Power adapter to prevent chip overheating

Abstract

The utility model relates to a power adapter for preventing chip overheating, comprising an AC input terminal, an input rectifier filter circuit, a transformer TR101, a control circuit, an output feedback circuit and an output rectifier filter circuit; the output rectifier circuit comprises a rectifier chip IC201, a GND pin of the rectifier chip IC201 is connected to a secondary winding of a transformer TR1, a D pin of the rectifier chip IC201 is connected to a DC output terminal through a voltage stabilizing filter circuit, and a positive electrode and a negative electrode of a diode D201 are respectively connected to a GND pin and a D pin of the rectifier chip IC201; when the rectifier chip IC201 fails, most of the current from the transformer TR101 is changed to be rectified by the diode D201, thereby reducing the current flowing through the rectifier chip IC201, thereby reducing the temperature of a shell corresponding to the rectifier chip IC201, and protecting the service life of the shell.

Description

Technical Field

[0001] The utility model relates to the technical field of power adapters, in particular to a power adapter for preventing a chip from overheating. Background Art

[0002] As an AC-DC and strong-weak current conversion device, consumer power adapters need to adapt to various complex and harsh working environments and withstand various abnormal energy impacts that exceed the rated design specifications. At the same time, they need to provide stable output to ensure the use requirements of subsequent terminal equipment.

[0003] Therefore, the quality and reliability of power adapters have always been an important topic for power supply manufacturers to study and improve.

[0004] There is a rectifier chip before the output of the power adapter. When the current output from the transformer of the power adapter is abnormal, the abnormal current will be rectified by the body diode in the rectifier chip. The forward conduction voltage VF of this body diode is very large, which will cause the rectifier chip to heat up seriously. After testing, it is about 150 degrees Celsius. It will cause the PCB board where the rectifier chip is located and the corresponding shell surface to heat up seriously, which will affect the service life of the shell.

[0005] Therefore, in the utility model patent application, the applicant carefully studied a power adapter that prevents chip overheating to solve the above problem. Utility Model Content

[0006] The utility model aims to overcome the deficiencies of the above-mentioned prior art and its main purpose is to provide a power adapter that prevents chip overheating. When the rectifier chip IC201 fails, most of the current from the transformer TR101 will be rectified by the diode D201, thereby reducing the current flowing through the rectifier chip IC201, thereby reducing the temperature of the shell corresponding to the rectifier chip IC201 and protecting the service life of the shell.

[0007] In order to achieve the above-mentioned purpose, the utility model adopts the following technical solutions:

[0008] A power adapter for preventing chip from overheating, comprising an AC input terminal, an input rectifying and filtering circuit, a transformer TR101, a control circuit, an output feedback circuit and an output rectifying and filtering circuit;

[0009] The AC input terminal is connected to the first end of the primary winding of the transformer TR101 through the input rectifier and filter circuit, the control circuit is respectively connected to the second end of the primary winding of the transformer TR101 and the first end of the auxiliary winding of the transformer TR101, and the second end of the auxiliary winding of the transformer TR101 is connected to the primary ground GND1;

[0010] The output rectifier and filter circuit includes a diode D201 and an output rectifier circuit, a voltage stabilizing filter circuit and a DC output terminal connected in sequence, and the output rectifier circuit is connected to the control circuit through an output feedback circuit;

[0011] The output rectifier circuit includes a rectifier chip IC201, a GND pin of the rectifier chip IC201 is connected to a first end of a secondary winding of a transformer TR101, a second end of the secondary winding of the transformer TR101 is connected to a secondary ground GND2, a D pin of the rectifier chip IC201 is connected to a DC output terminal via a voltage stabilizing filter circuit, and a positive and negative poles of a diode D201 are respectively connected to a GND pin and a D pin of the rectifier chip IC201;

[0012] When the rectifier chip IC201 fails, most of the current from the transformer TR101 will be output in sequence through the diode D201, the voltage stabilizing filter circuit and the DC output terminal.

[0013] As a preferred solution, the output rectifier circuit further includes a capacitor C201, a capacitor C202 and a resistor R201 and a resistor R202 connected in parallel;

[0014] The GND pin of the rectifier chip IC201 is connected to the D pin of the rectifier chip IC201 through the capacitor C201 and the resistor R201, and the VCC pin of the rectifier chip IC201 is connected to the GND pin of the rectifier chip IC201 through the capacitor C202.

[0015] As a preferred solution, the voltage stabilizing filter circuit includes a voltage stabilizing diode ZD201, a polar capacitor EC201, a polar capacitor EC202, a polar capacitor EC203, a resistor R203, a capacitor C203 and a coil LF201;

[0016] The positive electrode of polar capacitor EC201, the negative electrode of voltage zener diode ZD201, the positive electrode of polar capacitor EC202 and the positive electrode of polar capacitor EC203 are respectively connected to the D pin of rectifier chip IC201, the resistor R203 and the capacitor C203 are connected in parallel with polar capacitor EC201, and the negative electrode of polar capacitor EC201, the positive electrode of voltage zener diode ZD201, the negative electrode of polar capacitor EC202 and the negative electrode of polar capacitor EC203 are all connected to the secondary ground GND2;

[0017] One end of the left side of the coil LF201 is connected to the D pin of the rectifier chip IC201, the other end of the left side of the coil LF201 is connected to the secondary ground GND2, and the two ends of the right side of the coil LF201 are respectively connected to the positive and negative poles of the DC output terminal.

[0018] As a preferred solution, the output feedback circuit includes a resistor R205, a resistor R204, a resistor R206, a resistor R210, a resistor R207, a resistor R208, a resistor R209, a capacitor C204, a capacitor CY101, a controllable precision voltage regulator IC202 and an optical coupler PC101B;

[0019] The resistor R204 and the resistor R210 are connected in series, the non-series node of the resistor R210 is connected to the output rectifier circuit, the non-series node of the resistor R204 is connected to the negative electrode of the transmitting end of the optocoupler PC101B through the resistor R207 and the capacitor C204, the positive electrode of the transmitting end of the optocoupler PC101B is connected to the output rectifier circuit through the resistor R205, and the resistor R206 is connected in parallel with the optocoupler PC101B;

[0020] One end of the resistor R208 is connected to the control end of the controllable precision voltage regulator IC202 and the non-series node of the resistor R204 at the same time, the resistor R208 is connected in parallel with the resistor R209, and the negative electrode of the controllable precision voltage regulator IC202 is connected to the negative electrode of the transmitting end of the optical coupler PC101B;

[0021] The other end of the resistor R208 and the positive electrode of the controllable precision voltage regulator IC202 are connected to the secondary ground GND2, the negative electrode of the controllable precision voltage regulator IC202 is connected to the primary ground GND1 through the capacitor CY101, and the receiving end of the optical coupler PC101B is used to send a voltage detection signal to the control circuit.

[0022] As a preferred solution, an RCD circuit is also included, and the RCD circuit is respectively connected to the input rectification and filtering circuit, the control circuit and the primary winding of the transformer TR101.

[0023] As a preferred solution, the RCD circuit includes a diode D101, a capacitor C102, a resistor R105 and a resistor R107 connected in series, a resistor R108 and a resistor R106 connected in series, the capacitor C102 is connected in parallel with the resistor R105, the resistor R105 and the resistor R106 are connected in parallel, and the resistor R107 and the resistor R108 are connected in parallel;

[0024] The non-series node of resistor R105 is respectively connected to the input rectifier filter circuit and the first end of the primary winding of transformer TR101, the non-series node of resistor R107 is connected to the cathode of diode D101, and the anode of diode D101 is respectively connected to the control circuit and the second end of the primary winding of transformer TR101.

[0025] As a preferred solution, the control circuit includes a voltage zener diode ZD101, a resistor R110, a resistor R109, a resistor R112, a resistor R111, a resistor R120, a resistor R121, a resistor R113, a resistor R114, a resistor R115, a resistor R116, a resistor R117, a resistor R118, a resistor R119, a polar capacitor EC102, a capacitor C104, a capacitor C105, a capacitor C103, a capacitor C106, a diode D102, a diode D103, a MOS tube Q101 and a control chip IC101 of model LP8776E;

[0026] The VCC pin of the control chip IC101 is connected to the positive electrode of the polar capacitor EC102, the capacitor C104 is connected in parallel with the polar capacitor EC102, the resistor R110 and the resistor R109 are connected in series, the non-series node of the resistor R110, the cathode of the voltage zener diode ZD101 and one end of the resistor R112 are all connected to the VCC pin of the control chip IC101, and the non-series node of the resistor R109 is connected to the first end of the primary winding of the transformer TR101;

[0027] The positive electrode of the voltage zener diode ZD101 is connected to the FAULT pin of the control chip IC101 through the resistor R120, the FAULT pin of the control chip IC101 is connected to the primary ground through the resistor R121, the other end of the resistor R112 is connected to the negative electrode of the diode D102, the positive electrode of the diode D102 is connected to the first end of the secondary winding of the transformer TR101, the resistor R111 and the capacitor C106 are connected in series and then connected in parallel with the diode D102;

[0028] The FB pin of the control chip IC101 is connected to the output feedback circuit, and the FB pin of the control chip IC101 is also connected to the primary ground GND1 through the capacitor C105. The resistors R113 and R114 are connected in series. The OUT pin of the control chip IC101 is connected to the non-series node of the resistor R113. The cathode of the diode D103 is connected to the series node of the resistor R113 and R114. The resistors R116 and R117 are connected in series. The anode of the diode D103, the non-series node of the resistor R114, and the non-series node of the resistor R116 are all connected to the gate of the MOS tube Q101. The drain of the MOS tube Q101 is connected to the second end of the primary winding of the transformer TR101.

[0029] The CS pin of the control chip IC101 is connected to the source of the MOS tube Q101 through the resistor R115, the source of the MOS tube Q101 is connected to the primary ground GND1 through the resistor R119, the resistor R118 is connected in parallel with the parallel resistor R119, the CS pin of the control chip IC101 is connected to the primary ground GND1 through the capacitor C103, the series node of the resistor R116 and the resistor R117 is connected to the source of the MOS tube Q101, and the negative electrode of the polar capacitor EC102, the non-series node of the resistor R117 and the GND pin of the control chip IC101 are all connected to the primary ground GND1.

[0030] As a preferred solution, the input rectifier filter circuit includes a fuse F101, a safety capacitor CX101, a varistor MOV101, a thermistor NTC101, a coil LF101, a coil LF102, a capacitor C101, a resistor unit, a rectifier tube BD101 and a polarity capacitor EC101;

[0031] The L input end of the AC input terminal is connected to one end of the left side of the coil LF101 through the fuse F101 and the thermistor NTC101, one end of the left side of the coil LF101 is connected to the other end of the left side of the coil LF101 through the varistor MOV101, the other end of the left side of the coil LF101 is connected to the N input end of the AC input terminal, and one end of the right side of the coil LF101 is connected to the other end of the right side of the coil LF101 through the safety capacitor CX101;

[0032] The first end of the resistance unit is respectively connected to one end on the left side of the coil LF102 and one end on the right side of the coil LF102, the second end of the resistance unit is respectively connected to the other end on the left side of the coil LF102 and the other end on the right side of the coil LF102, and one end on the right side of the coil LF102 is connected to the other end on the right side of the coil LF102 through the capacitor C101;

[0033] The positive input end of the rectifier tube BD101 is connected to the negative input end of the rectifier tube BD101 through the capacitor C101, the positive output end of the rectifier tube BD101 is respectively connected to the positive electrode of the polarity capacitor EC101, the control circuit, and the first end of the primary winding of the transformer TR101, and the negative electrode of the polarity capacitor EC101 and the negative output end of the rectifier tube BD101 are both connected to the primary ground GND1.

[0034] Compared with the prior art, the utility model has obvious advantages and beneficial effects. Specifically, the utility model mainly connects the GND pin and the D pin of the rectifier chip IC201 respectively through the positive and negative electrodes of the diode D201. When the rectifier chip IC201 fails, most of the current from the transformer TR101 will be rectified by the diode D201, thereby reducing the current flowing through the rectifier chip IC201, and then reducing the temperature of the shell corresponding to the rectifier chip IC201, thereby protecting the service life of the shell.

[0035] In order to more clearly illustrate the structural features and effects of the present invention, it is described in detail below in conjunction with the accompanying drawings and specific embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Figure 1 It is a schematic circuit diagram of an embodiment of the utility model.

[0037] Description of Figure Numbers:

[0038] 10. AC input terminal 20. Input rectifier filter circuit

[0039] 30. Control circuit 40. Output feedback circuit

[0040] 51. Output rectifier circuit 52. Voltage stabilizing filter circuit

[0041] 53. DC output terminal 60. RCD circuit. DETAILED DESCRIPTION

[0042] The utility model is further described below in conjunction with the accompanying drawings and specific implementation methods.

[0043] Please refer to Figure 1 As shown, it shows the specific structure of a preferred embodiment of the utility model, which is a power adapter for preventing chip overheating, including an AC input terminal 10, an input rectifier filter circuit 20, a transformer TR101, a control circuit 30, an output feedback circuit 40 and an output rectifier filter circuit;

[0044] The AC input terminal 10 is connected to the first end of the primary winding of the transformer TR101 through the input rectifier filter circuit 20, the control circuit 30 is respectively connected to the second end of the primary winding of the transformer TR101 and the first end of the auxiliary winding of the transformer TR101, and the second end of the auxiliary winding of the transformer TR101 is connected to the primary ground GND1;

[0045] The output rectifier and filter circuit includes a diode D201 and an output rectifier circuit 51, a voltage stabilizing filter circuit 52 and a DC output terminal 53 connected in sequence. The output rectifier circuit 51 is connected to the control circuit 30 through the output feedback circuit 40.

[0046] In this embodiment, the output rectifier circuit 51 includes a rectifier chip IC201, a capacitor C201, a capacitor C202, and resistors R201 and R202 connected in parallel;

[0047] The GND pin of the rectifier chip IC201 is connected to the first end of the secondary winding of the transformer TR101, the second end of the secondary winding of the transformer TR101 is connected to the secondary ground GND2, the D pin of the rectifier chip IC201 is connected to the DC output terminal 53 through the voltage stabilizing filter circuit 52, the positive and negative electrodes of the diode D201 are respectively connected to the GND pin and the D pin of the rectifier chip IC201; the GND pin of the rectifier chip IC201 is connected to the D pin of the rectifier chip IC201 through the capacitor C201 and the resistor R201, and the VCC pin of the rectifier chip IC201 is connected to the GND pin of the rectifier chip IC201 through the capacitor C202. Preferably, the diode D201 is a Schottky diode.

[0048] When the rectifier chip IC201 fails, most of the current from the transformer TR101 will be outputted through the diode D201, the voltage stabilizing filter circuit 52 and the DC output terminal 53 in sequence.

[0049] When the rectifier chip IC201 fails, since the forward conduction voltage VF of the diode D201 is smaller than the body diode in the rectifier chip IC201, most of the current from the transformer TR101 will be directly rectified through the diode D201, reducing the current entering the rectifier chip IC201, thereby avoiding the heating of the rectifier chip IC201, thereby reducing the heating of the circuit board where the rectifier chip IC201 is located and the corresponding shell surface, thereby extending the service life of the shell.

[0050] In this embodiment, the control circuit 30 includes a voltage zener diode ZD101, a resistor R110, a resistor R109, a resistor R112, a resistor R111, a resistor R120, a resistor R121, a resistor R113, a resistor R114, a resistor R115, a resistor R116, a resistor R117, a resistor R118, a resistor R119, a polar capacitor EC102, a capacitor C104, a capacitor C105, a capacitor C103, a capacitor C105, a capacitor C106, a diode D102, a diode D103, a MOS tube Q101, and a control chip IC101 of model LP8776E;

[0051] The VCC pin of the control chip IC101 is connected to the positive electrode of the polar capacitor EC102, the capacitor C104 is connected in parallel with the polar capacitor EC102, the resistor R110 and the resistor R109 are connected in series, the non-series node of the resistor R110, the cathode of the voltage zener diode ZD101 and one end of the resistor R112 are all connected to the VCC pin of the control chip IC101, and the non-series node of the resistor R109 is connected to the first end of the primary winding of the transformer TR101;

[0052] The positive electrode of the voltage zener diode ZD101 is connected to the FAULT pin of the control chip IC101 through the resistor R120, the FAULT pin of the control chip IC101 is connected to the primary ground through the resistor R121, the other end of the resistor R112 is connected to the negative electrode of the diode D102, the positive electrode of the diode D102 is connected to the first end of the secondary winding of the transformer TR101, the resistor R111 and the capacitor C106 are connected in series and then connected in parallel with the diode D102;

[0053] The FB pin of the control chip IC101 is connected to the output feedback circuit 40, and the FB pin of the control chip IC101 is also connected to the primary ground GND1 through the capacitor C105, the resistor R113 and the resistor R114 are connected in series, the OUT pin of the control chip IC101 is connected to the non-series node of the resistor R113, the cathode of the diode D103 is connected to the series node of the resistor R113 and the resistor R114, the resistor R116 and the resistor R117 are connected in series, the anode of the diode D103, the non-series node of the resistor R114 and the non-series node of the resistor R116 are all connected to the gate of the MOS tube Q101, and the drain of the MOS tube Q101 is connected to the second end of the primary winding of the transformer TR101;

[0054] The CS pin of the control chip IC101 is connected to the source of the MOS tube Q101 through the resistor R115, the source of the MOS tube Q101 is connected to the primary ground GND1 through the resistor R119, the resistor R118 is connected in parallel with the parallel resistor R119, the CS pin of the control chip IC101 is connected to the primary ground GND1 through the capacitor C103, the series node of the resistor R116 and the resistor R117 is connected to the source of the MOS tube Q101, and the negative electrode of the polar capacitor EC102, the non-series node of the resistor R117 and the GND pin of the control chip IC101 are all connected to the primary ground GND1.

[0055] In this embodiment, the voltage stabilizing filter circuit 52 includes a voltage stabilizing diode ZD201, a polar capacitor EC201, a polar capacitor EC202, a polar capacitor EC203, a resistor R203, a capacitor C203 and a coil LF201;

[0056] The positive electrode of polar capacitor EC201, the negative electrode of voltage zener diode ZD201, the positive electrode of polar capacitor EC202 and the positive electrode of polar capacitor EC203 are respectively connected to the D pin of rectifier chip IC201, the resistor R203 and the capacitor C203 are connected in parallel with polar capacitor EC201, and the negative electrode of polar capacitor EC201, the positive electrode of voltage zener diode ZD201, the negative electrode of polar capacitor EC202 and the negative electrode of polar capacitor EC203 are all connected to the secondary ground GND2;

[0057] One end of the left side of the coil LF201 is connected to the D pin of the rectifier chip IC201, the other end of the left side of the coil LF201 is connected to the secondary ground GND2, and the two ends of the right side of the coil LF201 are respectively connected to the positive and negative poles of the DC output terminal 53.

[0058] In this embodiment, the output feedback circuit 40 includes a resistor R205, a resistor R204, a resistor R206, a resistor R210, a resistor R207, a resistor R208, a resistor R209, a capacitor C204, a capacitor CY101, a controllable precision voltage regulator IC202, and an optical coupler PC101B;

[0059] The resistor R204 and the resistor R210 are connected in series, the non-series node of the resistor R210 is connected to the D pin of the rectifier chip IC201 of the output rectifier circuit 51, the non-series node of the resistor R204 is connected to the negative electrode of the transmitting end of the optical coupler PC101B through the resistor R207 and the capacitor C204, the positive electrode of the transmitting end of the optical coupler PC101B is connected to the D pin of the rectifier chip IC201 of the output rectifier circuit 51 through the resistor R205, and the resistor R206 is connected in parallel with the optical coupler PC101B;

[0060] One end of the resistor R208 is connected to the control end of the controllable precision voltage regulator IC202 and the non-series node of the resistor R204 at the same time, the resistor R208 is connected in parallel with the resistor R209, and the negative electrode of the controllable precision voltage regulator IC202 is connected to the negative electrode of the transmitting end of the optical coupler PC101B;

[0061] The other end of resistor R208 and the positive electrode of controllable precision voltage regulator IC202 are connected to the secondary ground GND2, the negative electrode of controllable precision voltage regulator IC202 is connected to the primary ground GND1 through capacitor CY101, and the receiving end of the optocoupler PC101B is used to send a voltage detection signal to the FB pin of the control chip IC101 of the control circuit 30.

[0062] The system further comprises an RCD circuit 60 , which is respectively connected to the input rectifying and filtering circuit 20 , the control circuit 30 and the primary winding of the transformer TR101 .

[0063] In this embodiment, the RCD circuit 60 includes a diode D101, a capacitor C102, a resistor R105 and a resistor R107 connected in series, a resistor R108 and a resistor R106 connected in series, the capacitor C102 is connected in parallel with the resistor R105, the resistor R105 and the resistor R106 are connected in parallel, and the resistor R107 and the resistor R108 are connected in parallel;

[0064] The non-series node of the resistor R105 is respectively connected to the positive electrode of the polarity capacitor EC101 of the input rectifier and filter circuit 20 and the first end of the primary winding of the transformer TR101. The non-series node of the resistor R107 is connected to the negative electrode of the diode D101. The positive electrode of the diode D101 is respectively connected to the drain of the MOS tube Q101 of the control circuit 30 and the second end of the primary winding of the transformer TR101.

[0065] In this embodiment, the input rectifier filter circuit 20 includes a fuse F101, a safety capacitor CX101, a varistor MOV101, a thermistor NTC101, a coil LF101, a coil LF102, a capacitor C101, a resistor unit, a rectifier tube BD101 and a polar capacitor EC101;

[0066] The L input end of the AC input terminal 10 is connected to one end of the left side of the coil LF101 through the fuse F101 and the thermistor NTC101, one end of the left side of the coil LF101 is connected to the other end of the left side of the coil LF101 through the varistor MOV101, the other end of the left side of the coil LF101 is connected to the N input end of the AC input terminal 10, and one end of the right side of the coil LF101 is connected to the other end of the right side of the coil LF101 through the safety capacitor CX101;

[0067] The first end of the resistance unit is respectively connected to one end on the left side of the coil LF102 and one end on the right side of the coil LF102, the second end of the resistance unit is respectively connected to the other end on the left side of the coil LF102 and the other end on the right side of the coil LF102, and one end on the right side of the coil LF102 is connected to the other end on the right side of the coil LF102 through the capacitor C101;

[0068] The positive input terminal of the rectifier BD101 is connected to the negative input terminal of the rectifier BD101 through the capacitor C101. The positive output terminal of the rectifier BD101 is respectively connected to the positive electrode of the polarity capacitor EC101, the non-series node of the resistor R109 of the control circuit 30, and the first end of the primary winding of the transformer TR101. The negative electrode of the polarity capacitor EC101 and the negative output terminal of the rectifier BD101 are both connected to the primary ground GND1.

[0069] The key point of the design of the utility model is that the positive and negative electrodes of the diode D201 are respectively connected to the GND pin and the D pin of the rectifier chip IC201. When the rectifier chip IC201 fails, most of the current from the transformer TR101 will be rectified by the diode D201, thereby reducing the current flowing through the rectifier chip IC201, and then reducing the temperature of the shell corresponding to the rectifier chip IC201, thereby protecting the service life of the shell.

[0070] The above description is only a preferred embodiment of the present invention and does not limit the technical scope of the present invention. Therefore, any minor modifications, equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention are still within the scope of the technical solution of the present invention.

Claims

1. A power adapter for preventing chip from overheating, characterized in that: It includes an AC input terminal, an input rectifier filter circuit, a transformer TR101, a control circuit, an output feedback circuit and an output rectifier filter circuit; The AC input terminal is connected to the first end of the primary winding of the transformer TR101 through the input rectifier and filter circuit, the control circuit is respectively connected to the second end of the primary winding of the transformer TR101 and the first end of the auxiliary winding of the transformer TR101, and the second end of the auxiliary winding of the transformer TR101 is connected to the primary ground GND1; The output rectifier and filter circuit includes a diode D201 and an output rectifier circuit, a voltage stabilizing filter circuit and a DC output terminal connected in sequence, and the output rectifier circuit is connected to the control circuit through an output feedback circuit; The output rectifier circuit includes a rectifier chip IC201, a GND pin of the rectifier chip IC201 is connected to a first end of a secondary winding of a transformer TR101, a second end of the secondary winding of the transformer TR101 is connected to a secondary ground GND2, a D pin of the rectifier chip IC201 is connected to a DC output terminal via a voltage stabilizing filter circuit, and a positive and negative poles of a diode D201 are respectively connected to a GND pin and a D pin of the rectifier chip IC201; When the rectifier chip IC201 fails, most of the current from the transformer TR101 will be output in sequence through the diode D201, the voltage stabilizing filter circuit and the DC output terminal.

2. The power adapter for preventing chip overheating according to claim 1, characterized in that: The output rectifier circuit also includes a capacitor C201, a capacitor C202 and a resistor R201 and a resistor R202 connected in parallel; The GND pin of the rectifier chip IC201 is connected to the D pin of the rectifier chip IC201 through the capacitor C201 and the resistor R201, and the VCC pin of the rectifier chip IC201 is connected to the GND pin of the rectifier chip IC201 through the capacitor C202.

3. The power adapter for preventing chip overheating according to claim 1, characterized in that: The voltage stabilizing filter circuit includes a voltage stabilizing diode ZD201, a polar capacitor EC201, a polar capacitor EC202, a polar capacitor EC203, a resistor R203, a capacitor C203 and a coil LF201; The positive electrode of polar capacitor EC201, the negative electrode of voltage zener diode ZD201, the positive electrode of polar capacitor EC202 and the positive electrode of polar capacitor EC203 are respectively connected to the D pin of rectifier chip IC201, the resistor R203 and the capacitor C203 are connected in parallel with polar capacitor EC201, and the negative electrode of polar capacitor EC201, the positive electrode of voltage zener diode ZD201, the negative electrode of polar capacitor EC202 and the negative electrode of polar capacitor EC203 are all connected to the secondary ground GND2; One end of the left side of the coil LF201 is connected to the D pin of the rectifier chip IC201, the other end of the left side of the coil LF201 is connected to the secondary ground GND2, and the two ends of the right side of the coil LF201 are respectively connected to the positive and negative poles of the DC output terminal.

4. The power adapter for preventing chip overheating according to claim 1, characterized in that: The output feedback circuit includes a resistor R205, a resistor R204, a resistor R206, a resistor R210, a resistor R207, a resistor R208, a resistor R209, a capacitor C204, a capacitor CY101, a controllable precision voltage regulator IC202 and an optical coupler PC101B; The resistor R204 and the resistor R210 are connected in series, the non-series node of the resistor R210 is connected to the output rectifier circuit, the non-series node of the resistor R204 is connected to the negative electrode of the transmitting end of the optocoupler PC101B through the resistor R207 and the capacitor C204, the positive electrode of the transmitting end of the optocoupler PC101B is connected to the output rectifier circuit through the resistor R205, and the resistor R206 is connected in parallel with the optocoupler PC101B; One end of the resistor R208 is connected to the control end of the controllable precision voltage regulator IC202 and the non-series node of the resistor R204 at the same time, the resistor R208 is connected in parallel with the resistor R209, and the negative electrode of the controllable precision voltage regulator IC202 is connected to the negative electrode of the transmitting end of the optical coupler PC101B; The other end of the resistor R208 and the positive electrode of the controllable precision voltage regulator IC202 are connected to the secondary ground GND2, the negative electrode of the controllable precision voltage regulator IC202 is connected to the primary ground GND1 through the capacitor CY101, and the receiving end of the optical coupler PC101B is used to send a voltage detection signal to the control circuit.

5. The power adapter for preventing chip overheating according to claim 1, characterized in that: It also includes an RCD circuit, which is respectively connected to the input rectification and filtering circuit, the control circuit and the primary winding of the transformer TR101.

6. The power adapter for preventing chip overheating according to claim 5, characterized in that: The RCD circuit includes a diode D101, a capacitor C102, a resistor R105 and a resistor R107 connected in series, a resistor R108 and a resistor R106 connected in series, the capacitor C102 is connected in parallel with the resistor R105, the resistor R105 and the resistor R106 are connected in parallel, and the resistor R107 and the resistor R108 are connected in parallel; The non-series node of resistor R105 is respectively connected to the input rectifier filter circuit and the first end of the primary winding of transformer TR101, the non-series node of resistor R107 is connected to the cathode of diode D101, and the anode of diode D101 is respectively connected to the control circuit and the second end of the primary winding of transformer TR101.

7. The power adapter for preventing chip overheating according to claim 1, characterized in that: The control circuit includes a voltage stabilizing diode ZD101, a resistor R110, a resistor R109, a resistor R112, a resistor R111, a resistor R120, a resistor R121, a resistor R113, a resistor R114, a resistor R115, a resistor R116, a resistor R117, a resistor R118, a resistor R119, a polar capacitor EC102, a capacitor C104, a capacitor C105, a capacitor C103, a capacitor C106, a diode D102, a diode D103, a MOS tube Q101 and a control chip IC101 of model LP8776E; The VCC pin of the control chip IC101 is connected to the positive electrode of the polar capacitor EC102, the capacitor C104 is connected in parallel with the polar capacitor EC102, the resistor R110 and the resistor R109 are connected in series, the non-series node of the resistor R110, the cathode of the voltage zener diode ZD101 and one end of the resistor R112 are all connected to the VCC pin of the control chip IC101, and the non-series node of the resistor R109 is connected to the first end of the primary winding of the transformer TR101; The positive electrode of the voltage zener diode ZD101 is connected to the FAULT pin of the control chip IC101 through the resistor R120, the FAULT pin of the control chip IC101 is connected to the primary ground through the resistor R121, the other end of the resistor R112 is connected to the negative electrode of the diode D102, the positive electrode of the diode D102 is connected to the first end of the secondary winding of the transformer TR101, the resistor R111 and the capacitor C106 are connected in series and then connected in parallel with the diode D102; The FB pin of the control chip IC101 is connected to the output feedback circuit, and the FB pin of the control chip IC101 is also connected to the primary ground GND1 through the capacitor C105. The resistors R113 and R114 are connected in series. The OUT pin of the control chip IC101 is connected to the non-series node of the resistor R113. The cathode of the diode D103 is connected to the series node of the resistor R113 and R114. The resistors R116 and R117 are connected in series. The anode of the diode D103, the non-series node of the resistor R114, and the non-series node of the resistor R116 are all connected to the gate of the MOS tube Q101. The drain of the MOS tube Q101 is connected to the second end of the primary winding of the transformer TR101. The CS pin of the control chip IC101 is connected to the source of the MOS tube Q101 through the resistor R115, the source of the MOS tube Q101 is connected to the primary ground GND1 through the resistor R119, the resistor R118 is connected in parallel with the parallel resistor R119, the CS pin of the control chip IC101 is connected to the primary ground GND1 through the capacitor C103, the series node of the resistor R116 and the resistor R117 is connected to the source of the MOS tube Q101, and the negative electrode of the polar capacitor EC102, the non-series node of the resistor R117 and the GND pin of the control chip IC101 are all connected to the primary ground GND1.

8. The power adapter for preventing chip overheating according to claim 1, characterized in that: The input rectifier filter circuit includes a fuse F101, a safety capacitor CX101, a varistor MOV101, a thermistor NTC101, a coil LF101, a coil LF102, a capacitor C101, a resistor unit, a rectifier tube BD101 and a polarity capacitor EC101; The L input end of the AC input terminal is connected to one end of the left side of the coil LF101 through the fuse F101 and the thermistor NTC101, one end of the left side of the coil LF101 is connected to the other end of the left side of the coil LF101 through the varistor MOV101, the other end of the left side of the coil LF101 is connected to the N input end of the AC input terminal, and one end of the right side of the coil LF101 is connected to the other end of the right side of the coil LF101 through the safety capacitor CX101; The first end of the resistance unit is respectively connected to one end on the left side of the coil LF102 and one end on the right side of the coil LF102, the second end of the resistance unit is respectively connected to the other end on the left side of the coil LF102 and the other end on the right side of the coil LF102, and one end on the right side of the coil LF102 is connected to the other end on the right side of the coil LF102 through the capacitor C101; The positive input end of the rectifier tube BD101 is connected to the negative input end of the rectifier tube BD101 through the capacitor C101, the positive output end of the rectifier tube BD101 is respectively connected to the positive electrode of the polarity capacitor EC101, the control circuit, and the first end of the primary winding of the transformer TR101, and the negative electrode of the polarity capacitor EC101 and the negative output end of the rectifier tube BD101 are both connected to the primary ground GND1.

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