Charger output circuit

Abstract

The utility model discloses a charger output circuit which is applied to a charger comprising a control circuit board, the control circuit board is provided with a connecting port, a control module and a charging circuit connected with the control module, and the charger output circuit is arranged on the control circuit board and connected with a transformer of the charging circuit. A secondary winding of the transformer is connected with the connection port through the charger output circuit, the charger output circuit comprises an output reverse connection protection module, the output reverse connection protection module comprises a first MOS tube, a second MOS tube, a sixth MOS tube and a tenth tube, a first end of the secondary winding of the transformer is connected with a second end of the connection port through the first MOS tube and the second MOS tube, and a second end of the secondary winding of the transformer is connected with a third end of the connection port through the third MOS tube and the fourth MOS tube. The grid electrode of the first MOS transistor and the grid electrode of the second MOS transistor are connected with the control module through a sixth MOS transistor, one end of the sixth MOS transistor is connected with the anode of a tenth transistor, and the cathode of the tenth transistor is grounded. And bidirectional conduction of the sixth MOS transistor is prevented through the tenth transistor.

Description

Technical Field

[0001] This utility model relates to the field of charger technology, and in particular to a charger output circuit. Background Technology

[0002] Existing chargers are prone to damage when the output positive and negative terminals are reversed, which can cause the MOSFET in the internal circuit of the charger to break down and damage the charger, resulting in low safety. Utility Model Content

[0003] The technical problem to be solved by this utility model is to provide a charger output circuit that protects the MOSFET when the output positive and negative terminals are reversed, thereby improving safety.

[0004] To solve the above-mentioned technical problems, this utility model provides a charger output circuit, applied to a charger. The charger includes a control circuit board, on which a connection port, a control module, and a charging circuit connected to the control module are provided. The charging circuit includes a transformer. The charger output circuit is disposed on the control circuit board and connected to the transformer. The secondary winding of the transformer is connected to the connection port through the charger output circuit. The charger output circuit includes an output reverse connection protection module, which includes a first MOSFET, a second MOSFET, a sixth MOSFET, and a tenth diode. The first end of the secondary winding of the transformer is connected to the second end of the connection port through the first MOSFET and the second MOSFET. The gates of the first MOSFET and the second MOSFET are connected to the control module through the sixth MOSFET. One end of the sixth MOSFET is connected to the anode of the tenth diode, and the cathode of the tenth diode is grounded.

[0005] The further technical solution is as follows: the first MOS transistor and the second MOS transistor are PMOS transistors, and the sixth MOS transistor is an NMOS transistor.

[0006] The further technical solution is as follows: the drain of the sixth MOS transistor is connected to the gate of the first MOS transistor and the gate of the second MOS transistor through the twenty-fifth resistor; the gate of the sixth MOS transistor is connected to the control module through the thirty-second resistor; and the source of the sixth MOS transistor is connected to the anode of the tenth diode.

[0007] The further technical solution is as follows: the drain of the first MOS transistor is connected to one end of the secondary winding of the transformer, the source of the first MOS transistor is connected to the source of the second MOS transistor, and the drain of the second MOS transistor is connected to the second end of the connection port.

[0008] The further technical solution is as follows: the drain of the sixth MOS transistor is connected to the anode of the first Zener diode through the twenty-fifth resistor, and the cathode of the first Zener diode is connected to the source of the first MOS transistor and the source of the second MOS transistor.

[0009] A further technical solution is as follows: the charger output circuit further includes a battery voltage detection module, and the output reverse connection protection module is electrically connected to the connection port through the battery voltage detection module.

[0010] The further technical solution is as follows: the battery voltage detection module includes a fourth switching transistor, the control terminal of the fourth switching transistor is connected to the control module through a twenty-sixth resistor, a thirty-eighth grounding resistor is electrically connected between the twenty-sixth resistor and the control terminal of the fourth switching transistor, one end of the fourth switching transistor is connected to the drain of the second MOS transistor through a twenty-fourth resistor, and the other end of the fourth switching transistor is connected to a nineteenth grounding capacitor and a forty-fourth grounding resistor connected in parallel.

[0011] The further technical solution is that the fourth switch is an NMOS transistor.

[0012] The beneficial technical effects of this utility model are as follows: The charger output circuit of this utility model is located between the charging circuit and the connection port of the charger's control circuit board. The charger output circuit includes an output reverse connection protection module, which includes a first MOSFET, a second MOSFET, a sixth MOSFET, and a tenth diode. The first end of the secondary winding of the transformer in the charging circuit is connected to the second end of the connection port through the first MOSFET and the second MOSFET. The gates of the first MOSFET and the second MOSFET are connected to the control module through the sixth MOSFET, so that the control module controls the operation of the first MOSFET and the second MOSFET through the sixth MOSFET. The use of two MOSFETs connected in series for output control can reduce the risk of leakage. At the same time, one end of the sixth MOSFET is connected to the anode of the tenth diode, and the cathode of the tenth diode is grounded. This utilizes the unidirectional conduction characteristic of the diode to prevent the second MOSFET from being damaged by the conduction of the clamping diode inside the sixth MOSFET when the output is reversed. This protects the first MOSFET and the second MOSFET from being broken down, improves the safety of the charging output, and has a simple circuit structure and high reliability. Attached Figure Description

[0013] To more clearly illustrate the technical solutions of the embodiments of this utility model, the drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0014] Figure 1 This is a schematic diagram illustrating a specific application of the charger output circuit provided by this utility model. Detailed Implementation

[0015] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of the present utility model.

[0016] Please see Figure 1 , Figure 1 This is a schematic diagram illustrating the specific application of the charger output circuit provided in this embodiment of the present invention. The charger output circuit 10 is applied to a charger, which includes a control circuit board. The control circuit board has a connection port JP1, a control module, and a charging circuit connected to the control module. The charging circuit includes a transformer T1. The charger output circuit 10 is located on the control circuit board and connected to the transformer T1. The secondary winding of the transformer T1 is connected to the connection port JP1 through the charger output circuit 10. The charger output circuit 10 includes an output reverse connection protection module 11. The output reverse connection protection module 11 includes a first MOSFET Q1, a second MOSFET Q2, a sixth MOSFET Q6, and a tenth diode D10. The first end of the secondary winding of the transformer T1 is connected to the second end of the connection port JP1 through the first MOSFET Q1 and the second MOSFET Q2. The gates of the first MOSFET Q1 and the second MOSFET Q2 are connected to the control module through the sixth MOSFET Q6. One end of the sixth MOSFET Q6 is connected to the anode of the tenth diode D10, and the cathode of the tenth diode D10 is grounded.

[0017] The control module is an MCU. The charger output circuit 10 is located between the charging circuit and the connection port JP1 on the charger's control circuit board. The charger output circuit 10 includes an output reverse connection protection module 11, which includes a first MOSFET Q1, a second MOSFET Q2, a sixth MOSFET Q6, and a tenth diode D10. The first terminal of the secondary winding of the transformer T1 in the charging circuit is connected to the second terminal of the connection port JP1 through the first MOSFET Q1 and the second MOSFET Q2. The gates of the first MOSFET Q1 and the second MOSFET Q2 are connected to the control module through the sixth MOSFET Q6, so that the control module can be connected to the control circuit. The control module controls the operation of the first MOSFET Q1 and the second MOSFET Q2 through the sixth MOSFET Q6. The output control is achieved by connecting the two MOSFETs in series, which reduces the risk of leakage. At the same time, one end of the sixth MOSFET Q6 is connected to the anode of the tenth diode D10, and the cathode of the tenth diode D10 is grounded. This utilizes the unidirectional conduction characteristic of the diode to prevent the second MOSFET Q2 from being damaged by the conduction of the clamping diode inside the sixth MOSFET Q6 when the output is reversed. This protects the first MOSFET Q1 and the second MOSFET Q2 from being broken down, improves the safety of the charging output, and results in a simple circuit structure with high reliability.

[0018] Specifically, in this embodiment, the first MOSFET Q1 and the second MOSFET Q2 are PMOS transistors, and the sixth MOSFET Q6 is an NMOS transistor. The first MOSFET Q1 and the second MOSFET Q2 are cut off when their gates are at a high level, and the sixth MOSFET Q6 is cut off when its gate is at a low level, ensuring normal charging output from the charger.

[0019] Specifically, the drain of the sixth MOSFET Q6 is connected to the gate of the first MOSFET Q1 and the gate of the second MOSFET Q2 through the twenty-fifth resistor R25. The gate of the sixth MOSFET Q6 is connected to the control module through the thirty-second resistor R32. The source of the sixth MOSFET Q6 is connected to the anode of the tenth diode D10. Preferably, the gate of the sixth MOSFET Q6 is connected to the RY1 pin of the MCU through the thirty-second resistor R32. A forty-fifth grounding resistor R45 and an eighteenth grounding capacitor C18 are electrically connected in parallel between the thirty-second resistor R32 and the gate of the sixth MOSFET Q6. One end of the forty-fifth grounding resistor R45 is grounded, and the other end of the forty-fifth grounding resistor R45 is connected to the thirty-second resistor R32 and the gate of the sixth MOSFET Q6. One end of the eighteenth grounding capacitor C18 is grounded, and the other end of the eighteenth grounding capacitor C18 is connected to the thirty-second resistor R32 and the gate of the sixth MOSFET Q6.

[0020] Specifically, the drain of the first MOS transistor Q1 is connected to one end of the secondary winding of the transformer T1, the source of the first MOS transistor Q1 is connected to the source of the second MOS transistor Q2, and the drain of the second MOS transistor Q2 is connected to the second end of the connection port JP1.

[0021] Specifically, the drain of the sixth MOS transistor Q6 is connected to the anode of the first Zener diode ZD1 through the twenty-fifth resistor R25, and the cathode of the first Zener diode ZD1 is connected to the source of the first MOS transistor Q1 and the source of the second MOS transistor Q2.

[0022] Specifically, in this embodiment, the charger output circuit 10 further includes a battery voltage detection module 12, and the output reverse connection protection module 11 is electrically connected to the connection port JP1 through the battery voltage detection module 12.

[0023] Specifically, the battery voltage detection module 12 includes a fourth switch Q4. The control terminal of the fourth switch Q4 is connected to the control module through a twenty-sixth resistor R26. A thirty-eighth grounding resistor R38 is electrically connected between the twenty-sixth resistor R26 and the control terminal of the fourth switch Q4. One end of the fourth switch Q4 is connected to the drain of the second MOS transistor Q2 through a twenty-fourth resistor R24. The other end of the fourth switch Q4 is connected to a nineteenth grounding capacitor C19 and a forty-fourth grounding resistor R44 connected in parallel. One end of the forty-fourth grounding resistor R44 is grounded, and the other end of the forty-fourth grounding resistor R44 is connected to the other end of the fourth switch Q4. One end of the nineteenth grounding capacitor C19 is grounded, and the other end of the nineteenth grounding capacitor C19 is connected to the other end of the fourth switch Q4.

[0024] Preferably, the fourth switch Q4 is an NMOS transistor. The gate of the fourth switch Q4 is connected to the P1 pin of the MCU through a 26th resistor R26. A 38th grounding resistor R38 is electrically connected between the 26th resistor R26 and the gate of the fourth switch Q4. One end of the 38th grounding resistor R38 is grounded, and the other end is connected to the 26th resistor R26 and the gate of the fourth switch Q4. The drain of the fourth switch Q4 is connected to the drain of the second MOS transistor Q2 through a 24th resistor R24. The source of the fourth switch Q4 is connected in parallel with a 19th grounding capacitor C19 and a 44th grounding resistor R44. The 24th resistor R24 ​​can be connected to the drain of the second MOS transistor Q2 through a 15th resistor R15. A 13th grounding capacitor can be electrically connected between the 26th resistor R26 and the gate of the fourth switch Q4.

[0025] Preferably, the connection port JP1 is a two-port port, with the first and second ends of the connection port JP1 respectively connected to the two ends of the bidirectional transient voltage suppressor diode TVS1.

[0026] Based on the above design, in normal standby mode, the MCU's RY1 pin outputs a low level, the sixth MOSFET is cut off, and the first and second MOSFETs are high and cut off. The output of the reverse connection protection module is 0, so the charger output circuit is 0 and does not charge. During normal charging (i.e., when the external device's positive and negative terminals are not reversed), the MCU's RY1 pin outputs a high level, the sixth MOSFET is turned on, and the first and second MOSFETs are low and turned on. The reverse connection protection module outputs normally, and the charger output circuit outputs normally, supplying power to the external device through the connection port. The external device connected to the connection port is charged. If the positive and negative terminals of the external device are reversed, the battery voltage detection module will receive a negative voltage, the MCU's R1 pin will output a low level, the MCU's RY1 pin will output a low level, the sixth MOSFET will be cut off, and at this time, the first and second MOSFETs will be high and cut off. The output of the reverse connection protection module will be 0, so the charger output circuit will be 0 and will not charge. Since the tenth diode is connected to the source of the sixth MOSFET, it avoids the clamping diode inside the sixth MOSFET from forming a circuit, preventing the first and second MOSFETs from being broken down.

[0027] In summary, the charger output circuit of this utility model is located between the charging circuit and the connection port on the control circuit board of the charger. The charger output circuit includes an output reverse connection protection module, which includes a first MOSFET, a second MOSFET, a sixth MOSFET, and a tenth diode. The first end of the secondary winding of the transformer in the charging circuit is connected to the second end of the connection port through the first MOSFET and the second MOSFET. The gates of the first MOSFET and the second MOSFET are connected to the control module through the sixth MOSFET, so that the control module controls the operation of the first MOSFET and the second MOSFET through the sixth MOSFET. The use of two MOSFETs connected in series for output control can reduce the risk of leakage. At the same time, one end of the sixth MOSFET is connected to the anode of the tenth diode, and the cathode of the tenth diode is grounded. This utilizes the unidirectional conduction characteristic of the diode to prevent the second MOSFET from being damaged by the conduction of the clamping diode inside the sixth MOSFET when the output is reversed. This protects the first MOSFET and the second MOSFET from being broken down, improves the safety of the charging output, and has a simple circuit structure and high reliability.

[0028] The above description is merely a specific embodiment of this utility model, but the protection scope of this utility model is not limited thereto. Any person skilled in the art can easily conceive of various equivalent modifications or substitutions within the technical scope disclosed in this utility model, and these modifications or substitutions should all be covered within the protection scope of this utility model. Therefore, the protection scope of this utility model should be determined by the scope of the claims.

Claims

1. A charger output circuit, characterized by, The application is applied to a charger, the charger includes a control circuit board, the control circuit board is provided with a connection port, a control module and a charging circuit connected with the control module, the charging circuit includes a transformer, the charger output circuit is arranged on the control circuit board and connected with the transformer, a secondary winding of the transformer is connected with the connection port through the charger output circuit, the charger output circuit includes an output reverse connection protection module, the output reverse connection protection module includes a first MOS tube, a second MOS tube, a sixth MOS tube and a twelfth diode, a first end of the secondary winding of the transformer is connected with a second end of the connection port through the first MOS tube and the second MOS tube, the gate of the first MOS tube and the gate of the second MOS tube are connected with the control module through the sixth MOS tube, one end of the sixth MOS tube is connected with the anode of the twelfth diode, and the cathode of the twelfth diode is grounded.

2. The charger output circuit of claim 1, wherein The first MOS tube and the second MOS tube are PMOS tubes, and the sixth MOS tube is an NMOS tube.

3. The charger output circuit of claim 2, wherein, The drain of the sixth MOS tube is connected with the gate of the first MOS tube and the gate of the second MOS tube through a twenty-fifth resistor, the gate of the sixth MOS tube is connected with the control module through a thirty-second resistor, and the source of the sixth MOS tube is connected with the anode of the twelfth diode.

4. The charger output circuit of claim 2, wherein, The drain of the first MOS tube is connected with one end of the secondary winding of the transformer, the source of the first MOS tube is connected with the source of the second MOS tube, and the drain of the second MOS tube is connected with the second end of the connection port.

5. The charger output circuit of claim 4, wherein, The drain of the sixth MOS tube is connected with the anode of a first voltage stabilizing diode through a twenty-fifth resistor, and the cathode of the first voltage stabilizing diode is connected with the source of the first MOS tube and the source of the second MOS tube.

6. The charger output circuit of claim 2, wherein, The charger output circuit further includes a battery voltage detection module, and the output reverse connection protection module is connected with the connection port through the battery voltage detection module.

7. The charger output circuit of claim 6, wherein, The battery voltage detection module includes a fourth switch tube, the control end of the fourth switch tube is connected with the control module through a twenty-sixth resistor, a thirty-eighth grounding resistor is electrically connected between the twenty-sixth resistor and the control end of the fourth switch tube, one end of the fourth switch tube is connected with the drain of the second MOS tube through a twenty-fourth resistor, and the other end of the fourth switch tube is connected with a nineteenth grounding capacitor and a forty-fourth grounding resistor in parallel connection.

8. The charger output circuit of claim 7, wherein, The fourth switch tube is an NMOS tube.

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