Dual over-temperature protection circuit and charger

Abstract

The utility model provides a dual over-temperature protection circuit and a charger. The dual over-temperature protection circuit comprises a first temperature detection module and a second temperature detection module. The input end of the first temperature detection module is connected with the first control module, and the first temperature detection module is used for detecting the environment temperature; the input end of the second temperature detection module is connected with the second control module, and the second temperature detection module is used for detecting the environment temperature. According to the utility model, burnout of the charger can be avoided, and risks are reduced.

Description

Technical Field

[0001] The utility model relates to the technical field of chargers, and particularly relates to a dual over-temperature protection circuit and a charger. Background Art

[0002] Chargers are used to charge various electronic devices. For electrical safety and to avoid damage to the charger, various protection circuits are usually provided in the charger, and the over-temperature protection circuit is one of the more important circuits.

[0003] Currently, most chargers are provided with an over-temperature protection circuit to protect the circuit. When the over-temperature protection circuit fails, the charger is likely to be damaged due to excessive temperature, posing a certain safety risk. Summary of the Utility Model

[0004] The utility model provides a dual over-temperature protection circuit and a charger, aiming to solve the problem of safety risks existing in current chargers.

[0005] In a first aspect, the utility model provides a dual over-temperature protection circuit, which is applied to a charger. The charger includes a first control module and a second control module. The dual over-temperature protection circuit includes a first temperature detection module and a second temperature detection module. The input end of the first temperature detection module is connected to the first control module and is used to detect the ambient temperature. The input end of the second temperature detection module is connected to the second control module and is used to detect the ambient temperature.

[0006] Further, the first temperature detection module includes a first thermistor. One end of the first thermistor is connected to the first control module, and the other end of the first thermistor is grounded.

[0007] Further, the first temperature detection module further includes a first resistor. One end of the first resistor is connected to the first control module, and the other end of the first resistor is connected to the first thermistor.

[0008] Further, the second temperature detection module includes a second thermistor. One end of the second thermistor is connected to the second control module, and the other end of the second thermistor is grounded.

[0009] Further, the second temperature detection module further includes a second resistor. One end of the second resistor is connected to the second control module, and the other end of the second resistor is connected to the second thermistor.

[0010] Further, the second temperature detection module further includes a third resistor. One end of the third resistor is connected to the second control module, and the other end of the third resistor is grounded.

[0011] Further, the temperature threshold of the first temperature detection module is higher than that of the second temperature detection module, where the temperature threshold is used to trigger over-temperature protection.

[0012] In a second aspect, the present utility model further provides a charger, which includes a first control module, a second control module, and the dual over-temperature protection circuit described in any one of the above; both the first control module and the second control module are connected to the dual over-temperature protection circuit.

[0013] Further, the first control module includes a first control chip, and the second control module includes a second control chip; the OTP pin of the first control chip is connected to the first temperature detection module of the dual over-temperature protection circuit, and the NTC pin of the second control chip is connected to the second temperature detection module of the dual over-temperature protection circuit.

[0014] Further, the first control chip is the primary control chip of the charger, and the second control chip is the secondary control chip of the charger.

[0015] The charger disclosed in the present utility model includes a first control module, a second control module, and a dual over-temperature protection circuit. The dual over-temperature protection circuit includes a first temperature detection module and a second temperature detection module. The first temperature detection module is connected to the first control module, and the second temperature detection module is connected to the second control module. Both the first temperature detection module and the second temperature detection module are used to detect the ambient temperature. When any one of the first temperature detection module and the second temperature detection module detects that the temperature is too high, an over-temperature signal will be sent to the first control module or the second control module, so as to perform over-temperature protection. That is, through dual over-temperature protection, it is ensured that when any one of the temperature detection modules fails, over-temperature protection can still be performed, reducing the risk. Description of the Drawings

[0016] In order to more clearly illustrate the technical solutions of the embodiments of the present utility model, the drawings required for the description of the embodiments will be briefly introduced below. Obviously, the drawings in the following description are some embodiments of the present utility model. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0017] Figure 1 is a block diagram of a dual over-temperature protection circuit provided by an embodiment of the present utility model;

[0018] Figure 2 is a circuit diagram of the first temperature detection module of the dual over-temperature protection circuit provided by an embodiment of the present utility model;

[0019] Figure 3It is the circuit diagram of the second temperature detection module of the dual over-temperature protection circuit provided by an embodiment of the present utility model;

[0020] Figure 4 It is the circuit diagram of the first control module provided by an embodiment of the present utility model;

[0021] Figure 5 It is the circuit diagram of the second control module provided by an embodiment of the present utility model. Detailed implementation manners

[0022] Next, the technical solutions in the embodiments of the present utility model will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present utility model. Obviously, the described embodiments are part of the embodiments of the present utility model, rather than all the embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present utility model.

[0023] It should be understood that when used in this specification and the appended claims, the terms "comprising" and "including" indicate the presence of the described features, wholes, operations, elements and / or components, but do not exclude the presence or addition of one or more other features, wholes, operations, elements, components and / or their combinations.

[0024] It should also be understood that the terms used in this specification of the present utility model are only for the purpose of describing specific embodiments and are not intended to limit the present utility model. As used in this specification of the present utility model and the appended claims, unless the context clearly indicates otherwise, the singular forms "a", "an" and "the" are intended to include the plural forms. It should be further understood that the term " / and / " used in this specification of the present utility model and the appended claims refers to any combination and all possible combinations of one or more of the related listed items, and includes these combinations.

[0025] In addition, the directional terms mentioned in the present utility model, such as "up", "down", "front", "back", "left", "right", "inside", "outside", "side", etc., are only references to the directions of the attached drawings and the usage state of the product. Therefore, the directional terms used are for explaining and understanding the present utility model, rather than for limiting the present utility model. In addition, in the drawings, structures that are similar or the same are denoted by the same reference numerals.

[0026] See Figures 1 to 5 , Figure 1 It is the block diagram of the dual over-temperature protection circuit 100 provided by an embodiment of the present utility model; Figure 2 It is the circuit diagram of the first temperature detection module 10 of the dual over-temperature protection circuit 100 provided by an embodiment of the present utility model;Figure 3 It is the circuit diagram of the second temperature detection module 20 of the dual over-temperature protection circuit 100 provided by an embodiment of the present utility model; Figure 4 It is the circuit diagram of the first control module 200 provided by an embodiment of the present utility model; Figure 5 It is the circuit diagram of the second control module 300 provided by an embodiment of the present utility model. As Figure 1 shown, the dual over-temperature protection circuit 100 includes a first temperature detection module 10 and a second temperature detection module 20; the input end of the first temperature detection module 10 is connected to the first control module 200 for detecting the ambient temperature; the input end of the second temperature detection module 20 is connected to the second control module 300 for detecting the ambient temperature.

[0027] Specifically, the charger may include a primary circuit and a secondary circuit. The primary circuit is used to charge the secondary circuit so that the secondary circuit charges the electronic device. The first control module 200 serves as the main control module and is respectively connected to the primary circuit and the second control module 300. The second control module 300 serves as an auxiliary control module and is connected to the secondary circuit. It can be understood that the primary circuit and the secondary circuit are both circuits commonly used in the art, and their specific circuit structures are not described here.

[0028] The first temperature detection module 10 is connected to the first control module 200 for detecting the current temperature of the charger. The second temperature detection module 20 is connected to the second control module 300 for detecting the current temperature of the charger. The temperature thresholds of the first temperature detection module 10 and the second temperature detection module 20 may be the same or different. Here, the temperature threshold refers to the temperature at which over-temperature protection is triggered. For example, if the temperature threshold is 90 °C, when the first temperature detection module 10 or the second detection module detects that the temperature exceeds 90 °C, an over-temperature signal is sent to the first control module 200 or the second control module 300, and the first control module 200 or the second control module 300 performs over-temperature protection.

[0029] The temperature thresholds of the first temperature detection module 10 and the second temperature detection module 20 may be different. For example, if the temperature threshold of the first temperature detection module 10 is 90°C and the temperature threshold of the second temperature detection module 20 is 80°C, then when the second temperature detection module 20 detects that the temperature exceeds 80°C, the second control module 300 performs over-temperature protection. When the second temperature detection module 20 fails, if the first temperature detection module 10 detects that the temperature exceeds 90°C, the first control module 200 performs over-temperature protection. It can be understood that the temperature threshold of the first temperature detection module 10 may be greater than or less than the temperature threshold of the second temperature detection module 20, and the specific form is not limited here. Preferably, when the first control module 200 is the main control module and the second control module 300 is the auxiliary control module, the temperature threshold of the first temperature detection module 10 is less than the temperature threshold of the second temperature detection module 20, that is, the second temperature detection module 20 gives priority to over-temperature protection.

[0030] See Figure 2 As a further embodiment, the first temperature detection module 10 includes a first thermistor RNTC1. One end of the first thermistor RNTC1 is connected to the first control module 200, and the other end of the first thermistor RNTC1 is grounded. The first temperature detection module 10 further includes a first resistor R1. One end of the first resistor R1 is connected to the first control module 200, and the other end of the first resistor R1 is connected to the first thermistor RNTC1.

[0031] Among them, the first temperature detection module 10 may include a first thermistor RNTC1. One end of the first thermistor RNTC1 is connected to the first control module 200, and the other end of the first thermistor RNTC1 is grounded. The resistance value of the first thermistor RNTC1 may change with the temperature, and then the first control module 200 can determine the temperature according to the resistance value of the first thermistor RNTC1 and judge whether over-temperature protection is required.

[0032] The first thermistor RNTC1 may be a positive temperature coefficient thermistor or a negative temperature coefficient thermistor. The resistance value of the positive temperature coefficient thermistor increases with the increase of temperature, and the resistance value of the negative temperature coefficient thermistor decreases with the increase of temperature.

[0033] The resistance value of the first thermistor RNTC1 corresponds to the temperature. A resistance threshold can be set, and this resistance threshold is corresponded to a temperature threshold. For example, if the first thermistor RNTC1 is a positive temperature coefficient thermistor, when the first control module 200 detects that the resistance value of the first thermistor RNTC1 is greater than the resistance threshold, over-temperature protection is triggered. If the first thermistor RNTC1 is a negative temperature coefficient thermistor, when the first control module 200 detects that the resistance value of the first thermistor RNTC1 is less than the resistance threshold, over-temperature protection is triggered.

[0034] See Figure 3 , as a further embodiment, the second temperature detection module 20 includes a second thermistor RNTC2. One end of the second thermistor RNTC2 is connected to the second control module 300, and the other end of the second thermistor RNTC2 is grounded. The second temperature detection module 20 further includes a second resistor R2. One end of the second resistor R2 is connected to the second control module 300, and the other end of the second resistor R2 is connected to the second thermistor RNTC2. The second temperature detection module 20 further includes a third resistor R3. One end of the third resistor R3 is connected to the second control module 300, and the other end of the third resistor R3 is grounded.

[0035] Among them, the second temperature detection module 20 may include a second thermistor RNTC2. One end of the second thermistor RNTC2 is connected to the second control module 300, and the other end of the second thermistor RNTC2 is grounded. The resistance value of the second thermistor RNTC2 can change with the temperature, and then the second control module 300 can determine the temperature according to the resistance value of the second thermistor RNTC2 and judge whether over-temperature protection is required.

[0036] The second thermistor RNTC2 can be a positive temperature coefficient thermistor or a negative temperature coefficient thermistor. The resistance value of the positive temperature coefficient thermistor increases with the increase of temperature, and the resistance value of the negative temperature coefficient thermistor decreases with the increase of temperature.

[0037] The resistance value of the second thermistor RNTC2 corresponds to the temperature. A resistance threshold can be set, and this resistance threshold is corresponded to a temperature threshold. For example, if the second thermistor RNTC2 is a positive temperature coefficient thermistor, when the second control module 300 detects that the resistance value of the second thermistor RNTC2 is greater than the resistance threshold, over-temperature protection is triggered. If the second thermistor RNTC2 is a negative temperature coefficient thermistor, when the second control module 300 detects that the resistance value of the second thermistor RNTC2 is less than the resistance threshold, over-temperature protection is triggered.

[0038] The resistance thresholds of the first control module 200 and the second control module 300 can be set separately, and the resistance thresholds of the first control module 200 and the second control module 300 can be the same or different. Preferably, when the first thermistor RNTC1 and the second thermistor RNTC2 are both positive temperature coefficient thermistors, the resistance threshold of the first control module 200 is greater than that of the second control module 300, that is, the second control module 300 gives priority to over-temperature protection.

[0039] As a further embodiment, the temperature threshold of the first temperature detection module 10 is higher than that of the second temperature detection module 20, wherein the temperature threshold is used to trigger over-temperature protection.

[0040] Among them, the first control module 200 is connected to the primary circuit as the main control module, and the second control module 300 is connected to the secondary circuit as the auxiliary control module. It can be set that the second control module 300 gives priority to over-temperature protection. That is, the temperature threshold of the first temperature detection module 10 is set to be higher than that of the second temperature detection module 20.

[0041] The present utility model further provides a charger, which includes a first control module 200, a second control module 300, and the dual over-temperature protection circuit 100 according to any one of the above embodiments; the dual over-temperature protection circuit 100 includes a first temperature detection module 10 and a second temperature detection module 20; the input end of the first temperature detection module 10 is connected to the first control module 200 for detecting the ambient temperature; the input end of the second temperature detection module 20 is connected to the second control module 300 for detecting the ambient temperature.

[0042] Specifically, the charger may include a primary circuit and a secondary circuit. The primary circuit is used to charge the secondary circuit so that the secondary circuit charges the electronic device. The first control module 200 is used as the main control module and is respectively connected to the primary circuit and the second control module 300. The second control module 300 is used as the auxiliary control module and is connected to the secondary circuit. It can be understood that the primary circuit and the secondary circuit are both conventional circuits in the art, and their specific circuit structures are not described here.

[0043] The first temperature detection module 10 is connected to the first control module 200 and is used to detect the current temperature of the charger. The second temperature detection module 20 is connected to the second control module 300 and is used to detect the current temperature of the charger. The temperature thresholds of the first temperature detection module 10 and the second temperature detection module 20 can be the same or different. Herein, the temperature threshold refers to the temperature at which over-temperature protection is triggered. For example, if the temperature threshold is 90 °C, when the first temperature detection module 10 or the second detection module detects that the temperature exceeds 90 °C, an over-temperature signal is sent to the first control module 200 or the second control module 300, and the first control module 200 or the second control module 300 performs over-temperature protection.

[0044] The temperature thresholds of the first temperature detection module 10 and the second temperature detection module 20 can be different. For example, the temperature threshold of the first temperature detection module 10 is 90 °C, and the temperature threshold of the second temperature detection module 20 is 80 °C. Then, when the second temperature detection module 20 detects that the temperature exceeds 80 °C, the second control module 300 performs over-temperature protection. When the second temperature detection module 20 fails, if the first temperature detection module 10 detects that the temperature exceeds 90 °C, the first control module 200 performs over-temperature protection. It can be understood that the temperature threshold of the first temperature detection module 10 can be greater than or less than the temperature threshold of the second temperature detection module 20, and the specific form is not limited herein. Preferably, when the first control module 200 is the main control module and the second control module 300 is the auxiliary control module, the temperature threshold of the first temperature detection module 10 is less than the temperature threshold of the second temperature detection module 20, that is, the second temperature detection module 20 preferentially performs over-temperature protection.

[0045] See Figure 4 and Figure 5 As a further embodiment, the first control module 200 includes a first control chip U1, and the second control module 300 includes a second control chip U2; the OTP pin of the first control chip U1 is connected to the first temperature detection module 10 of the dual over-temperature protection circuit 100, and the NTC pin of the second control chip U2 is connected to the second temperature detection module 20 of the dual over-temperature protection circuit 100. The first control chip U1 is the primary control chip of the charger, and the second control chip U2 is the secondary control chip of the charger.

[0046] Among them, the first control module 200 may include a first control chip U1, and the second control module 300 may include a second control chip U2. As Figure 4 shown, Figure 4It is the circuit diagram of the first control module 200, which mainly includes the first control chip U1 and the peripheral circuit of the first control chip U1. The peripheral circuit of the first control chip U1 is used to ensure the operation of the first control chip U1 and the basic functions of the charger. As Figure 5 shown, Figure 5 It is the circuit diagram of the second control module 300, which mainly includes the second control chip U2 and the peripheral circuit of the second control chip U2. The peripheral circuit of the second control chip U2 is used to ensure the operation of the second control chip U2 and the basic functions of the charger.

[0047] As Figure 4 shown, the OTP pin of the first control chip U1 is also connected to a detection circuit for detecting the OTP voltage. When the OTP voltage is lower than the VFault_OTP_In voltage, over-temperature protection can also be triggered. When the OTP voltage is higher than Fault_OTP_Out, normal operation is restored.

[0048] As Figure 5 shown, the NTC pin of the second control chip U2 is connected to the third resistor R3. The third resistor R3 is also connected in parallel with the second resistor R2 and the second thermistor RNTC2. The NTC pin of the second control chip U2 can also detect the circuit voltage. When the second control chip U2 detects that the temperature of the second thermistor RNTC2 is higher than the temperature threshold, it will further determine whether the voltage of the NTC pin is less than or equal to 0.3V. When the voltage of the NTC pin is less than or equal to 0.3V, the second control chip U2 will not immediately perform over-temperature protection, but reduce the power to continue to maintain the output. If at this time the second control chip U2 detects that the temperature of the second thermistor RNTC2 drops to the safety threshold, the normal power output is restored. When the voltage of the NTC pin is greater than 0.3V, the second control chip U2 performs over-temperature protection.

[0049] The dual over-temperature protection circuit and charger disclosed by the present utility model detect the temperature by providing two temperature detection modules, namely the first temperature detection module and the second temperature detection module. When any one of the temperature detection modules fails, the other temperature detection module can work normally, ensuring that the charger will not burn out and reducing the risk.

[0050] The above is only the specific implementation manner of the present utility model, but the protection scope of the present utility model is not limited thereto. Any person skilled in the art within the technical scope disclosed by the present utility model can easily think of various equivalent modifications or substitutions, and these modifications or substitutions should all be covered within the protection scope of the present utility model. Therefore, the protection scope of the present utility model should be subject to the protection scope of the claims.

Claims

1. A dual over-temperature protection circuit, characterized in that: Applied to a charger, the charger includes a first control module and a second control module, and the dual over-temperature protection circuit includes: A first temperature detection module, wherein an input end of the first temperature detection module is connected to the first control module and is used to detect the ambient temperature; A second temperature detection module, wherein an input end of the second temperature detection module is connected to the second control module and is used to detect the ambient temperature.

2. The dual over-temperature protection circuit according to claim 1, characterized in that: The first temperature detection module includes a first thermistor, one end of the first thermistor is connected to the first control module, and the other end of the first thermistor is grounded.

3. The dual over-temperature protection circuit as claimed in claim 2, characterized in that: The first temperature detection module further includes a first resistor, one end of which is connected to the first control module, and the other end of which is connected to the first thermistor.

4. The dual over-temperature protection circuit as claimed in claim 2, characterized in that: The second temperature detection module includes a second thermistor, one end of the second thermistor is connected to the second control module, and the other end of the second thermistor is grounded.

5. The dual over-temperature protection circuit as claimed in claim 4, characterized in that: The second temperature detection module further includes a second resistor, one end of the second resistor is connected to the second control module, and the other end of the second resistor is connected to the second thermistor.

6. The dual over-temperature protection circuit as claimed in claim 5, characterized in that: The second temperature detection module further includes a third resistor, one end of the third resistor is connected to the second control module, and the other end of the third resistor is grounded.

7. The dual over-temperature protection circuit according to claim 1, characterized in that: The temperature threshold of the first temperature detection module is higher than that of the second temperature detection module, wherein the temperature threshold is used to trigger over-temperature protection.

8. A charger, characterized in that: It comprises a first control module, a second control module and a dual over-temperature protection circuit as claimed in any one of claims 1 to 7; The first control module and the second control module are both connected to the dual over-temperature protection circuit.

9. The charger according to claim 8, characterized in that: The first control module includes a first control chip, and the second control module includes a second control chip; The OTP pin of the first control chip is connected to the first temperature detection module of the dual over-temperature protection circuit, and the NTC pin of the second control chip is connected to the second temperature detection module of the dual over-temperature protection circuit.

10. The charger according to claim 9, characterized in that: The first control chip is a primary control chip of the charger, and the second control chip is a secondary control chip of the charger.

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