Leakage protection circuit, electrical equipment and leakage protection method

Abstract

The invention relates to the technical field of protection circuits, and discloses an electric leakage protection circuit, electrical equipment and an electric leakage protection method.The electric leakage protection circuit comprises an electric leakage detection switch; the voltage detection unit is configured to detect the input voltage of the power supply end so as to generate a voltage detection signal; the driving unit is configured to determine the input voltage type of the power supply end according to the voltage detection signal; the threshold value generation unit is configured to generate a leakage protection threshold value according to the input voltage type; and the electric leakage protection unit is configured to detect the working current flowing through the electric leakage detection switch and control the load to be in an off state under the condition of judging that the electric leakage phenomenon exists. According to the invention, corresponding electric leakage detection protection can be carried out by detecting different input voltage types, the application scene is expanded, the accuracy and reliability of electric leakage protection under different voltage input conditions can be ensured, and the requirement of users for safe electricity utilization is fully met.

Description

Technical Field

[0001] The present application relates to the technical field of protection circuits, and in particular to a leakage protection circuit, an electrical device, and a leakage protection method. Background Art

[0002] During the installation of some equipment, partial connection may occur. If the human body accidentally touches it, electric shock may occur, affecting safe operation. For example, in the field of lighting, since many lamp holders still retain double-ended interfaces, when replacing the original lamp tubes, double-ended input lamp tubes are generally used. In this case, the user generally inserts one end into the lamp holder first, and then the other end. If the user does not operate properly at this time, it is possible to touch the conductive part of the end, resulting in electric shock. Therefore, leakage protection is required.

[0003] In the related technology, a switch tube is generally connected to the power input end, and the current flowing through the switch tube is detected to determine whether there is leakage. Once leakage occurs, the load is directly disconnected to achieve leakage protection. However, this leakage protection function is relatively simple and cannot meet the increasing demand for intelligent electrical equipment, nor can it meet the safety needs of users for power systems. Summary of the invention

[0004] The present application provides a leakage protection circuit, electrical equipment and leakage protection method, which solves the current technical problem that it is difficult to perform effective leakage detection and protection for different electrical equipment. By accurately identifying different power supply types, leakage detection and protection for different electrical equipment can be achieved, expanding the application scenarios and fully meeting the user's needs for safe electricity use.

[0005] In order to achieve the above objectives, the main technical solutions adopted in this application include:

[0006] In a first aspect, an embodiment of the present application provides a leakage protection circuit, comprising: a leakage detection switch, which is arranged between a power supply end and a load; a voltage detection unit, which is configured to detect an input voltage at the power supply end to generate a voltage detection signal; a driving unit, which is configured to determine the input voltage type of the power supply end according to the voltage detection signal, and drive the leakage detection switch to work; a threshold generation unit, which is configured to generate a leakage protection threshold according to the input voltage type; a leakage protection unit, which is configured to detect an operating current flowing through the leakage detection switch, and when it is determined that there is a leakage phenomenon according to the leakage protection threshold and the operating current of the leakage detection switch, control the load to be in a disconnected state.

[0007] According to the leakage protection circuit proposed in the embodiment of the present application, the input voltage of the power supply end is detected by the voltage detection unit to generate a voltage detection signal, so that the driving unit can determine the input voltage type of the power supply end according to the voltage detection signal, so that the threshold generation unit can generate a leakage protection threshold according to the input voltage type, so that the leakage protection unit can control the load to be in a disconnected state when it is judged that there is leakage according to the leakage protection threshold and the working current of the leakage detection switch, thereby realizing a fast and effective leakage detection protection function. Therefore, the present application can perform corresponding leakage detection protection by detecting different input voltage types, which not only expands the application scenarios, but also can generate corresponding leakage protection thresholds for different input voltage types, reducing the risk of leakage failure or misdetection due to input voltage changes, so as to ensure the accuracy and reliability of leakage protection under different voltage input conditions, and fully meet the user's needs for safe electricity use.

[0008] Optionally, in some embodiments of the present application, the threshold generating unit is further configured to generate a first leakage protection threshold according to the input voltage of the power supply end when the input voltage type is a direct current power supply.

[0009] Optionally, in some embodiments of the present application, the magnitude of the first leakage protection threshold is positively correlated with the supply voltage of the DC power supply.

[0010] Optionally, in some embodiments of the present application, the threshold generation unit includes: a sampler and holder, which is configured to hold the voltage detection signal based on a DC power supply flag signal to obtain a sampled and held value, and the DC power supply flag signal is obtained according to the input voltage type; a multiplier, which is configured to multiply the sampled and held value by a preset coefficient to obtain a voltage adjustment value; and an adder, which is configured to add a preset margin to the voltage adjustment value to obtain the first leakage protection threshold.

[0011] In the embodiment of the present application, for the case where the input voltage type is a DC power supply, a first leakage protection threshold value that is positively correlated with the supply voltage of the DC power supply is generated. Since the first leakage protection threshold value changes dynamically based on the supply voltage of the DC power supply, accurate and effective leakage protection can be performed even if the supply voltage changes over a large range, thereby improving the reliability and applicability of the leakage protection circuit.

[0012] Optionally, in some embodiments of the present application, the threshold generating unit is further configured to generate a preset second leakage protection threshold when the input voltage type is an AC power supply.

[0013] Optionally, in some embodiments of the present application, the threshold generating unit further includes: a selector, which is configured to select one of the first leakage protection threshold and the second leakage protection threshold as the leakage protection threshold according to the input voltage type, and provide it to the leakage protection unit.

[0014] The embodiment of the present application implements the selection of the leakage protection threshold through a selector, and selects different leakage protection thresholds for different input voltage types. This enables the leakage protection circuit proposed in the present application to be compatible with AC power input and DC power input while ensuring that the leakage protection circuit selects a suitable and accurate leakage protection threshold under different voltage input conditions, thereby improving the accuracy and reliability of leakage detection.

[0015] Optionally, in some embodiments of the present application, the leakage detection switch is arranged on the bus path between the power supply end and the load, or the leakage detection switch is arranged between a node of the bus path between the power supply end and the load and the ground end.

[0016] Optionally, in some embodiments of the present application, the leakage protection unit includes: a current-sensing resistor, which is connected in series with the leakage detection switch and has a first node; a first comparator, the positive input terminal of the first comparator is connected to the first node, and the negative input terminal of the first comparator is connected to the output terminal of the threshold generation unit, the first comparator is configured to compare the leakage detection value with the leakage protection threshold to output a first comparison signal, wherein the leakage detection value is used to characterize the working current of the leakage detection switch; a controller, the controller is configured to control the load to be in a disconnected state when it is determined that there is a leakage phenomenon according to the first comparison signal.

[0017] Optionally, in some embodiments of the present application, the controller is further configured to determine that there is a leakage phenomenon when it is judged that the leakage detection value is less than the leakage protection threshold according to the first comparison signal.

[0018] The embodiment of the present application monitors the working current flowing through the leakage detection switch in real time through a current detection resistor, and inputs the real-time monitored leakage detection value into the first comparator to compare the leakage detection value with the leakage protection threshold. Once the leakage detection value is less than the leakage protection threshold, it is determined that there is a leakage phenomenon, and the load is quickly disconnected by the controller. Therefore, the present application helps to timely and accurately identify leakage situations, improve the real-time response speed of leakage protection, and prevent safety hazards caused by leakage of electrical equipment.

[0019] Optionally, in some embodiments of the present application, the controller is further configured to determine that there is no leakage when the number of times the leakage detection value is greater than or equal to the leakage protection threshold value according to the first comparison signal reaches a preset number of times.

[0020] In the embodiment of the present application, the leakage detection value is set to be greater than or equal to the leakage protection threshold number of times, and only when the preset number of times is reached, it is determined that there is no leakage phenomenon. By setting multiple judgment logics, it is ensured that only when the leakage detection value is stably greater than or equal to the leakage protection threshold, it is determined that there is no leakage phenomenon, which effectively reduces the possibility of misjudgment due to interference factors such as short-term current fluctuations. Under the premise of ensuring the leakage protection effect, it avoids the controller from frequently controlling unnecessary connection and disconnection of the load, so as to improve the accuracy and anti-interference ability of the leakage protection.

[0021] Optionally, in some embodiments of the present application, the controller is further configured to, in the absence of leakage, control the connection between the load and the power supply terminal, and drive the leakage detection switch to stop working through the driving unit.

[0022] The embodiment of the present application configures the leakage detection switch to stop working when there is no leakage, so as to reduce the power consumption of the leakage protection circuit and help avoid the device aging problem caused by the long-term operation of the leakage detection switch.

[0023] Optionally, in some embodiments of the present application, the driving unit includes: a voltage type judgment module, the voltage type judgment module is configured to judge the input voltage type of the power supply end according to the voltage detection signal, and send the judgment result to the threshold generation unit; a first pulse generation module, the first pulse generation module is configured to generate a first detection pulse signal when the input voltage type is a DC power supply; a second pulse generation module, the second pulse generation module is configured to generate a second detection pulse signal when the input voltage type is an AC power supply; a driving module, the driving module is configured to drive the leakage detection switch to work according to one of the first detection pulse signal and the second detection pulse signal.

[0024] Optionally, in some embodiments of the present application, the voltage type judgment module includes: a second comparator, the second comparator is configured to compare the voltage detection signal with the first reference voltage signal to output a second comparison signal, wherein the second comparison signal is used to determine whether the input voltage type is a DC power supply; a third comparator, the third comparator is configured to compare the voltage detection signal with the second reference voltage signal to output a third comparison signal, wherein the third comparison signal is used to determine whether the input voltage type is an AC power supply.

[0025] The present application uses the second comparator and the third comparator in the voltage type judgment module to compare the voltage detection signal with the corresponding reference voltage signal to realize the judgment of the input voltage type of the power supply end, thereby generating different detection pulse signals corresponding to different input voltage types to drive the leakage detection switch to work. Therefore, the present application realizes the judgment of the input voltage type by setting the second comparator and the third comparator, thereby improving the compatibility of the leakage protection circuit with different input voltage types.

[0026] Optionally, in some embodiments of the present application, one of the first detection pulse signal and the second detection pulse signal is used to control the leakage detection switch to be intermittently turned on and off.

[0027] The present application controls the intermittent on and off of the leakage detection switch, thereby realizing a judgment on the leakage phenomenon each time the leakage detection switch is turned on, and continuously judges whether there is a leakage phenomenon through intermittent on and off for multiple times, so as to improve the accuracy of leakage protection and reduce the possibility of misjudgment of leakage phenomenon.

[0028] In a second aspect, an embodiment of the present application provides an electrical device, comprising: a load; a controllable switch for controlling whether the load is disconnected; and a leakage protection circuit according to the embodiment of the first aspect above, wherein the leakage protection circuit is configured to control the controllable switch to be disconnected when it is determined that the electrical device has a leakage phenomenon, so as to put the load in a disconnected state.

[0029] According to the electrical equipment proposed in the embodiment of the present application, effective leakage detection under different input voltage types is realized through the leakage protection circuit, and the controllable switch is controlled to be disconnected in the presence of leakage, so that the load is in a disconnected state, thereby realizing a fast and effective leakage protection function. Therefore, the present application can perform corresponding leakage detection protection by detecting different input voltage types, which not only expands the application scenarios, but also generates corresponding leakage protection thresholds for different input voltage types, reducing the risk of leakage failure or misdetection due to input voltage changes, so as to ensure the accuracy and reliability of leakage protection under different voltage input conditions, and fully meet the user's needs for safe electricity use.

[0030] Optionally, in some embodiments of the present application, the controllable switch may be a switch connected in series with the load, or a switch driving a driving circuit in the load.

[0031] In a third aspect, an embodiment of the present application provides a leakage protection method, which is applied to the leakage protection circuit according to the embodiment of the first aspect above, and the method includes: detecting the input voltage of the power supply end to generate a voltage detection signal; determining the input voltage type of the power supply end according to the voltage detection signal, and driving the leakage detection switch to work; detecting the working current flowing through the leakage detection switch, and when it is judged that there is a leakage phenomenon according to the leakage protection threshold and the working current of the leakage detection switch, controlling the load to be in a disconnected state, wherein the leakage protection threshold is generated according to the input voltage type.

[0032] According to the leakage protection method proposed in the embodiment of the present application, a voltage detection signal is generated by detecting the input voltage of the power supply end, and the input voltage type of the power supply end is determined according to the voltage detection signal, and a leakage protection threshold is generated according to the input voltage type, so that when it is judged that there is leakage according to the leakage protection threshold and the working current of the leakage detection switch, the load can be controlled to be in a disconnected state, thereby realizing a fast and effective leakage detection protection function. Therefore, the present application can perform corresponding leakage detection protection by detecting different input voltage types, which not only expands the application scenarios, but also can generate corresponding leakage protection thresholds for different input voltage types, reducing the risk of leakage failure or misdetection due to input voltage changes, so as to ensure the accuracy and reliability of leakage protection under different voltage input conditions, and fully meet the user's needs for safe electricity use. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] In order to more clearly illustrate the specific implementation methods of the present application or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0034] Figure 1A A schematic diagram of the circuit structure of a leakage protection circuit proposed in one embodiment of the present application;

[0035] Figure 1B A schematic diagram of the circuit structure of a leakage protection circuit proposed in another embodiment of the present application;

[0036] Figure 2 A schematic diagram of the circuit structure of a driving unit proposed in one embodiment of the present application;

[0037] Figure 3 A schematic diagram of the circuit structure of a threshold value generating unit proposed in one embodiment of the present application;

[0038] Figure 4A schematic diagram of the circuit structure of a leakage protection unit proposed in one embodiment of the present application;

[0039] Figure 5 A schematic diagram of the circuit structure of a driving module proposed in one embodiment of the present application;

[0040] Figure 6 A schematic diagram of a signal waveform of an embodiment of the leakage protection circuit proposed in this application;

[0041] Figure 7 A schematic diagram of another signal waveform of the leakage protection circuit proposed in the present application in one embodiment;

[0042] Figure 8 A schematic diagram of a signal waveform of another embodiment of the leakage protection circuit proposed in the present application;

[0043] Fig. 9 A schematic diagram of another signal waveform of the leakage protection circuit proposed in the present application in another embodiment;

[0044] Fig.10 A schematic diagram of the structure of an electrical device proposed in one embodiment of the present application;

[0045] Fig.11 A schematic flow chart of a leakage protection method proposed in one embodiment of the present application. DETAILED DESCRIPTION

[0046] In order to make the purpose, technical solution and advantages of the embodiments of the present application clearer, the technical solution in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of the present application.

[0047] In the relevant leakage detection and protection technology, a switch tube is usually connected in the circuit, and the current flowing through the switch tube is detected to determine whether there is a leakage phenomenon. Once leakage occurs, the load is directly disconnected to achieve leakage protection.

[0048] However, as users have higher and higher demands for the safe use of electrical equipment and electrical equipment is becoming more and more intelligent, in some application scenarios, the leakage detection protection function in related technologies cannot effectively achieve protection, which greatly reduces the accuracy of leakage protection. It cannot meet the increasingly intelligent demands of electrical equipment, nor can it meet users' safety needs for power systems.

[0049] The present application embodiment provides a leakage protection circuit 10, such as Figure 1Aor Figure 1B As shown, the leakage protection circuit 10 can be used in electrical equipment with lighting loads 30 such as light-emitting diodes, and by accurately identifying different power supply types, leakage detection and protection of different electrical equipment can be achieved, which not only expands the application scenarios, but also can generate corresponding leakage protection thresholds for different input voltage types, reducing the risk of leakage failure or misdetection due to input voltage changes, so as to ensure the accuracy and reliability of leakage protection under different voltage input conditions, and fully meet the user's needs for safe electricity use.

[0050] like Figure 1A or Figure 1B As shown, the leakage protection circuit 10 includes: a leakage detection switch Q 1 , a voltage detection unit 100 , a driving unit 200 , a threshold generation unit 300 and a leakage protection unit 400 .

[0051] Among them, the leakage detection switch Q 1 Set between the power supply terminal 20 and the load 30. For example, in some embodiments of the present application, the leakage detection switch Q 1 It can be set between a node of the bus path between the power supply end and the load and the ground end, such as Figure 1A As shown; in some other embodiments of the present application, the leakage detection switch Q 1 It can also be set on the bus path between the power supply end and the load, such as Figure 1B This application does not impose any specific restrictions on this, and the setting of the leakage detection switch can provide conditions for leakage current detection.

[0052] The voltage detection unit 100 is configured to detect the input voltage of the power supply terminal 20 to generate a voltage detection signal. The driving unit 200 is configured to determine the input voltage type of the power supply terminal 20 according to the voltage detection signal and drive the leakage detection switch Q 1 The threshold generation unit 300 is configured to generate a leakage protection threshold according to the input voltage type. The leakage protection unit 400 is configured to detect the leakage current flowing through the leakage detection switch Q 1 The working current is detected and based on the leakage protection threshold and the leakage detection switch Q 1 When it is determined that there is leakage based on the working current, the load 30 is controlled to be in a disconnected state.

[0053] The leakage protection circuit provided in this embodiment detects the input voltage of the power supply terminal 20 through the voltage detection unit 100, generates a voltage detection signal, and provides the voltage detection signal to the driving unit 200 to determine the input voltage type of the power supply terminal, thereby driving the leakage detection unit Q 1The threshold generating unit 300 generates a corresponding leakage protection threshold according to the input voltage type, and provides the leakage protection threshold together with the working current flowing through the leakage detection switch to the leakage protection unit 400, so that the leakage protection unit 400 can judge whether there is leakage according to the leakage protection threshold and the working current, and control the load 30 to be disconnected in time and accurately when there is leakage, so as to reduce the risk of power safety caused by leakage and realize fast and effective leakage protection.

[0054] In summary, the present application can detect different input voltage types to perform corresponding leakage protection, greatly improving the compatibility of the leakage protection circuit with different input voltage types and expanding the application scenarios. In addition, the present application can also generate corresponding leakage protection thresholds for different input voltage types, reducing the risk of leakage failure or misdetection due to input voltage changes, so as to ensure the accuracy and reliability of leakage protection under different voltage input conditions.

[0055] It should be noted that in Figure 1A or Figure 1B In the circuit structure shown, the power supply terminal 20 is used to supply power to the load 30, and the power supply terminal 20 can be an AC power supply or a DC power supply. Figure 1A The resistor R shown LMT is the current limiting resistor, Figure 1A or Figure 1B The resistor R shown HM is the resistance of the human body connected to the line in the case of leakage. In addition, by setting the switch tube Q 2 To realize the connection and disconnection of the load 30 in the line, for example, in some examples of the present application, the switch tube Q 2 The gate of the switch tube Q is connected to the output end of the leakage protection unit 400. 2 The drain of the switch is connected to a load of 30, and the switch tube Q 2 The source is connected to ground via current limiting resistor R3.

[0056] Among them, Figure 1A In the leakage protection circuit shown, the leakage detection switch Q 1 It is set between the node of the bus path between the power supply terminal 20 and the load 30 and the ground terminal. Figure 1B In the leakage protection circuit shown, the leakage detection switch Q 1 It can also be arranged on the bus path between the power supply end and the load to detect the current change between the power supply end 20 and the load 30, so as to judge whether there is leakage according to the current change.

[0057] like Figure 1A or Figure 1BAs shown, the voltage detection unit 100 is connected to the power supply terminal 20, wherein the voltage detection unit 100 includes a sampling resistor R 1 And the sampling resistor R 2 , sampling resistor R 1 And the sampling resistor R 2 connected in series to form a voltage divider circuit, and the sampling resistor R 1 And the sampling resistor R 2 A voltage detection signal is output at the connection node of , and the voltage detection signal can represent the input voltage of the power supply terminal 20, so that the input voltage type can be determined by using the voltage detection signal.

[0058] In some embodiments of the present application, the driving unit 200 drives the leakage detection switch Q according to the input voltage type. 1 The leakage protection unit 400 is turned on and off so that the leakage detection switch Q 1 Each time the switch is turned on, the current flowing through the leakage detection switch Q 1 The working current is used to judge whether there is leakage. Figure 2 As shown, the driving unit 200 includes a voltage type determination module 210 , a first pulse generation module 220 , a second pulse generation module 230 and a driving module 240 .

[0059] The voltage type determination module 210 is configured to determine the input voltage type of the power supply terminal 20 according to the voltage detection signal, and send the determination result to the threshold generation unit 300 .

[0060] Furthermore, if Figure 2 As shown, the voltage type determination module 210 includes a second comparator 211 and a third comparator 212 .

[0061] The second comparator 211 is configured to compare the voltage detection signal with the first reference voltage signal V REF3 Specifically, the voltage detection signal can be input to the positive input terminal of the second comparator 211, and the first reference voltage signal V REF3 The second comparator 211 compares the voltage detection signal with the first reference voltage signal V REF3 The second comparison signal CP2 is outputted based on the size between the two. It can be obtained that the second comparison signal CP2 can be used to determine whether the input voltage type is a DC power supply.

[0062] The third comparator 212 is configured to compare the voltage detection signal with the second reference voltage signal V REF4 Specifically, the voltage detection signal is input to the positive input terminal of the third comparator 212, and the second reference voltage signal VREF4 The third comparator 212 compares the voltage detection signal with the second reference voltage signal V REF4 The third comparison signal CP3 is outputted based on the size between them. It can be obtained that the third comparison signal CP3 can be used to determine whether the input voltage type is an AC power supply.

[0063] The first pulse generating module 220 is configured to generate a first detection pulse signal P when the input voltage type is a DC power supply. 1 The second pulse generating module 230 is configured to generate a second detection pulse signal P when the input voltage type is an AC power supply. 2 The driving module 240 is configured to drive the leakage detection switch Q according to one of the first detection pulse signal and the second detection pulse signal. 1 to carry out the work.

[0064] Among them, in some embodiments of the present application, such as Figure 1A As shown, the leakage detection switch Q 1 When the first detection pulse signal P is set between the node of the bus path between the power supply end and the load and the ground end, 1 and the second detection pulse signal P 2 One of them is used to control the leakage detection switch Q 1 Intermittent on and off. In other embodiments of the present application, Figure 1B As shown, the leakage detection switch Q 1 When the first detection pulse signal P is set on the bus path between the power supply end and the load, 1 and the second detection pulse signal P 2 One of them is used to control the leakage detection switch Q 1 Conductivity.

[0065] Specifically, if the input voltage type is a DC power supply, the first pulse generating module 220 will receive the second comparison signal CP2 generated by the second comparator 211, which may be always at a high level. DC After a delay of , the second comparison signal CP2 is responded to and a first detection pulse signal P is generated. 1 The driving module 240 receives the first detection pulse signal P 1 The trigger generates a drive leakage detection switch Q 1 The driving signal V g1 It should be noted that, in some embodiments of the present application, the driving module 240 detects the pulse signal P 1 The rising edge triggers the drive signal V g1In some other embodiments of the present application, the driving module 240 may also detect the pulse signal P 1 The falling edge triggers the drive signal V g1 In addition, the leakage detection switch Q 1 In the case where the driving signal V g1 is a pulse signal, and every two adjacent drive signals V g1 There is a time interval Td 1 , that is, control the leakage detection switch Q 1 Every time interval Td 1 Turn on once to control the leakage detection switch Q 1 Intermittent on and off. 1 When the bus path between the power supply terminal and the load is set, the driving signal V g1 A continuous signal to control the leakage detection switch Q 1 Conductivity.

[0066] If the input voltage type is an AC power source, due to the periodic fluctuation of the AC power source, the second pulse generating module 230 will periodically receive the third comparison signal CP3 generated by the third comparator 212 as a high level, and generate the second detection pulse signal P in response to the third comparison signal CP3. 2 And input to the driving module 240, the driving module 240 at the second detection pulse signal P 2 The trigger generates a drive leakage detection switch Q 1 The driving signal V g1 It should be noted that, in some embodiments of the present application, the driving module 240 generates a pulse signal P 2 The rising edge triggers the drive signal V g1 In some other embodiments of the present application, the driving module 240 may also 2 The falling edge triggers the drive signal V g1 In addition, the leakage detection switch Q 1 In the case where the driving signal V g1 is a pulse signal, and every two adjacent drive signals V g1 There is a time interval Td 2 , that is, control the leakage detection switch Q 1 Every time interval Td 2 Turn on once to control the leakage detection switch Q 1 Intermittent on and off. 1When the bus path between the power supply terminal and the load is set, the driving signal V g1 A continuous signal to control the leakage detection switch Q 1 Conductivity.

[0067] The present application compares the voltage detection signal with the corresponding reference voltage signal through the second comparator 211 and the third comparator 212 in the voltage type judgment module 210 to judge the input voltage type of the power supply terminal 20, thereby generating different detection pulse signals corresponding to different input voltage types to drive the leakage detection switch Q. 1 Therefore, the embodiment of the present application realizes the judgment of the input voltage type by setting the second comparator 211 and the third comparator 212, thereby improving the compatibility of the leakage protection circuit 10 with different input voltage types, and the judgment circuit is simple, reliable and low in cost.

[0068] In some embodiments of the present application, the threshold generation unit 300 generates different leakage protection thresholds corresponding to different input voltage types, thereby ensuring that accurate and effective leakage protection can be achieved regardless of whether the power supply terminal 20 is an AC power supply or a DC power supply.

[0069] Specifically, the threshold generation unit 300 is configured to generate a first leakage protection threshold V according to the input voltage of the power supply terminal 20 when the input voltage type is a DC power supply. REF1 .

[0070] Furthermore, in some embodiments of the present application, the first leakage protection threshold V REF1 The size of is positively correlated with the supply voltage of the DC power supply.

[0071] like Figure 3 As shown in FIG. 1 , for the case where the input voltage type is a DC power supply, the threshold generation unit 300 includes: a sample holder 310, a multiplier 320, and an adder 330. The sample holder 310 is configured to hold the voltage detection signal based on the DC power supply flag signal to obtain a sample hold value. The multiplier 320 is configured to multiply the sample hold value by a preset coefficient to obtain a voltage adjustment value. The adder 330 is configured to add a preset margin to the voltage adjustment value to obtain a first leakage protection threshold value V REF1 .

[0072] Depend on Figure 3 As shown in the circuit structure, the voltage detection signal generated by the voltage detection unit 100 is sampled and held by the sample and hold device 310 to obtain the sample and hold value V HOLDIn addition, after determining that the input voltage type is a DC power supply, the driving unit 200 generates a DC power supply flag signal and inputs it to the sample and hold device 310. When the sample and hold device 310 receives the DC power supply flag signal, it samples and holds the value V HOLD is input to the multiplier 320 so that the multiplier 320 can convert the sample hold value V HOLD The voltage adjustment value is obtained by multiplying the voltage adjustment value by the preset coefficient k, and then the voltage adjustment value is added to the preset margin b by the adder 330, that is, the first leakage protection threshold V REF1 Determined by the following formula (1):

[0073] V REF1 =k*V HOLD +b (1)

[0074] In the embodiment of the present application, for the case where the input voltage type is a DC power supply, a first leakage protection threshold V is generated which is positively correlated with the supply voltage of the DC power supply. REF1 , since the first leakage protection threshold V REF1 It is based on the dynamic change of the supply voltage of the DC power supply. Even if the supply voltage changes in a large range, it can generate an accurate leakage protection threshold accordingly. Therefore, the leakage protection circuit 10 proposed in the present application can ensure the normal operation of the leakage protection function within a wider DC voltage input range, thereby improving the reliability and adaptability of the leakage protection circuit and fully meeting the wide range of power supply requirements of electrical equipment.

[0075] In some embodiments of the present application, the threshold generation unit 300 is further configured to generate a preset second leakage protection threshold V when the input voltage type is an AC power supply. REF2 .

[0076] Combination Figure 1A or Figure 1B It can be seen that when there is no leakage, the human body is not connected to the circuit. At this time, the current sensing resistor R S The voltage across the two ends is determined by the following formula (2):

[0077] V RS_H =I DET *R S =V BUS / (R LMT +R DSON +R S )* R S (2)

[0078] Where V RS_H The current sensing resistor R is the current sensing resistor R when there is no leakage. S The voltage across the terminals, I DET is the current flowing through the leakage detection switch Q1 The operating current, V BUS is the bus voltage of the rectifier output at the power supply terminal 20, R LMT The resistance value can be zero, R DSON For leakage detection switch Q 1 When there is leakage, the human body is connected to the line. At this time, the current sensing resistor R in the leakage protection unit 400 S The voltage across the two ends is determined by the following formula (3):

[0079] V RS_L =I DET *R S =V BUS / (R HM +R LMT +R DSON +R S )* R S (3)

[0080] Where V RS_L The current sensing resistor R is the current sensing resistor R in the presence of leakage. S The voltage across R HM is the resistance of the line connected to the human body, which is equivalent to 500Ω.

[0081] In some embodiments of the present application, the second leakage protection threshold V REF2 The value can be between V RS_L and V RS_H Between, that is, V RS_L <V REF2 <V RS_H .

[0082] By properly setting the second leakage protection threshold V REF2 The value of can realize accurate and effective leakage protection when the power supply end 20 is an AC power supply.

[0083] It can be seen that the first leakage protection threshold V generated for the DC power supply REF1The second leakage protection threshold value generated for the AC power supply is a static threshold value. For an electrical device with a load 30, the input voltage of the AC power supply can be a 220V mains power supply that changes periodically, and the change in its amplitude is relatively stable. In the case where the voltage input type is a DC power supply, the change in the amplitude of its input voltage is unstable. For example, for different working states and different loads of the electrical device, the DC power supply can input input voltages of different amplitudes. Therefore, if there is a leakage, the amplitude of the leakage current corresponding to the AC power supply also changes periodically within a foreseeable range. Compared with the DC power supply, the amplitude of the leakage current corresponding to the AC power supply is relatively fixed. Therefore, a static second leakage protection threshold value can be set, and in the case where the input voltage type is a DC power supply, a dynamic first leakage protection threshold value that is adjusted positively with the change in the supply voltage of the DC power supply is set.

[0084] Therefore, the present application performs corresponding leakage detection and protection by detecting different input voltage types, which not only expands the application scenarios, but also can generate corresponding leakage protection thresholds for different input voltage types, reducing the risk of leakage failure or misdetection due to input voltage changes, thereby ensuring the accuracy and reliability of leakage protection under different voltage input conditions, and fully meeting the user's needs for safe electricity use.

[0085] like Figure 3 As shown, the threshold generation unit 300 further includes a selector 340, which is configured to select a first leakage protection threshold V according to the input voltage type. REF1 and the second leakage protection threshold V REF2 As a leakage protection threshold, one of the selectors 340 is provided to the leakage protection unit 400. In some embodiments of the present application, the selector 340 is a data selector MUX, which is connected to the driving unit 200 to receive the judgment result of the input voltage type, and then select the first leakage protection threshold V according to the judgment result. REF1 and the second leakage protection threshold V REF2 One of the signals is input into the leakage protection unit 400 .

[0086] The embodiment of the present application implements the selection of the leakage protection threshold through the selector MUX, and selects different leakage protection thresholds for different input voltage types. This enables the leakage protection circuit proposed in the present application to be compatible with AC power input and DC power input while ensuring that the leakage protection circuit selects a suitable and accurate leakage protection threshold under different voltage input conditions, thereby improving the accuracy and reliability of leakage detection.

[0087] When the leakage protection threshold corresponding to the input voltage type is determined, the present application implements the comparison of the working current flowing through the leakage detection switch 100 with the determined leakage protection threshold by the leakage protection unit 400 to determine whether there is leakage.

[0088] Specifically, in some embodiments of the present application, Figure 4 As shown, the leakage protection unit 400 includes a current detection resistor R S , a first comparator 410 and a controller 420. Wherein, the current sensing resistor R S With leakage detection switch Q 1 The first comparator 410 is connected in series and has a first node. The positive input terminal of the first comparator 410 is connected to the first node, and the negative input terminal of the first comparator 410 is connected to the output terminal of the threshold generation unit 300. The first comparator 410 is configured to compare the leakage detection value with the leakage protection threshold to output a first comparison signal CP1, wherein the leakage detection value is used to characterize the leakage detection switch Q 1 The controller 420 is configured to control the load 30 to be in a disconnected state when it is determined according to the first comparison signal CP1 that there is a leakage phenomenon.

[0089] Furthermore, the controller 420 is further configured to determine that there is a leakage phenomenon when it is determined according to the first comparison signal CP1 that the leakage detection value is less than the leakage protection threshold.

[0090] Specifically, through the current sensing resistor R S The current flowing through the leakage detection switch Q 1 The working current of the first comparator 410 is detected, and the detected working current is sent to the positive input terminal of the first comparator 410. In addition, the output terminal of the threshold generation unit 300 is connected to the negative input terminal of the first comparator 410, so that the leakage protection threshold output by the threshold generation unit 300 is sent to the negative input terminal of the first comparator 410. 1 When the working current is less than the leakage protection threshold, it is determined that there is leakage and a first comparison signal CP1 is generated through the output terminal of the first comparator 410. The first comparison signal CP1 is sent to the controller 420, and the switch tube Q is controlled by the controller 420. 2 The load 30 is turned off to be in an off state.

[0091] In this embodiment of the present application, the current sensing resistor R S The current flowing through the leakage detection switch Q 1The working current is monitored in real time, and the real-time monitored leakage detection value is input into the first comparator 410 to compare the leakage detection value with the leakage protection threshold. Once the leakage detection value is less than the leakage protection threshold, it is determined that there is leakage, and the load 30 is quickly controlled to be disconnected through the controller 420. Therefore, the present application helps to timely and accurately identify leakage, improves the real-time response speed of leakage protection, and prevents safety hazards caused by leakage of electrical equipment.

[0092] In some embodiments of the present application, the controller 420 is further configured to determine that there is no leakage phenomenon when the number of times the leakage detection value is greater than or equal to the leakage protection threshold value according to the first comparison signal reaches a preset number of times.

[0093] Furthermore, the controller 420 is also configured to control the connection between the load 30 and the power supply terminal 20 when there is no leakage, and drive the leakage detection switch Q through the driving unit 200. 1 Stop working.

[0094] In order to realize the above configuration of the controller 420, the embodiment of the present application sets the following in the controller 420: Figure 5 The counting logic circuit 430 shown, specifically, includes an OR gate 431 , a counter 432 , an inverter 433 , and an AND gate 434 .

[0095] exist Figure 5 In the counting logic circuit 430 shown in FIG. 1 , the first detection pulse signal P generated by the first pulse generating module 220 is respectively 1 and the second detection pulse signal P generated by the second pulse generating module 230 2 The first comparison signal CP1 generated by the first comparator 410 in the leakage protection unit 400 is input to the counter 432, and the output of the counter 432 is connected to the second input of the AND gate 434 through the inverter 433. The output of the AND gate 434 is used to output the final control of the leakage detection switch Q 1 Control signal to turn on or off.

[0096] Based on the above counting logic circuit, the OR gate 431 receives the first detection pulse signal P 1 and the second detection pulse signal P 2In the case of one of the above, a high level is output to the first input terminal of the AND gate 434. The number of times that the leakage detection value is greater than or equal to the leakage protection threshold is recorded. If the number does not reach the preset number, the output terminal of the counter 432 outputs a low level, which is inverted by the inverter 433 and converted to a high level and sent to the second input terminal of the AND gate 434. The output terminal of the AND gate 434 outputs a high level and is sent to the driving unit 200. At this time, it will not affect the driving unit 200 to control the leakage detection switch Q 1 The process of intermittent turn-on and turn-off.

[0097] If the number reaches the preset number, the output terminal of the counter 432 outputs a high level, which is inverted by the inverter 433 and converted into a low level and sent to the second input terminal of the AND gate 434. At this time, the output terminal of the AND gate 434 is a low level and sent to the driving unit 200, which determines that there is no leakage phenomenon. In the absence of leakage phenomenon, the leakage detection switch Q is driven by the driving unit 200. 1 Stop working.

[0098] The embodiment of the present application controls the leakage detection switch to stop working when there is no leakage, so as to reduce the power consumption of the leakage protection circuit and help avoid the device aging problem caused by the leakage detection switch working for a long time.

[0099] In addition, the embodiment of the present application sets the above-mentioned multiple judgment logic to ensure that only when the leakage detection value is stably greater than or equal to the leakage protection threshold, it is judged that there is no leakage phenomenon, thereby effectively reducing the possibility of leakage misjudgment, and on the premise of ensuring the leakage protection effect, avoid the controller frequently controlling the unnecessary connection and disconnection of the load to improve the accuracy and anti-interference ability of leakage protection. For example, in the case of leakage phenomenon, it may be detected that the leakage detection value is greater than or equal to the leakage protection threshold at a certain instantaneous current fluctuation. If the above-mentioned multiple judgment logic is not set, the controller 420 will judge this accidental fluctuation as the absence of leakage phenomenon, thereby controlling the load 30 to be in the connected state. But then the instantaneous current fluctuation is eliminated, and the next time the leakage detection value is detected to be less than the leakage protection threshold, at this time the controller 420 will control the load 30 to be in the disconnected state again. It can be seen from this that in the case of such instantaneous current occasional fluctuations, if the above-mentioned multiple judgment logic is not set, the controller 420 is easy to misjudge that there is no leakage phenomenon, thereby mistakenly controlling the load 30 to be in the connected state, causing the frequent connection and disconnection of the load 30 in the line, which not only affects the user's experience in using electrical equipment, but also affects the life of the device.

[0100] From this, it can be seen that the configuration of the above-mentioned controller 420 in multiple judgment logics can, under the premise of ensuring the leakage protection effect, not only avoid the controller from frequently controlling unnecessary connection and disconnection of the load, but also control the leakage detection switch to stop working when there is no leakage, thereby reducing the power consumption of the leakage protection circuit and helping to avoid device aging problems caused by long-term operation of the leakage detection switch.

[0101] Figures 6 to 9 The signal waveforms of leakage protection are shown in Figure 1 for the two cases where the input voltage type is a DC power supply and an AC power supply. Figure 6 and Figure 7 As shown, the voltage detection signal V DC Greater than the first reference voltage signal V REF3 Therefore, the input voltage type is determined to be a DC power supply, and the second comparator 211 generates a second comparison signal CP2. The first pulse generating module 220 generates a second comparison signal CP2 after a period of time T. DC After a delay of , the second comparison signal CP2 is responded to and a first detection pulse signal P is generated. 1 The driving module 240 detects the pulse signal P 1 The trigger generates a drive leakage detection switch Q 1 The driving signal V g1 , every two adjacent driving signals V g1 There is a time interval Td 1 . Each time the driving signal V g1 When the driver is turned on, the current flowing through the leakage detection switch Q 1 The working current is tested once, and the leakage detection value V RS The first leakage protection threshold V REF1 Compare. Figure 6 As shown, the leakage detection value V RS Less than the first leakage protection threshold V REF1 , indicating that there is a human body connected to the line, resulting in a large line impedance, and current flows through the leakage detection switch Q 1 The working current becomes smaller, so it is determined that there is leakage. At this time, the Standby signal is set to a high level to keep the load 30 in a disconnected state. Figure 7 As shown, the leakage detection value V RS Greater than the first leakage protection threshold V REF1 , indicating that there is no human body connected to the line and the line impedance is small, so it is determined that there is no leakage phenomenon. At this time, the Standby signal is converted from a high level to a low level to keep the load 30 in the on state.

[0102] Similarly, if Figure 8 and Fig. 9 As shown, there is a voltage detection signal VAC Greater than the second reference voltage signal V REF4 Therefore, the input voltage type is determined to be an AC power source, and the third comparator 212 generates a third comparison signal CP3, and the second pulse generating module 230 responds to the third comparison signal CP3 and generates a second detection pulse signal P 2 The driving module 240 generates a second detection pulse signal P 2 The trigger generates a drive leakage detection switch Q 1 The driving signal V g1 , every two adjacent drive signals V g1 There is a time interval Td 2 . Each time the driving signal V g1 When the driver is turned on, the current flowing through the leakage detection switch Q 1 The working current is tested once, and the leakage detection value V RS The second leakage protection threshold V REF2 Compare. Figure 8 As shown, the leakage detection value V RS Less than the second leakage protection threshold V REF2 , indicating that there is a human body connected to the line, resulting in a large line impedance, and current flows through the leakage detection switch Q 1 The working current becomes smaller, so it is determined that there is leakage. At this time, the Standby signal is set to a high level to keep the load 30 in a disconnected state. Fig. 9 As shown, the leakage detection value V RS Greater than the second leakage protection threshold V REF2 , indicating that there is no human body connected to the line and the line impedance is small, so it is determined that there is no leakage phenomenon. At this time, the Standby signal is converted from a high level to a low level to keep the load 30 in the on state.

[0103] Accordingly, please refer to Fig.10 An embodiment of the present application provides an electrical device 1, which includes a load 30, a controllable switch Q2 and the leakage protection circuit 10 described in the above embodiment.

[0104] It should be noted that the controllable switch Q2 may be a switch connected in series with the load, or a switch driving a driving circuit in the load.

[0105] Among them, the controllable switch Q 2 The leakage protection circuit 10 is configured to control the controllable switch Q when it is determined that there is leakage in the electrical device 1. 2 The controllable switch is disconnected to put the load 30 in the disconnected state. Those skilled in the art will appreciate that the controllable switch may also be a controllable switch in a driving circuit for driving an LED.

[0106] The electrical device proposed in the embodiment of the present application can realize effective leakage detection under different input voltage types through the leakage protection circuit, and control the controllable switch to disconnect in the presence of leakage, so that the load is in a disconnected state, thereby realizing a fast and effective leakage protection function. Therefore, the electrical device proposed in the embodiment of the present application performs corresponding leakage detection protection by detecting different input voltage types, which not only expands the application scenarios, but also can generate corresponding leakage protection thresholds for different input voltage types, reducing the risk of leakage failure or misdetection due to input voltage changes, so as to ensure the accuracy and reliability of leakage protection under different voltage input conditions, and fully meet the user's needs for safe electricity use.

[0107] The further functional description of each of the above modules and units is the same as that of the above corresponding embodiments and will not be repeated here.

[0108] Accordingly, please refer to Fig.11 The present application embodiment provides a leakage protection method, which is applied to the leakage protection circuit in the above embodiment, and the method includes the following steps:

[0109] Step S1, detecting the input voltage of the power supply end to generate a voltage detection signal;

[0110] Step S3, determining the input voltage type of the power supply end according to the voltage detection signal, and driving the leakage detection switch to work;

[0111] Step S5, detecting the working current flowing through the leakage detection switch, and controlling the load to be in a disconnected state when it is determined that there is leakage according to the leakage protection threshold and the working current of the leakage detection switch, wherein the leakage protection threshold is generated according to the input voltage type.

[0112] The above-mentioned leakage protection method proposed in the implementation of this application generates a voltage detection signal by detecting the input voltage of the power supply end, and determines the input voltage type of the power supply end according to the voltage detection signal, and generates a leakage protection threshold according to the input voltage type, so that when it is judged that there is leakage according to the leakage protection threshold and the working current of the leakage detection switch, the load can be controlled to be in a disconnected state, thereby realizing a fast and effective leakage detection protection function. Therefore, the present application can perform corresponding leakage detection protection by detecting different input voltage types, which not only expands the application scenarios, but also can generate corresponding leakage protection thresholds for different input voltage types, reducing the risk of leakage failure or misdetection due to input voltage changes, so as to ensure the accuracy and reliability of leakage protection under different voltage input conditions, and fully meet the user's needs for safe electricity use.

[0113] The further functional description of each of the above method steps is the same as that of the above corresponding embodiments and will not be repeated here.

[0114] It should be noted that the steps shown in the flowcharts of the accompanying drawings can be executed in a computer system such as a set of computer executable instructions, and that, although a logical order is shown in the flowcharts, in some cases, the steps shown or described can be executed in an order different from that shown here.

[0115] Although the embodiments of the present application are described in conjunction with the accompanying drawings, those skilled in the art may make various modifications and variations without departing from the spirit and scope of the present application, and such modifications and variations are all within the scope defined by the appended claims.

[0116] For the convenience of description, the above device is described in various units according to their functions. Of course, when implementing the present application, the functions of each unit can be implemented in the same or multiple software and / or hardware.

[0117] The present application is described with reference to the flowchart and / or block diagram of the method, device (system) and computer program product according to the embodiment of the present application. It should be understood that each process and / or box in the flowchart and / or block diagram, and the combination of the process and / or box in the flowchart and / or block diagram can be realized by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor or other programmable data processing device to produce a machine, so that the instructions executed by the processor of the computer or other programmable data processing device produce a device for realizing the function specified in one process or multiple processes in the flowchart and / or one box or multiple boxes in the block diagram.

[0118] These computer program instructions may also be stored in a computer-readable memory that can direct a computer or other programmable data processing device to work in a specific manner, so that the instructions stored in the computer-readable memory produce a manufactured product including an instruction device that implements the functions specified in one or more processes in the flowchart and / or one or more boxes in the block diagram.

[0119] These computer program instructions may also be loaded onto a computer or other programmable data processing device so that a series of operational steps are executed on the computer or other programmable device to produce a computer-implemented process, whereby the instructions executed on the computer or other programmable device provide steps for implementing the functions specified in one or more processes in the flowchart and / or one or more boxes in the block diagram.

[0120] It should also be noted that the terms "include", "comprises" or any other variations thereof are intended to cover non-exclusive inclusion, so that a process, method, commodity or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, commodity or device. In the absence of more restrictions, the elements defined by the sentence "comprises a ..." do not exclude the existence of other identical elements in the process, method, commodity or device including the elements.

[0121] Each embodiment in this specification is described in a progressive manner, and the same or similar parts between the embodiments can be referred to each other, and each embodiment focuses on the differences from other embodiments. In particular, for the method embodiment, since it is basically similar to the hardware circuit embodiment, the description is relatively simple, and the relevant parts can be referred to the partial description of the method embodiment.

[0122] The above is only an embodiment of the present application and is not intended to limit the present application. For those skilled in the art, the present application may have various changes and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application should be included in the scope of the claims of the present application.

[0123] Although the embodiments of the present application have been described in conjunction with the accompanying drawings, those skilled in the art may make various modifications and variations without departing from the spirit and scope of the present application, and such modifications and variations are all within the scope defined by the appended claims.

Claims

1. A leakage protection circuit, characterized in that: include: A leakage detection switch, which is arranged between the power supply end and the load; a voltage detection unit, wherein the voltage detection unit is configured to detect an input voltage of the power supply end to generate a voltage detection signal; a driving unit, wherein the driving unit is configured to determine the input voltage type of the power supply terminal according to the voltage detection signal, and drive the leakage detection switch to operate; A threshold generating unit, wherein the threshold generating unit is configured to generate a leakage protection threshold according to the input voltage type; A leakage protection unit is configured to detect the working current flowing through the leakage detection switch, and control the load to be in a disconnected state when it is determined that there is leakage according to the leakage protection threshold and the working current of the leakage detection switch.

2. The leakage protection circuit according to claim 1, characterized in that: The threshold generating unit is further configured to generate a first leakage protection threshold according to the input voltage of the power supply end when the input voltage type is a direct current power supply.

3. The leakage protection circuit according to claim 2, characterized in that: The magnitude of the first leakage protection threshold is positively correlated with the supply voltage of the DC power supply.

4. The leakage protection circuit according to claim 3, characterized in that: The threshold generating unit comprises: A sample and hold device, wherein the sample and hold device is configured to hold the voltage detection signal based on a DC power supply flag signal to obtain a sample and hold value, wherein the DC power supply flag signal is obtained according to an input voltage type; a multiplier configured to multiply the sample-and-hold value by a preset coefficient to obtain a voltage adjustment value; An adder is configured to add a preset margin to the voltage adjustment value to obtain the first leakage protection threshold.

5. The leakage protection circuit according to claim 2, characterized in that: The threshold generating unit is further configured to generate a preset second leakage protection threshold when the input voltage type is an AC power supply.

6. The leakage protection circuit according to claim 5, characterized in that: The threshold generating unit further includes: A selector is configured to select one of the first leakage protection threshold and the second leakage protection threshold as the leakage protection threshold according to the input voltage type, and provide the threshold to the leakage protection unit.

7. The leakage protection circuit according to claim 1, characterized in that: The leakage detection switch is arranged on the bus path between the power supply end and the load, or the leakage detection switch is arranged between a node of the bus path between the power supply end and the load and the ground end.

8. The leakage protection circuit according to claim 1, characterized in that: The leakage protection unit comprises: a current-sensing resistor, the current-sensing resistor being connected in series with the leakage detection switch and having a first node; a first comparator, wherein a positive input terminal of the first comparator is connected to the first node, a negative input terminal of the first comparator is connected to an output terminal of the threshold generation unit, and the first comparator is configured to compare a leakage detection value with the leakage protection threshold value to output a first comparison signal, wherein the leakage detection value is used to characterize an operating current of the leakage detection switch; A controller is configured to control the load to be in a disconnected state when it is determined according to the first comparison signal that there is a leakage phenomenon.

9. The leakage protection circuit according to claim 8, characterized in that: The controller is further configured to determine that a leakage phenomenon exists when it is determined according to the first comparison signal that the leakage detection value is less than the leakage protection threshold.

10. The leakage protection circuit according to claim 8, characterized in that: The controller is further configured to determine that there is no leakage phenomenon when it is determined according to the first comparison signal that the leakage detection value is greater than or equal to the leakage protection threshold for a preset number of times.

11. The leakage protection circuit according to claim 10, characterized in that: The controller is also configured to, in the absence of leakage, control the connection between the load and the power supply terminal, and drive the leakage detection switch to stop working through the driving unit.

12. The leakage protection circuit according to claim 1, characterized in that: The driving unit comprises: a voltage type determination module, the voltage type determination module being configured to determine the input voltage type of the power supply terminal according to the voltage detection signal, and to send the determination result to the threshold generation unit; A first pulse generating module, wherein the first pulse generating module is configured to generate a first detection pulse signal when the input voltage type is a direct current power supply; A second pulse generating module, wherein the second pulse generating module is configured to generate a second detection pulse signal when the input voltage type is an AC power supply; A driving module is configured to drive the leakage detection switch to operate according to one of the first detection pulse signal and the second detection pulse signal.

13. The leakage protection circuit according to claim 12, characterized in that: The voltage type determination module comprises: a second comparator, the second comparator being configured to compare the voltage detection signal with a first reference voltage signal to output a second comparison signal, wherein the second comparison signal is used to determine whether the input voltage type is a DC power supply; A third comparator is configured to compare the voltage detection signal with a second reference voltage signal to output a third comparison signal, wherein the third comparison signal is used to determine whether the input voltage type is an AC power supply.

14. The leakage protection circuit according to claim 12, characterized in that: One of the first detection pulse signal and the second detection pulse signal is used to control the leakage detection switch to be intermittently turned on and off.

15. An electrical device, characterized in that: include: load; A controllable switch for controlling whether the load is disconnected; According to any one of claims 1-14, the leakage protection circuit is configured to control the controllable switch to be disconnected when it is determined that the electrical equipment has leakage, so that the load is in a disconnected state.

16. The electrical device according to claim 15, characterized in that: The controllable switch may be a switch connected in series with the load, or a switch driving a driving circuit in the load.

17. A leakage protection method, characterized in that: Applied to the leakage protection circuit according to any one of claims 1 to 14, the method comprises: Detecting the input voltage of the power supply end to generate a voltage detection signal; Determine the input voltage type of the power supply terminal according to the voltage detection signal, and drive the leakage detection switch to work; The working current flowing through the leakage detection switch is detected, and when it is determined that there is leakage according to the leakage protection threshold and the working current of the leakage detection switch, the load is controlled to be in a disconnected state, wherein the leakage protection threshold is generated according to the input voltage type.

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