A high-current charging circuit with a 0V charging port

Abstract

This utility model provides a high-current charging circuit with a 0V charging port, relating to the field of charging equipment technology. It includes: a battery pack, a first resistor, an operational amplifier, a first MOSFET, and a second MOSFET. The positive terminal of the charging port is connected to the negative terminal of the charging circuit via the battery pack, the first resistor, the first MOSFET, and the second MOSFET, forming a charging loop. The operational amplifier is connected in parallel across the first resistor. The positive terminal of the first resistor is connected to the non-inverting input of the operational amplifier; the negative terminal of the first resistor is connected to the inverting input of the operational amplifier; the output of the operational amplifier is connected to the second MOSFET; the positive terminal of the operational amplifier's power supply is connected to VCC; and the negative terminal of the operational amplifier's power supply is grounded. The operational amplifier detects the current flowing through the first resistor and outputs a turn-on current to turn on the second MOSFET, thus completing the charging loop. This significantly reduces the heat generated during charging.

Description

Technical Field

[0001] This utility model relates to the field of charging equipment technology, and in particular to a high-current charging circuit with a 0V charging port. Background Technology

[0002] The 0V high-current charging circuit is designed to maintain a 0V charging port voltage while supporting high-current charging. Its main purpose is to keep the charging port voltage at 0V during high-current charging and effectively prevent overheating and damage caused by excessive charging current.

[0003] However, for high-current charging at 0V charging ports, the main method used in the market is to achieve high current and heat dissipation through parallel diodes. During charging, the MOSFET conducts, current flows through the battery cell, and the current returns to the negative terminal of the charging circuit via the sampling resistor, charging MOSFET, and diode. When not charging, the diode isolates the negative terminal, and the voltage between the positive and negative terminals is 0V. During charging, the diode conduction generates a voltage drop of 0.5V to 0.7V. Based on a charging current of 20A, diode D3 generates 10W to 14W of heat. To address this heat issue, multiple diodes are usually connected in parallel to distribute the current and reduce the heat generated by individual diodes. However, even with multiple diodes connected in parallel, each diode still generates a similar voltage drop and heat. Therefore, although multiple diodes can be connected in parallel to distribute the current, the total heat remains high, failing to effectively reduce heat generation and still causing heat loss and potential damage to the equipment.

[0004] In summary, current high-current charging circuits with 0V charging ports cannot reduce heat generation during charging, posing a safety hazard. Utility Model Content

[0005] In view of the shortcomings of the prior art, the purpose of this utility model embodiment is to provide a high-current charging circuit with a 0V charging port, which can solve the technical problem that the existing high-current charging circuit with a 0V charging port cannot reduce the heat generated during charging, thus posing a safety hazard.

[0006] In a first aspect of this utility model, a high-current charging circuit with a 0V charging port is provided, comprising: a battery pack, a first resistor, an operational amplifier, a first MOSFET, and a second MOSFET. The positive terminal of the charging port of the charging circuit is connected to the negative terminal of the charging port of the charging circuit in sequence through the battery pack, the first resistor, the first MOSFET, and the second MOSFET to form a charging circuit. An operational amplifier is connected in parallel across the first resistor; the positive terminal of the first resistor is connected to the non-inverting input of the operational amplifier; the negative terminal of the first resistor is connected to the inverting input of the operational amplifier; the output of the operational amplifier is connected to the second MOSFET; the positive terminal of the operational amplifier power supply is connected to VCC; the negative terminal of the operational amplifier power supply is grounded. The operational amplifier is used to detect the current flowing through the first resistor and output a turn-on current to turn on the second MOSFET and conduct the charging circuit.

[0007] Optionally, the battery pack includes multiple battery cells connected in series; Connect the positive terminal of the battery pack to the positive terminal of the charging port, and connect the negative terminal of the battery pack to the negative terminal of the charging port.

[0008] Optionally, it may also include: a second resistor and a third resistor; The third resistor is connected in series between the negative terminal of the first resistor and the negative terminal of the operational amplifier power supply. The second resistor is connected in series between the positive terminal of the third resistor and VCC; The second and third resistors are used to adjust the magnitude of the turn-on current.

[0009] Optionally, it also includes: a fourth resistor; One end of the fourth resistor is connected to the negative terminal of the charging port, and the other end of the fourth resistor is connected to the positive terminal of the charging port.

[0010] Optionally, it also includes: a second MOSFET driving circuit; The second MOSFET driver circuit is connected in series between the output of the operational amplifier and the second MOSFET.

[0011] Optionally, it also includes: a charging control circuit; The charging control circuit is connected to the first MOSFET.

[0012] The beneficial effects of the technical solution provided by this utility model embodiment include at least the following: In this embodiment of the invention, the 0V high-current charging circuit effectively solves the problem of excessive heat generation during high-current charging by using a low-resistance MOSFET instead of a traditional diode. The voltage drop generated by the current passing through the first resistor is detected by the operational amplifier and controls the second MOSFET to conduct, ensuring a smooth and efficient charging circuit. The low internal resistance of the MOSFET significantly reduces heat generation, avoiding equipment damage and safety hazards caused by thermal damage. This design not only improves charging efficiency but also ensures that the charging port voltage is 0V, enhancing safety and stability during the charging process. Attached Figure Description

[0013] The accompanying drawings are for illustrative purposes only and are not intended to limit the scope of this invention. Throughout the drawings, the same reference numerals denote the same components. Obviously, the drawings described below are merely some embodiments of this invention, and those skilled in the art can obtain other drawings based on these drawings without any creative effort.

[0014] Figure 1 This is a schematic diagram of a high-current charging circuit with a 0V charging port provided in an embodiment of the present invention.

[0015] Explanation of reference numerals in the attached figures: BT, battery cell; 1, operational amplifier output; 2, operational amplifier negative power supply terminal; 3, operational amplifier non-inverting input; 4, operational amplifier inverting input; 5, operational amplifier positive power supply terminal; R1, first resistor; R2, second resistor; R3, third resistor; R4, fourth resistor; Q1, first MOSFET; Q2, second MOSFET; U1, operational amplifier; P+, charging port positive terminal; C-, charging port negative terminal; VCC, positive power supply; B-, ground terminal. Detailed Implementation

[0016] To enable those skilled in the art to better understand the technical solutions in the embodiments of this utility model, the technical solutions of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this utility model, not all embodiments. It should be understood that these descriptions are exemplary only and are not intended to limit the scope of this utility model. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort should fall within the protection scope of this utility model.

[0017] Furthermore, descriptions of well-known structures and techniques are omitted in the following description to avoid unnecessarily obscuring the concepts disclosed in this utility model.

[0018] Exemplary embodiments will now be described in detail, examples of which are illustrated in the accompanying drawings. When the following description relates to the drawings, unless otherwise indicated, the same numbers in different drawings denote the same or similar elements. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with this invention.

[0019] Reference manual attached Figure 1 The diagram shows an exploded view of a high-current charging circuit with a 0V charging port provided in an embodiment of this utility model.

[0020] The present invention provides a structure for a high-current charging circuit with a 0V charging port, comprising: a battery pack, a first resistor, an operational amplifier, a first MOSFET, and a second MOSFET.

[0021] The positive terminal of the charging port of the charging circuit is connected to the negative terminal of the charging port of the charging circuit in sequence through the battery pack, the first resistor, the first MOSFET, and the second MOSFET to form a charging circuit.

[0022] An operational amplifier is connected in parallel across the first resistor. The positive terminal of the first resistor is connected to the non-inverting input of the operational amplifier. The negative terminal of the first resistor is connected to the inverting input of the operational amplifier. The output of the operational amplifier is connected to the second MOSFET. The positive terminal of the operational amplifier's power supply is connected to VCC. The negative terminal of the operational amplifier's power supply is grounded. The operational amplifier detects the current flowing through the first resistor and outputs a turn-on current to turn on the second MOSFET, thus activating the charging circuit.

[0023] The battery pack provides power and is the energy source for the charging circuit. The positive (P+) and negative (C-) terminals of the battery pack are connected by a circuit to provide energy for the charging process. A first resistor is located between the battery pack and the operational amplifier (OPA) and is used to detect the current. A voltage drop occurs when current flows through the resistor; the OPA uses this voltage drop to determine the current magnitude, thereby controlling other components in the circuit. The OPA (U1) measures the voltage drop across the first resistor and outputs a signal based on the voltage drop value to control the switching of the second MOSFET. It is the core control component of the circuit, ensuring stable conduction of the charging circuit through real-time current detection and feedback adjustment. The first MOSFET (Q1) mainly controls the current flow; when charging current needs to flow into the battery, the first MOSFET turns on, allowing current to flow. The second MOSFET (Q2) controls the switching state of the charging circuit. Its on / off state is controlled by the signal output from the OPA, ensuring that the current flow during charging meets requirements and avoiding unnecessary heat generation. The OPA's power supply terminal is connected to the positive power supply (VCC), and the negative power supply terminal is grounded, providing the necessary power for the OPA's operation.

[0024] The working principle of this 0V high-current charging circuit is as follows: a first resistor detects the voltage drop as current flows through it, and this voltage drop is input to an operational amplifier. The operational amplifier outputs a signal based on the voltage drop value to control the conduction and shutdown of the second MOSFET, ensuring effective conduction of the charging circuit. When current flows through the first resistor, the operational amplifier detects the current magnitude by comparing its inverting and non-inverting inputs, and adjusts the charging current by controlling the switching of the second MOSFET. Because a low-resistance MOSFET is used, heat generation is significantly reduced compared to traditional diodes, thus solving the safety hazard caused by excessive heat during high-current charging. Furthermore, the efficient conduction of the MOSFET ensures that the charging port voltage remains at 0V, avoiding voltage imbalance or reverse current between the battery negative terminal and the charger, improving safety and stability during charging, and making it suitable for high-current fast charging scenarios.

[0025] The beneficial effects of the technical solution provided by this utility model embodiment include at least the following: In this embodiment of the invention, the 0V high-current charging circuit effectively solves the problem of excessive heat generation during high-current charging by using a low-resistance MOSFET instead of a traditional diode. The voltage drop generated by the current passing through the first resistor is detected by the operational amplifier and controls the second MOSFET to conduct, ensuring a smooth and efficient charging circuit. The low internal resistance of the MOSFET significantly reduces heat generation, avoiding equipment damage and safety hazards caused by thermal damage. This design not only improves charging efficiency but also ensures that the charging port voltage is 0V, enhancing safety and stability during the charging process.

[0026] like Figure 1 The battery pack consists of multiple battery cells connected in series, namely BT1 to BT2. n , where n represents the total number of battery cells.

[0027] In one possible implementation, the battery pack includes multiple battery cells connected in series.

[0028] Connect the positive terminal of the battery pack to the positive terminal of the charging port, and connect the negative terminal of the battery pack to the negative terminal of the charging port.

[0029] Understandably, a battery pack consists of multiple individual cells connected in series to provide the required high voltage. The positive terminal of the battery pack is connected to the positive terminal of the charging port, while the negative terminal is connected to the negative terminal of the charging port, forming a complete current loop to ensure that the battery pack can charge and provide power normally during the charging process.

[0030] In one possible implementation, it also includes a second resistor and a third resistor.

[0031] The third resistor is connected in series between the negative terminal of the first resistor and the negative terminal of the operational amplifier power supply.

[0032] The second resistor is connected in series between the positive terminal of the third resistor and VCC.

[0033] The second and third resistors are used to adjust the magnitude of the turn-on current.

[0034] It should be noted that the second and third resistors are used to adjust the turn-on current. The third resistor is connected in series between the negative terminal of the first resistor and the negative terminal of the operational amplifier power supply, while the second resistor is connected in series between the positive terminal of the third resistor and VCC. The settings of these resistors control the amplitude of the turn-on current. Too low a turn-on current will result in poor circuit immunity to interference, making it prone to malfunctions and causing the charging port to become energized. Too high a turn-on current will cause the isolation MOSFET Q2 to overheat, affecting circuit stability. By adjusting the values ​​of these two resistors, the current can be balanced according to actual needs, ensuring stable circuit operation while avoiding overheating and malfunctions.

[0035] In one possible implementation, a fourth resistor is also included.

[0036] One end of the fourth resistor is connected to the negative terminal of the charging port, and the other end of the fourth resistor is connected to the positive terminal of the charging port.

[0037] It should be noted that the fourth resistor is connected between the positive and negative terminals of the charging port, with one end connected to the negative terminal and the other end connected to the positive terminal. When charging is not in progress, operational amplifier U1 cannot detect any current, the second MOSFET Q2 has a very high impedance, and the voltage between P+ and C- is 0V. Considering that the second MOSFET may have slight leakage current, resistor R4 can be used to shield against this leakage.

[0038] In one possible implementation, a second MOS transistor drive circuit is also included.

[0039] The second MOSFET driver circuit is connected in series between the output of the operational amplifier and the second MOSFET.

[0040] It should be noted that the second MOSFET driver circuit is connected in series between the operational amplifier output and the second MOSFET, and is used to control the turn-on and turn-off of the second MOSFET. This driver circuit converts the operational amplifier's control signal into sufficient drive current to ensure that the second MOSFET can conduct stably according to the current detection result, thereby effectively controlling the current flow in the charging circuit and ensuring the safety and efficiency of the charging process.

[0041] In one possible implementation, it also includes a charging control circuit.

[0042] The charging control circuit is connected to the first MOSFET.

[0043] Understandably, the charging control circuit is connected to the first MOSFET and is used to control the switching state of the first MOSFET. Based on the detection results of current and voltage, the charging control circuit precisely adjusts the conduction and shutdown of the first MOSFET to ensure a stable flow of charging current and avoid damage to the battery or circuit caused by overcurrent or overvoltage, thereby improving the safety and efficiency of the charging process.

[0044] In practical applications, the charging current passing through the first resistor R1 will generate a voltage drop. The operational amplifier detects the voltage drop generated by R1, and the turn-on signal of the second MOSFET is transmitted through the second MOSFET driver circuit to turn on the second MOSFET Q2. After the second MOSFET Q2 is turned on, since its on-resistance is lower than the on-state voltage drop of the body diode, the body diode is directly shielded. This solves the problem of heat generation during high-current charging.

[0045] Specifically, the principle of this 0V high-current charging circuit is based on detecting the voltage drop generated when current flows through the first resistor using an operational amplifier, and controlling the conduction state of the second MOSFET. The operational amplifier converts the voltage drop into a control signal, adjusting the conduction of the second MOSFET to ensure a stable current flow in the charging circuit. The first MOSFET is used to control the charging current, preventing excessive or insufficient current. By using a low-resistance MOSFET instead of a traditional diode, heat generation during charging is reduced, avoiding equipment damage and safety hazards caused by high temperatures. Furthermore, the circuit design ensures that the charging port voltage is always 0V, preventing voltage imbalance or reverse current between the battery negative terminal and the charger, thereby improving the safety and efficiency of the charging process. This design supports high-current charging while optimizing thermal management and stability.

[0046] This utility model encompasses any substitutions, modifications, equivalent methods, and solutions made within the spirit and scope of this utility model. To provide the public with a thorough understanding of this utility model, specific details are described in detail in the preferred embodiments; however, those skilled in the art can fully understand this utility model without these details. Furthermore, to avoid unnecessary confusion regarding the essence of this utility model, well-known methods, processes, procedures, components, and circuits are not described in detail.

[0047] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present utility model, and not to limit it. Although the present utility model has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present utility model. Any changes or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in the present utility model should be included within the protection scope of the present utility model.

Claims

1. A high-current charging circuit with a 0V charging port, characterized in that, include: Battery pack, first resistor, operational amplifier, first MOSFET, second MOSFET; The positive terminal of the charging port of the charging circuit is connected to the negative terminal of the charging port of the charging circuit in sequence through the battery pack, the first resistor, the first MOSFET, and the second MOSFET to form a charging circuit. The operational amplifier is connected in parallel across the first resistor; the positive terminal of the first resistor is connected to the non-inverting input terminal of the operational amplifier; the negative terminal of the first resistor is connected to the inverting input terminal of the operational amplifier; the output terminal of the operational amplifier is connected to the second MOSFET; the positive terminal of the operational amplifier power supply is connected to VCC; the negative terminal of the operational amplifier power supply is grounded. The operational amplifier is used to detect the current flowing through the first resistor and output a turn-on current to turn on the second MOSFET and conduct the charging circuit.

2. The high-current charging circuit with a 0V charging port according to claim 1, characterized in that, The battery pack comprises multiple battery cells connected in series; The positive terminal of the battery pack is connected to the positive terminal of the charging port, and the negative terminal of the battery pack is connected to the negative terminal of the charging port.

3. The high-current charging circuit with a 0V charging port according to claim 1, characterized in that, Also includes: The second and third resistors; The third resistor is connected in series between the negative terminal of the first resistor and the negative terminal of the operational amplifier power supply. The second resistor is connected in series between the positive terminal of the third resistor and VCC; The second resistor and the third resistor are used to adjust the magnitude of the turn-on current.

4. The high-current charging circuit with a 0V charging port according to claim 1, characterized in that, Also includes: Fourth resistor; One end of the fourth resistor is connected to the negative terminal of the charging port, and the other end of the fourth resistor is connected to the positive terminal of the charging port.

5. The high-current charging circuit with a 0V charging port according to claim 1, characterized in that, Also includes: Second MOS transistor drive circuit; The second MOS transistor driver circuit is connected in series between the output of the operational amplifier and the second MOS transistor.

6. The high-current charging circuit with a 0V charging port according to claim 1, characterized in that, Also includes: Charging control circuit; The charging control circuit is connected to the first MOS transistor.

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