Charging pile output control external device circuit

Abstract

This utility model discloses an external device circuit for output control of a charging pile, specifically relating to the field of charging piles. It includes a PCB board on which a microcontroller unit, a Q14 input module, an optocoupler chip, a Q5 output module, and terminal blocks are integrated. This utility model outputs a high-level signal through the microcontroller unit and inputs it to the base of transistor Q14 through resistor R10. Under the action of resistor R342, the current flowing through the collector of transistor Q14 is approximately 20mA. At this time, the input current of the optocoupler is also 20mA. To ensure normal operation even under extreme conditions, the current transfer ratio of the optocoupler is minimized, resulting in an output current of approximately 10mA. In this case, transistor Q5 and the optocoupler combine to form a composite transistor to enhance the output current, preventing insufficient output drive capability when high current output is required. This circuit, which can be implemented with simple components such as optocouplers, transistors, and resistors, is low in cost.

Description

Technical Field

[0001] This utility model relates to the field of charging pile technology, and more specifically, to a circuit for an external device for output control of a charging pile. Background Technology

[0002] With more and more charging pile manufacturers joining the market, competition in the charging pile market is becoming increasingly fierce. To maintain a good advantage in this increasingly stable and mature market, it is necessary to optimize the product.

[0003] Currently, most charging piles control their output via relays through the MCU on the control board. Since there are many output nodes and relays consume a significant amount of current during operation, the power consumption of the entire control board is high when multiple relays are active. This can affect the stability of the entire power system, leading to issues such as overheating. Furthermore, relays are large and expensive, requiring sufficient space in the control board design, thus increasing the board's area. The switching process of relays also generates electromagnetic interference, affecting the stability of surrounding functions. Utility Model Content

[0004] In order to overcome the above-mentioned defects of the prior art, the embodiments of this utility model provide a charging pile output control external device circuit. The technical problem to be solved by the present invention is to specifically solve the problems of high power consumption, high price and interference of traditional relay solutions in the prior art.

[0005] To achieve the above objectives, this utility model provides the following technical solution: a charging pile output control external device circuit, including a PCB board, on which a microcontroller unit, a Q14 input module, an optocoupler chip, a Q5 output module and wiring terminals are integrated. The microcontroller unit is electrically connected to the Q14 input module, the Q14 input module is electrically connected to the optocoupler chip, the optocoupler chip is electrically connected to the Q5 output module, and the Q5 output module is electrically connected to the wiring terminals.

[0006] The Q14 input module consists of a transistor Q14 and resistors R10, R197, and R342 forming a current conversion circuit.

[0007] The input terminal of the optocoupler chip is connected to the emitter of Q14, and the output terminal of the optocoupler chip drives the terminal block through the output module of Q5.

[0008] In a preferred embodiment, the Q14 input module includes a resistor R10, the base of a transistor Q14 connected in series with the resistor R10, a resistor R197 connected in series with the base of the transistor Q14, the resistor R197 being connected to ground, the emitter of the transistor Q14 being connected in series with pin 1 on the optocoupler chip, and a resistor R342 connected in series with the collector of the transistor Q14, the resistor R342 being connected to VCC-3.3V.

[0009] In a preferred embodiment, the optocoupler chip is configured as a four-pin chip including pin 1, pin 2, pin 3 and pin 4;

[0010] Among them, pin 2 on the optocoupler chip is connected to the ground terminal; pin 1 is connected to the emitter of Q14.

[0011] In a preferred embodiment, the Q5 output module includes a resistor R328, the resistor R328 is connected in parallel to the base and emitter of a transistor Q5, and the emitter and collector of the transistor Q5 are connected in parallel to a transient diode D95.

[0012] The collector of transistor Q5 is connected in series with pin 3 on the optocoupler chip, and pin 3 on the optocoupler chip is connected to the ground terminal. The emitter of transistor Q5 is connected to the terminal block.

[0013] The technical effects and advantages of this utility model are as follows:

[0014] This invention outputs a high-level signal through a microcontroller unit and inputs it to the base of transistor Q14 through resistor R10. Under the action of resistor R342, the current flowing through the collector of transistor Q14 is approximately 20mA. At this time, the input current of the optocoupler is also 20mA. In order to ensure that the circuit can work normally under extreme conditions, the current transfer ratio of the optocoupler is taken to be the minimum. It can be known that the output current of the optocoupler is about 10mA. At this time, transistor Q5 and optocoupler are combined into a composite transistor to enhance the output current, so as to avoid insufficient output drive capability when a large current output is required. That is, to realize the external device circuit for output control of charging pile. This circuit can be implemented with simple optocoupler, transistor, resistor and other components, and the cost is low.

[0015] The optocoupler pre-stage drive current of this utility model is about 20mA. Compared with the traditional relay drive circuit, although the relay drive current is 17mA, the voltage of the optocoupler pre-stage drive circuit is reduced by three to four times, and the overall power consumption is also reduced by three to four times, which is beneficial to the heat dissipation problem of the power supply system.

[0016] When this device is arranged on a PCB board, there is no need to worry about interference during the relay engagement process, and the overall layout occupies little space. Attached Figure Description

[0017] Figure 1 This is the circuit schematic diagram of this utility model.

[0018] The attached diagram is labeled as follows: 1 Microcontroller unit, 2 Q14 input module, 3 Optocoupler chip, 4 Q5 output module, 5 Terminal block. Detailed Implementation

[0019] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0020] This utility model provides, for example Figure 1 The circuit for an external device for output control of a charging pile shown includes a PCB board. The PCB board integrates a microcontroller unit 1, a Q14 input module 2, an optocoupler chip 3, a Q5 output module 4, and a terminal block 5. The microcontroller unit 1 is electrically connected to the Q14 input module 2, the Q14 input module 2 is electrically connected to the optocoupler chip 3, the optocoupler chip 3 is electrically connected to the Q5 output module 4, and the Q5 output module 4 is electrically connected to the terminal block 5.

[0021] The Q14 input module 2 consists of a transistor Q14 and resistors R10, R197, and R342 forming a current conversion circuit. The Q14 input module 2 includes a resistor R10, which is connected in series with the base of transistor Q14. The base of transistor Q14 is connected in series with resistor R197, which is connected to the ground terminal. The emitter of transistor Q14 is connected in series with pin 1 on optocoupler chip 3. The collector of transistor Q14 is connected in series with resistor R342, which is connected to VCC-3.3V.

[0022] The input terminal of optocoupler chip 3 is connected to the emitter of Q14, and the output terminal of optocoupler chip 3 drives terminal 5 through output module 4 of Q5; optocoupler chip 3 is configured as a four-pin chip including pin 1, pin 2, pin 3 and pin 4; wherein, pin 2 on optocoupler chip 3 is connected to the ground terminal; pin 1 is connected to the emitter of Q14.

[0023] Q5 output module 4 includes resistor R328, with resistor R328 connected in parallel to the base and emitter of transistor Q5, and transient diode D95 connected in parallel to the emitter and collector of transistor Q5; the collector of transistor Q5 is connected in series with pin 3 on optocoupler chip 3, and pin 3 on optocoupler chip 3 is connected to ground terminal; the emitter of transistor Q5 is connected to terminal 5.

[0024] Microcontroller unit 1 outputs a 3.3V PWM control signal;

[0025] The Q14 input module 2 consists of a transistor 2N3904 (Q14), resistors R10, R197, and R342, which convert the MCU signal into a 20mA optocoupler drive current.

[0026] Optical coupler chip 3 Current transfer ratio (CTR) 50%-600%;

[0027] The Q5 output module 4 consists of a transistor TIP31C (Q5), a transient diode D95, and a resistor R328 (10kΩ), and can output a current of up to 1A.

[0028] Terminal 5 J1 is used to connect an external load;

[0029] Resistors R10 and R197 form a voltage divider network to ensure that the conduction voltage of Q14 is stable at 0.7±0.05V;

[0030] The transient diode D95 suppresses transient voltages >15V caused by sudden load changes and is used for output protection;

[0031] The specific implementation method is as follows:

[0032] Microcontroller unit 1 outputs a high level (3.3V) → Q14 input module 2 is saturated and turned on → 20mA current flows through the primary side of optocoupler chip 3;

[0033] When the secondary side of the optocoupler chip 3 is turned on, the base of the Q5 output module 4 receives a 10mA drive current (calculated at 50% CTR) and the Q5 output module 4 outputs a 1A load current.

[0034] When the load is short-circuited, the transient diode D95 clamps the voltage to below 15V within 1ns, protecting the output module 4 of Q5.

[0035] Table 1 Key Parameter Verification

[0036] parameter Measured value Traditional relay solution Single-channel power consumption 66mW 225mW Response time 1.2ms 8ms Volume ratio 15% 40%

[0037] As shown in the table above, by utilizing the cascaded architecture of signal flow from microcontroller unit 1 → Q14 input module 2 → optocoupler chip 3 → Q5 output module 4 → terminal block 5, a control function of 3.3V low-voltage drive and 1A high-current output can be achieved. Compared with the relay solution, power consumption is reduced by 70%, volume is reduced by 62%, and cost is reduced by 59%. It is suitable for high-density charging pile control board design, thus solving the three major technical defects of high power consumption, large size, and electromagnetic interference of the relay solution.

[0038] Finally, the following points should be noted: First, in the description of this application, it should be noted that, unless otherwise specified and limited, the terms "installation", "connection", and "linkage" should be interpreted broadly, and can be mechanical or electrical connections, or internal connections between two components, or direct connections. "Up", "down", "left", "right", etc. are only used to indicate relative positional relationships. When the absolute position of the described object changes, the relative positional relationship may change.

[0039] Secondly: The accompanying drawings of the embodiments disclosed in this utility model only involve the structures involved in the embodiments disclosed in this utility model. Other structures can refer to the general design. In the absence of conflict, the same embodiment and different embodiments of this utility model can be combined with each other.

[0040] Finally: The above description is only a preferred embodiment of the present utility model and is not intended to limit the present utility model. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present utility model should be included within the protection scope of the present utility model.

Claims

1. A circuit for controlling external devices in a charging pile output, comprising a PCB board, characterized in that: The PCB board integrates a microcontroller unit (1), a Q14 input module (2), an optocoupler chip (3), a Q5 output module (4), and a terminal block (5). The microcontroller unit (1) is electrically connected to the Q14 input module (2), the Q14 input module (2) is electrically connected to the optocoupler chip (3), the optocoupler chip (3) is electrically connected to the Q5 output module (4), and the Q5 output module (4) is electrically connected to the terminal block (5). The Q14 input module (2) consists of a transistor Q14 and resistors R10, R197, and R342 forming a current conversion circuit. The input terminal of the optocoupler chip (3) is connected to the emitter of Q14, and the output terminal of the optocoupler chip (3) drives the terminal block (5) through the output module (4) of Q5.

2. The charging pile output control external device circuit according to claim 1, characterized in that: The Q14 input module (2) includes a resistor R10, the base of a transistor Q14 is connected in series with the resistor R10, the base of a transistor Q14 is connected in series with a resistor R197, the resistor R197 is connected to the ground terminal, the emitter of a transistor Q14 is connected in series with pin 1 on an optocoupler chip (3), the collector of a transistor Q14 is connected in series with a resistor R342, and the resistor R342 is connected to VCC-3.3V.

3. The charging pile output control external device circuit according to claim 2, characterized in that: The optocoupler chip (3) is configured as a four-pin chip including pin 1, pin 2, pin 3 and pin 4; Among them, pin 2 on the optocoupler chip (3) is connected to the ground terminal; pin 1 is connected to the emitter of Q14.

4. The charging pile output control external device circuit according to claim 3, characterized in that: The Q5 output module (4) includes a resistor R328, the resistor R328 is connected in parallel with the base and emitter of a transistor Q5, and the emitter and collector of the transistor Q5 are connected in parallel with a transient diode D95; The collector of the transistor Q5 is connected in series with pin 3 on the optocoupler chip (3), and pin 3 on the optocoupler chip (3) is connected to the ground terminal. The emitter of the transistor Q5 is connected to the terminal block (5).

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