Electric vehicle charger circuit integrated with battery charging protection and charger

Abstract

The utility model relates to the related technical field of power supply chargers, and provides an electric vehicle charger circuit integrated with battery charging protection and a charger, the output end of the charger circuit is provided with a charging switch circuit, an MCU control circuit and a battery voltage detection terminal; through circuit design, the charging switch circuit and the MCU control circuit are arranged, when the output end is abnormal, the charging switch circuit is driven by signals of the MCU control circuit to disconnect charging, and safety is improved.

Description

Technical Field

[0001] This utility model relates to the field of power charger technology, specifically to an electric vehicle charger circuit and charger with integrated battery charging protection. Background Technology

[0002] The statements in this section are merely background information related to this utility model and do not necessarily constitute prior art.

[0003] With the increasing popularity of electric vehicles, the performance of electric vehicle chargers, as core power supply equipment, directly affects charging efficiency, safety, and user experience. As electronic technology rapidly advances, chargers are evolving towards higher power density, miniaturization, and intelligence, which places higher demands on their heat dissipation design, electrical performance, and safety protection.

[0004] However, while existing electric vehicle chargers are shrinking in size, safety issues are becoming increasingly prominent. Because electric vehicles may be connected to the charger interface or have the battery polarity reversed during use, some traditional chargers lack effective reverse connection protection mechanisms. This can lead to internal short circuits, overcurrent burnout of power devices, and even battery explosions or fires, seriously threatening the lives and property of users. Utility Model Content

[0005] To address the aforementioned problems, this invention proposes an electric vehicle charger circuit and charger with integrated battery charging protection. By designing the circuit, a charging switch circuit and an MCU control circuit are included, which can disconnect charging when an abnormality is detected at the output end, thereby improving safety.

[0006] To achieve the above objectives, the present invention adopts the following technical solution:

[0007] One or more embodiments provide an electric vehicle charger circuit with integrated battery charging protection. The output terminal of the charger circuit is provided with a charging switch circuit, an MCU control circuit, and a battery voltage detection terminal.

[0008] The battery voltage detection terminal is connected to the positive terminal of the rechargeable battery; the battery voltage detection terminal is also connected to the signal detection terminal of the first controller U1 of the MCU control circuit.

[0009] The charging switch circuit includes a seventh switch Q7, a sixth switch Q6, and a fifth switch Q5; the driving terminals of the sixth switch Q6 and the fifth switch Q5 are connected to form a series connection circuit, and the seventh switch Q7 is connected to the driving terminals of the sixth switch Q6 and the fifth switch Q5; the output terminal of the first controller U1 is connected to the driving terminal of the seventh switch Q7 to control the on / off state of the seventh switch Q7 according to the data received by the signal detection terminal.

[0010] Compared with the prior art, the beneficial effects of this utility model are as follows:

[0011] This invention improves charger safety by incorporating a charging switch circuit. When the battery voltage detection terminal detects an abnormal voltage, such as a reverse-connected battery, it controls the charger's on / off state. The switch circuit consists of a fifth switch Q5, a sixth switch Q6, and a seventh switch Q7. The seventh switch Q7 controls the on / off state of the charger by detecting the battery's output voltage through a first controller U1. By controlling the on / off state of the seventh switch Q7, the fifth switch Q5 and the sixth switch Q6 are also simultaneously controlled, thus improving the charger's safety.

[0012] The advantages and additional benefits of this utility model will be described in detail in the following specific embodiments. Attached Figure Description

[0013] The accompanying drawings, which form part of this specification, are used to provide a further understanding of this utility model. The illustrative embodiments of this utility model and their descriptions are used to explain this utility model and do not constitute a limitation thereof.

[0014] Figure 1 This is a block diagram of the electric vehicle charger circuit with integrated battery charging protection according to Embodiment 1 of this utility model;

[0015] Figure 2 This is a circuit diagram of the first part of the electric vehicle charger circuit with integrated battery charging protection according to Embodiment 1 of this utility model;

[0016] Figure 3 This is the second part of the circuit diagram of the electric vehicle charger circuit with integrated battery charging protection according to Embodiment 1 of this utility model;

[0017] Figure 4 This is the third part of the circuit diagram of the electric vehicle charger circuit with integrated battery charging protection according to Embodiment 1 of this utility model;

[0018] Figure 5 This is a circuit diagram of the charging switch circuit of Embodiment 1 of this utility model;

[0019] Figure 6 This is a circuit diagram of the battery voltage detection circuit of Embodiment 1 of this utility model;

[0020] Figure 7 This is a circuit diagram of the power factor correction circuit of Embodiment 1 of this utility model;

[0021] Figure 8 This is a circuit diagram of the power factor correction control circuit of Embodiment 1 of this utility model;

[0022] Figure 9This is a circuit diagram of the fan control circuit of Embodiment 1 of this utility model;

[0023] Figure 10 This is a circuit diagram of the voltage conversion control circuit and feedback circuit of Embodiment 1 of this utility model;

[0024] Figure 11 This is a circuit diagram of the output rectifier and filter circuit of Embodiment 1 of this utility model;

[0025] Figure 12 This is a circuit diagram of the output voltage detection and control circuit of Embodiment 1 of this utility model;

[0026] Figure 13 This is a circuit diagram of the output current detection and control circuit of Embodiment 1 of this utility model;

[0027] Figure 14 This is a circuit diagram of the output voltage detection circuit of Embodiment 1 of this utility model;

[0028] Figure 15 This is a circuit diagram of the over-temperature protection circuit of Embodiment 1 of this utility model; Detailed Implementation

[0029] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0030] It should be noted that the following detailed description is exemplary and intended to provide further explanation of the present invention. Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains.

[0031] It should be noted that the terminology used herein is for descriptive purposes only and is not intended to limit the exemplary embodiments according to this invention. As used herein, the singular form is intended to include the plural form as well, unless the context clearly indicates otherwise. Furthermore, it should be understood that when the terms "comprising" and / or "including" are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof. It should be noted that, without conflict, the various embodiments and features within those embodiments can be combined with each other. The embodiments will now be described in detail with reference to the accompanying drawings.

[0032] In one or more of the technical solutions disclosed in the embodiments, such as Figures 1 to 15 As shown, an electric vehicle charger circuit with integrated battery charging protection is provided at the output terminal of the charger circuit, which includes a charging switch circuit, an MCU control circuit, and a battery voltage detection terminal.

[0033] The battery voltage detection terminal (BAT+) is connected to the positive terminal of the rechargeable battery; the battery voltage detection terminal is connected to the signal detection terminal P03 / AD of the first controller U1 of the MCU control circuit.

[0034] The charging switch circuit includes a seventh switch Q7, a sixth switch Q6, and a fifth switch Q5; the driving terminals of the sixth switch Q6 and the fifth switch Q5 are connected to form a series connection circuit, and the seventh switch Q7 is connected to the driving terminals of the sixth switch Q6 and the fifth switch Q5; the output terminal of the first controller U1 is connected to the driving terminal of the seventh switch Q7 to control the on / off state of the seventh switch Q7 according to the data received by the signal detection terminal;

[0035] In this embodiment, a charging switch circuit is provided, such as... Figure 5 As shown, when the battery voltage detection terminal detects an abnormal voltage, such as a reverse-connected battery, the charger is controlled to switch on and off. The switching circuit consists of the fifth switch Q5, the sixth switch Q6, and the seventh switch Q7. The seventh switch Q7 controls the on / off state of the charger by detecting the battery's output voltage through the first controller U1. The on / off state of the fifth switch Q5 and the sixth switch Q6 are also controlled simultaneously by the seventh switch Q7, which can improve the safety of the charger.

[0036] The first controller U1 controls the switching of the seventh switch Q7 based on the data received from the signal detection terminal. This can be achieved through simple settings in the first controller U1. For example, if the received data exceeds a certain range, the seventh switch Q7 will be turned on, thereby turning off the sixth switch Q6 and the fifth switch Q5. Specifically, the seventh switch Q7 is connected to pin P21 of the first controller U1 via a voltage divider circuit composed of resistors R55 and R61.

[0037] Specifically, in this embodiment, the seventh switch Q7 is set as an N-channel MOSFET, and the sixth switch Q6 and the fifth switch Q5 are set as P-channel MOSFETs.

[0038] When the seventh switch Q7 is turned on, the fifth switch Q5 and the sixth switch Q6 are turned off; when the seventh switch Q7 is turned off, the fifth switch Q5 and the sixth switch Q6 are turned on.

[0039] In this embodiment, this design effectively drives high-power MOSFETs, including the sixth switch Q6 and the fifth switch Q5, by performing small-signal control on the seventh switch Q7, thereby improving the efficiency and reliability of the circuit.

[0040] A circuit that can be implemented, such as Figure 5As shown, the driving terminals of the sixth switch Q6 and the fifth switch Q5 are connected. Specifically, the source terminals of the sixth switch Q6 and the fifth switch Q5 are connected to form the first connection point, and the gate terminals of the sixth switch Q6 and the fifth switch Q5 are connected to form the second connection point. A Zener diode DZ3, a resistor R48, and a capacitor C21 are connected in parallel between the first connection point and the second connection point.

[0041] Among them, Zener diode DZ3 is mainly used to clamp the voltage and protect the MOSFET from overvoltage damage; capacitor C21 is connected in parallel across the MOSFET to buffer voltage spikes and improve switching stability.

[0042] Furthermore, a resistor R54 is connected between the gate of the fifth switch Q5 and the drain of the seventh switch Q7, and the source of the seventh switch Q7 is grounded through a resistor R62.

[0043] In the above scheme, resistors R48, R54, and R62 are set as current-limiting resistors to control the turn-on speed of the switching transistor and reduce electromagnetic interference and peak current.

[0044] In a specific circuit structure, the output terminal of the charging switch circuit is connected in parallel with inductor LF3, filter capacitor C24 and fuse F2.

[0045] In some embodiments, the battery voltage detection circuit of the MCU control circuit ensures that the output voltage does not exceed a set value, such as 60V, and the output current does not exceed a set value, such as 3A. It can detect the charging status in real time and automatically cut off the power when fully charged. In addition, the internally integrated timer switch improves the product's service life and charging safety.

[0046] Specifically, such as Figure 4 As shown, the MCU control circuit includes a battery voltage detection circuit, an output voltage detection circuit, an output voltage detection and control circuit, an output current detection circuit, an output current detection and control circuit, a battery voltage detection circuit, an over-temperature protection circuit, and a fan control circuit.

[0047] One feasible technical solution is that the battery voltage detection terminal is connected to the signal detection terminal P03 / AD through the battery voltage detection circuit. The battery voltage detection circuit is used to detect the charging voltage of the battery and feed the detection result back to the first controller U1.

[0048] Specifically, such as Figure 6 As shown, the battery voltage detection circuit includes a second transistor Q2, a third transistor Q3, a sampling resistor R7, a sampling resistor R11, a voltage divider resistor R1, a voltage divider resistor R5, and a filter capacitor C2.

[0049] The emitter of the second transistor Q2 is connected to the positive terminal BAT+ of the battery, the base is connected to BAT+ through the voltage divider resistor R1, and the collector is connected to the sampling resistor R7. The sampling resistors R7 and R11 are connected in series and then grounded. The sampling resistor R11 is connected in parallel with the filter capacitor C2. The series connection point of the sampling resistors R7 and R11, BAT-ADC, is connected to the detection pin P05 / AD of the first controller U1.

[0050] The collector of the third transistor Q3 is connected to the series connection of voltage divider resistors R5 and R1 to BAT+. The series connection point of voltage divider resistors R5 and R1 is connected to the base of the second transistor Q2. The emitter of the third transistor Q3 is grounded, and the base is connected to the control pin of the first controller U1 through resistor R9.

[0051] In this embodiment, the voltage detection circuit improves the detection sensitivity through a composite amplification structure composed of two transistors (Q2, Q3), ensuring that a stable and reliable detection signal can be provided even under low current conditions. This enables accurate measurement of the battery charging voltage and feedback to the controller U1, thus enhancing the safety of the charging circuit.

[0052] In some embodiments, a fan control circuit is also included, such as Figure 9 As shown, the fan control circuit includes a fan control execution circuit and an output current detection circuit. The fan control execution circuit includes a first transistor Q1. The collector of the first transistor Q1 is connected to the power supply SRVDD through a first diode D1. The two ends of the first diode D1 are connected in parallel to the fan interface P1. The emitter of the first transistor Q1 is grounded through a resistor R8. The connection point with the resistor R8 is connected to one control terminal (P04 / AD) of the first controller U1 through a capacitor C1. The two ends of the resistor R8 and the capacitor C1 are connected in parallel to a resistor R6 and a second Zener diode D2. The base of the first transistor Q1 is connected to another control terminal (P02 / AD) of the first controller U1 through a resistor R2.

[0053] The output current detection circuit includes a sampling resistor R10 and a capacitor C3. The output current detection circuit is connected to a signal input interface (P16 / AD) of the first controller U1. One end of the sampling resistor R10 is connected to the negative terminal OUT- of the charging switch circuit.

[0054] During use, the current detected by the output current detection circuit reflects the heat inside the charger. The fan control circuit controls the operation of the fan by controlling the current magnitude. In this embodiment, there is no need to set up a separate temperature sensor. The circuit directly controls the fan's on and off by detecting the current magnitude, which improves the lightweight design of the charger.

[0055] In some embodiments, such as Figure 14As shown, the output voltage detection circuit includes resistors R13 and R15 connected in series, a filter capacitor C6 connected in parallel across resistor R15, resistor R13 connected to the output voltage sampling terminal V0; one end of resistor R15 (Vo-ADC) is connected to the interface P16 / AD of the first controller U1, and the other end is grounded.

[0056] The output voltage detection circuit uses resistors R13 and R15 to divide the voltage and then filters it through capacitor C6 to achieve real-time monitoring of the output voltage V0.

[0057] In some embodiments, such as Figure 12 As shown, the output voltage detection and control circuit includes resistors R16, R20, R22, R17, R23, and R24, a filter capacitor C7, and a filter capacitor C9 connected in series with resistor R24.

[0058] The voltage detection terminal V0 is connected to one end of resistor R17. The other end of resistor R17 is connected to one end of resistors R20, R22 and R23 respectively to form a parallel circuit. The other end of resistor R20 is connected to capacitor C7 and then grounded. It is connected to the voltage setting terminal SET-V of the first controller U1 through resistor R16. The other ends of R22 and R23 are grounded respectively.

[0059] The output voltage detection and control circuit in this embodiment uses a voltage divider network composed of multiple resistors and filters the output voltage V0 through filter capacitors C7 and C9 to achieve real-time monitoring of the output voltage V0 and provide a stable feedback signal to the first controller U1 for voltage adjustment and stabilization control.

[0060] In some embodiments, such as Figure 15 As shown, the over-temperature protection circuit is connected to the auxiliary power supply output terminal VDD of the voltage conversion circuit, the filter capacitor C4 connected to the output terminal of the voltage conversion circuit and ground, the resistor R12 and the thermistor R14 connected in series across the filter capacitor C4, and the filter capacitor C5 connected in parallel across the thermistor R14. The connection point of the resistor R12 and the thermistor R14 is connected to the P06 / AD pin of the first controller U1.

[0061] In this embodiment, over-temperature protection is achieved based on the detection of the output voltage. This can be implemented based on a setting. If the current or power is too high, the temperature of the adapter will rise. The resistance of the thermistor R14 will decrease due to the temperature. This is controlled by the P06 / AD pin of the first controller U1 so that protective measures can be taken when the temperature is too high, such as reducing the power or shutting down the system, to prevent overheating damage.

[0062] In some embodiments, such as Figure 1As shown, the charger circuit also includes a pre-stage protection circuit, an EMI filter circuit, an input rectifier and filter circuit, a power factor correction circuit, a power factor correction control circuit, a voltage conversion circuit, a voltage conversion control circuit, a feedback circuit, and an output rectifier and filter circuit.

[0063] In some embodiments, the pre-stage protection circuit provides initial protection against inrush current and overvoltage damage to subsequent circuits. The pre-stage protection circuit includes a first fuse F1, a first thermistor NTC1, and a first varistor RV1.

[0064] In some embodiments, the EMI filter circuit is used to suppress electromagnetic interference at the input terminal and improve the power quality of the system. The EMI filter circuit includes a first common-mode inductor LF1, a second common-mode inductor LF2, a capacitor CX2, and a resistor network; it also includes a sixth diode D6, a fifth diode D5, a current-limiting resistor R27, and a current-limiting resistor R28; the resistor network consists of RX1, RX2, RX3, and RX4 connected in series and parallel.

[0065] In some embodiments, the input rectifier and filter circuit adopts a bridge rectifier circuit BD1, and the output of the bridge rectifier circuit BD1 is connected to an LC filter circuit, which includes an inductor L1, a capacitor CB1 and a capacitor CB2.

[0066] In some embodiments, such as Figure 7 As shown, the power factor correction circuit is used to adjust the phase of the input current to keep it synchronized with the input voltage, thereby improving the power factor and reducing grid harmonic interference. The power factor correction circuit includes a power switch Q4, a fourth diode D4, a ferrite bead FB1, a capacitor C11, and a resistor RS1. The drain D of the fourth switch Q4 is connected to the output of the rectifier filter circuit through the ferrite bead FB1 and the boost transformer T1. The boost transformer T1 is connected to the output of the power factor correction circuit through the fourth diode D4.

[0067] The source S of the fourth switch Q4 is grounded through resistor RS1, and a filter capacitor C11 is connected between the source S and drain D of the fourth switch Q4; the gate G of the fourth switch Q4 is connected to the drive terminal of the power factor correction control circuit to receive control signals.

[0068] The fourth switch, Q4, is a PFC MOS, which uses a new type of semiconductor material. Compared with silicon (Si) MOS, it has lower on-resistance, higher power density, and smaller overall size under the same conditions.

[0069] In this embodiment, the filter capacitor C11 is connected in parallel between the drain and source of the fourth switching transistor Q4 to reduce switching noise and transient voltage spikes, and protect the MOSFET from damage.

[0070] In some embodiments, the power factor correction control circuit is used to control the operating state of the power factor correction circuit. By adjusting the on and off states of the fourth switch Q4, the input current and input voltage are kept synchronized to improve the power factor and reduce grid harmonic interference.

[0071] In some embodiments, such as Figure 8 As shown, the power factor correction control circuit includes a power factor correction control chip U2, as well as a chip power supply circuit, a first current detection circuit, a compensation circuit, and a drive control circuit.

[0072] The chip power supply circuit is connected to the Vin terminal of the control chip U2 and is used to provide a stable operating voltage for the power factor correction control chip. The chip power supply circuit includes a resistor R32, a rectifier diode D8, and capacitors C12 and C13 connected in parallel. The connection point of the rectifier diode D8 and capacitor C12 is connected to the control chip U2.

[0073] Resistor R32 limits the startup current to prevent damage to the device from excessive current during chip power-on. Rectifier diode D8 is connected after resistor R32, with its anode connected to resistor R32 and its cathode connected to a filter network. This prevents reverse voltage flow after power supply reversal and provides unidirectional conduction, ensuring the chip only receives the correct polarity supply voltage. Capacitors C12 and C13 form a filter network to smooth the rectified DC voltage, reduce high-frequency ripple, and ensure stable power supply to the control chip.

[0074] The compensation circuit includes a capacitor C15 and a resistor R39 connected in series, and a capacitor C16 connected in parallel across the capacitor C15 and the resistor R39.

[0075] The first current detection circuit includes a resistor RS1 connected in series with the source of the fourth switching transistor Q4. One end of the resistor RS1 is connected to a resistor R36, and the other end is grounded. The other end of the resistor R36 is connected to a filter capacitor C14 and a controller U2. The other end of the filter capacitor C14 is grounded. A capacitor C17 is connected to the ZCD sampling point of the power factor correction circuit. The other end of the capacitor C17 is connected to a resistor R31. The other end of the resistor R31 is connected to a capacitor C14 and a control chip U2.

[0076] The drive control circuit includes drive resistor R29, resistor R30, resistor R33, seventh diode D7, and current-limiting resistor R36. Resistor R29 is connected to the second parallel resistor R30 after the seventh diode D7 is connected in series. One end of resistor R30 is connected to the control terminal of control chip U2, and the other end is connected to the fourth switch Q4 to be driven. Resistor R33 is connected between the source S and gate G of the fourth switch Q4, and is grounded through current-limiting resistor R36 and capacitor C14.

[0077] Specifically, the voltage conversion circuit uses transformer T2;

[0078] In some embodiments, such as Figure 10 As shown, the voltage conversion control circuit is used to regulate the input voltage and drive the power converter to provide a stable output voltage. The voltage conversion control circuit includes a control chip U3 and an eighth transistor Q8. The collector of the eighth transistor Q8 is connected to the secondary winding T2B of transformer T2 through diode D15 and resistor R68. The emitter of the driving transistor Q8 is connected to VCC. A resistor R69 is connected between the base and collector of the eighth transistor Q8. The base of the eighth transistor Q8 is grounded through a Zener diode DZ1.

[0079] Furthermore, the voltage conversion control circuit also includes an overvoltage protection circuit, which includes an optocoupler U6, a Zener diode DZ2, and a resistor R70. The optocoupler U6 is used to detect the output voltage V0 to achieve overvoltage protection.

[0080] In some embodiments, the secondary winding T2D of the transformer is rectified and filtered by diode D14, capacitor C30, capacitor C31, and capacitor C32, and then outputs a stable voltage through voltage regulator U5 to provide auxiliary power supply VDD to the first controller U1.

[0081] Furthermore, the use of transistor chips in the control chip U3 reduces the size of the adapter. Compared to traditional controllers and transistor-based solutions, integrating transistor chips results in higher integration, a more compact structure, less space occupation, and a smaller overall size under the same conditions.

[0082] The control chip U3 integrates a MOS transistor. The DRIN pin (drain of the MOS transistor) and CS pin (source of the MOS transistor) are controlled by the PWM of the internal controller to turn the MOS transistor on and off.

[0083] The current detection circuit and overcurrent protection control are connected in series from the CS of the control chip U3 to resistors R67, R66, and R67, and capacitor C33 in parallel. The other end is connected to ground in parallel. The internal reference of CS is 0.75V. When the current is too large, the voltage across resistors R66 and R67 will also increase. When it reaches 0.75V, the voltage will be protected and enter the hiccup mode to protect the power supply.

[0084] The Vcc power supply is provided by the auxiliary winding of T2B, and after passing through the current limiting resistor R68, rectifier diode D8, and energy storage filter capacitor C34, it is connected to the collector of Q8. At the same time, it is connected through resistor R69 to the base of the eighth transistor Q8 and the cathode of Zener diode DZ1. The anode of Zener diode DZ1 is grounded. The emitter of Q8 is connected to the energy storage filter capacitor C36 and the anode of diode D16. The cathode of D16 is connected to the filter capacitor C35 and the VCC pin of chip U3.

[0085] Transformer T2 is a high-frequency transformer. By adjusting the pulse width signal and duty cycle of the PWM, it can adjust the output power and voltage to convert AC voltage in the range of 100-240V to DC voltage of 35V-60V, enabling constant voltage and constant current adaptive switching charging for lithium battery products.

[0086] In some embodiments, such as Figure 10 As shown, the feedback circuit includes an optocoupler U4, the input terminal of which is connected to the voltage output terminal VDD.

[0087] The output rectifier and filter circuit is used to rectify the AC power supplied by the secondary winding of the transformer and reduce voltage ripple through filter devices to provide a stable DC output voltage.

[0088] In some embodiments, such as Figure 11 As shown, the output rectifier and filter circuit includes a rectifier diode D10, capacitors C26 and C37 connected in parallel with the cathodes of the rectifier diode D10, resistors R56 and R57; it also includes a voltage clamping circuit, which includes an energy storage capacitor C22 connected in sequence and resistors R46, R47, R49 and R50 connected in parallel.

[0089] Gallium nitride (GaN) is a novel semiconductor material that, compared to silicon (Si), can handle higher energy densities at high temperatures. It offers higher reliability due to its lower on-resistance and consequently lower conduction losses. Furthermore, GaN possesses a high switching frequency. This increased switching frequency allows for a smaller transformer size and casing, and avoids assembly issues during production caused by excessive transformer speeds, such as interference and casing problems.

[0090] Example 2

[0091] Based on Embodiment 1, this embodiment provides a charger, which can be a charger for electric vehicles, using an electric vehicle charger circuit with integrated battery charging protection as described in Embodiment 1.

[0092] The charger includes a charger housing, an AC cable for input power supply, a PCB assembly for laying out the electric vehicle charger circuit with integrated battery charging protection as described in Embodiment 1, and a positioning slot for fixing the PCB assembly.

[0093] Optionally, screws can be used to secure the PCB assembly within the positioning slot.

[0094] The above description is merely a preferred embodiment of this utility model and is not intended to limit the utility model. Various modifications and variations can be made to this utility model by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this utility model should be included within the protection scope of this utility model.

[0095] Although the specific embodiments of the present utility model have been described above in conjunction with the accompanying drawings, this is not intended to limit the scope of protection of the present utility model. Those skilled in the art should understand that various modifications or variations that can be made by those skilled in the art without creative effort based on the technical solution of the present utility model are still within the scope of protection of the present utility model.

Claims

1. An electric vehicle charger circuit integrated with battery charging protection, characterized in that: an output end of the charger circuit is provided with a charging switch circuit, an MCU control circuit and a battery voltage detection terminal; the battery voltage detection terminal is connected to a positive electrode of a charging battery; and the battery voltage detection terminal is connected to a signal detection end of a first controller U1 of the MCU control circuit; the charging switch circuit comprises a seventh switch tube Q7, a sixth switch tube Q6 and a fifth switch tube Q5; the driving ends of the sixth switch tube Q6 and the fifth switch tube Q5 are connected in series to form a series connection circuit, and the seventh switch tube Q7 is connected to the driving ends of the sixth switch tube Q6 and the fifth switch tube Q5; and an output end of the first controller U1 is connected to a driving end of the seventh switch tube Q7 to control the on-off of the seventh switch tube Q7 according to data received by the signal detection end.

2. An integrated battery charge protection electric vehicle charger circuit as defined in claim 1, wherein: The sources of the sixth switch tube Q6 and the fifth switch tube Q5 are connected to form a first connection point, and the gates of the sixth switch tube Q6 and the fifth switch tube Q5 are connected to form a second connection point; and a parallel-connected voltage stabilizing diode DZ3, a resistor R48 and a capacitor C21 are connected between the first connection point and the second connection point; a resistor R54 is connected between the gate of the fifth switch tube Q5 and the drain of the seventh switch tube Q7, and the source of the seventh switch tube Q7 is grounded through a resistor R62.

3. An integrated battery charge protection electric vehicle charger circuit as defined in claim 1, wherein: The MCU control circuit comprises a battery voltage detection circuit, an output voltage detection circuit, an output voltage detection and control circuit, an output current detection circuit, an output current detection and control circuit, a battery voltage detection circuit, an over-temperature protection circuit and a fan control circuit; the battery voltage detection terminal is connected to a signal detection end P03 / AD through the battery voltage detection circuit, and the battery voltage detection circuit is used for detecting the charging voltage of the battery and feeding back the detection result to the first controller U1.

4. An integrated battery charge protection electric vehicle charger circuit as defined in claim 3, wherein: The battery voltage detection circuit comprises a second triode Q2, a third triode Q3, a sampling resistor R7, a sampling resistor R11, a voltage dividing resistor R1, a voltage dividing resistor R5 and a filter capacitor C2; the emitter of the second triode Q2 is connected to a positive electrode BAT+ of the battery, the base is connected to the BAT+ through the voltage dividing resistor R1, the collector is connected to the sampling resistor R7, the sampling resistor R7 and the sampling resistor R11 are connected in series and then grounded, the sampling resistor R11 has the filter capacitor C2 connected in parallel across the two ends thereof; and a connection point BAT-ADC of the sampling resistor R7 and the sampling resistor R11 in series is connected to a detection pin of the first controller U1; the collector of the third triode Q3 is connected to the BAT+ through the series connection of the voltage dividing resistor R5 and the voltage dividing resistor R1, a connection point of the voltage dividing resistor R5 and the voltage dividing resistor R1 is connected to the base of the second triode Q2, the emitter of the third triode Q3 is grounded, and the base is connected to a control pin of the first controller U1 through a resistor R9.

5. An integrated battery charge protection electric vehicle charger circuit as defined in claim 3, wherein: The output voltage detection circuit comprises a series-connected resistor R13 and a resistor R15, and a filter capacitor C6 is connected in parallel across the two ends of the resistor R15; the resistor R13 is connected to an output voltage sampling end V0; one end of the resistor R15 is connected to the first controller U1, and the other end is grounded; and Alternatively, the output voltage detection and control circuit includes resistors R16, R20, R22, R17, R23, R24, filter capacitor C7, and filter capacitor C9 connected in series with resistor R24; The voltage detection end V0 is connected to one end of resistor R17, and the other end of resistor R17 is connected to one end of resistors R20, R22, and R23 to form a parallel circuit; the other end of resistor R20 is connected to capacitor C7 and then to ground, and is connected to the voltage setting end SET-V of the first controller U1 through resistor R16; the other ends of resistors R22 and R23 are connected to ground.

6. An integrated battery charge protection electric vehicle charger circuit as defined in claim 3, wherein: The fan control circuit includes a fan control execution circuit and an output current detection circuit. The fan control execution circuit includes a first transistor Q1, the collector of the first transistor Q1 is connected to the power supply SRVDD through the first diode D1, and the first diode D1 is connected in parallel across the fan interface P1; the emitter of the first transistor Q1 is connected to ground through resistor R8, and the connection point of resistor R8 is connected to one control end of the first controller U1 through capacitor C1; resistor R8 and capacitor C1 are connected in parallel across resistor R6 and the second zener D2, and the base of the first transistor Q1 is connected to the other control end of the first controller U1 through resistor R2; The output current detection circuit includes a sampling resistor R10 and a capacitor C3, and is connected to one signal input interface of the first controller U1, and one end of the sampling resistor R10 is connected to the negative end OUT- of the charging switch circuit.

7. An integrated battery charge protection electric vehicle charger circuit as defined in claim 1, wherein: The charger circuit further includes a front-stage protection circuit, an EMI filter circuit, an input end rectification filter circuit, a power factor correction circuit, a power factor correction control circuit, a voltage conversion circuit, a voltage conversion control circuit, a feedback circuit, and an output end rectification filter circuit.

8. An integrated battery charge protection electric vehicle charger circuit as defined in claim 7, wherein: The power factor correction circuit includes a power switch Q4, a fourth diode D4, a magnetic bead FB1, a capacitor C11, and a resistor RS1; the drain D of the fourth switch Q4 is connected to the output end of the rectification filter circuit through the magnetic bead FB1 and the boost transformer T1; The boost transformer T1 is connected to the output end of the power factor correction circuit through the fourth diode D4; The source S of the fourth switch Q4 is connected to ground through the resistor RS1, and the filter capacitor C11 is connected between the source S and the drain D of the fourth switch Q4; the gate G of the fourth switch Q4 is connected to the driving end of the power factor correction control circuit for receiving a control signal.

9. An integrated battery charge protection electric vehicle charger circuit as defined in claim 1, wherein: The power factor correction control circuit includes a power factor correction control chip U2, and a chip power supply circuit, a first current detection circuit, a compensation circuit, and a driving control circuit.

10. A charger characterized by: An electric vehicle charger circuit integrated with battery charging protection according to any one of claims 1-9.

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