阅读说明：本技术 短路保护电路、电器设备和电气系统 (Short-circuit protection circuit, electrical equipment and electrical system ) 是由 刘均 何乐 于 2020-04-24 设计创作，主要内容包括：本申请适用于电气系统技术领域,提供一种短路保护电路、电器设备和电气系统,其中,短路保护电路包括电源输入端口、开关电路、保护电路、电源输出端口和控制电路,保护电路实时检测电源输出端口是否发生短路,在电源输出端口发生短路时,输出反馈信号控制开关电路关断,从而切换电源输出,达到保护电路的目的,从而解决了传统的保险丝过流保护方案可靠性低的技术问题。(The utility model is suitable for an electrical system technical field, a short-circuit protection circuit, electrical equipment and electrical system are provided, wherein, short-circuit protection circuit includes power input port, a switch circuit, a protection circuit, power output port and control circuit, whether protection circuit real-time detection power output port takes place the short circuit, when power output port takes place the short circuit, output feedback signal control switch circuit turn-off, thereby switch over power output, reach protection circuit's purpose, thereby the technical problem that traditional fuse overcurrent protection scheme reliability is low has been solved.)

1. A short-circuit protection circuit is characterized by comprising a power input port, a switch circuit, a protection circuit, a power output port and a control circuit, wherein the power input port is connected with a power input end of the switch circuit;

the switch circuit is used for inputting a working power supply through the power supply input port;

the control circuit is used for controlling the switch circuit to be switched on or switched off according to the trigger signal;

the protection circuit is used for detecting whether the power output port is short-circuited or not, and outputting a feedback signal to control the switching circuit to be switched off when the power output port is short-circuited; and when the power output port is not short-circuited and the switch circuit is switched on, outputting the working power supply to a load through the power output port.

2. The short-circuit protection circuit of claim 1, wherein the protection circuit comprises an isolation protection circuit and a feedback control circuit;

the power supply input end of the isolation protection circuit is the power supply input end of the protection circuit, the power supply output end of the isolation protection circuit is connected with the signal input end of the feedback control circuit to form the power supply output end of the protection circuit, and the signal output end of the feedback control circuit is the feedback end of the protection circuit;

the isolation protection circuit is used for outputting the working power supply output by the switch circuit to the power supply output port in a single direction;

the feedback control circuit is used for detecting whether the power output port is short-circuited or not, and outputting a feedback signal to control the switching circuit to be switched off when the power output port is short-circuited; and stopping outputting the feedback signal to the switch circuit when the power output port is not short-circuited.

3. The short-circuit protection circuit of claim 2, wherein the isolation protection circuit comprises a first diode, an anode of the first diode being a power input of the isolation protection circuit, and a cathode of the first diode being a power output of the isolation protection circuit.

4. The short-circuit protection circuit of claim 2, wherein the feedback control circuit comprises a second diode, a cathode of the second diode being connected to the power output port, and an anode of the second diode being connected to the controlled terminal of the switching circuit.

5. The short-circuit protection circuit of claim 2, wherein the feedback control circuit comprises a second diode, a first electronic switching tube, a first resistor, a second resistor, and a positive power supply terminal;

the cathode of the second diode is connected with the power output port, the anode of the second diode is connected with the first end of the first resistor, the second end of the first resistor is connected with the controlled end of the first electronic switching tube, the input end of the first electronic switching tube is connected with the positive power supply end, the output end of the first electronic switching tube and the first end of the second resistor are connected in common to form the feedback end of the feedback control circuit, and the second end of the second resistor is grounded.

6. The short-circuit protection circuit of claim 4 or 5, wherein the second diode is a Schottky diode.

7. The short-circuit protection circuit of claim 1, wherein the switching circuit comprises a second electronic switching tube, a third resistor, and a fourth resistor;

the first end of the third resistor and the input end of the second electronic switching tube are connected together to form the power input end of the switching circuit, the second end of the third resistor, the first end of the fourth resistor and the controlled end of the second electronic switching tube are interconnected, the second end of the fourth resistor is the controlled end of the switching circuit, and the output end of the second electronic switching tube is the power output end of the switching circuit.

8. The short-circuit protection circuit of claim 1, wherein the switching circuit comprises a third electronic switching tube, a fourth electronic switching tube, a fifth resistor, a sixth resistor, a seventh resistor, and an eighth resistor;

the first end of the fifth resistor and the input end of the fourth electronic switching tube are connected in common to form the power input end of the switching circuit, the second end of the fifth resistor, the controlled end of the fourth electronic switching tube and the second end of the sixth resistor are interconnected, the output end of the fourth electronic switching tube is the power output end of the switching circuit, the second end of the sixth resistor is connected with the input end of the third electronic switching tube, the first end of the seventh resistor is the controlled end of the switching circuit, the second end of the seventh resistor, the first end of the eighth resistor and the controlled end of the third electronic switching tube are interconnected, and the second end of the eighth resistor and the output end of the third electronic switching tube are connected and grounded.

9. An electrical apparatus comprising the short-circuit protection circuit according to any one of claims 1 to 8.

10. An electrical system comprising a load and an electrical device according to claim 9, the power terminals of the electrical device being connected to the power terminals of the load.

Technical Field

The application belongs to the technical field of electrical systems, and particularly relates to a short-circuit protection circuit, electrical equipment and an electrical system.

Background

In an electrical system, an electrical device usually drives another electrical device, for example, a vehicle-mounted entertainment information terminal to supply power to a reversing camera, and during operation, a line short circuit may be caused by a failure of a rear-end device or improper modification of the electrical device, and finally a short-circuit overcurrent fault occurs in the two electrical devices that are related, so that a short-circuit protection process needs to be performed between the two electrical devices, for example, at an output port position, to protect the normal operation of the whole electrical system.

However, the fuse is a short-time continuous process, and a short-time large current which can be borne by the whole circuit needs to be considered in the design process, otherwise, the circuit itself may be damaged before the fuse is fused, and the fuse is influenced by the temperature due to the material characteristics, namely, the high-temperature fusing current is small, and the low-temperature fusing current is large, which can lead to early or late intervention of protection, so that the traditional fuse overcurrent protection scheme has low reliability.

Disclosure of Invention

The application aims to provide a short-circuit protection circuit and aims to solve the technical problem that a traditional fuse overcurrent protection scheme is low in reliability.

A first aspect of an embodiment of the present application provides a short-circuit protection circuit, which includes a power input port, a switch circuit, a protection circuit, a power output port, and a control circuit, where the power input port is connected to the power input port of the switch circuit, the power output port of the switch circuit is connected to the power input port of the protection circuit, the power output port of the protection circuit is interconnected to the power output port, and the control terminal of the control circuit and the feedback terminal of the protection circuit are respectively connected to a controlled terminal of the switch circuit;

the switch circuit is used for inputting a working power supply through the power supply input port;

the control circuit is used for controlling the switch circuit to be switched on or switched off according to the trigger signal;

the protection circuit is used for detecting whether the power output port is short-circuited or not, and outputting a feedback signal to control the switching circuit to be switched off when the power output port is short-circuited; and when the power output port is not short-circuited and the switch circuit is switched on, outputting the working power supply to a load through the power output port.

In one embodiment, the protection circuit includes an isolation protection circuit and a feedback control circuit;

the power supply input end of the isolation protection circuit is the power supply input end of the protection circuit, the power supply output end of the isolation protection circuit is connected with the signal input end of the feedback control circuit to form the power supply output end of the protection circuit, and the signal output end of the feedback control circuit is the feedback end of the protection circuit;

the isolation protection circuit is used for outputting the working power supply output by the switch circuit to the power supply output port in a single direction;

the feedback control circuit is used for detecting whether the power output port is short-circuited or not, and outputting a feedback signal to control the switching circuit to be switched off when the power output port is short-circuited; and stopping outputting the feedback signal to the switch circuit when the power output port is not short-circuited.

In one embodiment, the isolation protection circuit comprises a first diode, wherein an anode of the first diode is a power supply input end of the isolation protection circuit, and a cathode of the first diode is a power supply output end of the isolation protection circuit.

In one embodiment, the feedback control circuit includes a second diode, a cathode of the second diode is connected to the power output port, and an anode of the second diode is connected to the controlled terminal of the switching circuit.

In one embodiment, the feedback control circuit comprises a second diode, a first electronic switching tube, a first resistor, a second resistor and a positive power supply end;

the cathode of the second diode is connected with the power output port, the anode of the second diode is connected with the first end of the first resistor, the second end of the first resistor is connected with the controlled end of the first electronic switching tube, the input end of the first electronic switching tube is connected with the positive power supply end, the output end of the first electronic switching tube and the first end of the second resistor are connected in common to form the feedback end of the feedback control circuit, and the second end of the second resistor is grounded.

In one embodiment, the second diode is a schottky diode.

In one embodiment, the switching circuit comprises a second electronic switching tube, a third resistor and a fourth resistor;

the first end of the third resistor and the input end of the second electronic switching tube are connected together to form the power input end of the switching circuit, the second end of the third resistor, the first end of the fourth resistor and the controlled end of the second electronic switching tube are interconnected, the second end of the fourth resistor is the controlled end of the switching circuit, and the output end of the second electronic switching tube is the power output end of the switching circuit.

In one embodiment, the switching circuit comprises a third electronic switching tube, a fourth electronic switching tube, a fifth resistor, a sixth resistor, a seventh resistor and an eighth resistor;

the first end of the fifth resistor and the input end of the fourth electronic switching tube are connected in common to form the power input end of the switching circuit, the second end of the fifth resistor, the controlled end of the fourth electronic switching tube and the second end of the sixth resistor are interconnected, the output end of the fourth electronic switching tube is the power output end of the switching circuit, the second end of the sixth resistor is connected with the input end of the third electronic switching tube, the first end of the seventh resistor is the controlled end of the switching circuit, the second end of the seventh resistor, the first end of the eighth resistor and the controlled end of the third electronic switching tube are interconnected, and the second end of the eighth resistor and the output end of the third electronic switching tube are connected and grounded.

A second aspect of embodiments of the present application provides an electrical apparatus including the short-circuit protection circuit as described above.

A third aspect of embodiments of the present application provides an electrical system comprising a load and an electrical device as described above, a power supply terminal of the electrical device being connected to a power supply terminal of the load.

Compared with the prior art, the embodiment of the application has the advantages that: the short-circuit protection circuit realizes short-circuit protection through the power input port, the switch circuit, the protection circuit, the power output port and the control circuit, the protection circuit detects whether the power output port is short-circuited in real time, when the power output port is short-circuited, the feedback signal is output to control the switch circuit to be turned off, so that power output is switched, the purpose of the protection circuit is achieved, when the power output port is not short-circuited and the switch circuit is turned on, the working power supply is output to a load through the power output port, the transmission effect of the working power supply is achieved, and the operation reliability is improved.

Drawings

Fig. 1 is a schematic block diagram of a short-circuit protection circuit according to an embodiment of the present disclosure;

fig. 2 is a schematic diagram of another module structure of a short-circuit protection circuit according to an embodiment of the present disclosure;

fig. 3 is a schematic circuit structure diagram of a short-circuit protection circuit according to an embodiment of the present disclosure;

fig. 4 is a schematic circuit diagram of another circuit structure of the short-circuit protection circuit according to the embodiment of the present application;

fig. 5 is a schematic structural diagram of a module of an electrical system according to an embodiment of the present disclosure.

Detailed Description

The following describes a technical solution of an embodiment of the present invention clearly and completely with reference to the accompanying drawings of the embodiment of the present application.

It is to be understood that the terms "first", "second" and "first" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of the present application, "a plurality" means two or more unless specifically limited otherwise.

As shown in fig. 1, fig. 1 is a schematic block diagram of a short-circuit protection circuit according to an embodiment of the present disclosure, the short-circuit protection circuit is suitable for use in an electrical system, to achieve short-circuit protection between an electrical device 100 and a load 200 to be driven, in the electrical system, the electrical apparatus 100 drives the load 200 to operate, the load 200 may supply power to the reverse camera for another electrical apparatus 100 such as an in-vehicle infotainment terminal, in operation, a short circuit may be caused by a failure of the backend device or improper modification, which may eventually cause a short-circuit overcurrent fault of the two associated electrical devices 100, therefore, a short-circuit protection process is required between two electrical devices 100, for example, at the output port position, to protect the normal operation of the entire electrical system, the short-circuit protection circuit may be disposed in the electrical apparatus 100, and detect a short-circuit state of the power output port OUT of the electrical apparatus 100 in real time.

IN one embodiment, the short-circuit protection circuit includes a power input port IN, a switch circuit 110, a protection circuit 120, a power output port OUT, and a control circuit 130, where the power input port IN is connected to a power input terminal of the switch circuit 110, the power output terminal of the switch circuit 110 is connected to a power input terminal of the protection circuit 120, the power output terminal of the protection circuit 120 and the power output port OUT are interconnected, and a control terminal of the control circuit 130 and a feedback terminal of the protection circuit 120 are respectively connected to a controlled terminal of the switch circuit 110;

a switching circuit 110 for inputting a working power through a power input port IN;

a control circuit 130 for controlling the switching circuit 110 to be turned on or off according to the trigger signal;

the protection circuit 120 is configured to detect whether the power output port OUT is short-circuited, and output a feedback signal to control the switching circuit 110 to turn off when the power output port OUT is short-circuited; when the power output port OUT is not short-circuited and the switching circuit 110 is turned on, the operating power is output to the load 200 through the power output port OUT.

IN this embodiment, the working power input by the power input port IN may be provided by a power module of the electrical apparatus 100 itself, or provided to the electrical apparatus 100 by another power module, the electrical apparatus 100 converts the working power and outputs the converted working power to the power input port IN, and a specific source of the working power may be specifically selected and set according to a structure of the electrical apparatus 100, which is not limited herein.

The control Circuit 130 may be a control module composed of components or functional modules, or may be a controller, and a Specific structure may be designed according to requirements, in an embodiment, the control Circuit 130 is a controller, and the controller may be a Central Processing Unit (CPU), or may also be other general purpose processors, Digital Signal Processors (DSP), Application Specific Integrated Circuits (ASIC), ready-made Programmable Gate arrays (FPGA), or other Programmable logic devices, discrete gates or transistor logic devices, discrete hardware components, or the like. A general purpose processor may be a microprocessor or the processor may be any conventional processor or the like.

The control circuit 130 is configured to enable and control the switch circuit 110 to be turned on or off according to an enable signal, that is, when the electrical system needs to drive the load 200, the control circuit 130 controls the switch circuit 110 to be turned on according to the enable signal, so that the working power is output to the power output port OUT through the switch circuit 110 and the protection circuit 120 and then output to the load 200, and meanwhile, when the electrical system needs to turn off the load 200, the control circuit 130 controls the switch circuit 110 to be turned off according to the enable signal, so as to switch the output of the working power, and complete power supply control of the load 200.

The switch circuit 110 may be a switch device or a switch module with controlled on/off capability, such as a switch tube, a relay, a switch chip, etc., and the specific structure is not limited.

In this embodiment, the protection circuit 120, on one hand, implements transmission of a working power supply, and on the other hand, performs a function of detecting a short-circuit state of the power output port OUT, when the load 200 normally operates, the power output port OUT is not short-circuited, at this time, the protection circuit 120 outputs the working power supply output by the switch circuit 110 to the power output port OUT to drive the load 200 to operate, and when the power output port OUT is short-circuited due to abnormal operation of the load 200, the protection circuit 120 immediately outputs a feedback signal to the switch circuit 110, thereby controlling the switch circuit 110 to be turned off, isolating the electrical apparatus 100 from the load 200, protecting the safety of the circuit 120 and the electrical apparatus 100, and improving the driving reliability.

Referring to fig. 2, fig. 2 is another schematic structural diagram of a short-circuit protection circuit according to an embodiment of the present disclosure, in which a protection circuit 120 includes an isolation protection circuit 121 and a feedback control circuit 122; the power input end of the isolation protection circuit 121 is the power input end of the protection circuit 120, the power output end of the isolation protection circuit 121 is connected with the signal input end of the feedback control circuit 122 to form the power output end of the protection circuit 120, and the signal output end of the feedback control circuit 122 is the feedback end of the protection circuit 120.

The isolation protection circuit 121 is configured to output the working power output by the switch circuit 110 to the power output port OUT in a single-way manner, so as to implement transmission of the working power and reverse voltage protection, the feedback control circuit 122 performs a function of detecting a short-circuit state of the power output port OUT, and outputs a feedback signal to control the switch circuit 110 to turn off when the power output port OUT is short-circuited; when no short circuit occurs at the power output port OUT, the output of the feedback signal to the switch circuit 110 is stopped, and the control circuit 130 controls the switch circuit 110 to be turned on or off, wherein the isolation protection circuit 121 may be a unidirectional conducting module, such as a diode or an optocoupler, and the feedback control circuit 122 may be a voltage detection circuit, a voltage trigger circuit, or other components, and the specific structure is not limited.

As shown in fig. 3, in one embodiment, the isolation protection circuit 121 includes a first diode D1, an anode of the first diode D1 is a power input terminal of the isolation protection circuit 121, a cathode of the first diode D1 is a power output terminal of the isolation protection circuit 121, the feedback control circuit 122 includes a second diode D2, a cathode of the second diode D2 is connected to the power output port OUT, and an anode of the second diode D2 is connected to the controlled terminal of the switch circuit 110.

In this embodiment, when the power output port OUT is short-circuited, the voltages of the cathode and the anode of the second diode D2 are pulled down rapidly, so as to output a low-level feedback signal to the controlled terminal of the switch circuit 110, the switch circuit 110 is turned off according to the feedback signal, when the power output port OUT is not short-circuited, the cathode voltage and the anode voltage of the second diode D2 are maintained at a high level, the switch circuit 110 is not triggered by mistake, and the switch circuit 110 may be designed correspondingly according to the structure of the protection circuit 120 and the on-off manner of the switch circuit 110, as shown in fig. 3, in an embodiment, the switch circuit 110 includes a third electronic switch Q3, a fourth electronic switch Q4, a fifth resistor R5, a sixth resistor R6, a seventh resistor R7, and an eighth resistor R8;

a first end of the fifth resistor R5 and an input end of the fourth electronic switch tube Q4 are commonly connected to form a power input end of the switch circuit 110, a second end of the fifth resistor R5, a controlled end of the fourth electronic switch tube Q4 and a second end of the sixth resistor R6 are interconnected, an output end of the fourth electronic switch tube Q4 is a power output end of the switch circuit 110, a second end of the sixth resistor R6 is connected to an input end of the third electronic switch tube Q3, a first end of the seventh resistor R7 is a controlled end of the switch circuit 110, a second end of the seventh resistor R7, a first end of the eighth resistor R8 and a controlled end of the third electronic switch tube Q3 are interconnected, and a second end of the eighth resistor R8 and an output end of the third electronic switch tube Q3 are connected and grounded.

IN this embodiment, the third electronic switch Q3 and the fourth electronic switch Q4 may be transistors such as a triode and a MOS transistor, and the specific type is selected according to the requirement, IN one embodiment, the third electronic switch Q3 is a PMOS transistor, the fourth electronic switch Q4 is an NPN transistor, when the power output port OUT is not short-circuited, the control circuit 130 outputs a high level to the fourth electronic switch Q4 through the control port Ctr, the seventh resistor R7 and the eighth resistor R8, the fourth electronic switch Q4 is turned on, so as to control the turn-on of the third electronic switch Q3, the working power input from the power input port IN is output to the power output port OUT through the isolation protection circuit 121, so as to drive the load 200 to work, when the power output port OUT is short-circuited, the feedback control circuit 122 outputs a low level to the fourth electronic switch Q35 4, so as to control the third electronic switch Q3 to turn off, the switching circuit 110 switches the output.

As shown in fig. 4, in a further embodiment, the isolation protection circuit 121 includes a first diode D1, and the feedback control circuit 122 includes a second diode D2, a first electronic switch Q1, a first resistor R1, a second resistor R2, and a positive power supply terminal;

the cathode of the second diode D2 is connected to the power output port OUT, the anode of the second diode D2 is connected to the first end of the first resistor R1, the second end of the first resistor R1 is connected to the controlled end of the first electronic switch Q1, the input end of the first electronic switch Q1 is connected to the positive power source, the output end of the first electronic switch Q1 and the first end of the second resistor R2 are connected in common to form the feedback end of the feedback control circuit 122, and the second end of the second resistor R2 is grounded.

In this embodiment, the first resistor R1, the second resistor R2 and the first electronic switch Q1 form a level shift circuit, when the power output port OUT is not short-circuited, the cathode and the anode of the second diode D2 are at high levels, the first switch is turned off and outputs a low level to the switch circuit 110, when the power output port OUT is short-circuited, the cathode and the anode of the second diode D2 are pulled down to be at low levels, the first switch is turned on and outputs a high level to the switch circuit 110, the switch circuit 110 is turned off, according to the structure of the protection circuit 120 and the on-off manner of the switch circuit 110, when the power output port OUT is short-circuited, the cathode and the anode of the second diode D2 are pulled down to be at low levels, the first electronic switch Q1 is turned on and outputs a high level to the switch circuit 110, the switch circuit 110 may be correspondingly designed, in one embodiment, the switch circuit 110 includes the second electronic switch Q2, a high level, A third resistor R3 and a fourth resistor R4;

the first end of the third resistor R3 and the input end of the second electronic switch Q2 are commonly connected to form a power input end of the switch circuit 110, the second end of the third resistor R3, the first end of the fourth resistor R4 and the controlled end of the second electronic switch Q2 are interconnected, the second end of the fourth resistor R4 is the controlled end of the switch circuit 110, and the output end of the second electronic switch Q2 is the power output end of the switch circuit 110.

IN this embodiment, the first electronic switch Q1 and the second electronic switch Q2 may be transistors such as transistors, MOS transistors, etc., and the specific type is selected according to the requirement, IN one embodiment, the second electronic switch Q2 is a PMOS transistor, the first electronic switch Q1 is a PNP transistor, when the power output port OUT is not short-circuited, the control circuit 130 outputs a low level to the second electronic switch Q2 through the control port Ctr, the third resistor R3 and the fourth resistor R4, the second electronic switch Q2 is turned on, the working power input from the power input port IN is output to the power output port OUT through the isolation protection circuit 121, so as to drive the load 200 to work, when the power output port OUT is short-circuited, the feedback control circuit 122 outputs a low level to the first switch Q4, the fourth electronic switch Q1 is turned on, and outputs a high level to the second electronic switch Q2, so as to control the second electronic switch Q2 to turn off, the switching circuit 110 switches the output to realize short-circuit protection.

In one embodiment, in order to improve the short circuit feedback time, the second diode D2 is a schottky diode, and according to the characteristics of the schottky diode, when the power output port OUT is short-circuited, the second diode D2 has a faster response time than the first diode D1, and therefore, the anode voltage of the second diode D2 is rapidly pulled low, thereby controlling the switching circuit 110 to be rapidly turned off, and improving the reliability of short circuit protection.

In one embodiment, at least one filter circuit is disposed in the switch circuit 110 and/or the protection circuit 120, respectively, to filter at least one of the input working power, the output working power, the feedback signal and the enable signal, such as the first capacitor C1, the second capacitor C2, the third capacitor C3 and the fourth capacitor C4 in fig. 3 and 4.

As shown in fig. 5, a second aspect of the embodiment of the present application provides an electrical apparatus 100, where the electrical apparatus 100 includes a short-circuit protection circuit, and a specific structure of the short-circuit protection circuit refers to the above embodiments, and since the electrical apparatus 100 adopts all technical solutions of all the above embodiments, at least all beneficial effects brought by the technical solutions of the above embodiments are achieved, and details are not repeated here.

The third aspect of the embodiment of the present application provides an electrical system, which includes a load 200 and an electrical apparatus 100, a power end of the electrical apparatus 100 is connected to a power end of the load 200, the electrical apparatus 100 drives the load 200 to operate, the load 200 can supply power to a reversing camera for another electrical apparatus 100, for example, a vehicle-mounted entertainment information terminal, a short-circuit protection circuit in the electrical apparatus 100 realizes the transmission of working power, and at the same time, detects a short-circuit state at a connection position between the electrical apparatus 100 and the load 200, and switches the output of the working power when detecting a short circuit, so as to realize short-circuit protection.

The above-mentioned embodiments are only used for illustrating the technical solutions of the present application, and not for limiting the same; although the present application has been described in detail with reference to the foregoing embodiments, it should be understood by those of ordinary skill in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some technical features may be equivalently replaced; such modifications and substitutions do not substantially depart from the spirit and scope of the embodiments of the present application and are intended to be included within the scope of the present application.