WO2019061139A1

WO2019061139A1 - Short circuit protection method and apparatus

Info

Publication number: WO2019061139A1
Application number: PCT/CN2017/103928
Authority: WO
Inventors: 徐家林
Original assignee: 深圳传音通讯有限公司
Priority date: 2017-09-28
Filing date: 2017-09-28
Publication date: 2019-04-04

Abstract

A short circuit protection method and apparatus. The method comprises: setting a working voltage and a working current of a power supply, wherein the working current is the maximum working current allowed, under the working voltage, by a circuit; and detecting whether a first current of the circuit is less than a pre-set limiting current, if so, the circuit working normally according to the working voltage and the working current, and replacing the value of the pre-set limiting current with the value of the working current, and if not, disconnecting the circuit. By means of providing a method for detecting whether the current in a circuit is greater than or equal to a pre-set limiting current when the circuit is connected, the technical solution can disconnect the circuit in a timely manner when the current in the circuit is greater than or equal to a pre-set current so as to protect a device in the circuit.

Description

Short circuit protection method and device

Technical field

The present invention relates to the field of electronic circuits, and in particular, to a method and apparatus for circuit short circuit protection.

Background technique

With the continuous development of technology, the field of switching power supply is increasingly based on safety and reliability. Under the premise that electrical technical indicators meet normal use, the power supply is safe and reliable in harsh environments and sudden faults. The work must be designed with a variety of protection circuits.

For electronic systems, short-circuit protection is one of the most serious faults. Insulated Gate Bipolar Transistors (IGBTs) are one of the commonly used devices in power systems, and have high input impedance and drive of field effect transistors. The characteristics of small power and bipolar transistor voltage, large current capacity and reduced tube voltage are the most commonly used power electronic switching devices for medium and large power switching power supplies. The current that the IGBT can withstand depends on its saturation voltage drop and the amount of short-circuit current. If the current is too large, the system will be seriously damaged.

Summary of the invention

The technical problem to be solved by the embodiment of the present invention is to determine whether the circuit is short-circuited when the circuit is turned on, and to determine whether the current is greater than or equal to the preset current-limiting current when the circuit is turned on, thereby realizing the current when the circuit is turned on. The circuit is turned off when the preset current limiting current is greater than or equal to the purpose of protecting the power supply and the electrical equipment in the circuit.

In a first aspect, the present invention provides a circuit short circuit protection method, the method comprising:

Setting an operating voltage and an operating current of the power source, wherein the operating current is a maximum current allowed by the circuit at the operating voltage;

Detecting whether the first current of the circuit at the instant of turn-on is less than a preset current limit current, and if so, the power source is normally powered according to the working voltage and the working current, and the value of the preset current limiting current is Replaced with the value of the operating current, if not, the circuit is turned off.

Optionally, a second current of the circuit is detected, and if the second current is greater than the operating current, the circuit is turned off.

Optionally, the preset current limiting current is 2 milliamps.

Optionally, the operating voltage and the operating current are determined according to a rated voltage and a rated current of the circuit load.

Optionally, the method further comprises: setting a temperature threshold of the circuit, and when the temperature of the circuit is detected to reach the threshold, disconnecting the circuit.

In a second aspect, an embodiment of the present invention provides a circuit short circuit protection device, where the device includes:

a power module, a setting module, a detecting module, a control module, and a load module;

Wherein the power module is used to provide electrical energy to the circuit;

The setting module is configured to set an operating voltage, an operating current, and a current limiting current of the power module;

The detecting module is configured to detect a size of the first current and the second current in the circuit;

The control module is configured to: when the first current detected by the detecting module at a moment when the circuit is turned on is greater than or equal to a preset current limiting current, disconnect the circuit, and the detecting module is connected in the circuit When the first current detected instantaneously is less than the preset current limiting current, controlling the circuit to work normally and replacing the value of the preset current limiting current with the value of the working current;

The load module is configured to be electrically connected to the power module to form a complete power supply circuit.

Optionally, the setting module sets an operating voltage and an operating current of the current module according to a rated voltage and a rated current of the load.

Optionally, the detecting module is further configured to detect a value of a value of the second current of the circuit after the circuit works normally.

Optionally, the control unit is further configured to: when the detecting module detects that the second current of the circuit is not less than the operating current after the circuit is working normally, disconnect the circuit.

Optionally, the prime device further includes a thermal protection module in series with the load module for disconnecting the circuit when the temperature exceeds a set value.

By implementing the embodiment of the present invention, the circuit determines whether the circuit has a short circuit fault by detecting whether the first current in the circuit is greater than or equal to the preset current limit current at the moment of turning on, if the circuit is connected If it is detected that the first current is greater than or equal to the preset current limiting current, the circuit is considered to be short-circuited, and the circuit is turned off to protect various devices in the circuit, if the circuit is in an instant If the first current is less than the current limiting current, it is considered that the circuit does not have a short circuit, the circuit is normally powered to make it work normally, and the value of the preset current limiting current is replaced by the working power The value of the stream continues to detect the second current of the circuit. If greater than the operating current, the circuit is opened and the circuit is further protected.

DRAWINGS

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the embodiments or the description of the prior art will be briefly described below. Obviously, the drawings in the following description are only It is a certain embodiment of the present invention, and other drawings can be obtained from those skilled in the art without any creative work.

1 is a schematic flow chart of a circuit short circuit protection method according to an embodiment of the present invention;

2 is a schematic flow chart of another circuit short circuit protection method according to an embodiment of the present invention;

2A is a schematic circuit diagram of a circuit short circuit protection method according to an embodiment of the present invention;

FIG. 3 is a schematic structural diagram of a circuit short circuit protection device according to an embodiment of the present invention.

Detailed ways

The technical solutions in the embodiments of the present invention are clearly and completely described in the following with reference to the accompanying drawings in the embodiments of the present invention. It is a partial embodiment of the invention, and not all of the embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative efforts are within the scope of the present invention.

It is to be understood that the terminology used in the embodiments of the present invention is for the purpose of describing the particular embodiments, and is not intended to limit the invention. The singular forms "a", "the" and "the" It should also be understood that the term "and/or" as used herein refers to and encompasses any and all possible combinations of one or more of the associated listed items.

It is to be noted that the embodiments of the present invention are described in detail below, and the examples of the embodiments are illustrated in the drawings, wherein the same or similar reference numerals are used to refer to the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the drawings are intended to be illustrative of the invention and are not to be construed as limiting.

The following disclosure provides many different embodiments or examples for implementing different structures of the present invention. In order to simplify the disclosure of the present invention, the components and arrangements of the specific examples are described below. Of course, they are merely examples and are not intended to limit the invention. Furthermore, the present invention may repeat reference numerals and/or letters in different examples. This repetition is for the purpose of simplicity and clarity, and is not in the nature of the description of the various embodiments and/or arrangements discussed.

In the description of the present invention, it should be noted that the terms "installation", "connected", "connected", and "connected" are to be understood broadly, and may be mechanical or electrical, for example, unless otherwise specified and defined. It can also be the internal communication between the two components, which can be directly connected or indirectly connected through an intermediate medium. For those skilled in the art, the specific meanings of the above terms can be understood according to specific situations.

In the embodiment of the present invention, the rated voltage refers to a standard voltage for long-term stable operation of electrical equipment (including electrical equipment and power supply equipment), and the rated voltage can be understood from two aspects of the electric equipment and the power supply equipment, and the rated value of the electric equipment The voltage represents the optimum input voltage that the device is designed from the factory, and is usually the power supply voltage that is relatively easy to obtain. The rated voltage of the power supply equipment represents the optimal output voltage of the power supply system and needs to be matched with the rated voltage of the power equipment, including the rated voltage of the power grid, the rated voltage of the engine, and the rated voltage of the power transformer.

In the embodiment of the present invention, the rated current refers to the current when the electrical equipment is operated at the rated voltage according to the rated power, and the current should not exceed the rated current when the electrical appliance is in operation.

In the embodiment of the present invention, the rated power refers to the power when the electrical appliance is working normally, and its value is the rated voltage of the electrical appliance multiplied by the rated current. If the actual power of the appliance is greater than the rated power, the appliance may be damaged. If the actual power of the appliance is less than the rated power, the appliance may not work properly.

The embodiment of the invention discloses a circuit short circuit protection method, which can detect whether the current in the circuit exceeds the preset current limiting current and then the control circuit is turned on and off to protect the device in the circuit from damage when the circuit is turned on.

Please refer to FIG. 1. FIG. 1 is a schematic flowchart of a short circuit protection method according to an embodiment of the present invention. As shown in FIG. 1, the circuit short circuit protection method includes:

101. Set an operating voltage and an operating current of the power source, wherein the operating current is a maximum current allowed by the circuit at the operating voltage.

It will be appreciated that the circuit includes at least a power source, a load, and a connecting lead. Wherein, the power source is indispensable for outputting electrical energy in the circuit, and is a device for converting other forms of energy into electrical energy. The load refers to an electronic component that is connected across the power supply in the circuit and is a device that converts electrical energy into other forms of energy. The connecting wire electrically connects a power source, a load, and other accessory devices for transmitting electricity The medium of energy. The accessory devices include, but are not limited to, various types of control devices, protection devices, measurement devices, and the like.

Optionally, the power source may be a DC power source or an AC power source. The DC power source refers to two electrodes having positive and negative electrodes. When the two electrodes are connected to the circuit, a constant potential difference can be maintained between the two ends of the circuit, thereby forming a current from the positive electrode to the negative electrode in the external circuit. For example, zinc-manganese dry batteries, lithium batteries, lead-acid batteries, and the like. AC power refers to the power supply whose current magnitude and direction change regularly with time, such as the domestic 220V mains. It should be understood that the source of the power of the DC power source or the AC power source includes, but is not limited to, chemical energy, solar energy, wind energy, water energy, nuclear energy, and the like, which are not specifically limited in the embodiment of the present invention.

Optionally, the load may be an inductive load, may be a capacitive load, or may be a resistive load according to different load effects exhibited by the powered device, or may be combined into two or two or three of the above three loads. Load. The inductive load refers to a load whose load current lags the load voltage by one phase, such as a transformer, an electric motor, or the like. The capacitive load refers to a load whose load voltage lags the load current by one phase. A resistive load is a resistor that has no phase difference between the load current and the load voltage compared to the power source, such as an incandescent lamp or a resistor in an electric water heater. It is to be understood that the number of the load in the circuit may be one or more, which is not specifically limited in the embodiment of the present invention. It should be understood that the above examples are by way of example only and are not to be construed as limiting.

It can be understood that the operating voltage and the operating current of the circuit are set according to the load of the circuit, and the circuit sets the output voltage and output current of the power supply according to the rated voltage and rated current indicated on the nameplate of the load device. To ensure the normal operation of the load device. The working voltage and the working current of the circuit may be set by using physical buttons or knobs on the power source, or the power source may provide a user interaction interface, and the user may click on the screen or voice. The input may also be a model in which the user directly inputs the load device, and the power source automatically sets its output voltage and output current according to the model of the load device. It can be understood that the load can also adjust the rated voltage and the rated current of the working voltage according to the output voltage and the output current of the power supply, which are not specifically limited in the embodiment of the present invention.

102. Detect whether the first current of the circuit at the moment of turning on is less than a preset current limit current. If yes, the circuit normally supplies power according to the working voltage and the working current, and the preset current limiting current is The value is replaced by the value of the operating current, and if not, the circuit is turned off.

It can be understood that it is generally considered that the leakage current is greater than 1 mA and can be regarded as a short circuit, such as power supply filtering. The leakage current of the device refers to the current from the filter case to any end of the AC input line under the rated AC voltage. Since the leakage current of the power supply filter involves personal safety, international countries have strict standards for this, for 220V/ A 50 Hz AC grid generally requires a leakage current of less than 1 mA. Therefore, the device for detecting the current in the circuit must reach the milliamp level, which may be a milliampere meter or a microampere meter, which may be an electromagnetic milliampere meter/microampere meter or a magnetoelectric milliampere meter/microampere The table, according to whether the power source in the circuit is a DC power source or an AC power source, selects a DC current meter or an AC current meter, or an AC/DC current meter. The embodiment of the invention is not specifically limited.

Optionally, the leakage current includes, but is not limited to, a power supply leakage current, a semiconductor element leakage current, a capacitance leakage current, and a filter leakage current. For example, in the switching power supply, in order to reduce interference, an EMI filter circuit is generally provided, so that the switching power supply has a small current to the ground after the power is connected, that is, the power supply leakage current, and the capacitive medium cannot be absolutely non-conductive. When the capacitor is added with a DC voltage, the capacitor will have a leakage current. If the leakage current is large, the capacitor will be damaged by heat.

It can be understood that the preset current limiting current is the maximum current allowed by the circuit at the initial moment of conduction, that is, the circuit detects that the leakage current is greater than or equal to the preset current limiting current. When the circuit is considered to be a short circuit accident, when a short circuit accident occurs, the circuit is disconnected to protect the equipment in the circuit, and the user is reminded of a short circuit, and the fault needs to be eliminated. If the circuit does not detect a current greater than or equal to the preset current limiting current at the initial moment of conduction, it is considered that the circuit does not have a short circuit and can work normally, and the circuit is switched to a normal power supply at this time. a state, resetting the value of the preset current limiting current to a value of the operating current to make the circuit work normally.

It can be seen that, in the method described in FIG. 1, the circuit determines whether the circuit has a short-circuit fault by detecting whether the current in the circuit is greater than or equal to the preset current-limiting current at the moment of turning on, if the current is greater than Or equal to the preset current limiting current, the circuit is considered to be short-circuited, the circuit is turned off to protect various devices in the circuit, and if the current is less than the current limiting current, the circuit is considered not to occur. Short circuit, the circuit is normally powered to make it work properly.

Referring to FIG. 2, FIG. 2 is a schematic flowchart diagram of another short circuit protection method according to an embodiment of the present invention. As shown in FIG. 2, the short circuit protection method includes the following steps:

201. Set an operating voltage and an operating current of the power supply, wherein the operating current is a maximum current allowed by the circuit at the operating voltage.

It can be understood that the operating voltage and the operating current of the circuit are set according to the load of the circuit, and the circuit is set according to the rated voltage and rated current indicated on the nameplate of the load device. The output voltage and output current of the power supply ensure the normal operation of the load device. For example, if the load is a white paper lamp, marked "12V, 40W" on it, it indicates that its operating voltage is 12V and the operating current is 3.33A. It should be understood that the operating voltage may also be a range value, for example The operating voltage of the STC89C52 is 3.3V to 5.5V, so it can be set to operate at 5.5V. The working voltage and the working current of the circuit may be set by using physical buttons or knobs on the power source, or the power source may provide a user interaction interface, and the user may click on the screen or voice. The input may also be a model in which the user directly inputs the load device, and the power source automatically sets its output voltage and output current according to the model of the load device. It can be understood that the load can also adjust the rated voltage and the rated current of the working voltage according to the output voltage and the output current of the power supply, which are not specifically limited in the embodiment of the present invention.

It will be appreciated that the circuit includes at least a power source, a load, and a connecting lead. Wherein, the power source is a device for outputting electric energy in the circuit, and is a device for converting other forms of energy into electric energy. The load refers to an electronic component that is connected across the power supply in the circuit and is a device that converts electrical energy into other forms of energy. The connecting wire is a medium that electrically connects a power source, a load, and other accessory devices for transmitting electrical energy. The accessory devices include, but are not limited to, various types of control devices, protection devices, measurement devices, and the like.

202. Detect whether the first current of the circuit at the moment of being turned on is less than a preset current limit current. If yes, the circuit normally supplies power according to the working voltage and the working current, and the preset current limiting current is The value is replaced by the value of the operating current, and if not, the circuit is turned off.

It can be understood that the preset current limiting current is the maximum current allowed to pass by the circuit at the initial moment of conduction, and the preset current limiting current can be set according to the power source or the load, in the embodiment of the present invention. In the research and experiment by the inventors of the present invention, the preset current limiting current is set to 2 mA. That is, when the first current is greater than or equal to the preset current limiting current when the circuit is turned on, the circuit may be regarded as a short circuit accident, and when a short circuit accident occurs, the circuit is disconnected. In order to protect the equipment in the circuit and remind the user that the circuit is short-circuited, it is necessary to eliminate the fault. If the circuit does not detect a first current greater than or equal to the preset current limiting current at the initial moment of conduction, then the circuit is considered to have no short circuit and can work normally, according to the operating voltage and the The operating current is normally supplied, and the value of the preset current limiting current is replaced with the value of the operating current to cause the circuit to operate normally.

For example, as shown in FIG. 2A, FIG. 2A is a simple simple circuit for controlling an LED with a 89C51 single-chip microcomputer. In the circuit, the operating voltage VCC is set to +5 volts, and the operating current is 15 mA. The preset current limiting current is 2 milliamps. At the instant of turning on the circuit, the detecting circuit detects a first current output by the power source. If the value of the first current is greater than or equal to 2 milliamps, the The detecting circuit sends a first disconnection command to the control circuit, instructing the control circuit to open the circuit, if the first current detected by the detecting circuit at the moment of circuit turning is less than 2 milliamps, The circuit is normally powered according to the set operating voltage and operating current, and the value of the preset current limiting current is replaced by 15 mA, and the detecting circuit continues to detect the second current of the circuit, and if the When the two currents are greater than 15 mA, the circuit is turned off. If the second current is less than 15 mA, the LED of the circuit is turned on or off under the control of the relevant control program.

It can be understood that it is generally considered that the leakage current is greater than 1 mA, which can be regarded as a short circuit. For example, the leakage current of the power supply filter refers to the current of the filter housing to any end of the AC input line under the rated AC voltage, due to the leakage current of the power supply filter. The size involves personal safety. International countries have strict standards for this. For 220V/50Hz AC grids, the leakage current of the power filter is generally less than 1 mA. Therefore, the device for detecting the current in the circuit must reach the milliamp level, which may be a milliampere meter or a microampere meter, which may be an electromagnetic milliampere meter/microampere meter or a magnetoelectric milliampere meter/microampere Table, according to whether the power source in the circuit is a DC power source or an AC power source, select to use a DC current meter or an AC current meter, or DC dual-purpose ammeter. The embodiment of the invention is not specifically limited.

It can be seen that, in the method described in FIG. 2, the circuit determines whether the circuit has a short-circuit fault by detecting whether the current in the circuit is greater than or equal to the preset current-limiting current in an initial stage of being turned on. If the current is greater than or equal to the predetermined current limiting current, the circuit is considered to be short-circuited, the circuit is turned off to protect various devices in the circuit, and if the current is less than the current limiting current, the circuit is considered No short circuit has occurred and the circuit is normally powered to operate properly.

Optionally, the circuit short circuit protection method may further include the following steps:

21) setting a temperature threshold of the circuit, turning off the circuit when it is detected that the temperature of the circuit reaches the threshold.

It can be understood that when the circuit is short-circuited, the circuit will instantaneously generate a large current to raise the temperature of the circuit, resulting in damage to the power supply and/or the electrical equipment. The overheat protection refers to a series thermal protection switch on the circuit. The thermal protection switch is a thermostat with a bimetal as a temperature sensing component. When the electrical appliance is working normally, the bimetal is in a free state and the contacts are closed. / Disconnected state, when the temperature reaches the operating temperature, the bimetal is heated to generate an internal stress 2, and the contact is opened/closed to cut/close the circuit, thereby controlling the temperature. In the embodiment of the present invention, the normally closed type thermal protection switch is selected. If the circuit does not have a short circuit fault, the circuit works normally, and the thermal protection switch is always in a closed state, if the circuit has a short circuit fault or If the circuit is overheated due to other reasons and the temperature threshold is reached, the bimetal of the thermal protection switch is quickly disconnected due to internal stress caused by heat, and the circuit is cut off.

203. Detect a second current of the circuit, and if the second current is greater than the operating current, disconnect the circuit.

It can be understood that when the circuit is in normal operation, the device in the circuit may also have a short circuit fault. Therefore, the power supply is normally powered according to the working voltage and the working current, and the preset is After the value of the current limiting current is replaced by the operating current, the second current in the circuit is continuously detected, and when the second current is greater than the operating current, the circuit is turned off to protect the circuit device.

It can be seen that, in the method described in FIG. 2, the circuit determines whether the circuit has a short circuit fault by detecting whether the first current in the circuit is greater than or equal to the preset current limiting current at an initial moment of being turned on. If the first current is greater than or equal to the preset current limiting current when the circuit is turned on, the circuit is considered to be short-circuited, and the circuit is turned off to protect various devices in the circuit, if When the first current is less than the current limiting current when the circuit is turned on, it is considered that the circuit does not have a short circuit, the circuit is normally powered to make it work normally, and the value of the preset current limiting current is After the value of the operating current is replaced, the second current of the circuit is continuously detected. If the working current is greater than the operating current, the circuit is disconnected, and the circuit is further protected.

Referring to FIG. 3, FIG. 3 is a schematic structural diagram of a circuit short circuit protection device according to an embodiment of the present invention. Specifically, as shown in FIG. 3, the circuit short circuit protection device in the embodiment of the present invention includes: a power module 301, and a setting Module 302, detection module 303, control module 304, thermal protection module 305, and load module 306.

The power module 301 is configured to provide power to the circuit. Specifically, the power module may be a DC power source or an AC power source.

The setting module 302 is configured to set an operating voltage, an operating current, and a current limiting current of the power module. Specifically, the setting module 302 is configured to set an operating voltage and an operating current of the power module according to a rated power and a rated load of the load of the circuit, and set a current limiting current in an initial stage of the circuit. The setting module 302 may be configured to set the working voltage, the working current, and the current limiting current through a physical button or a knob, or may be input through a voice or a touch screen by providing a user interface, when setting the voltage and current, The functional operating voltage, the operating current, and the value of the current limiting current may be directly input, or may be a model of the input of the load, and the setting module 302 automatically sets according to the pre-stored load data.

The detecting module 303 is configured to detect a first current and a second current in the circuit, specifically, to detect a first current in the circuit when the circuit is turned on, if the first current And being greater than or equal to the preset current limiting current, sending a first disconnection command to the control module 304, wherein the detecting module 303 is further configured to detect a second current in the circuit when the circuit is working normally And sending a second disconnection command to the control module 304 when the second current is greater than the operating current.

The control module 304 is configured to control to disconnect the circuit or control the normal power supply operation of the circuit. Specifically, the detecting module 303 detects the first power at the moment when the circuit is turned on. When the current is greater than or equal to the preset current limiting current, the circuit is turned off, and when the first current detected at the moment when the circuit is turned on is less than the preset current limiting current, the circuit is controlled to work normally. And replacing the value of the preset current limiting current set by the setting module 302 with the value of the working current, the control module 304 is further configured to: after the circuit works normally, if the detecting module 303 detects the When the second current is greater than the operating current, the circuit is turned off.

The thermal protection module 305 is configured to disconnect the circuit when the circuit temperature is too high. Specifically, in the embodiment of the present invention, the thermal protection module is a normally closed thermal protection switch, and the thermal protection switch turns off the circuit when the temperature in the circuit exceeds a preset temperature threshold.

The load module 306 is configured to be electrically connected to the power module to form a complete power supply circuit. Specifically, the load module may be an inductive load, a capacitive load or a resistive load, or may be a load formed by combining two or two or a combination of the three.

The above disclosure is only a preferred embodiment of the present invention, and of course, the scope of the present invention is not limited thereto, and those skilled in the art can understand all or part of the process of implementing the above embodiments, and according to the present invention. The equivalent changes required are still within the scope of the invention.

Claims

A circuit short circuit protection method, characterized in that

Setting an operating voltage and an operating current of the power source, wherein the operating current is a maximum current allowed by the circuit at the operating voltage;

Detecting whether the first current of the circuit at the instant of turn-on is less than a preset current limit current, and if so, the circuit is normally powered according to the working voltage and the working current, and the value of the preset current limiting current is Replaced with the value of the operating current, if not, the circuit is turned off.
The method according to claim 1, wherein the circuit supplies power normally according to the operating voltage and the operating current, and replaces the value of the preset current limiting current with the value of the operating current. Also includes:

A second current of the circuit is detected, and if the second current is greater than the operating current, the circuit is turned off, wherein the second current is a current when the circuit operates at the operating voltage.
The method of claim 2 wherein said predetermined current limit current is 2 milliamps.
The method of claim 1 wherein said operating voltage and said operating current are determined based on a rated voltage and a rated current of the circuit load.
The method of claim 1 further comprising:

A temperature threshold of the circuit is set, and when it is detected that the temperature of the circuit reaches the threshold, the circuit is turned off.
A circuit short circuit protection device, characterized in that

a power module, a setting module, a detecting module, a control module, and a load module;

Wherein the power module is used to provide electrical energy to the circuit;

The setting module is configured to set an operating voltage, an operating current, and a current limiting current of the power module;

The detecting module is configured to detect a size of the first current and the second current in the circuit;

The control module is configured to: when the first current detected by the detecting module is not less than a preset current limiting current, the circuit is disconnected, and the circuit is detected when the circuit is turned on. When the first current is less than the preset current limiting current, controlling the circuit to work normally and replacing the value of the preset current limiting current with the value of the working current;

The load module is configured to be electrically connected to the power module to form a complete power supply circuit.
The device according to claim 5, characterized in that

The setting module sets an operating voltage and an operating current of the current module according to a rated voltage and a rated current of the load.
The device according to claim 5, characterized in that

The detecting module is further configured to detect a value of a value of the second current of the circuit after the circuit is working normally.
The device according to claim 5, characterized in that

The control unit is further configured to: when the detecting module detects that the second current of the circuit is not less than the operating current after the circuit is working normally, disconnect the circuit.
The device according to claim 5, wherein the device further comprises:

a thermal protection module in series with the load module for disconnecting the circuit when the temperature exceeds a set value.