A detection circuit capable of identifying a charging mode and reporting a corresponding charging port temperature

Abstract

The application discloses a detection circuit capable of identifying a charging mode and reporting a corresponding charging port temperature, which comprises a first detection circuit for detecting the charging mode and a second detection circuit for self-checking and temperature detection, wherein the second detection circuit comprises thermistors arranged in slow charging ports and fast charging ports, the second detection circuit determines the resistance value of the thermistors by detecting a voltage, and then performs temperature detection. Compared with the prior art, the application can identify the charging type of a charger, detect the temperature of the charging port of the corresponding type, has better detection effect, and has a self-checking mode, so that the resistance value of each detection resistor can be detected to determine whether each detection resistor is out of specification, the influence of abnormal detection resistors on detection data is avoided, and the detection resistors are connected in series and in parallel, so that normal temperature detection can be realized even if a single resistor fails.

Description

Technical Field

[0001] This invention relates to the field of electric vehicle charging and discharging technology, and in particular to a detection circuit that can identify the charging mode and report the corresponding charging port temperature. Background Technology

[0002] With the increasing demand for energy conservation, emission reduction, and air pollution control, new energy vehicles are gradually being commercialized, with electric vehicles being the mainstay. As a crucial component of electric vehicles, the charger converts electrical energy from the grid into energy stored in the electric vehicle's battery. Currently, the input current of slow-charging cables for electric vehicles reaches 32A, while the peak current of fast-charging cables can exceed 200A. Prolonged high-current charging causes the charging interface and cable temperature to rise continuously, potentially leading to thermal runaway and damage to the charger. Therefore, it is necessary to monitor the charging port temperature to prevent thermal runaway.

[0003] Therefore, how to design a detection circuit that can identify the charging mode and report the corresponding charging port temperature to achieve charging port temperature detection is a technical problem that the industry urgently needs to solve. Summary of the Invention

[0004] In response to the problem in existing technologies where the temperature of the charging interface and cable rises, which can easily lead to thermal runaway and requires the design of a detection circuit to detect the temperature of the charging port, this invention proposes a detection circuit that can identify the charging mode and report the corresponding charging port temperature.

[0005] The technical solution of the present invention is to propose a detection circuit that can identify the charging mode and report the corresponding charging port temperature. The circuit includes a first detection circuit for detecting the charging mode and a second detection circuit for self-testing and temperature detection. The second detection circuit includes a thermistor disposed in the slow charging port and the fast charging port. The second detection circuit determines the resistance value of the thermistor by detecting the voltage, and then performs temperature detection.

[0006] Furthermore, the second detection circuit includes: resistors R2, R3, R4, Rref1, Rref2, thermistors RT1 and RT2, switches S1, S2, S3, and S4.

[0007] One end of switch S2 is connected to the power supply, and the other end is connected in series with resistor R4, resistor Rref2, switch S3, and resistor R3 before being grounded. One end of switch S1 is connected to the power supply, and the other end is connected in series with resistor R2 before being connected to the thermistor RT1. The other end of the thermistor RT1 is connected between switch S3 and resistor R3. One end of the thermistor RT2 is connected between resistor R4 and resistor Rref2, and the other end is connected between switch S3 and resistor R3. One end of resistor Rref1 is connected between resistor R2 and thermistor RT1, and the other end is connected between resistor Rref2 and switch S3. Switch S4 is connected in parallel across resistor R3.

[0008] The thermistor RT1 is located in the slow charging port. When the charging mode is slow charging, the thermistor RT1 is connected to the second detection circuit. The thermistor RT2 is located in the fast charging port. When the charging mode is fast charging, the thermistor RT2 is connected to the second detection circuit.

[0009] Furthermore, the second detection circuit also includes a second detection point located between resistor R2 and resistor Rref1, a third detection point located between resistor R3 and switch S3, and a fourth detection point located between resistor R4 and resistor Rref2. The second detection circuit performs self-testing and temperature detection by detecting the voltage at the second detection point, the third detection point, and the fourth detection point.

[0010] Furthermore, the first detection circuit includes: resistor R1 and resistor R5, one end of resistor R1 is connected to the power supply and the other end is connected to the slow charging port, and one end of resistor R5 is connected to the power supply and the other end is connected to the fast charging port.

[0011] Furthermore, the first detection circuit also includes a first detection point located between the resistor R1 and the slow charging port, and a fifth detection point located between the resistor R5 and the fast charging port. The first detection circuit determines the charging mode by detecting the voltage at the first detection point and the fifth detection point.

[0012] Furthermore, the detection circuit includes three detection modes, namely:

[0013] In self-test mode, the second detection circuit determines whether the detection circuit is abnormal and whether the resistance values ​​of resistors R2 and R3 are abnormal by detecting the voltage at the second and third detection points.

[0014] In the charging detection mode, the first detection circuit determines the charging mode by detecting the voltage at the first detection point and the fifth detection point.

[0015] In temperature detection mode, the second detection circuit calculates the resistance value of the thermistor RT1 or thermistor RT2 by detecting the voltage at the second detection point, the third detection point, and the fourth detection point, in order to perform temperature detection of the slow charging port or the fast charging port.

[0016] Furthermore, when the detection circuit is in self-test mode and is used to detect whether the detection circuit is abnormal, switches S1, S3, and S4 are closed. When the voltage at the second detection point is equal to 0 or the power supply voltage, the detection circuit is abnormal.

[0017] When the detection circuit is in self-test mode and is used to detect the resistance value of resistor R2, switches S1, S3, and S4 are closed, and the resistance value of resistor R2 is...

[0018] When the detection circuit is in self-test mode and is used to detect the resistance value of resistor R3, switches S1 and S3 are closed, and the resistance value of resistor R3 is...

[0019] When the detection circuit is in self-test mode and is used to detect the resistance value of resistor R4, switches S2, S3, and S4 are closed, and the resistance value of resistor R4 is...

[0020] Wherein, the voltage of the power supply is 5V, the resistance of the resistors Rref1 and Rref2 is 10K, V2 is the voltage of the second detection point, V3 is the voltage of the third detection point, and V4 is the voltage of the fourth detection point.

[0021] Furthermore, when the detection circuit is in charging detection mode, and the voltage at the first detection point is... When the detection circuit is in slow charging mode, and when the detection circuit is in charging mode, and the voltage at the fifth detection point is... At that time, the detection circuit is in fast charging mode;

[0022] Wherein, the voltage of the power supply is 5V, Rcc1 is the resistance of the internal circuit of the slow charging port, and Rcc2 is the resistance of the internal circuit of the fast charging port.

[0023] Furthermore, when the detection circuit is in temperature detection mode and the charging mode is slow charging mode, the switch S1 is closed, and the resistance of the thermistor RT1 is [value missing].

[0024] When the detection circuit is in temperature detection mode and the charging mode is fast charging mode, the switch S2 is closed, and the resistance of the thermistor RT2 is [value missing].

[0025] The detection circuit obtains the temperature of the fast charging port or the slow charging port by measuring the temperatures corresponding to thermistors RT1 and RT2.

[0026] Wherein, the voltage of the power supply is 5V, V2 is the voltage of the second detection point, V3 is the voltage of the third detection point, and V4 is the voltage of the fourth detection point.

[0027] Furthermore, resistors R2 and R3 are both composed of four 10K resistors connected in series and parallel. The series and parallel connection is that the four 10K resistors are connected end to end, and there is a connection between two adjacent 10K resistors and between the other two 10K resistors.

[0028] Compared with the prior art, the present invention has at least the following beneficial effects:

[0029] This invention proposes a detection circuit that can identify charging modes and report the corresponding charging port temperature. It can recognize the charging mode of the charger, detect the temperature of the charging port under the corresponding mode, and report it to the charger to prevent thermal runaway. Simultaneously, this invention also features a self-test mode that can check the resistance values ​​of each detection resistor to determine if any resistor is out of specification, avoiding the influence of abnormal detection resistors on the detection data. Furthermore, the detection resistors are composed of four resistors connected in series and parallel, so even if one resistor fails, normal temperature detection can still be achieved, resulting in higher safety. Attached Figure Description

[0030] To more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0031] Figure 1 This is a schematic diagram of the temperature detection circuit of the present invention.

[0032] Figure 2 This is a schematic diagram of the temperature detection principle of the detection circuit of the present invention in slow charging mode;

[0033] Figure 3 This is a schematic diagram of the temperature detection principle of the detection circuit of the present invention in fast charging mode;

[0034] Figure 4 This is a schematic diagram illustrating the principle of series and parallel resistors in the detection circuit of this invention.

[0035] Figure 5 This is a flowchart illustrating the implementation of the detection circuit of the present invention. Detailed Implementation

[0036] To make the technical problems to be solved, the technical solutions, and the beneficial effects of the present invention clearer, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the present invention and are not intended to limit the present invention.

[0037] Therefore, a feature pointed out in this specification is used to describe one feature of one embodiment of the invention, and does not imply that every embodiment of the invention must have the described feature. Furthermore, it should be noted that this specification describes many features. Although certain features may be combined to illustrate possible system designs, these features may also be used in other combinations not explicitly stated. Therefore, unless otherwise stated, the described combinations are not intended to be limiting.

[0038] The principles and structure of the present invention will be described in detail below with reference to the accompanying drawings and embodiments.

[0039] Currently, the input current of slow-charging cables for electric vehicles reaches 32A, while the peak current of fast-charging cables can exceed 200A. Prolonged high-current charging causes the charging interface and cable temperature to rise continuously, potentially leading to thermal runaway and damage to the charger. Therefore, temperature monitoring of the charging port is necessary to prevent thermal runaway. The technical solution of this invention is to propose a detection circuit that can identify the charging mode and report the corresponding charging port temperature. This circuit identifies the specific charging mode by detecting the voltage at each detection point, and simultaneously calculates the resistance of the thermistors inside both the fast-charging and slow-charging ports to achieve temperature detection of the corresponding charging port.

[0040] Specifically, the detection circuit proposed in this invention includes: a first detection circuit for detecting the charging mode, and a second detection circuit for self-testing and temperature detection.

[0041] Please see Figure 1 The first detection circuit includes: resistor R1 and resistor R5. One end of resistor R1 is connected to the power supply and the other end is connected to the slow charging port. One end of resistor R5 is connected to the power supply and the other end is connected to the fast charging port.

[0042] The invention includes a first detection point (detection point 1) between resistor R1 and the slow charging port, and a fifth detection point (detection point 5) between resistor R5 and the fifth detection point. Since one end of resistor R1 is connected to the power supply and the other end is connected to the slow charging port, a circuit can only be formed at resistor R1 when the charging mode is slow charging mode, and the first detection point will generate a voltage. Similarly, a circuit can only be formed at resistor R5 when the charging mode is fast charging mode, and the fifth detection point will generate a voltage. Therefore, the invention can be used to determine the charging mode by detecting the voltage at the first and fifth detection points.

[0043] The second detection circuit includes: resistors R2, R3, R4, Rref1, Rref2, thermistors RT1 and RT2, switches S1, S2, S3, and S4.

[0044] One end of switch S2 is connected to the power supply, and the other end is connected in series with resistor R4, resistor Rref2, switch S3, and resistor R3 before being grounded. One end of switch S1 is connected to the power supply, and the other end is connected in series with resistor R2 before being connected to thermistor RT1. The other end of thermistor RT1 is connected between switch S3 and resistor R3. One end of thermistor RT2 is connected between resistor R4 and resistor Rref2, and the other end is connected between switch S3 and resistor R3. One end of resistor Rref1 is connected between resistor R2 and thermistor RT1, and the other end is connected between resistor Rref2 and switch S3. Switch S4 is connected in parallel across resistor R3.

[0045] Thermistor RT1 is located in the slow charging port and will only be connected to the circuit when the charging mode is slow charging. Thermistor RT2 is located in the fast charging port and will only be connected to the circuit when the charging mode is fast charging.

[0046] A second detection point (detection point 2) is set between resistor R2 and resistor Rref1, a third detection point (detection point 3) is set between resistor R3 and switch S3, and a fourth detection point (detection point 4) is set between resistor R4 and resistor Rref2. After the charging mode is determined, by adjusting the conduction state of switches S1, S2, S3 and S4, the resistance values ​​of thermistors RT1 and RT2 can be calculated based on the voltages of the second, third and fourth detection points. Since the resistance value of the thermistors changes with temperature, the temperature of the charging port can be obtained by reversing the resistance value of the thermistors, thus realizing temperature detection.

[0047] The detection circuit proposed in this invention includes three detection modes, namely:

[0048] In self-test mode, the second detection circuit is used to determine whether the detection circuit is abnormal and whether the resistance values ​​of resistors R2 and R3 are abnormal by detecting the voltage at the second and third detection points.

[0049] Charging detection mode: In this mode, the first detection circuit is used to determine whether the specific charging mode is fast charging mode or slow charging mode by the voltage of the first detection point and the fifth detection point.

[0050] Temperature detection mode: In this mode, the second detection circuit calculates the resistance value of thermistor RT1 or thermistor RT2 by detecting the voltage of the second detection point, the third detection point and the fourth detection point, so as to perform temperature detection of the slow charging port or the fast charging port.

[0051] It should be noted that resistors R1 and R5 are used to detect the specific charging mode. Theoretically, it is only necessary to determine whether there is voltage at the first detection point and the fifth detection point to determine the charging mode. Deviations in their resistance will not affect the judgment of the result. Therefore, in the self-test mode of this invention, it is not necessary to detect whether the resistance values ​​of resistors R1 and R5 are abnormal. It is only necessary to detect the resistance values ​​of resistors R2, R3, and R4.

[0052] The detection principles of each mode of this invention are explained below, including the self-test mode:

[0053] Please see Figure 1 When the charger is activated by the vehicle, control switches S1, S3, and S4 close. Because switch S4 is closed, resistor R3 is short-circuited. At this time, resistors R2 and Rref1 are connected to the circuit. Current flows sequentially through the power supply, switch S1, resistor R2, resistor Rref1, switch S3, switch S4, and ground. The voltage at the second detection point is the voltage between resistors R2 and Rref1. According to the series voltage divider principle, the voltage at the second detection point should be... Here, 5V represents the power supply voltage. If the detection circuit experiences an abnormality such as a short circuit, open circuit, or power supply failure, the voltage at the second detection point will become 0 or 5V. That is, when the voltage at the second detection point is equal to 0 or 5V, the detection circuit is abnormal; when the voltage at the second detection point is equal to... At that time, the detection circuit was normal;

[0054] When used to detect the resistance of resistor R2, switches S1, S3, and S4 are kept closed. In this case, the voltage at the second detection point should be equal to the voltage across resistor Rref1. Since the circuit only connects resistors R2 and Rref1, the voltage across resistor R2 is 5V / 2. The voltage at the second detection point is then calculated. After simplification, we can obtain

[0055] When used to detect the resistance of resistor R3, control switches S1 and S3 are closed, causing switch S4 to open, connecting resistor R3 into the circuit. Current flows sequentially through the power supply, switch S1, resistor R2, resistor Rref1, switch S3, resistor R3, and ground. At this time, resistor Rref1, resistor R2, and resistor R3 are connected in series, dividing the voltage of the power supply. The voltage at the third detection point is... Simplification yields Here, the resistance value of resistor R3 needs to be obtained based on resistor R2. In this invention, the resistance value of resistor R2 can be detected first, and then the resistance value of resistor R3 can be detected.

[0056] When used to detect the resistance value of resistor R4, control switches S2 and S3 are closed, causing switches S4 and S1 to open. Since switch S4 is closed, resistor R3 is short-circuited. At this time, resistor R4 and resistor Rref2 are connected in series in the circuit. The current flows sequentially through the power supply, switch S2, resistor R4, resistor Rref2, switch S3, switch S4, and ground. Since resistors Rref2 and R4 are connected in series, they divide the voltage of the power supply. The voltage at the fourth detection point is... Since the circuit only connects resistors R4 and Rref2, the voltage across resistor R4 is 5V / 4V. This voltage is then applied to the fourth detection point. After simplification, we can obtain

[0057] The power supply voltage is 5V, the resistance values ​​of resistors Rref1 and Rref2 are both 10K, V2 is the voltage at the second detection point, and V3 is the voltage at the third detection point.

[0058] This invention, through the setting of a self-test mode, can not only detect whether there is a circuit malfunction, but also specifically detect the resistance value of each measuring resistor to determine whether its resistance deviation exceeds the specification, and report it to the whole vehicle, thus avoiding the impact of the measuring resistor value exceeding the specification on the measurement accuracy.

[0059] For further details, please see Figure 4 Resistors R2 and R3 are both composed of four 10K resistors connected in series and parallel. The series and parallel connection involves the four 10K resistors being connected end-to-end, with one connection between two adjacent 10K resistors and another two 10K resistors. Using this connection method, the detection circuit can still function normally when a single resistor or two resistors in series fail and open-circuit. Considering the case of two resistors in series failing and opening-circuiting, the upper limit for judging resistance R2 and R3 is 2 * 10K = 20K. Since resistors do not have a short-circuit failure mode, considering resistance and sampling accuracy errors, the lower limit is set to 10K * (1 - 10%) = 9K. If the resistance values ​​of R2 and R3 obtained through detection are not within this range, it is determined that the resistance offset of the detection circuit is out of specification, indicating an abnormal resistance, and this is reported to the entire vehicle.

[0060] Charging detection mode:

[0061] This mode is performed after the self-test mode. In this case, the circuit is not in an abnormal state. Please refer to [link / reference needed]. Figure 2 When the charging mode is slow charging, resistor R5 inside the slow charging port is closed. At this time, resistor R1 and resistor Rcc1 inside the slow charging port are connected in series in the circuit, and the voltage is divided by the power supply. According to the principle of series voltage division, the voltage at the first detection point is... Therefore, when the voltage at the first detection point is detected as When this happens, the charging mode can be identified as slow charging mode;

[0062] Similarly, please see Figure 3 When the charging mode is fast charging, resistor R5 and resistor Rcc2 inside the fast charging port are connected in series in the circuit to divide the power supply voltage. According to the series voltage divider principle, the voltage at the fifth detection point is... Therefore, when the voltage at the fifth detection point is detected, When the charging mode is activated, it can be identified as fast charging mode.

[0063] The power supply voltage is 5V, Rcc1 is the resistor in the internal circuit of the slow charging port, and Rcc2 is the resistor in the internal circuit of the fast charging port.

[0064] This invention, through the setting of a charging detection mode, can detect the charging mode of the charger in real time, and in the temperature detection mode, detect the temperature of each charging port to determine the specific temperature of each charging port.

[0065] Temperature detection mode:

[0066] This mode is used after the charging detection mode determines the specific charging mode. Please refer to [link / reference]. Figure 2 When the charging mode is slow charging, control switch S1 is closed. At this time, resistor R2, thermistor RT1, and resistor R3 in the second detection circuit are connected to the circuit together. The current will flow sequentially through the power supply, switch S1, resistor R2, thermistor RT1, resistor R3, and ground. In this case, resistors R2, R3, and thermistor RT1 together divide the voltage of the power supply. According to the series voltage divider principle, the voltage at the second detection point is... The voltage at the third detection point is Therefore, the voltage across the thermistor RT1 can be determined to be... Simplifying, the resistance of the thermistor RT1 is... Since the voltage across the thermistor RT1 cannot be directly obtained, it can be converted into the voltage difference between the second and third detection points, i.e., the resistance value of the thermistor RT1 is expressed as... After obtaining the resistance value of the thermistor RT1, the temperature of the slow charging port can be calculated based on the correspondence between the thermistor and temperature, and reported to the vehicle controller in real time.

[0067] Please see Figure 3 When the charging mode is fast charging, control switch S2 is closed. At this time, resistor R4, thermistor RT2, and resistor R3 in the second detection circuit are connected to the circuit together. The current will flow sequentially through the power supply, switch S2, resistor R4, thermistor RT2, resistor R3, and ground. In this case, resistors R3, R4, and thermistor RT2 together divide the voltage of the power supply. According to the series voltage divider principle, the voltage at the fourth detection point is... The voltage at the third detection point is Therefore, the voltage across the thermistor RT2 can be determined to be... Simplifying, the resistance of the thermistor RT2 is found to be... Since the voltage across the thermistor RT2 cannot be directly obtained, it can be converted into the voltage difference between the fourth and third detection points, i.e., the resistance value of the thermistor RT1 is expressed as... After obtaining the resistance value of the thermistor RT2, the temperature of the fast charging port can be calculated based on the relationship between the thermistor and temperature, and reported to the vehicle controller in real time.

[0068] The power supply voltage is 5V, V2 is the voltage of the second detection point, V3 is the voltage of the third detection point, and V4 is the voltage of the fourth detection point. When calculating the resistance values ​​of thermistors RT1 and RT2 using resistors R2, R3, and R4, the self-test resistance values ​​of resistors R2, R3, and R4 are used for calculation to improve measurement accuracy.

[0069] In summary, the detection circuit proposed in this invention can identify the charging mode of the charger and detect the temperature of the charging port under the corresponding mode, and report it to the charger to avoid thermal runaway problems.

[0070] Please see Figure 5The flowchart illustrates the implementation of the detection circuit of this invention. After the charger is powered on and woken up, it enters a self-test mode. By controlling switches S1, S2, S3, and S4, it completes the self-test of resistors R2, R3, and R4, avoiding the occurrence of out-of-specification measurement of resistors. During the self-test, it also detects whether the detection circuit is abnormal (when the detection circuit is abnormal, the voltage of the second, third, and fourth detection points is 0 or the power supply voltage, and it cannot be used for resistance detection). After the self-test is completed, it enters the charging detection mode. By detecting the voltage of the first and fifth detection points, it determines the charging type. After obtaining the charging type, it enters the temperature detection mode. By calculating the resistance values ​​of thermistors RT1 and RT2, it calculates the temperature of the corresponding charging port and reports the detected temperature to the vehicle controller, completing the detection of the entire vehicle.

[0071] Compared with existing technologies, the detection circuit proposed in this invention can identify the charging mode of the charger and detect the temperature of the charging port under the corresponding mode, reporting it to the charger to avoid thermal runaway. Simultaneously, this invention also features a self-test mode, which can detect the resistance values ​​of each detection resistor to determine if they are out of specification, avoiding the influence of abnormal detection resistors on the detection data. Furthermore, the detection resistors are composed of four resistors connected in series and parallel, ensuring normal temperature detection even if one resistor fails, thus enhancing safety.

[0072] The above embodiments are merely illustrative of specific implementations of the present invention. It should be noted that those skilled in the art can make various modifications and variations without departing from the concept of the present invention, and all such modifications and variations should fall within the protection scope of the present invention.

Claims

1. A detection circuit capable of identifying charging modes and reporting the corresponding charging port temperature, characterized in that, It includes a first detection circuit for detecting the charging mode and a second detection circuit for self-testing and temperature detection. The second detection circuit includes a thermistor disposed in the slow charging port and the fast charging port. The second detection circuit determines the resistance value of the thermistor by detecting the voltage, and then performs temperature detection. The second detection circuit includes: resistors R2, R3, R4, Rref1, Rref2, thermistors RT1 and RT2, switches S1, S2, S3, and S4. One end of switch S2 is connected to the power supply, and the other end is connected in series with resistor R4, resistor Rref2, switch S3, and resistor R3 before being grounded. One end of switch S1 is connected to the power supply, and the other end is connected in series with resistor R2 before being connected to the thermistor RT1. The other end of the thermistor RT1 is connected between switch S3 and resistor R3. One end of the thermistor RT2 is connected between resistor R4 and resistor Rref2, and the other end is connected between switch S3 and resistor R3. One end of resistor Rref1 is connected between resistor R2 and thermistor RT1, and the other end is connected between resistor Rref2 and switch S3. Switch S4 is connected in parallel across resistor R3. The thermistor RT1 is located in the slow charging port. When the charging mode is slow charging mode, the thermistor RT1 is connected to the second detection circuit. The thermistor RT2 is located in the fast charging port. When the charging mode is fast charging mode, the thermistor RT2 is connected to the second detection circuit. The second detection circuit further includes a second detection point located between resistor R2 and resistor Rref1, a third detection point located between resistor R3 and switch S3, and a fourth detection point located between resistor R4 and resistor Rref2. The second detection circuit performs self-testing and temperature detection by detecting the voltage at the second detection point, the third detection point, and the fourth detection point. The first detection circuit includes: resistor R1 and resistor R5. One end of resistor R1 is connected to the power supply and the other end is connected to the slow charging port. One end of resistor R5 is connected to the power supply and the other end is connected to the fast charging port. The first detection circuit further includes a first detection point located between the resistor R1 and the slow charging port, and a fifth detection point located between the resistor R5 and the fast charging port. The first detection circuit determines the charging mode by detecting the voltage at the first detection point and the fifth detection point.

2. The detection circuit according to claim 1, characterized in that, The detection circuit includes three detection modes: In self-test mode, the second detection circuit determines whether the detection circuit is abnormal and whether the resistance values ​​of resistors R2 and R3 are abnormal by detecting the voltage at the second and third detection points. In the charging detection mode, the first detection circuit determines the charging mode by detecting the voltage at the first detection point and the fifth detection point. In temperature detection mode, the second detection circuit calculates the resistance value of the thermistor RT1 or thermistor RT2 by detecting the voltage at the second detection point, the third detection point, and the fourth detection point, in order to perform temperature detection of the slow charging port or the fast charging port.

3. The detection circuit according to claim 2, characterized in that, When the detection circuit is in self-test mode and is used to detect whether the detection circuit is abnormal, switches S1, S3, and S4 are closed. When the voltage at the second detection point is equal to 0 or the power supply voltage, the detection circuit is abnormal. When the detection circuit is in self-test mode and is used to detect the resistance value of resistor R2, switches S1, S3, and S4 are closed, and the resistance value of resistor R2 is R. ; When the detection circuit is in self-test mode and is used to detect the resistance value of resistor R3, switches S1 and S3 are closed, and the resistance value of resistor R3 is R3. K; When the detection circuit is in self-test mode and is used to detect the resistance value of resistor R4, switches S2, S3, and S4 are closed, and the resistance value of resistor R4 is R4. K; Wherein, the voltage of the power supply is 5V, the resistance of the resistors Rref1 and Rref2 is 10K, V2 is the voltage of the second detection point, V3 is the voltage of the third detection point, and V4 is the voltage of the fourth detection point.

4. The detection circuit according to claim 2, characterized in that, When the detection circuit is in charging detection mode, and the voltage at the first detection point is When the detection circuit is in slow charging mode, and when the detection circuit is in charging mode, and the voltage at the fifth detection point is... At that time, the detection circuit is in fast charging mode; Wherein, the voltage of the power supply is 5V, Rcc1 is the resistance of the internal circuit of the slow charging port, and Rcc2 is the resistance of the internal circuit of the fast charging port.

5. The detection circuit according to claim 2, characterized in that, When the detection circuit is in temperature detection mode and the charging mode is slow charging mode, the switch S1 is closed, and the resistance of the thermistor RT1 is [value missing]. ; When the detection circuit is in temperature detection mode and the charging mode is fast charging mode, the switch S2 is closed, and the resistance of the thermistor RT2 is [value missing]. ; The detection circuit obtains the temperature of the fast charging port or the slow charging port by measuring the temperatures corresponding to thermistors RT1 and RT2. Wherein, the voltage of the power supply is 5V, V2 is the voltage of the second detection point, V3 is the voltage of the third detection point, and V4 is the voltage of the fourth detection point.

6. The detection circuit according to claim 1, characterized in that, The resistors R2 and R3 are both composed of four 10K resistors connected in series and parallel. The series and parallel connection is that the four 10K resistors are connected end to end, and there is a connection between two adjacent 10K resistors and the other two 10K resistors.

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