillator X1 is connected to pin 18 of the U2 chip; pin 20 of the U2 chip is connected to the PB3_AUX terminal; pin 21 of the U2 chip is connected to the MIC_CS terminal. The following connections are used for MIC selection output: Pin 22 of the U2 chip is connected in series with capacitor C15, and the other end of capacitor C5 is connected to the DT_SPK terminal for walkie-talkie audio signal input; Pin 23 of the U2 chip is connected in series with resistor R26 and diode LED3, and the other end of diode LED3 is grounded for power-on indication and power indicator; Pin 24 of the U2 chip is connected to switch SW2, and the other end of switch SW2 is grounded; Pins 1 and 2 of the CN7 terminal are connected to the V_BAT terminal and the PB3_AUX terminal respectively, and pin 3 of the common terminal CN7 is grounded; The power amplification control unit includes a power amplification control circuit, which includes a U4 chip. Pin 1 of the U4 chip is connected in series with resistor R7, and the other end of resistor R7 is connected to the V_BAT terminal. Pin 2 of the U4 chip is connected in series with capacitor C34, and the other end of capacitor C34 is connected in parallel with pin 4 of the U4 chip. Pin 3 of the U4 chip is grounded. Pin 5 of the U4 chip is connected in series with capacitor C36, and the other end of capacitor C36 is grounded. Pin 6 of the U4 chip is grounded. Pins 7 and 8 of the U4 chip are connected to the PINR+ and PINR- terminals, respectively. Pin 9 of the U4 chip is connected in series with capacitor C44, and the other end of capacitor C44 is grounded. Pins 10, 12, 14, and 15 of the U4 chip are connected to the SPKR, SPKL, PINL+, and PINL- terminals, respectively. Pin 11 of the U4 chip is connected in series with capacitor C11. The other end of capacitor C11 is grounded. Resistor R42 and capacitor C42 are connected in parallel between pins 12 and 14 of the U4 chip, respectively. Resistors R25 and R21 are connected in parallel on pin 16 of the U4 chip. Resistor R25 is connected to the MUTE terminal, and the other end of resistor R21 is grounded. Capacitors C33 and C35 are connected in series. Pins 1 and 9 of the U4 chip are connected in parallel across the two ends of capacitors C33 and C35. Resistor R39 is connected in parallel on pin 15 of the U4 chip. The other end of resistor R39 is grounded. Capacitor C41 is connected in parallel across the two ends of resistor R39. One end of resistor R9 is connected in parallel on pin 7 of the U4 chip, and the other end of resistor R9 is grounded. Capacitor C37 is connected in parallel between resistor R19 and pin 7 of the U4 chip. One end of resistor R20 is connected in parallel on pin 8 of the U4 chip, and the other end of resistor R20 is connected in parallel on pin 10 of the U4 chip. Capacitor C40 is connected in parallel between pins 8 and 10 of the U4 chip. The main microphone noise reduction / voice enhancement control unit includes a main microphone noise reduction / voice enhancement control circuit. This circuit includes a U7 chip, with pin 3 of the U7 chip connected in series with capacitor C7. Capacitor C7 is connected to pin 4 of the U5 chip, pin 5 of the U5 chip is connected to a 3.3V power supply, pin 6 of the U5 chip is connected to the MIC_CS terminal, and pin 2 of the U5 chip is grounded. Pin 4 of the U7 chip is connected in series with capacitor C14, capacitor C14 is connected to pin 4 of the U6 chip, and pin 5 of the U6 chip is connected to a 3.3V power supply.On the 3V power supply side, pin 6 of chip U6 is connected to the MIC_CS terminal, and pin 2 of chip U6 is grounded; pins 3 of chips U5 and U6 are connected to pins 1 and 2 of bone conduction MIC1, respectively; pins 1 of chips U5 and U6 are connected to pins 1 and 2 of ordinary MIC2, respectively; pins 5 and 6 of chip U7 are connected in series with capacitors C18 and C19, respectively, and the other ends of capacitors C18 and C19 are connected to pins 1 and 2 of voice enhancement MIC3, respectively; pins 11-13 of chip U7 are connected in series with capacitors C24, C25, and C26, respectively, and the other ends of capacitors C24, C25, and C26 are connected to ENC, respectively. _RP terminal, ENC_RN terminal, DT_MIC terminal; pins 16 and 17 of the U7 chip are connected to the two pins of crystal oscillator X2 respectively; pin 23 of the U7 chip is connected in series with capacitor C27, and the other end of capacitor C27 is grounded; pin 24 of the U7 chip is connected to the VDD12 terminal; capacitors C45, C38, C29, and C28 are connected in parallel to pins 24-27 of the U7 chip respectively; pins 29, 31, and 33 of the U7 chip are connected to the VDD33_AON terminal, VDD18_AON terminal, and VDD08 terminal respectively; capacitors C53, C51, C49, C48, and C47 are connected to the VDD12 terminal; Capacitor C46 is connected in parallel to pins 28-31, 33, and 35 of the U7 chip; pin 39 of the U7 chip is grounded, and pins 40-52 of the U7 chip are connected in parallel to pin 39 of the U7 chip; pin 69 of the U7 chip is grounded, and pins 63-68 of the U7 chip are connected in parallel to pin 69 of the U7 chip; pin 73 of the U7 chip is connected in series with inductor L2, inductor L4, and capacitor C56, with the other end of capacitor C56 grounded; pin 74 of the U7 chip is connected to the VDD12 terminal; pin 75 of the U7 chip is connected in series with inductor L6, inductor L6, and capacitor C57, with the other end of capacitor C57 grounded; pin 76 of the U7 chip is connected to the VDD08 terminal; U7 Pin 77 of the chip is connected in series with inductors L8 and L9, and capacitor C58, with the other end of capacitor C58 grounded; pin 78 of the U7 chip is connected to the VDD19 terminal; pins 79-84 of the U7 chip are connected to the VDD18_AUX, VDD18_FLASH_LDO, VDD33 / 18_IO, TXD, and RXD terminals respectively; pin 88 of the U7 chip is connected to the VDD33 / 18_IO terminal, one end of capacitor C62 is connected in parallel with pin 88 of the U7 chip, and the other end of capacitor C62 is grounded; pin 114 of the U7 chip is connected in series with resistor R8, and the other end of resistor R8 is connected to the VDD18_AON terminal. The LDO 3.3V power supply unit includes a power control circuit, which includes a U8 chip. Pin 1 of the U8 chip is connected to the V_BAT terminal. One end of capacitor C39 is connected in parallel with pin 1 of the U8 chip, and the other end of capacitor C39 is grounded. Pin 2 of the U8 chip is grounded. Pin 3 of the U8 chip is connected to the ENC_EN terminal. Pin 5 of the U8 chip is connected to the 3.3V power supply. One end of capacitor C21 is connected in parallel with pin 5 of the U8 chip, and the other end of capacitor C21 is grounded. The battery charging unit includes a battery charging circuit, which includes a U1 chip. Pins 1 and 3 of the U1 chip are grounded. Pin 2 of the U1 chip is connected in series with resistor R3, and the other end of resistor R3 is grounded. Pin 4 of the U1 chip is connected to pin 2 of terminal CN1. One end of capacitors C1, C2, and C3 is connected in parallel with pin 4 of the U1 chip, and the other ends of capacitors C1, C2, and C3 are grounded. Pin 3 of terminal CN1 is connected in series with magnetic core inductor RD6, and the other end of magnetic core inductor RD6 is connected to the DT_MIC terminal. Pin 4 of terminal CN1 is connected in series with resistor R1, and the other end of resistor R1 is grounded. One end of varistor M6 is connected in parallel with pin 3 of terminal CN1, and the other end of varistor M6 is grounded. One end of varistor M4 is connected in parallel with pin 2 of CN1, and the other end of varistor M4 is grounded. One end of varistor M1 is connected to pin 3 of CN1. The varistor M1 is connected in parallel, with the other end grounded. Pin 8 of terminal CN1 is connected in series with the magnetic core inductor RD7 and resistor R31, and the other end of resistor R31 is connected to the DT_SPK terminal. Pin 1 of terminal CN1 is grounded, and pins 12-18 of terminal CN1 are connected in parallel with pin 1 of CN1. One end of resistors R30 and R32 is connected in parallel across resistor R31, and the other ends of resistors R30 and R32 are grounded. Pin 5 of chip U1 is connected to the V_BAT terminal. Pin 6 of chip U1 is connected in series with diode LED1 and resistor R14, and the other end of resistor R14 is connected in parallel with pin 4 of chip U1. Pin 6 of chip U1 is connected in series with diode LED2, and the other end of diode LED2 is connected in parallel with diode LED1. Capacitors C4 and C5, and pin 1 of terminal CN5 are connected in parallel with pin 5 of chip U1, and the other ends of capacitors C4 and C5, and pin 2 of terminal CN5 are grounded.

2. The control circuit for a microphone on a cycling helmet according to claim 1, characterized in that: The U2 chip is a Bluetooth audio SoC chip with the model number BT8892.

3. The control circuit for a microphone on a cycling helmet according to claim 1, characterized in that: The U4 chip is a single-channel, Class AB audio power amplifier chip with model number HT97180.

4. The control circuit for a microphone on a cycling helmet according to claim 1, characterized in that: The U7 chip is an AI voice processing chip.

5. The control circuit for a microphone on a cycling helmet according to claim 1, characterized in that: The U5 and U6 chips are single-cell lithium battery charging management chips with model number LN3657.

6. The control circuit for a microphone on a cycling helmet according to claim 1, characterized in that: The U8 chip is a low dropout linear regulator chip with model number SGM2036-3.3.

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