Over-current temperature protection circuit and over-current temperature protection device
By designing an overcurrent temperature protection circuit, using components such as NTC negative temperature coefficient thermistor and NMOS transistors, the fuse temperature range is accurately set, which solves the problem of single fuse function and complex and high cost in the existing technology, and realizes overcurrent and overtemperature protection for later-stage circuits.
Patent Information
- Application Number
- CN202421414372.4
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-06-20
- Publication Date
- 2025-07-08
- Estimated Expiration
- 2034-06-20
AI Technical Summary
In the prior art, conventional fuses have a single function and cannot provide both overcurrent and overtemperature protection. The circuit structure is complex and costly when using a microcontroller to detect temperature.
The overcurrent temperature protection circuit is adopted, including protection circuits, temperature detection circuits, switching circuits, voltage stabilization circuits and voltage divider circuits. Through components such as NTC negative temperature coefficient thermistors and NMOS transistors, the fuse temperature range is accurately set, simplifying the circuit structure and reducing costs.
Overcurrent and overtemperature protection of the subsequent circuit is realized, the circuit structure is simplified and the cost is reduced, and further damage caused by circuit overload is avoided.
Smart Images
Figure CN223079750U_ABST
Abstract
Description
Technical Field
[0001] The embodiments of the present utility model relate to the technical field of circuit protection, and particularly to an overcurrent temperature protection circuit and an overcurrent temperature protection device. Background Art
[0002] With the development of electronic technology, more and more electronic and electrical products have entered into work and life. The increase in ambient temperature and the heat generated by the products themselves may increase the risk of fire. In order to reduce the occurrence of fire, the temperature insurance circuit has emerged.
[0003] Figure 1 It is a schematic diagram of a conventional overcurrent fuse in the prior art. Figure 2 It is a schematic diagram of a temperature fuse in the prior art. Refer to Figure 1 and Figure 2 , the existing fuses have a single function and do not have an over-temperature protection function. With the popularization of high-power products, the current is getting larger and larger. However, the fuses with temperature protection function are limited by material characteristics and do not have the ability to pass large currents. The prior art usually uses a microcontroller for temperature detection. When the temperature rises to the set desired fusing temperature range, the overcurrent fuse is controlled to fuse, but there are problems of complex circuit structure and high cost. Summary of the Utility Model
[0004] The present utility model provides an overcurrent temperature protection circuit and an overcurrent temperature protection device, which have overcurrent and over-temperature protection functions, simplify the circuit structure, and reduce the cost.
[0005] According to one aspect of the present utility model, an overcurrent temperature protection circuit is provided. The overcurrent temperature protection circuit includes: a protection circuit, a temperature detection circuit, a switch circuit, a voltage regulation circuit, a voltage division circuit, and a subsequent stage circuit;
[0006] The first end of the protection circuit is connected to the power supply terminal, the second end of the protection circuit is connected to the first end of the subsequent stage circuit and the first end of the temperature detection circuit, the second end of the temperature detection circuit is connected to the first end of the voltage regulation circuit, the second end of the voltage regulation circuit is connected to the control terminal of the switch circuit and the first end of the voltage division circuit, the second end of the voltage division circuit is connected to the second end of the switch circuit and the second end of the subsequent stage circuit and then grounded, and the first end of the switch circuit is connected to the third end of the protection circuit.
[0007] Optionally, the subsequent stage circuit includes: a DC / DC module;
[0008] The first end of the DC / DC module is connected to the second end of the protection circuit and the first end of the temperature detection circuit. The second end of the DC / DC module is connected to the second end of the voltage division circuit and the second end of the switch circuit and then grounded.
[0009] Optionally, the protection circuit includes: a three-terminal fuse;
[0010] The first end of the three-terminal fuse is connected to the power supply terminal. The second end of the three-terminal fuse is connected to the subsequent circuit and the first end of the temperature detection circuit. The third end of the three-terminal fuse is connected to the first end of the switch circuit.
[0011] Optionally, the temperature detection circuit includes: an NTC negative temperature coefficient thermistor;
[0012] The first end of the NTC negative temperature coefficient thermistor is connected to the second end of the protection circuit. The second end of the NTC negative temperature coefficient thermistor is connected to the first end of the voltage stabilization circuit.
[0013] Optionally, the switch circuit includes: an NMOS transistor or a thyristor;
[0014] The first end of the NMOS transistor is connected to the third end of the protection circuit. The control end of the NMOS transistor is connected to the second end of the voltage stabilization circuit and the first end of the voltage division circuit. The second end of the NMOS transistor is connected to the second end of the voltage division circuit and then grounded;
[0015] The first end of the thyristor is connected to the third end of the protection circuit. The control end of the thyristor is connected to the second end of the voltage stabilization circuit and the first end of the voltage division circuit. The second end of the thyristor is connected to the second end of the voltage division circuit and then grounded.
[0016] Optionally, the voltage stabilization circuit includes: a voltage stabilizing diode;
[0017] The first end of the voltage stabilizing diode is connected to the second end of the temperature detection circuit. The second end of the voltage stabilizing diode is connected to the control end of the switch circuit and the first end of the voltage division circuit.
[0018] Optionally, the voltage division circuit includes: a voltage dividing resistor;
[0019] The first end of the voltage dividing resistor is connected to the second end of the voltage stabilization circuit and the control end of the switch circuit. The second end of the voltage dividing resistor is connected to the second end of the switch circuit and then grounded.
[0020] According to another aspect of the present utility model, an overcurrent temperature protection device is provided, and the overcurrent temperature protection device includes the overcurrent temperature protection circuit described in any one of the above-mentioned aspects.
[0021] Optionally, the overcurrent temperature protection device further includes a power supply circuit, the power supply circuit is connected to the protection circuit, and the power supply circuit is used to supply power to the overcurrent temperature protection device.
[0022] The technical solution of the embodiment of the present utility model can provide protection for overcurrent and over-temperature of the subsequent circuit simultaneously by using a voltage stabilizing circuit with relatively accurate turning voltage and current, setting a smaller and more accurate fusing temperature range, and cooperating with a temperature detection circuit, a switching circuit, and a protection circuit. Compared with the prior art, the overcurrent temperature protection circuit of the present utility model has the functions of overcurrent and over-temperature protection, simplifies the circuit structure, and reduces the cost. In summary, the present utility model solves the problem that the prior art usually uses a microcontroller for temperature detection, and when the temperature rises to the set desired fusing temperature range, controls the fusing of the overcurrent fuse, but there are problems of complex circuit structure and high cost.
[0023] It should be understood that the content described in this part is not intended to identify the key or important features of the embodiments of the present utility model, nor is it used to limit the scope of the present utility model. Other features of the present utility model will become easily understood through the following description. Brief Description of the Drawings
[0024] In order to more clearly illustrate the technical solutions in 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 only some embodiments of the present utility model, and for those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.
[0025] Figure 1 is a schematic diagram of a conventional overcurrent fuse in the prior art;
[0026] Figure 2 is a schematic diagram of a temperature fuse in the prior art;
[0027] Figure 3 is a schematic structural diagram of an overcurrent temperature protection circuit provided according to an embodiment of the present utility model;
[0028] Figure 4 is a working principle diagram of an overcurrent temperature protection circuit provided according to an embodiment of the present utility model. Detailed Description of the Embodiments
[0029] To enable those skilled in the art to better understand the solution of the present utility model, the technical solutions in the embodiments of the present utility model will be clearly and completely described below in conjunction with the accompanying drawings in the embodiments of the present utility model. Obviously, the described embodiments are only a part of the embodiments of the present utility model, rather than all of the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present utility model without creative efforts shall fall within the scope of protection of the present utility model.
[0030] It should be noted that the terms "first", "second", etc. in the specification and claims of the present utility model and the above-mentioned drawings are used to distinguish similar objects, and do not necessarily need to be used to describe a specific order or sequence. It should be understood that such data can be interchanged under appropriate circumstances so that the embodiments of the present utility model described herein can be implemented in an order other than those illustrated or described herein. In addition, the terms "comprising" and "having" and any variations thereof are intended to cover non-exclusive inclusion. For example, a process, method, system, product or device comprising a series of steps or units does not necessarily have to be limited to those steps or units clearly listed, but may include other steps or units not clearly listed or inherent to these processes, methods, products or devices.
[0031] Figure 3 is a schematic structural diagram of an overcurrent temperature protection circuit provided according to an embodiment of the present utility model. Refer to Figure 3 In this regard, an embodiment of the present utility model provides an overcurrent temperature protection circuit. The overcurrent temperature protection circuit includes: a protection circuit 10, a temperature detection circuit 20, a switch circuit 30, a voltage stabilization circuit 40, a voltage division circuit 50, and a subsequent stage circuit 60; the first end of the protection circuit 10 is connected to the power supply terminal VCC, the second end of the protection circuit 10 is connected to the first end of the subsequent stage circuit 60 and the first end of the temperature detection circuit 20, the second end of the temperature detection circuit 20 is connected to the first end of the voltage stabilization circuit 40, the second end of the voltage stabilization circuit 40 is connected to the control end of the switch circuit 30 and the first end of the voltage division circuit 50, the second end of the voltage division circuit 50 is connected to the second end of the switch circuit 30 and the second end of the subsequent stage circuit 50 and then grounded, and the first end of the switch circuit 30 is connected to the third end of the protection circuit 10.
[0032] Specifically, when the external temperature rises, the resistance value of the detection resistor in the temperature detection circuit 20 decreases. The voltage stabilizing circuit 40 is not completely broken down, and only a very small current flows through the voltage stabilizing circuit 40. The voltage divider circuit 50 gets a small voltage and does not turn on the switch circuit 30 to cut off the protection circuit 10. Only when the temperature rises to the expected fusing temperature range set by the protection circuit 10, the resistance value of the detection resistor in the temperature detection circuit 20 becomes small enough, and the current flowing through the voltage divider circuit 50 is large enough, and the voltage division is high enough to turn on the switch circuit 30, causing the protection circuit 10 to fuse and preventing the subsequent circuit 60 from further consuming power, generating heat, and catching fire. When the current of the subsequent circuit 60 is too large and exceeds the I 2 T value (fusing thermal energy value), the protection circuit 10 automatically fuses to prevent the subsequent circuit 60 from being overloaded and further damaged.
[0033] The technical solution of the embodiment of the present utility model can provide protection for overcurrent and over-temperature of the subsequent circuit simultaneously by utilizing the relatively precise turning voltage and current of the voltage stabilizing circuit, setting a smaller and more precise fusing temperature range, and cooperating with the temperature detection circuit, the switch circuit, and the protection circuit. Compared with the prior art, the overcurrent temperature protection circuit of the present utility model has the functions of overcurrent and over-temperature protection, simplifies the circuit structure, and reduces the cost. In summary, the present utility model solves the problems of complex circuit structure and high cost in the prior art, which usually uses a microcontroller for temperature detection and controls the fusing of an overcurrent fuse when the temperature rises to the expected fusing temperature range.
[0034] Continue to refer to Figure 3 , optionally, the subsequent circuit 60 includes: a DC / DC module; the first end of the DC / DC module is connected to the second end of the protection circuit 10 and the first end of the temperature detection circuit 20, and the second end of the DC / DC module is connected to the second end of the voltage divider circuit 50 and the second end of the switch circuit 30 and then grounded.
[0035] Specifically, the subsequent circuit 60 can be a DC / DC module, which mainly performs voltage conversion according to the needs of the circuit. Only when the temperature rises to the expected fusing temperature range set by the protection circuit 10, the resistance value of the detection resistor in the temperature detection circuit 20 becomes small enough, and the current flowing through the voltage divider circuit 50 is large enough, and the voltage division is high enough to turn on the switch circuit 30, causing the protection circuit 10 to fuse and preventing the subsequent circuit 60 from further consuming power, generating heat, and catching fire. When the current of the subsequent circuit 60 is too large and exceeds the I2T value (fusing thermal energy value), the protection circuit 10 automatically fuses to prevent the subsequent circuit 60 from being overloaded and further damaged.
[0036] Figure 4 is the working principle diagram of an overcurrent temperature protection circuit provided according to the embodiment of the present utility model. Refer to Figure 4, optionally, the protection circuit 10 includes: a three-terminal fuse; a first end of the three-terminal fuse is connected to the power supply terminal VCC, a second end of the three-terminal fuse is connected to the subsequent circuit 60 and a first end of the temperature detection circuit 20, and a third end of the three-terminal fuse is connected to a first end of the switching circuit 30.
[0037] Continue to refer to Figure 4 , optionally, the temperature detection circuit 20 includes: an NTC negative temperature coefficient thermistor; a first end of the NTC negative temperature coefficient thermistor is connected to a second end of the protection circuit 10, and a second end of the NTC negative temperature coefficient thermistor is connected to a first end of the voltage stabilization circuit 40.
[0038] Continue to refer to Figure 4 , optionally, the switching circuit 30 includes: an NMOS transistor or a thyristor; a first end of the NMOS transistor is connected to a third end of the protection circuit 10, a control end of the NMOS transistor is connected to a second end of the voltage stabilization circuit 40 and a first end of the voltage dividing circuit 50, and a second end of the NMOS transistor is connected to a second end of the voltage dividing circuit 50 and then grounded to GND; a first end of the thyristor is connected to a third end of the protection circuit 10, a control end of the thyristor is connected to a second end of the voltage stabilization circuit 40 and a first end of the voltage dividing circuit 50, and a second end of the thyristor is connected to a second end of the voltage dividing circuit 50 and then grounded to GND.
[0039] Continue to refer to Figure 4 , optionally, the voltage stabilization circuit 40 includes: a voltage stabilizing diode; a first end of the voltage stabilizing diode is connected to a second end of the temperature detection circuit 20, and a second end of the voltage stabilizing diode is connected to a control end of the switching circuit 30 and a first end of the voltage dividing circuit 50.
[0040] Continue to refer to Figure 4 , optionally, the voltage dividing circuit 50 includes: a voltage dividing resistor; a first end of the voltage dividing resistor is connected to a second end of the voltage stabilization circuit 40 and a control end of the switching circuit 30, and a second end of the voltage dividing resistor is connected to a second end of the switching circuit 30 and then grounded to GND.
[0041] Specifically, the overcurrent temperature protection circuit includes a three-terminal fuse, an NTC negative temperature coefficient thermistor, an NMOS transistor or thyristor, a voltage regulator diode, voltage-dividing resistors, and a subsequent-stage circuit. When the external temperature rises, the resistance value of the NTC negative temperature coefficient thermistor decreases. The voltage regulator diode is not completely broken down, and only a very small current flows through the voltage regulator diode. The voltage-dividing resistors get a small voltage and do not turn on the NMOS transistor to break the three-terminal fuse. Only when the temperature rises to the expected fusing temperature range set by the three-terminal fuse, the resistance value of the NTC negative temperature coefficient thermistor becomes small enough, the voltage regulator diode is completely broken down, the current flowing through the voltage-dividing resistors is large enough, and the voltage division is high enough to turn on the NMOS transistor, causing the three-terminal fuse to blow and preventing the subsequent-stage circuit from further consuming power, generating heat, and catching fire. When the current in the subsequent-stage circuit is too large and exceeds the I 2 T value (fusing thermal energy value), the fuse automatically blows to prevent further damage caused by the overload of the subsequent-stage circuit.
[0042] An embodiment of the present invention further provides an overcurrent temperature protection device, which includes the overcurrent temperature protection circuit provided by any embodiment of the present invention.
[0043] Specifically, the present invention provides an overcurrent and over-temperature protection device for a high-power DC circuit.
[0044] Since the overcurrent temperature protection device includes the overcurrent temperature protection circuit provided by any embodiment of the present invention, the beneficial effects of the above-mentioned overcurrent temperature protection device and the overcurrent temperature protection circuit are the same and will not be elaborated here.
[0045] Optionally, the overcurrent temperature protection device further includes a power supply circuit, which is connected to the protection circuit and is used to supply power to the overcurrent temperature protection device.
[0046] The above specific implementation manners do not constitute a limitation to the protection scope of the present invention. Those skilled in the art should understand that various modifications, combinations, sub-combinations, and substitutions can be made according to design requirements and other factors. Any modifications, equivalent substitutions, and improvements made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.
Claims
1. An overcurrent temperature protection circuit, characterized in that, Comprising: A protection circuit, a temperature detection circuit, a switching circuit, a voltage regulation circuit, a voltage division circuit, and a subsequent stage circuit; The first end of the protection circuit is connected to the power supply terminal, the second end of the protection circuit is connected to the first end of the subsequent stage circuit and the first end of the temperature detection circuit, the second end of the temperature detection circuit is connected to the first end of the voltage regulation circuit, the second end of the voltage regulation circuit is connected to the control end of the switching circuit and the first end of the voltage division circuit, the second end of the voltage division circuit is connected to the second end of the switching circuit and the second end of the subsequent stage circuit and then grounded, and the first end of the switching circuit is connected to the third end of the protection circuit.
2. The overcurrent temperature protection circuit according to claim 1, wherein, The subsequent stage circuit includes: a DC / DC module; The first end of the DC / DC module is connected to the second end of the protection circuit and the first end of the temperature detection circuit, and the second end of the DC / DC module is connected to the second end of the voltage division circuit and the second end of the switching circuit and then grounded.
3. The overcurrent temperature protection circuit according to claim 1, wherein The protection circuit includes: a three-terminal fuse; The first end of the three-terminal fuse is connected to the power supply terminal, the second end of the three-terminal fuse is connected to the subsequent stage circuit and the first end of the temperature detection circuit, and the third end of the three-terminal fuse is connected to the first end of the switching circuit.
4. The overcurrent temperature protection circuit according to claim 1, wherein The temperature detection circuit includes: an NTC negative temperature coefficient thermistor; The first end of the NTC negative temperature coefficient thermistor is connected to the second end of the protection circuit, and the second end of the NTC negative temperature coefficient thermistor is connected to the first end of the voltage regulation circuit.
5. The overcurrent temperature protection circuit according to claim 1, wherein The switching circuit includes: an NMOS transistor or a thyristor; The first end of the NMOS transistor is connected to the third end of the protection circuit, the control end of the NMOS transistor is connected to the second end of the voltage regulation circuit and the first end of the voltage division circuit, and the second end of the NMOS transistor is connected to the second end of the voltage division circuit and then grounded; The first end of the thyristor is connected to the third end of the protection circuit, the control end of the thyristor is connected to the second end of the voltage regulation circuit and the first end of the voltage division circuit, and the second end of the thyristor is connected to the second end of the voltage division circuit and then grounded.
6. The overcurrent temperature protection circuit according to claim 1, characterized in that, The voltage regulation circuit includes: a voltage regulator diode; The first end of the voltage regulator diode is connected to the second end of the temperature detection circuit, and the second end of the voltage regulator diode is connected to the control end of the switching circuit and the first end of the voltage division circuit.
7. The overcurrent temperature protection circuit according to claim 1, wherein The voltage division circuit includes: a voltage division resistor; The first end of the voltage division resistor is connected to the second end of the voltage regulation circuit and the control end of the switching circuit, and the second end of the voltage division resistor is connected to the second end of the switching circuit and then grounded.
8. An overcurrent temperature protection device, characterized in that, Comprising the overcurrent temperature protection circuit according to any one of claims 1-7.
9. The overcurrent temperature protection device according to claim 8, characterized in that, Further comprising a power supply circuit, the power supply circuit is connected to the protection circuit, and the power supply circuit is used to supply power to the overcurrent temperature protection device.