DC-DC (Direct Current-Direct Current) constant-voltage constant-current boosting electric vehicle charger

Abstract

The utility model discloses a DC-DC (direct current-direct current) constant-voltage constant-current boosting electric vehicle charger. The internal circuit comprises a DC input and detection circuit, an input MOSFET TTP switch circuit, a boost circuit, an output filter circuit, an output battery voltage detection circuit, an LDO step-down circuit, an RX / TX one-wire communication input and output circuit, an OTP over-temperature protection circuit, an MCU control circuit, an output voltage control circuit and an output current control circuit. According to the DC-DC direct-current constant-voltage constant-current boosting electric vehicle charger, the input MOSFET TTP switching circuit, the direct-current boosting circuit, the MCU control circuit, the output voltage control circuit and the output current control circuit are designed, so that a power supply charger can be used on a direct-current charging pile with lower output voltage to quickly charge a high-voltage battery pack with higher voltage; in addition, the charging efficiency is high, the working performance is stable, and the charger is safer.

Description

Technical Field

[0001] This utility model belongs to the field of power charger technology, specifically relating to a DC-DC constant voltage constant current boost electric vehicle charger. Background Technology

[0002] Electric bicycle charging stations are divided into AC and DC types, with DC charging stations offering significantly faster charging speeds than AC stations. DC charging stations for electric bicycles typically output voltages of 48V, 36V, 60V, and above, with 48V being the most common. High-performance electric bicycles or motorcycles may use batteries with voltages of 60V or even higher, requiring corresponding voltage outputs from the charging station. However, existing electric bicycle chargers commonly use AC input. Therefore, it is necessary to design electric bicycle chargers that can be used with DC charging stations that have lower output voltages, such as 48V, enabling fast charging of higher-voltage battery packs to meet user needs. Utility Model Content

[0003] The purpose of this invention is to address the above-mentioned problems by providing a DC-DC constant voltage and constant current boost electric vehicle charger, which enables fast charging of high-voltage battery packs with higher voltage on DC charging piles with lower output voltage, thus meeting people's usage needs.

[0004] This utility model is achieved through the following technical solution:

[0005] A DC-DC constant voltage and constant current boost electric vehicle charger, the internal circuit of which includes a DC input and detection circuit, an input MOSFETTP switching circuit, a boost circuit, an output filter circuit, an output battery voltage detection circuit, an LDO buck circuit, an RX / TX one-line communication input and output circuit, an OTP over-temperature protection circuit, an MCU control circuit, an output voltage control circuit, and an output current control circuit;

[0006] The DC input and detection circuit includes a DC input terminal, with a fuse F1 connected in series on the positive line of the DC input terminal, and detection resistors R7 and R6 connected between the positive and negative terminals of the DC input terminal. The detection resistors R7 and R6 are connected in series between the positive and negative terminals of the DC input terminal. The output terminal of the DC input and detection circuit is connected to the input MOSFET TP switching circuit and the LDO buck circuit, respectively.

[0007] The LDO step-down circuit reduces the voltage introduced by the DC input and the detection circuit, and outputs the 12V drive voltage required by the boost circuit and the +5V voltage required by other circuits.

[0008] The RX / TX one-line communication input / output circuit introduces the detection signal collected by the DC input and the detection resistor of the detection circuit, processes the detection signal, and outputs it to the MCU control circuit.

[0009] The MCU control circuit includes an MCU chip U4, the model of which is HT45F5Q-2A;

[0010] The input MOSFETTP switching circuit includes MOSFETs Q1, Q2, and Q3. The sources of MOSFETs Q1 and Q3 are connected together. The drain of MOSFET Q1 is connected to the positive output terminal of the DC input and detection circuit 1. The gates of MOSFETs Q1 and Q3 are connected together and connected to the drain of MOSFET Q2 through a resistor R10. The source of MOSFET Q2 is grounded. The gate of MOSFET Q2 is connected to the Gate2 drive pin of MCU chip U4 through a resistor R8. The drain of MOSFET Q3 is output as the positive terminal to the boost circuit.

[0011] The boost circuit includes a boost MOSFET Q7 and transistors Q5 and Q6. The emitters of transistors Q5 and Q6 are connected together and then connected to the gate of MOSFET Q7 via resistors R20 and R23. The collector of transistor Q5 is connected to a 12V drive voltage, and the collector of transistor Q6 is connected to the source of MOSFET Q7 and grounded. The bases of transistors Q5 and Q6 are connected to the Gate1 drive pin of MCU chip U4. The source and drain of MOSFET Q7 are connected to the output filter circuit, and the filtered voltage is output to the output battery voltage detection circuit.

[0012] The output battery voltage detection circuit includes series detection resistors R39 and R38 connected between the output terminals. The common terminal of resistors R39 and R38 is connected to the ADC0 input pin of MCU chip U4 through resistor R40.

[0013] The OTP over-temperature protection circuit includes a thermistor RT1, whose detection signal NTC3 is connected to the detection input pin PB2 (pin 14) of the MCU chip U4.

[0014] The output voltage control circuit and the output current control circuit respectively collect voltage and current sampling values ​​from the output battery voltage detection circuit and the output filter circuit, and obtain constant voltage and constant current output through the MCU control circuit.

[0015] Furthermore, the output voltage control circuit introduces a sampling voltage from the positive terminal of the output battery voltage detection circuit, and connects it to the OPA1N input pin (pin 5) of the MCU chip U4 through resistor R34. One end of the two input terminals of the optocoupler PC1 is connected to +5V through resistor R28, and the other end is connected to the OPAE input pin (pin 6) of the MCU chip U4 through resistor R27. One end of the two output terminals of the optocoupler PC1 is connected to the PB1 (pin 15) input pin of the MCU chip U4, and the other end is grounded.

[0016] Furthermore, the output current control circuit introduces the current sampling signal IOSEN from the output filter circuit, one path is connected to the OPA0N input pin (pin 7) of the MCU chip U4 through resistor R33, and the other path is connected to the OPA2P input pin (pin 8) of the MCU chip U4 through resistor R31.

[0017] Furthermore, the LDO step-down circuit includes a chip U1 with model number OB21085 and a chip U2 with model number CJ6385A50P.

[0018] Furthermore, the MCU control circuit is also connected to a charging indicator LED1. LED1 is a dual-channel indicator, with one channel connected between pin 10 of the MCU chip U4 and +5V, and the other channel connected between pin 11 of the MCU chip U4 and +5V.

[0019] The beneficial effects of this utility model are as follows: The DC-DC constant voltage and constant current boost electric vehicle charger of this utility model is designed with an input MOSFETTP switch circuit, a DC boost circuit, an MCU control circuit, an output voltage control circuit, and an output current control circuit. This allows the power charger to be used on DC charging piles with lower output voltages to fast charge high-voltage battery packs with higher voltages, meeting people's usage needs. It also has high charging efficiency, stable working performance, and is safer. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of the principle of this utility model.

[0021] Figure 2 This is the circuit schematic diagram of this utility model.

[0022] In the diagram, 1. DC input and detection circuit, 2. Input MOSFETTP switching circuit, 3. Boost circuit, 4. Output filter circuit, 5. Output battery voltage detection circuit, 6. LDO buck circuit, 7. RX / TX one-line communication input / output circuit, 8. OTP over-temperature protection circuit, 9. MCU control circuit, 10. Output voltage control circuit, and 11. Output current control circuit. Detailed Implementation

[0023] The present invention will be further illustrated below with reference to specific examples and accompanying drawings.

[0024] like Figure 1 , Figure 2 As shown, a DC-DC constant voltage and constant current boost electric vehicle charger includes the following internal circuits: 1. DC input and detection circuit; 2. Input MOSFET TP switching circuit; 3. Boost circuit; 4. Output filter circuit; 5. Output battery voltage detection circuit; 6. LDO buck circuit; 7. RX / TX one-line communication input and output circuit; 8. OTP over-temperature protection circuit; 9. MCU control circuit; 10. Output voltage control circuit; and 11. Output current control circuit.

[0025] The DC input and detection circuit 1 includes a DC input terminal, a fuse F1 connected in series on the positive line of the DC input terminal, and detection resistors R7 and R6 connected between the positive and negative terminals of the DC input terminal. The detection resistors R7 and R6 are connected in series between the positive and negative terminals of the DC input terminal. The output terminal of the DC input and detection circuit 1 is connected to the input MOSFET TP switching circuit 2 and the LDO buck circuit 6, respectively.

[0026] The LDO step-down circuit 6 steps down the voltage introduced by the DC input and detection circuit 1, and outputs the 12V drive voltage required by the boost circuit 3 and the +5V voltage required by other circuits; including chip U1 with model number OB21085 and chip U2 with model number CJ6385A50P.

[0027] The MCU control circuit 9 includes an MCU chip U4, model number HT45F5Q-2A; pin 1 VDD is connected to +5V, and pin 16 VSS is grounded.

[0028] The RX / TX one-line communication input / output circuit 7 introduces the detection signal collected by the detection resistor of the DC input and detection circuit 1, processes the detection signal, and outputs it to the second and third pins of the MCU control circuit 9.

[0029] The input MOSFETTP switching circuit 2 includes MOSFETs Q1, Q2, and Q3. The sources of MOSFETs Q1 and Q3 are connected together. The drain of MOSFET Q1 is connected to the positive output terminal of the DC input and detection circuit 1. The gates of MOSFETs Q1 and Q3 are connected together and connected to the drain of MOSFET Q2 through a resistor R10. The source of MOSFET Q2 is grounded. The gate of MOSFET Q2 is connected to the Gate2 drive pin of the MCU chip U4 through a resistor R8. The drain of MOSFET Q3 is output as the positive terminal to the boost circuit 3.

[0030] The boost circuit 3 includes a boost MOSFET Q7 and transistors Q5 and Q6. The emitters of transistors Q5 and Q6 are connected together and connected to the gate of MOSFET Q7 through resistors R20 and R23. The collector of transistor Q5 is connected to a 12V drive voltage, and the collector of transistor Q6 is connected to the source of MOSFET Q7 and grounded. The bases of transistors Q5 and Q6 are connected to the Gate1 drive pin (pin 13) of MCU chip U4. The source and drain of MOSFET Q7 are connected to the output filter circuit 4, and the filtered voltage is output to the output battery voltage detection circuit 5.

[0031] The output battery voltage detection circuit 5 includes series detection resistors R39 and R38 connected between the output terminals. The common terminal of resistors R39 and R38 is connected to the ADC0 input pin (pin 4) of the MCU chip U4 through resistor R40.

[0032] The OTP over-temperature protection circuit 8 includes a thermistor RT1, whose detection signal NTC3 is connected to the detection input pin PB2 (pin 14) of the MCU chip U4.

[0033] The output voltage control circuit 10 and the output current control circuit 11 respectively collect voltage and current sampling values ​​from the output battery voltage detection circuit 5 and the output filter circuit 4, and obtain constant voltage and constant current outputs through the MCU control circuit 9.

[0034] The output voltage control circuit 10 introduces a sampling voltage from the positive terminal of the output battery voltage detection circuit 5, and connects it to the OPA1N input pin (pin 5) of the MCU chip U4 through resistor R34. One end of the two input terminals of the optocoupler PC1 is connected to +5V through resistor R28, and the other end is connected to the OPAE input pin (pin 6) of the MCU chip U4 through resistor R27. One end of the two output terminals of the optocoupler PC1 is connected to the PB1 (pin 15) input pin of the MCU chip U4, and the other end is grounded.

[0035] The output current control circuit 11 introduces the current sampling signal IOSEN from the output filter circuit 4. One path is connected to the OPA0N input pin (pin 7) of the MCU chip U4 through resistor R33, and the other path is connected to the OPA2P input pin (pin 8) of the MCU chip U4 through resistor R31.

[0036] The MCU control circuit 9 is also connected to a charging indicator LED1. The LED1 is a dual-channel indicator, with one channel connected between pin 10 of the MCU chip U4 and +5V, and the other channel connected between pin 11 of the MCU chip U4 and +5V.

[0037] This utility model discloses a DC-DC constant voltage and constant current boost electric vehicle charger, which is designed with an input MOSFETTP switching circuit 2, a DC boost circuit 3, an MCU control circuit 9, an output voltage control circuit 10, and an output current control circuit 11. This allows the charger to be used on DC charging piles with lower output voltages (such as the more common 48V DC charging piles) and to fast charge higher voltage battery packs (such as 60V, 72V, etc.) to meet people's needs. The input MOSFETTP switching circuit 2, the DC boost circuit 3, the output voltage control circuit 10, and the output current control circuit 11 controlled by the MCU control circuit 9 result in high charging efficiency, stable operation, and enhanced safety of the charger.

[0038] The above embodiments are merely preferred embodiments of the present utility model and are only used to explain the present utility model, not to limit the present utility model. Any changes, substitutions, combinations, simplifications, modifications, etc., made by those skilled in the art without departing from the spirit and principle of the present utility model shall be considered equivalent substitutions and shall be included within the protection scope of the present utility model.

Claims

1. A DC-DC constant voltage constant current boost electric vehicle charger, characterized in that: Its internal circuitry includes a DC input and detection circuit, an input MOSFETTP switching circuit, a boost circuit, an output filter circuit, an output battery voltage detection circuit, an LDO buck circuit, an RX / TX one-line communication input / output circuit, an OTP over-temperature protection circuit, an MCU control circuit, an output voltage control circuit, and an output current control circuit. The DC input and detection circuit includes a DC input terminal, with a fuse F1 connected in series on the positive line of the DC input terminal, and detection resistors R7 and R6 connected between the positive and negative terminals of the DC input terminal. The detection resistors R7 and R6 are connected in series between the positive and negative terminals of the DC input terminal. The output terminal of the DC input and detection circuit is connected to the input MOSFET TP switching circuit and the LDO buck circuit, respectively. The LDO step-down circuit reduces the voltage introduced by the DC input and the detection circuit, and outputs the 12V drive voltage required by the boost circuit and the +5V voltage required by other circuits. The RX / TX one-line communication input / output circuit introduces the detection signal collected by the DC input and the detection resistor of the detection circuit, processes the detection signal, and outputs it to the MCU control circuit. The MCU control circuit includes an MCU chip U4, the model of which is HT45F5Q-2A; The input MOSFETTP switching circuit includes MOSFETs Q1, Q2, and Q3. The sources of MOSFETs Q1 and Q3 are connected together. The drain of MOSFET Q1 is connected to the positive output terminal of the DC input and detection circuit (1). The gates of MOSFETs Q1 and Q3 are connected together and connected to the drain of MOSFET Q2 through a resistor R10. The source of MOSFET Q2 is grounded. The gate of MOSFET Q2 is connected to the Gate2 drive pin of the MCU chip U4 through a resistor R8. The drain of MOSFET Q3 is output as the positive terminal to the boost circuit. The boost circuit includes a boost MOSFET Q7 and transistors Q5 and Q6. The emitters of transistors Q5 and Q6 are connected together and then connected to the gate of MOSFET Q7 via resistors R20 and R23. The collector of transistor Q5 is connected to a 12V drive voltage, and the collector of transistor Q6 is connected to the source of MOSFET Q7 and grounded. The bases of transistors Q5 and Q6 are connected to the Gate1 drive pin of MCU chip U4. The source and drain of MOSFET Q7 are connected to the output filter circuit, and the filtered voltage is output to the output battery voltage detection circuit. The output battery voltage detection circuit includes series detection resistors R39 and R38 connected between the output terminals. The common terminal of resistors R39 and R38 is connected to the ADC0 input pin of MCU chip U4 through resistor R40. The OTP over-temperature protection circuit includes a thermistor RT1, whose detection signal NTC3 is connected to the detection input pin PB2 of the MCU chip U4; The output voltage control circuit and the output current control circuit respectively collect voltage and current sampling values ​​from the output battery voltage detection circuit and the output filter circuit, and obtain constant voltage and constant current output through the MCU control circuit.

2. The DC-DC constant voltage constant current boost electric vehicle charger according to claim 1, characterized in that: The output voltage control circuit introduces a sampling voltage from the positive terminal of the output battery voltage detection circuit, and connects it to the OPA1N input pin of the MCU chip U4 through resistor R34. One end of the two input terminals of the optocoupler PC1 is connected to +5V through resistor R28, and the other end is connected to the OPAE input pin of the MCU chip U4 through resistor R27. One end of the two output terminals of the optocoupler PC1 is connected to the PB1 input pin of the MCU chip U4, and the other end is grounded.

3. The DC-DC constant voltage constant current boost electric vehicle charger according to claim 1, characterized in that: The output current control circuit introduces the current sampling signal IOSEN from the output filter circuit. One path is connected to the OPA0N input pin of the MCU chip U4 through resistor R33, and the other path is connected to the OPA2P input pin of the MCU chip U4 through resistor R31.

4. The DC-DC constant voltage constant current boost electric vehicle charger according to claim 1, characterized in that: The LDO step-down circuit includes chip U1 with model number OB21085 and chip U2 with model number CJ6385A50P.

5. The DC-DC constant voltage constant current boost electric vehicle charger according to claim 1, characterized in that: The MCU control circuit is also connected to a charging indicator LED1. LED1 is a dual-channel indicator, with one channel connected between pin 10 of the MCU chip U4 and +5V, and the other channel connected between pin 11 of the MCU chip U4 and +5V.

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