A PD charger circuit with voice playback capability

Abstract

This utility model discloses a PD charger circuit with voice playback capability, including a main control MCU, a preamplifier circuit electrically connected to the main control MCU, and a voice playback circuit. The preamplifier circuit includes a mains surge protection circuit, a full-wave rectifier circuit, an EMI filter electromagnetic interference suppression circuit, an absorption circuit and a high-frequency transformer conversion circuit, an integrated synchronous control circuit, an integrated MOSFET driver and PWM control circuit, and an optocoupler feedback loop circuit. The output terminal of the mains surge protection circuit is connected to the input terminal of the full-wave rectifier circuit, and the input terminal of the EMI filter electromagnetic interference suppression circuit is connected to the full-wave rectifier circuit. Furthermore, the output terminal of the EMI filter electromagnetic interference suppression circuit and the absorption circuit are connected to the high-frequency transformer conversion circuit. The integrated synchronous control circuit is connected to both the high-frequency transformer conversion circuit and the main control MCU. The PD charger circuit of this utility model has a reasonable design, comprehensive functionality, and voice playback capability, allowing users to know the charging level in real time and providing a good user experience.

Description

Technical Field

[0001] This utility model belongs to the technical field of charger circuits, specifically relating to a PD charger circuit with voice playback capability. Background Technology

[0002] A PD charger refers to a power adapter with the PD protocol. With the rapid development of the social economy and the advancement of technology in the PD charger industry, PD chargers are increasingly appearing in consumers' hands. Compared to ordinary chargers, PD chargers have two main characteristics: firstly, they achieve high efficiency in power management; and secondly, they can flexibly and adaptively adjust according to the power transmission protocol. However, existing PD chargers are functionally limited, only providing charging functionality and lacking voice playback capabilities. Users cannot monitor the charging level in real time, resulting in a poor user experience. Utility Model Content

[0003] The purpose of this utility model is to address the above-mentioned problems by providing a PD charger circuit with voice playback capability. This PD charger circuit has a reasonable design, full functionality, and voice playback function, allowing users to know the charging level in real time and providing a good user experience, thus solving the problems mentioned in the above technical background.

[0004] This utility model is achieved through the following technical solution: a PD charger circuit with voice playback capability, including a main control MCU and a pre-amplifier circuit and a voice playback circuit electrically connected to the main control MCU. The pre-amplifier circuit includes a mains surge protection circuit, a full-wave rectifier circuit, an EMI filter electromagnetic interference suppression circuit, an absorption circuit and a high-frequency transformer conversion circuit, an integrated synchronous control circuit, an integrated MOSFET driver and PWM control circuit, and an optocoupler feedback loop circuit. The output terminal of the mains surge protection circuit is connected to the input terminal of the full-wave rectifier circuit. The input terminal of the EMI filter electromagnetic interference suppression circuit is connected to the full-wave rectifier circuit, and the output terminal of the EMI filter electromagnetic interference suppression circuit is connected to the absorption circuit and the high-frequency transformer conversion circuit. The integrated synchronous control circuit is connected to the high-frequency transformer conversion circuit and the main control MCU. The integrated MOSFET driver and PWM control circuit is connected to the high-frequency transformer conversion circuit and the optocoupler feedback loop circuit. The optocoupler feedback loop circuit is also electrically connected to the main control MCU. The voice playback circuit consists of a voice chip U6, a protocol chip U7, resistors R105, R106, R107, R108, R109, R110, R111, and R112, capacitors C106, C107, C108, C109, C110, C111, C112, C113, and EC4, and a buzzer LS1. Pin 1 of the voice chip U6... Pin 1 is connected to resistor R107; pin 2 is connected to the main control MCU and resistor R110; pin 3 is connected to the main control MCU and resistor R111; pin 4 is connected to resistors R105 and R106; pin 7 is grounded; and pin 8 is connected to the main control MCU and resistor R121. Capacitors C106 and EC4 are connected in parallel, with one end of each capacitor grounded and the other end connected to resistor R108 and the voice chip, respectively. Pins 5 and 6 of U6 are connected; the end of resistor R108 away from capacitors C106 and EC4 is connected to resistor R107, capacitor C109, and pin 1 of protocol chip U7, respectively; one end of capacitor C110 is grounded, and the other end is connected to pins 2 and 3 of protocol chip U7, respectively; resistor R109 and capacitor C111 are connected in parallel, and one end of resistor R109 and capacitor C111 is connected to pin 4 of protocol chip U7 and capacitor C107, respectively. One end of capacitor C107 is connected to capacitor R108, and the other end is connected to pin 5 of protocol chip U7 and buzzer LS1 respectively; the end of capacitor C107 away from resistor R109 and capacitor C111 is connected to resistor R106; capacitors C112 and C113 are connected in parallel, and one end of capacitors C112 and C113 is grounded, while the other end is connected to pin 6 of protocol chip U7; pin 7 of protocol chip U7 is grounded, and pin 8 is connected to buzzer LS1.

[0005] Furthermore, the mains surge protection circuit consists of a fuse F1 and a thermistor NTC1, wherein one end of the fuse F1 is connected to the power supply terminal and the other end is connected to the thermistor NTC1, and the end of the thermistor NTC1 away from the fuse F1 is connected to the full-wave rectifier circuit.

[0006] Furthermore, the full-wave rectifier circuit includes a rectifier bridge chip BD1, which is an ABS210. Pins 1 and 2 of the rectifier bridge chip BD1 are connected to the EMI filter electromagnetic interference suppression circuit, pin 3 is connected to the power supply terminal, and pin 4 is connected to the thermistor NTC1.

[0007] Furthermore, the EMI filtering electromagnetic interference suppression circuit includes capacitor EC1, capacitor EC2 and inductor L1, wherein one end of capacitor EC1 is connected to pin 1 of rectifier bridge chip BD1, capacitor EC2 and high-frequency transformer conversion circuit respectively, and the other end is connected to pin 2 of rectifier bridge chip BD1 and inductor L1 respectively, and the end of capacitor EC2 away from capacitor EC1 is connected to inductor L1.

[0008] Furthermore, the high-frequency transformer conversion circuit includes resistors R2, R3, R4, R5, R8, and R18, capacitors C1, C2, C6, C7, and CY1, diodes D1 and D2, and a transformer T1. The secondary coil of transformer T1 is connected to an integrated synchronous control circuit, and lead 1 of the first primary coil of transformer T1 is connected to resistor R8, lead 2 is connected to capacitors C7 and CY1 respectively, and lead 6 of the second primary coil of transformer T1 is connected to diode D1 and the integrated MOSFET drive and PWM control respectively. The circuit is connected as follows: lead 5 is electrically connected to capacitors C7 and C1, resistors R2 and R3, and capacitors EC1 and EC2 of the EMI filter electromagnetic interference suppression circuit. Resistors R2 and R4 are connected in series, and the end of resistor R4 furthest from resistor R2 is connected to resistor R18, capacitor C2, and diode D2. Resistors R3 and R5 are connected in series, and the end of resistor R5 furthest from resistor R3 is connected to diode D1. Capacitor C1 is connected in parallel with resistor R3. Capacitor C6 is connected in series with resistor R18, and the end of capacitor C6 furthest from resistor R18 is connected to diode D2 and resistor R8.

[0009] Furthermore, the integrated synchronization control circuit includes a synchronization control chip U1, resistors R7 and R17, capacitors C3, C4, and EC3. Pins 1 and 2 of the synchronization control chip U1 are grounded, pin 4 is connected to the main control MCU and lead 7 of the secondary coil of transformer T1, respectively. Pins 5, 6, 7, and 8 of the synchronization control chip U1 are connected to resistor R7 and lead 8 of the secondary coil of transformer T1, respectively. Capacitor C4 is connected in series with resistor R7, and the end of capacitor C4 furthest from resistor R7 is grounded. One end of capacitor C3 is grounded, and the other end is connected to pin 3 of the synchronization control chip U1. Resistor R17 and capacitor EC3 are connected in parallel, with one end of resistor R17 and capacitor EC3 grounded, and the other ends connected to pin 4 of the synchronization control chip U1 and lead 7 of the secondary coil of transformer T1, respectively.

[0010] Furthermore, the integrated MOS transistor drive and PWM control circuit consists of a PWM control chip U2, resistors R11 and R12, capacitor C5, and capacitor C11. Resistors R11 and R12 are connected in parallel, with one end of each resistor grounded and the other end connected to capacitor C5 and pin 4 of the PWM control chip U2, respectively. One end of capacitor C11 is grounded and the other end is connected to pin 2 of the PWM control chip U2. The end of capacitor C5 furthest from resistors R11 and R12 is connected to the high-frequency transformer conversion circuit and pins 5, 6, 7, and 8 of the PWM control chip U2, respectively. Pin 3 of the PWM control chip U2 is connected to the optocoupler feedback loop circuit.

[0011] Furthermore, the optocoupler feedback loop circuit is composed of a Zener diode ZD1, capacitors C9 and C10, resistors R14, R15, and R16, and an optocoupler U3. Zener diode ZD1 and capacitor C10 are connected in parallel, with one end of both Zener diode ZD1 and capacitor C10 grounded and the other end connected to optocoupler U3. Capacitor C9 and resistor R14 are connected in parallel, with one end of capacitor C9 and resistor R14 connected to the main control MCU and the other end connected to optocoupler U3 and resistor R15, respectively. One end of resistor R16 is connected to resistor R15, and the other end is connected to the main control MCU.

[0012] This utility model employs a main control MCU and a preamplifier circuit and a voice playback circuit electrically connected to the main control MCU. The preamplifier circuit includes a mains surge protection circuit, a full-wave rectification circuit, an EMI filter electromagnetic interference suppression circuit, an absorption circuit and a high-frequency transformer conversion circuit, an integrated synchronous control circuit, an integrated MOSFET drive and PWM control circuit, and an optocoupler feedback loop circuit. The overall structure is simple and reasonably designed. By designing the voice playback circuit, it is fully functional and has a voice playback function, allowing users to know the charging level of the PD charger in real time. It also provides a good user experience and is worthy of widespread promotion and application. Attached Figure Description

[0013] Figure 1 This is a block diagram illustrating the principle of this utility model; Figure 2 This is the circuit schematic diagram of the main control MCU and its peripheral circuits of this utility model; Figure 3 This is the circuit schematic diagram of the preamplifier circuit of this utility model; Figure 4 This is the circuit diagram of the voice playback circuit of this utility model.

[0014] The attached figures are labeled as follows: 1. Main control MCU; 2. Preamplifier circuit; 21. Mains surge protection circuit; 22. Full-wave rectifier circuit; 23. EMI filter electromagnetic interference suppression circuit; 24. Absorption circuit and high-frequency transformer conversion circuit; 25. Integrated synchronous control circuit; 26. Integrated MOSFET drive and PWM control circuit; 27. Optocoupler feedback loop circuit; 3. Voice playback circuit. Detailed Implementation

[0015] The present invention will be further illustrated below with reference to specific examples and accompanying drawings.

[0016] like Figures 1-2 As shown, this utility model describes a PD charger circuit with voice playback capability, including a main control MCU1, a preamplifier circuit 2 electrically connected to the main control MCU1, and a voice playback circuit 3. The preamplifier circuit 2 includes a mains surge protection circuit 21, a full-wave rectifier circuit 22, an EMI filter electromagnetic interference suppression circuit 23, an absorption circuit and high-frequency transformer conversion circuit 24, an integrated synchronous control circuit 25, an integrated MOSFET drive and PWM control circuit 26, and an optocoupler feedback loop circuit 27. The output terminal of the mains surge protection circuit 21 is connected to the full-wave rectifier circuit 23. The input terminal of the EMI filter electromagnetic anti-interference circuit 23 is connected to the full-wave rectifier circuit 22, and the output terminal of the EMI filter electromagnetic anti-interference circuit 23 is connected to the absorption circuit and the high-frequency transformer conversion circuit 24. The integrated synchronous control circuit 25 is connected to the high-frequency transformer conversion circuit 24 and the main control MCU1 respectively. The integrated MOS tube drive and PWM control circuit 26 is connected to the high-frequency transformer conversion circuit 24 and the optocoupler feedback loop circuit 27 respectively. The optocoupler feedback loop circuit 27 is also electrically connected to the main control MCU1.

[0017] Please see Figure 2 , Figure 2 This is a circuit diagram of the main control MCU and its peripheral circuits of this utility model. U4 in the diagram is the main control MCU1, and its model number is IP2726.

[0018] Please see Figure 3 The surge protection circuit 21 in the figure consists of a fuse F1 and a thermistor NTC1. One end of the fuse F1 is connected to the power supply terminal, and the other end is connected to the thermistor NTC1. The end of the thermistor NTC1 away from the fuse F1 is connected to the full-wave rectifier circuit 22. In this embodiment, the input voltage of the power supply terminal is 100-240V.

[0019] Specifically, the full-wave rectifier circuit 22 includes a rectifier bridge chip BD1, which is an ABS210. Pins 1 and 2 of the rectifier bridge chip BD1 are connected to the EMI filter electromagnetic interference suppression circuit 23, pin 3 is connected to the power supply terminal, and pin 4 is connected to the thermistor NTC1.

[0020] Specifically, the EMI filtering electromagnetic interference suppression circuit 23 includes capacitor EC1, capacitor EC2 and inductor L1. One end of capacitor EC1 is connected to pin 1 of rectifier bridge chip BD1, capacitor EC2 and high-frequency transformer conversion circuit 24 respectively, and the other end is connected to pin 2 of rectifier bridge chip BD1 and inductor L1 respectively. The end of capacitor EC2 away from capacitor EC1 is connected to inductor L1.

[0021] Specifically, the high-frequency transformer conversion circuit 24 includes resistors R2, R3, R4, R5, R8, and R18, capacitors C1, C2, C6, C7, and CY1, diodes D1 and D2, and a transformer T1. The secondary coil of the transformer T1 is connected to the integrated synchronous control circuit 25, and lead 1 of the first primary coil of the transformer T1 is connected to resistor R8, lead 2 is connected to capacitors C7 and CY1 respectively, and lead 6 of the second primary coil of the transformer T1 is connected to diode D1 and the integrated MOSFET drive and PWM control respectively. Circuit 26 is connected with lead 5 electrically connected to capacitors C7 and C1, resistors R2 and R3, and capacitors EC1 and EC2 of EMI filter electromagnetic interference suppression circuit 23. Resistors R2 and R4 are connected in series, and the end of resistor R4 away from resistor R2 is connected to resistor R18, capacitor C2, and diode D2. Resistors R3 and R5 are connected in series, and the end of resistor R5 away from resistor R3 is connected to diode D1. Capacitor C1 is connected in parallel with resistor R3. Capacitor C6 is connected in series with resistor R18, and the end of capacitor C6 away from resistor R18 is connected to diode D2 and resistor R8.

[0022] Specifically, the integrated synchronization control circuit 25 includes a synchronization control chip U1, resistors R7 and R17, capacitors C3, C4, and EC3. Pins 1 and 2 of the synchronization control chip U1 are grounded, pin 4 is connected to the main control MCU1 and lead 7 of the secondary coil of transformer T1, pins 5, 6, 7, and 8 of the synchronization control chip U1 are connected to resistor R7 and lead 8 of the secondary coil of transformer T1, respectively. Capacitor C4 is connected in series with resistor R7, and the end of capacitor C4 furthest from resistor R7 is grounded. One end of capacitor C3 is grounded, and the other end is connected to pin 3 of the synchronization control chip U1. Resistor R17 and capacitor EC3 are connected in parallel, and one end of resistor R17 and capacitor EC3 is grounded, and the other end is connected to pin 4 of the synchronization control chip U1 and lead 7 of the secondary coil of transformer T1, respectively. In this embodiment, the synchronization control chip U1 is model CX7538B.

[0023] Specifically, the integrated MOSFET driver and PWM control circuit 26 consists of a PWM control chip U2, resistors R11 and R12, capacitor C5, and capacitor C11. Resistors R11 and R12 are connected in parallel, with one end of each resistor grounded and the other end connected to capacitor C5 and pin 4 of the PWM control chip U2, respectively. One end of capacitor C11 is grounded and the other end is connected to pin 2 of the PWM control chip U2. The end of capacitor C5 furthest from resistors R11 and R12 is connected to the high-frequency transformer conversion circuit 24 and pins 5, 6, 7, and 8 of the PWM control chip U2, respectively. Pin 3 of the PWM control chip U2 is connected to the optocoupler feedback loop circuit 27. In this embodiment, the PWM control chip U2 is model CX7527.

[0024] Specifically, the optocoupler feedback loop circuit 27 consists of a Zener diode ZD1, capacitors C9 and C10, resistors R14, R15, and R16, and an optocoupler U3. Zener diode ZD1 and capacitor C10 are connected in parallel, with one end of both connected to ground and the other end connected to optocoupler U3. Capacitor C9 and resistor R14 are connected in parallel, with one end of both connected to the main control MCU1 and the other end connected to optocoupler U3 and resistor R15, respectively. One end of resistor R16 is connected to resistor R15, and the other end is connected to the main control MCU1. In this embodiment, the optocoupler U3 is model TLP181.

[0025] Please see Figure 4The voice playback circuit 3 in the diagram consists of a voice chip U6, a protocol chip U7, resistors R105, R106, R107, R108, R109, R110, R111, and R112, capacitors C106, C107, C108, C109, C110, C111, C112, C113, and EC4, and a buzzer LS1. Pin 1 of the voice chip U6 is connected to resistor R107. Pin 2 is connected to the main control MCU1 and resistor R110, pin 3 is connected to the main control MCU1 and resistor R111, pin 4 is connected to resistors R105 and R106, pin 7 is grounded, and pin 8 is connected to the main control MCU1 and resistor R121. Capacitors C106 and EC4 are connected in parallel, with one end grounded and the other end connected to resistor R108 and pins 5 and 6 of the voice chip U6, respectively. The ends of capacitors C106 and EC4 furthest away are connected to resistor R107, capacitor C109, and pin 1 of protocol chip U7, respectively. One end of capacitor C110 is grounded, and the other end is connected to pins 2 and 3 of protocol chip U7, respectively. Resistor R109 and capacitor C111 are connected in parallel, with one end of resistor R109 and capacitor C111 connected to pin 4 of protocol chip U7, capacitor C107, and capacitor C108, respectively, and the other end connected to pin 5 of protocol chip U7 and... The buzzer LS1 is connected; one end of capacitor C107 away from resistor R109 and capacitor C111 is connected to resistor R106; capacitors C112 and C113 are connected in parallel, with one end of capacitors C112 and C113 grounded and the other end connected to pin 6 of protocol chip U7; pin 7 of protocol chip U7 is grounded, and pin 8 is connected to buzzer LS1. In this embodiment, the voice chip U6 is model NV040C-Q, and the protocol chip U7 is model 8002.

[0026] Please refer to it again. Figures 1 to 4In this utility model, the PD charger circuit is connected to 100-240V AC mains power during operation. The AC mains surge protection circuit 21 protects the device from voltage surges. The full-wave rectifier circuit 22 converts AC power to DC power. The EMI filter electromagnetic interference suppression circuit 23 smooths the waveform and filters out noise. The absorption circuit and high-frequency transformer conversion circuit 24 achieve isolation and voltage conversion. The integrated synchronous control circuit 25 improves conversion efficiency and reduces losses. The integrated MOS transistor drive and PWM control circuit 26 provides efficient switching control. The optocoupler feedback loop circuit 27 stabilizes the current and voltage output. The main control MCU1 has a built-in 431 voltage regulation protocol chip that performs PD protocol handshake with the PD charger to negotiate the output power and modulate the power supply circuit. The voice playback circuit 3 plays prompts for the PD charger's charging status and faults, and supports the device's power request through the TYPE-C or USB-D port.

[0027] The above embodiments are merely preferred embodiments of the present utility model and are only used to explain the present utility model, not to limit the present utility model. Any changes, substitutions, combinations, simplifications, modifications, etc., made by those skilled in the art without departing from the spirit and principle of the present utility model shall be considered equivalent substitutions and shall be included within the protection scope of the present utility model.

Claims

1. A PD charger circuit with voice playback capability, characterized in that: It includes a main control MCU (1) and a preamplifier circuit (2) and a voice playback circuit (3) electrically connected to the main control MCU (1). The preamplifier circuit (2) includes a mains surge protection circuit (21), a full-wave rectifier circuit (22), an EMI filter electromagnetic interference suppression circuit (23), an absorption circuit and a high-frequency transformer conversion circuit (24), an integrated synchronous control circuit (25), an integrated MOS transistor drive and PWM control circuit (26), and an optocoupler feedback loop circuit (27). The output terminal of the mains surge protection circuit (21) is connected to the input terminal of the full-wave rectifier circuit (22). The input terminal of the I-filter electromagnetic anti-interference circuit (23) is connected to the full-wave rectifier circuit (22), and the output terminal of the EMI filter electromagnetic anti-interference circuit (23) and the absorption circuit are connected to the high-frequency transformer conversion circuit (24). The integrated synchronous control circuit (25) is connected to the high-frequency transformer conversion circuit (24) and the main control MCU (1) respectively. The integrated MOS tube drive and PWM control circuit (26) is connected to the high-frequency transformer conversion circuit (24) and the optocoupler feedback loop circuit (27) respectively. The optocoupler feedback loop circuit (27) is also electrically connected to the main control MCU (1). The voice playback circuit (3) consists of a voice chip U6, a protocol chip U7, resistors R105, R106, R107, R108, R109, R110, R111, and R112, capacitors C106, C107, C108, C109, C110, C111, C112, C113, and EC4, and a buzzer LS1. The voice chip U6 has pin 1... Pin 1 is connected to resistor R107; pin 2 is connected to the main control MCU (1) and resistor R110; pin 3 is connected to the main control MCU (1) and resistor R111; pin 4 is connected to resistors R105 and R106; pin 7 is grounded; and pin 8 is connected to the main control MCU (1) and resistor R121. Capacitors C106 and EC4 are connected in parallel, with one end of C106 and EC4 grounded and the other end connected to resistor R107.

8. Connect resistor R108 to pins 5 and 6 of voice chip U6; connect the end of resistor R108 away from capacitors C106 and EC4 to resistor R107, capacitor C109, and pin 1 of protocol chip U7, respectively; connect one end of capacitor C110 to ground and the other end to pins 2 and 3 of protocol chip U7, respectively; connect resistor R109 and capacitor C111 in parallel, with one end of resistor R109 and capacitor C111 connected to pin 4 of protocol chip U7 and pin 1 of capacitor C107, respectively. 107 is connected to capacitor C108, and the other end is connected to pin 5 of protocol chip U7 and buzzer LS1 respectively; the end of capacitor C107 away from resistor R109 and capacitor C111 is connected to resistor R106; capacitors C112 and C113 are connected in parallel, and one end of capacitors C112 and C113 is grounded, and the other end is connected to pin 6 of protocol chip U7; pin 7 of protocol chip U7 is grounded, and pin 8 is connected to buzzer LS1.

2. The PD charger circuit with voice playback capability according to claim 1, characterized in that: The mains surge protection circuit (21) consists of a fuse F1 and a thermistor NTC1. One end of the fuse F1 is connected to the power supply terminal, and the other end is connected to the thermistor NTC1. The end of the thermistor NTC1 away from the fuse F1 is connected to the full-wave rectifier circuit (22).

3. The PD charger circuit with voice playback capability according to claim 1, characterized in that: The full-wave rectifier circuit (22) includes a rectifier bridge chip BD1, the model of which is ABS210. Pins 1 and 2 of the rectifier bridge chip BD1 are connected to the EMI filter electromagnetic anti-interference circuit (23) respectively, pin 3 is connected to the power supply terminal, and pin 4 is connected to the thermistor NTC1.

4. The PD charger circuit with voice playback capability according to claim 1, characterized in that: The EMI filtering electromagnetic anti-interference circuit (23) includes capacitor EC1, capacitor EC2 and inductor L1. One end of capacitor EC1 is connected to pin 1 of rectifier bridge chip BD1, capacitor EC2 and high frequency transformer conversion circuit (24) respectively, and the other end is connected to pin 2 of rectifier bridge chip BD1 and inductor L1 respectively. The end of capacitor EC2 away from capacitor EC1 is connected to inductor L1.

5. The PD charger circuit with voice playback capability according to claim 1, characterized in that: The high-frequency transformer conversion circuit (24) includes resistors R2, R3, R4, R5, R8, and R18, capacitors C1, C2, C6, C7, and CY1, diodes D1 and D2, and transformer T1. The secondary coil of transformer T1 is connected to the integrated synchronous control circuit (25), and lead 1 of the first primary coil of transformer T1 is connected to resistor R8, lead 2 is connected to capacitors C7 and CY1 respectively, and lead 6 of the second primary coil of transformer T1 is connected to diode D1 and the integrated MOS transistor drive and PWM control circuit respectively. (26) Connect the 5 lead to capacitors C7, C1, R2, R3 and EC1 and EC2 of the EMI filter electromagnetic interference circuit (23), respectively. R2 and R4 are connected in series, and the end of R4 away from R2 is connected to R18, C2 and D2 respectively. R3 and R5 are connected in series, and the end of R5 away from R3 is connected to D1. C1 and R3 are connected in parallel. C6 and R18 are connected in series, and the end of C6 away from R18 is connected to D2 and R8 respectively.

6. The PD charger circuit with voice playback capability according to claim 1, characterized in that: The integrated synchronous control circuit (25) includes a synchronous control chip U1, resistors R7 and R17, capacitors C3, C4, and EC3. Pins 1 and 2 of the synchronous control chip U1 are grounded, and pin 4 is connected to the main control MCU (1) and the 7th lead of the secondary coil of transformer T1, respectively. Pins 5, 6, 7, and 8 of the synchronous control chip U1 are connected to resistor R7 and the 8th lead of the secondary coil of transformer T1, respectively. Capacitor C4 is connected in series with resistor R7, and the end of capacitor C4 away from resistor R7 is grounded. One end of capacitor C3 is grounded, and the other end is connected to pin 3 of the synchronous control chip U1. Resistor R17 and capacitor EC3 are connected in parallel, and one end of resistor R17 and capacitor EC3 is grounded, and the other end is connected to pin 4 of the synchronous control chip U1 and the 7th lead of the secondary coil of transformer T1, respectively.

7. The PD charger circuit with voice playback capability according to claim 1, characterized in that: The integrated MOS transistor drive and PWM control circuit (26) consists of a PWM control chip U2, resistors R11 and R12, capacitor C5 and capacitor C11. Resistors R11 and R12 are connected in parallel, with one end of each resistor grounded and the other end connected to capacitor C5 and pin 4 of the PWM control chip U2, respectively. One end of capacitor C11 is grounded and the other end is connected to pin 2 of the PWM control chip U2. The end of capacitor C5 away from resistors R11 and R12 is connected to the high-frequency transformer conversion circuit (24) and pins 5, 6, 7, and 8 of the PWM control chip U2, respectively. Pin 3 of the PWM control chip U2 is connected to the optocoupler feedback loop circuit (27).

8. The PD charger circuit with voice playback capability according to claim 1, characterized in that: The optocoupler feedback loop circuit (27) consists of a Zener diode ZD1, a capacitor C9, a capacitor C10, a resistor R14, a resistor R15, a resistor R16 and an optocoupler U3. Zener diode ZD1 and capacitor C10 are connected in parallel, and one end of Zener diode ZD1 and capacitor C10 is grounded, while the other end is connected to optocoupler U3. Capacitor C9 and resistor R14 are connected in parallel, and one end of capacitor C9 and resistor R14 is connected to the main control MCU (1), while the other end is connected to optocoupler U3 and resistor R15 respectively. One end of resistor R16 is connected to resistor R15, and the other end is connected to the main control MCU (1).

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