Alternating current and direct current judgment circuit

Abstract

The utility model provides an alternating current and direct current judging circuit, which is used for judging the type of input voltage and comprises a voltage division circuit used for dividing the input voltage; the operational amplifier circuit is used for carrying out operational amplification on the input voltage after voltage division; the comparison circuit is used for comparing the operational amplified input voltage with a reference voltage and outputting a signal; the detection circuit is used for receiving the voltage output by the comparison circuit and collecting a level signal; and when the detection circuit collects a continuously unchanged level signal, the input voltage is judged to be a direct current, and when the detection circuit collects a level signal of a PWM waveform, the input voltage is judged to be an alternating current. According to the alternating current and direct current judgment circuit, the voltage type is judged by optimizing the circuit structure, so that the battery management system can carry out corresponding charging configuration.

Description

Technical Field

[0001] The utility model relates to the technical field of charging piles, and particularly relates to an AC / DC judgment circuit. Background Art

[0002] With the implementation of the global carbon reduction and greening strategy, the new energy electric vehicle (abbreviated as electric vehicle) industry has developed rapidly, and various types of electric vehicles such as SUVs, sedans, off-road vehicles, and light pickups have emerged one after another to meet the needs of different consumers. With the continuous expansion of the electric vehicle market, as an important supporting facility for electric vehicles, the performance and technical requirements of charging piles have also been increasingly emphasized.

[0003] Especially in the charging technology aspect, in order to meet the demand for rapid charging of electric vehicles, DC charging (fast charging) technology has been widely applied. However, in regions such as North America, with the update of charging standards (such as the implementation of the NACS standard), some electric vehicles integrate the functions of DC charging (fast charging) and AC charging (slow charging) into the same charging port. Although this design improves the charging convenience, it also brings new challenges to the charging identification and configuration of charging piles.

[0004] Specifically, when the charging gun of an electric vehicle is inserted into a charging pile, the battery management system (BMS) needs to be able to accurately judge whether it is currently DC charging (fast charging) or AC charging (slow charging) in order to perform corresponding charging configurations. If it is unable to judge whether it is currently DC charging (fast charging) or AC charging (slow charging), this may lead to the risk of misjudgment during the charging process of the charging pile, thereby affecting the charging efficiency and safety. Summary of the Utility Model

[0005] In view of this, the utility model aims to propose an AC / DC judgment circuit, in order to optimize the circuit structure to judge the voltage type and facilitate the battery management system to perform corresponding charging configurations.

[0006] To achieve the above object, the technical solution of the utility model is realized as follows:

[0007] An AC / DC judgment circuit is used to judge the type of the input voltage. The judgment circuit includes:

[0008] A voltage division circuit for dividing the input voltage.

[0009] An operational amplifier circuit for performing operational amplification on the input voltage after voltage division.

[0010] A comparison circuit for comparing the input voltage after operational amplification with a reference voltage and outputting a signal.

[0011] A detection circuit, which is used to receive the signal output by the comparison circuit and collect the signal;

[0012] When the detection circuit collects a signal that remains unchanged, it is determined that the input voltage is DC. When the detection circuit collects a signal with a PWM waveform, it is determined that the input voltage is AC.

[0013] Further, the voltage dividing circuit includes a first resistor, a second resistor, a third resistor, a fourth resistor, a first optocoupler module, and a fifth resistor;

[0014] One side pin of the first resistor is connected to the positive pole of the charging pile, the other side pin of the first resistor is connected to one side pin of the second resistor, the other side pin of the second resistor is connected to one side pin of the third resistor, and the other side pin of the third resistor is connected to one side pin of the fourth resistor;

[0015] The first optocoupler module includes a light emitter and a photosensitive element. One side pin of the light emitter is connected to a 5V input voltage, the other side pin of the light emitter is grounded. The other side pin of the fourth resistor is connected to one side pin of the photosensitive element, the other side pin of the photosensitive element is connected to one side pin of the fifth resistor, and the other side pin of the fifth resistor is connected to the negative pole of the charging pile.

[0016] Further, a switch is connected in series between the other side pin of the light emitter and the ground.

[0017] Further, the operational amplifier circuit includes an operational amplifier. The positive power supply terminal of the operational amplifier is connected to a 5V input voltage, the negative power supply terminal of the operational amplifier is connected to the negative pole of the charging pile. The non-inverting input terminal of the operational amplifier receives the output voltage of the voltage dividing circuit and a 2.5V input voltage. A sixth resistor is connected in series between the non-inverting input terminal of the operational amplifier and the 2.5V input voltage. The inverting input terminal of the operational amplifier is connected to the negative pole of the charging pile, and a seventh resistor is provided between the inverting input terminal of the operational amplifier and the negative pole of the charging pile. The output terminal of the operational amplifier is connected to the comparison circuit.

[0018] Further, the comparison circuit includes a comparator. The positive power supply terminal of the comparator is connected to a 5V input voltage, the negative power supply terminal of the comparator is connected to the negative pole of the charging pile. The inverting input terminal of the comparator is connected to the output terminal of the operational amplifier circuit. An eighth resistor is connected in series between the inverting input terminal of the comparator and the output terminal of the operational amplifier circuit. The non-inverting input terminal of the comparator is connected to a 2.5V power supply, and a ninth resistor is connected in series between the non-inverting input terminal of the comparator and the 2.5V power supply.

[0019] Further, the detection circuit includes a second optocoupler module, a tenth resistor, an eleventh resistor, and an acquisition module;

[0020] The second optocoupler module includes a light emitter and a photosensitive element. One pin of the photosensitive element is connected to the output terminal of the comparison circuit, and the other pin of the photosensitive element is connected to the negative pole of the charging pile. A tenth resistor is connected in series between the photosensitive element and the negative pole of the charging pile;

[0021] One pin of the photosensitive element is grounded, and the other pin of the photosensitive element is connected to a 5V input voltage. An eleventh resistor is connected in series between the photosensitive element and the 5V input voltage;

[0022] The acquisition module acquires the level signal between the photosensitive element and the eleventh resistor.

[0023] Further, the acquisition module is an MCU, and the MCU is configured to be able to continuously acquire the level signal in the circuit.

[0024] Further, the PWM waveform is a PWM waveform that changes at 50 / 60Hz.

[0025] Compared with the prior art, the present utility model has the following advantages:

[0026] The AC / DC judgment circuit of the present utility model divides the input voltage through a voltage division circuit, amplifies it through an operational amplifier circuit, and then inputs it to a comparison circuit for comparison and then outputs a signal. By detecting the circuit to receive the signal and collecting and judging whether the output level is a continuous level or the level signal of a PWM waveform, it can be judged whether the input voltage is AC or DC, which is beneficial to the charging situation configuration of the charging pile.

[0027] Isolate the voltage division circuit through the optocoupler module. When the optocoupler module is turned on, the input voltage can be connected to the subsequent circuit, which is beneficial to controlling whether the AC / DC judgment circuit is enabled. And through the series connection of multiple resistors, it is beneficial for the voltage division circuit to divide the voltage. The structure is simple and beneficial for design and implementation.

[0028] The opening and closing of the optocoupler module are facilitated by the setting of the switch, which is beneficial for design and implementation.

[0029] The input voltage after voltage division is amplified by the operational amplifier, which is beneficial for controlling the magnitude of the voltage entering the comparison module and is helpful for design and implementation.

[0030] The voltage after amplification is compared with the reference voltage by the comparator, so that different signals can be output after comparison, which is helpful for distinguishing the voltage type and is beneficial for design and implementation.

[0031] The acquisition module is separated from the comparison circuit through an optocoupler module, so that when the optocoupler module is turned on, the acquisition module can acquire the corresponding level signal, and when the optocoupler module is turned off, the acquisition module can acquire another level signal. The type of the input voltage can be obtained by comparing the changes in the acquired level signals.

[0032] Use the MCU to collect the levels, which is convenient for configuring the functions of the acquisition module and helps with the design implementation. Brief Description of the Drawings

[0033] The drawings forming a part of the present utility model are used to provide a further understanding of the present utility model. The schematic embodiments and descriptions thereof of the present utility model are used to explain the present utility model and do not constitute an improper limitation to the present utility model. In the drawings:

[0034] Figure 1 It is a composition diagram of the AC / DC judgment circuit according to the embodiment of the present utility model;

[0035] Figure 2 It is a circuit schematic diagram of the AC / DC judgment circuit according to the embodiment of the present utility model;

[0036] Description of the Reference Numerals in the Drawings:

[0037] R1, the first resistor; R2, the second resistor; R3, the third resistor; R4, the fourth resistor; R5, the fifth resistor; R6, the sixth resistor; R7, the seventh resistor; R8, the eighth resistor; R9, the ninth resistor; R10, the tenth resistor; R11, the eleventh resistor; UD1, the first optocoupler module; UD2, the second optocoupler module; UA1, the operational amplifier; UA2, the comparator. Detailed Embodiment

[0038] It should be noted that, without conflict, the embodiments in the present utility model and the features in the embodiments can be combined with each other.

[0039] In the description of the present utility model, it should be noted that if terms indicating orientation or positional relationship such as "upper", "lower", "inner", "outer", etc. appear, they are based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present utility model and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus should not be construed as a limitation to the present utility model. In addition, if terms such as "first", "second", etc. appear, they are also only for descriptive purposes and cannot be construed as indicating or implying relative importance.

[0040] In addition, in the description of the present utility model, unless otherwise clearly defined, the terms "installation", "connection", "connection", and "connector" shall be understood in a broad sense. For example, it may be a fixed connection, a detachable connection, or an integral connection; it may be a mechanical connection or an electrical connection; it may be directly connected or indirectly connected through an intermediate medium, and it may be the communication inside two components. For those of ordinary skill in the art, the specific meanings of the above terms in the present utility model can be understood in combination with specific situations.

[0041] The present utility model will be described in detail below with reference to the drawings and in conjunction with embodiments.

[0042] Embodiment 1

[0043] This embodiment relates to an AC / DC judgment circuit, aiming to judge the voltage type by optimizing the circuit structure to facilitate the corresponding charging configuration of the battery management system.

[0044] In terms of the overall structure, in combination with Figure 1 as shown, the AC / DC judgment circuit in this embodiment is used to judge the type of the input voltage, and the judgment circuit includes:

[0045] A voltage division circuit, which is used to divide the input voltage.

[0046] An operational amplifier circuit, which is used to perform operational amplification on the divided input voltage.

[0047] A comparison circuit, which is used to compare the amplified input voltage with a reference voltage and output a signal.

[0048] A detection circuit, which is used to receive the signal output by the comparison circuit and collect the signal.

[0049] When the detection circuit collects a continuously unchanged signal, it is judged that the input voltage is DC. When the detection circuit collects a signal with a PWM waveform, it is judged that the input voltage is AC.

[0050] With the above settings, the AC / DC judgment circuit in this embodiment divides the input voltage through the voltage division circuit, performs operational amplification through the operational amplifier circuit, then inputs it to the comparison circuit for comparison and outputs a signal. The detection circuit receives the signal and collects and judges whether the output level is a continuous level or a level signal with a PWM waveform, so as to judge whether the input voltage is AC or DC, which is beneficial to the charging situation configuration of the charging pile.

[0051] In this embodiment, when the type of the input voltage is alternating current, the detection circuit collects a PWM waveform that changes at 50 / 60 Hz.

[0052] In order to better control the voltage division circuit, in combination with Figure 2As shown, the voltage division circuit in this embodiment includes a first resistor R1, a second resistor R2, a third resistor R3, a fourth resistor R4, a first optocoupler module UD1, and a fifth resistor R5.

[0053] Among them, one side pin of the first resistor R1 is connected to the positive pole of the charging pile, the other side pin of the first resistor R1 is connected to one side pin of the second resistor R2, the other side pin of the second resistor R2 is connected to one side pin of the third resistor R3, and the other side pin of the third resistor R3 is connected to one side pin of the fourth resistor R4.

[0054] The first optocoupler module UD1 includes a light emitter and a photosensitive element. One side pin of the light emitter is connected to the 5V input voltage, the other side pin of the light emitter is grounded. The other side pin of the fourth resistor R4 is connected to one side pin of the photosensitive element, the other side pin of the photosensitive element is connected to one side pin of the fifth resistor R5, and the other side pin of the fifth resistor R5 is connected to the negative pole of the charging pile. The voltage division circuit is isolated through the optocoupler module. When the optocoupler module is turned on, the input voltage can be connected to the subsequent circuit, which is beneficial to controlling whether the AC-DC judgment circuit is enabled. And through the series connection of multiple resistors, it is beneficial for the voltage division circuit to divide the voltage. The structure is simple and beneficial for design and implementation.

[0055] Specifically, a switch is connected in series between the other side pin of the light emitter of the first optocoupler module UD1 in this embodiment and the ground. Through the setting of the switch, the opening and closing of the optocoupler module are convenient to control, which is beneficial for design and implementation.

[0056] For the convenience of operational amplifying the voltage after voltage division, combined with Figure 2 As shown, the operational amplifier circuit in this embodiment includes an operational amplifier UA1.

[0057] Among them, the positive power supply terminal of the operational amplifier UA1 is connected to the 5V input voltage, the negative power supply terminal of the operational amplifier UA1 is connected to the negative pole of the charging pile. The non-inverting input terminal of the operational amplifier UA1 receives the output voltage of the voltage division circuit and the 2.5V input voltage. A sixth resistor R6 is connected in series between the non-inverting input terminal of the operational amplifier UA1 and the 2.5V input voltage. The inverting input terminal of the operational amplifier UA1 is connected to the negative pole of the charging pile, and a seventh resistor R7 is provided between the inverting input terminal of the operational amplifier UA1 and the negative pole of the charging pile. The output terminal of the operational amplifier UA1 is connected to the comparison circuit. The operational amplifier UA1 operational amplifies the input voltage after voltage division, which is beneficial for controlling the magnitude of the voltage entering the comparison module and is helpful for design and implementation.

[0058] For the convenience of controlling the output signal, combined with Figure 2As shown in the figure, the comparison circuit in this embodiment includes a comparator UA2. The positive power supply terminal of the comparator UA2 is connected to the 5V input voltage, the negative power supply terminal of the comparator UA2 is connected to the negative pole of the charging pile, the negative input terminal of the comparator UA2 is connected to the output terminal of the operational amplifier circuit, and an eighth resistor R8 is connected in series between the negative input terminal of the comparator UA2 and the output terminal of the operational amplifier circuit. The positive input terminal of the comparator UA2 is connected to the 2.5V power supply, and a ninth resistor R9 is connected in series between the positive input terminal of the comparator UA2 and the 2.5V power supply. The comparator UA2 compares the voltage after being amplified by the operational amplifier with the reference voltage, so that different signals can be output after comparison, which helps to distinguish the voltage type and is beneficial to the design and implementation.

[0059] To facilitate the acquisition of the signal output by the comparison circuit, in combination with Figure 2 As shown in the figure, the detection circuit in this embodiment includes a second optocoupler module UD2, a tenth resistor R10, an eleventh resistor R11, and an acquisition module.

[0060] Among them, the second optocoupler module UD2 includes a light emitter and a photosensitive element. One side pin of the photosensitive element is connected to the output terminal of the comparison circuit, the other side pin of the photosensitive element is connected to the negative pole of the charging pile, and a tenth resistor R10 is connected in series between the photosensitive element and the negative pole of the charging pile.

[0061] One side pin of the photosensitive element is grounded, the other side pin of the photosensitive element is connected to the 5V input voltage, an eleventh resistor R11 is connected in series between the photosensitive element and the 5V input voltage, and the acquisition module acquires the level signal between the photosensitive element and the eleventh resistor R11. The optocoupler module separates the acquisition module from the comparison circuit, so that when the optocoupler module is turned on, the acquisition module can acquire the corresponding level signal, and when the optocoupler module is turned off, the acquisition module can acquire another level signal. By comparing the changes in the acquired level signals, the type of the input voltage can be obtained.

[0062] Specifically, the acquisition module in this embodiment is an MCU (Microcontroller Unit), and the MCU is configured to be able to continuously acquire the level signals in the circuit. Using the MCU to acquire the levels is convenient for configuring the functions of the acquisition module and is beneficial to the design and implementation.

[0063] More specifically, the MCU is electrically connected to the BMS (Battery Management System) of the vehicle's battery pack. Through the level signals acquired by the MCU, the BMS can be assisted in controlling the charging mode.

[0064] In the AC / DC judgment circuit of this embodiment, when the first optocoupler module UD1 is turned on and the input voltage is a positive voltage, voltage division is performed through the voltage division circuit. At this time, the voltage value input to the operational amplifier circuit is the voltage division value of the fifth resistor R5, and the voltage output by the operational amplifier circuit is the superimposed voltage of the voltage division value of the fifth resistor R5 and the 2.5V voltage. At this time, the voltage input to the comparison circuit is greater than 2.5V, so the comparison circuit outputs a low level. At this time, the second optocoupler module UD2 is not turned on, so the MCU collects a continuous high level, and it is judged that the type of the input voltage at this time is DC.

[0065] When the first optocoupler module UD1 is turned on and the input voltage is an AC voltage, voltage division is performed through the voltage division circuit. At this time, the voltage value input to the operational amplifier circuit is still the voltage division value of the fifth resistor R5, and the voltage output by the operational amplifier circuit is the superimposed voltage of the voltage division value of the fifth resistor R5 and the 2.5V voltage. When the input voltage is positive, the MCU still collects a high level. When the input voltage is negative, the voltage output by the operational amplifier circuit is less than 2.5V, the comparison circuit outputs a high level, and the second optocoupler module UD2 is turned on, so the MCU collects a low level. Since the AC voltage fluctuates continuously, the MCU will collect a PWM waveform that changes at 50 / 60Hz.

[0066] The AC / DC judgment circuit in this embodiment divides the input voltage through the voltage division circuit, superimposes the divided input voltage through the comparison circuit, and can output different signals after comparison by the comparison circuit, so that the second optocoupler module UD2 can be opened and closed, so that the MCU can collect different level signals to judge the type of the input voltage. The circuit is isolated by two optocoupler modules, which is beneficial to realizing the opening and closing of the AC / DC judgment circuit, and can make the MCU detect different signals through the on / off of the second optocoupler module UD2 to judge the type of the input voltage, which is beneficial to the design and implementation.

[0067] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. An AC / DC judgment circuit for judging the type of input voltage, characterized in that: The judgment circuit comprises: A voltage divider circuit, the voltage divider circuit is used to divide the input voltage; An operational amplifier circuit, the operational amplifier circuit is used to perform operational amplification on the divided input voltage; A comparison circuit, the comparison circuit is used to compare the input voltage after the operational amplifier with a reference voltage and output a signal; A detection circuit, the detection circuit is used to receive the signal output by the comparison circuit and collect the signal; When the detection circuit collects a continuous signal, it is determined that the input voltage is a direct current. When the detection circuit collects a signal with a PWM waveform, it is determined that the input voltage is an alternating current.

2. The AC / DC determination circuit according to claim 1, characterized in that: The voltage divider circuit includes a first resistor, a second resistor, a third resistor, a fourth resistor, a first optical coupling module and a fifth resistor; One side pin of the first resistor is connected to the positive electrode of the charging pile, the other side pin of the first resistor is connected to one side pin of the second resistor, the other side pin of the second resistor is connected to one side pin of the third resistor, and the other side pin of the third resistor is connected to one side pin of the fourth resistor; The first optocoupler module includes a light emitter and a photosensitive element, one side pin of the light emitter is connected to a 5V input voltage, the other side pin of the light emitter is grounded, the other side pin of the fourth resistor is connected to one side pin of the photosensitive element, the other side pin of the photosensitive element is connected to one side pin of the fifth resistor, and the other side pin of the fifth resistor is connected to the negative pole of the charging pile.

3. The AC / DC judgment circuit according to claim 2, characterized in that: A switch is connected in series between the pin on the other side of the light emitter and the ground.

4. The AC / DC judgment circuit according to claim 1, characterized in that: The operational amplifier circuit includes an operational amplifier; The positive power terminal of the operational amplifier is connected to a 5V input voltage, the negative power terminal of the operational amplifier is connected to the negative electrode of the charging pile, the same-direction input terminal of the operational amplifier receives the output voltage of the voltage divider circuit and the 2.5V input voltage, a sixth resistor is connected in series between the same-direction input terminal of the operational amplifier and the 2.5V input voltage, the negative input terminal of the operational amplifier is connected to the negative electrode of the charging pile, and a seventh resistor is provided between the negative input terminal of the operational amplifier and the negative electrode of the charging pile; the output terminal of the operational amplifier is connected to the comparison circuit.

5. The AC / DC judgment circuit according to claim 1, characterized in that: The comparison circuit includes a comparator, the positive power terminal of the comparator is connected to a 5V input voltage, the negative power terminal of the comparator is connected to the negative pole of the charging pile, the negative input terminal of the comparator is connected to the output terminal of the operational amplifier circuit, an eighth resistor is connected in series between the negative input terminal of the comparator and the output terminal of the operational amplifier circuit, the same-direction input terminal of the comparator is connected to a 2.5V power supply, and a ninth resistor is connected in series between the same-direction input terminal of the comparator and the 2.5V power supply.

6. The AC / DC determination circuit according to claim 1, characterized in that: The detection circuit includes a second optical coupling module, a tenth resistor, an eleventh resistor and a collection module; The second optical coupling module includes a light emitter and a photosensitive element, one side pin of the photosensitive element is connected to the output end of the comparison circuit, the other side pin of the photosensitive element is connected to the negative electrode of the charging pile, and a tenth resistor is connected in series between the photosensitive element and the negative electrode of the charging pile; One side pin of the photosensitive element is grounded, the other side pin of the photosensitive element is connected to a 5V input voltage, and an eleventh resistor is connected in series between the photosensitive element and the 5V input voltage; The acquisition module acquires a level signal between the photosensitive element and the eleventh resistor.

7. The AC / DC determination circuit according to claim 6, characterized in that: The acquisition module is an MCU, and the MCU is configured to continuously acquire level signals in the circuit.

8. The AC / DC judgment circuit according to any one of claims 1 to 7, characterized in that: The PWM waveform is a 50 / 60 Hz varying PWM waveform.

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