Electric leakage alarm device
By designing a leakage current alarm device that includes adjustable resistors and test connection components, the problems of traditional devices being difficult to adjust flexibly and prone to false alarms are solved. This achieves higher accuracy in leakage current detection, simplifies equipment maintenance, and reduces costs.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- BEIJING WANGUO CHANGAN TECH CO LTD
- Filing Date
- 2025-06-16
- Publication Date
- 2026-07-24
AI Technical Summary
Traditional leakage current alarm devices are difficult to adjust flexibly, cannot accurately detect minor leakage current in electrical equipment, and have a high false alarm rate, which affects equipment maintenance costs and safety.
Design a leakage current alarm device that includes a main unit, a DC power supply module, a leakage current detection module, and a leakage current alarm module. Utilize an adjustable resistor and test connection components for leakage current detection. Flexible detection is achieved by adjusting the resistance value of the adjustable resistor, and an alarm signal is generated when the current exceeds a threshold.
It enables accurate detection of leakage current in electrical equipment, reduces false alarm rate, simplifies equipment maintenance, reduces costs, and does not affect the normal operation of existing equipment.
Smart Images
Figure CN224553461U_ABST
Abstract
Description
Technical Field
[0001] This application relates to the field of electrical safety monitoring technology, and in particular to a leakage current alarm device. Background Technology
[0002] Data centers are business scenarios that require continuous power and cooling. In data centers and similar fields, the stable operation of electrical equipment is crucial. Among these, leakage current alarm devices play an indispensable role as key devices for preventing electrical fires and ensuring the safety of personnel and equipment. However, some companies are currently facing numerous challenges.
[0003] Traditional leakage current alarm devices often use nut-fixed current transformers. Once the device is installed on the electrical equipment and energized, the transformer is difficult to replace, requiring the electrical equipment to be de-energized before operation, increasing the difficulty and cost of equipment maintenance. Furthermore, the transformers used are difficult to adjust flexibly for different electrical equipment and different leakage conditions, making it difficult to accurately detect minor leakage or distinguish between minor and severe leakage, leading to false alarms and low reliability in leakage detection.
[0004] Therefore, it is necessary to develop a simple and reliable technology for detecting leakage current in electrical equipment. Utility Model Content
[0005] The purpose of this application is to provide a leakage current alarm device to solve at least one of the above-mentioned technical problems.
[0006] To achieve the above objectives, this application proposes a leakage current alarm device, which includes: a main unit, a DC power supply module, a leakage current detection module, and a leakage current alarm module;
[0007] The DC power supply module is located inside the main unit and is used to supply power to the leakage detection module and the leakage alarm module.
[0008] The leakage current detection module includes an adjustable resistor and a test connection component. The test connection component is used to detect leakage current at the test point on the electrical circuit. The first end of the adjustable resistor can be electrically connected to the DC power supply module through the test connection component, and the second end of the adjustable resistor is electrically connected to the signal input terminal of the leakage current alarm module.
[0009] When the current signal received at the signal input terminal of the leakage current alarm module exceeds the preset current threshold, the leakage current alarm module is activated and generates a leakage current alarm signal.
[0010] Optionally, the host body is connected to multiple test connection components, and the leakage current detection module includes the same number of adjustable resistors as the test connection components. The first end of each adjustable resistor is electrically connected to a DC power supply module through a corresponding test connection component.
[0011] Optionally, multiple adjustable resistors are connected in parallel, and the second ends of the multiple adjustable resistors are connected to the signal input terminal of the leakage current alarm module. When the sum of the currents in the circuits containing the multiple adjustable resistors exceeds a preset current threshold, the signal input terminal of the leakage current alarm module is activated.
[0012] Optionally, the leakage current alarm module has multiple modules, and the second end of each adjustable resistor is connected to the signal input terminal of a leakage current alarm module. When the current in the circuit where one of the adjustable resistors is located exceeds a preset current threshold, the signal input terminal of the corresponding leakage current alarm module is activated, generating a leakage current alarm signal to indicate that leakage has occurred at the detection point corresponding to the adjustable resistor that exceeds the current threshold.
[0013] Optionally, the signal input terminals of the leakage current alarm module include multiple terminals;
[0014] The second end of each adjustable resistor is connected to a signal input terminal of the leakage current alarm module. When the current in the circuit containing one of the adjustable resistors exceeds the preset current threshold, the corresponding signal input terminal of the leakage current alarm module is activated, generating an alarm signal corresponding to the activated signal input terminal.
[0015] Optionally, the DC power supply module includes a transformer unit and a rectifier bridge unit. The transformer unit is used to convert the input mains power into a preset AC voltage, and the rectifier bridge unit is used to convert the AC voltage into a DC voltage.
[0016] Optionally, the adjustable resistor is a rotary resistor;
[0017] The leakage current detection module also includes a current display unit connected in series with the adjustable resistor.
[0018] Optionally, when the signal input terminal of the leakage current alarm module receives different current signal strengths, it generates different alarm signals accordingly.
[0019] Optionally, the leakage current alarm module includes a speaker and an alarm light, and the leakage current alarm signal includes an audio signal and a light signal.
[0020] Optionally, the leakage current alarm device further includes a backup power module, which is used to supply power to the leakage current detection module and the leakage current alarm module.
[0021] The leakage current alarm device in this application uses a leakage current detection module to detect leakage current at a point on the electrical circuit. It measures the leakage current at that point and issues an alarm when the leakage current exceeds a current threshold. The leakage current detection module has an adjustable resistor, which allows for adjustment of its resistance value within a certain range, thus expanding the range of leakage current detection. By adjusting the adjustable resistor to a suitable value, the leakage current at the point can be reliably detected, accurately determining whether there is a leakage. This method has the advantages of low implementation cost and does not affect the normal operation of existing equipment. Attached Figure Description
[0022] To more clearly illustrate the technical solutions of the embodiments of this application, the accompanying drawings used in the embodiments will be briefly described below. It should be understood that the following drawings only show some embodiments of this application and should not be regarded as a limitation on the scope of this application.
[0023] Figure 1 This is a schematic diagram of the overall structure of a leakage current alarm device in one embodiment of this application;
[0024] Figure 2 This is a schematic diagram of the overall structure of a leakage current alarm device in another embodiment of this application;
[0025] Figure 3 This is a schematic diagram of the connection between the test connection component and the test connection point in one embodiment of this application.
[0026] Explanation of reference numerals: 100, Main unit; 200, DC power supply module; 300, Leakage detection module; 400, Leakage alarm module; 500, Backup power supply module; 210, Transformer unit; 220, Rectifier bridge unit; 310, Adjustable resistor; 320, Current display unit; 600, Test connection point; 700, Test connection assembly. Detailed Implementation
[0027] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the application, not all embodiments. The components of the embodiments of this application described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.
[0028] Therefore, the following detailed description of the embodiments of this application provided in the accompanying drawings is not intended to limit the scope of the claimed application, but merely to illustrate selected embodiments of the application. All other embodiments obtained by those skilled in the art based on the embodiments of this application without inventive effort are within the scope of protection of this application.
[0029] In the description of this application, it should be noted that the terms "center," "upper," "lower," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship commonly used when the product is in use. They are used only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application. In addition, the terms "first," "second," and "third," etc., are used only to distinguish descriptions and should not be construed as indicating or implying relative importance.
[0030] Furthermore, terms such as "horizontal," "vertical," and "sag" do not imply that components must be absolutely horizontal or suspended, but rather that they can be slightly tilted. For example, "horizontal" simply means that its direction is more horizontal relative to "vertical," and does not mean that the structure must be completely horizontal, but can be slightly tilted.
[0031] In the description of this application, it should be noted that, unless otherwise expressly specified and limited, the terms "set up," "install," "connect," and "link" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal communication between two components. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.
[0032] Combination Figures 1 to 3 As shown, a leakage current alarm device is provided, comprising: a main unit 100, a DC power supply module 200, a leakage current detection module 300, and a leakage current alarm module 400. The DC power supply module 200 is located within the main unit 100 and supplies power to the leakage current detection module 300 and the leakage current alarm module 400. The leakage current detection module 300 includes an adjustable resistor 310 and a test connection component 700. The test connection component 700 is used to detect leakage current at a point on the electrical circuit. The first end of the adjustable resistor 310 is electrically connected to the DC power supply module 200 via the test connection component 700, and the second end of the adjustable resistor 310 is electrically connected to the signal input terminal of the leakage current alarm module 400. When the current signal received at the signal input terminal of the leakage current alarm module 400 exceeds a preset current threshold, the leakage current alarm module 400 is activated and generates a leakage current alarm signal.
[0033] The main unit 100 can be the electrical box for the equipment, such as a low-voltage box made of fire-retardant materials. The main unit 100 serves as the physical carrier for each module, providing mechanical protection, electromagnetic shielding (such as an internal metal shielding layer), and installation interfaces.
[0034] The main unit 100 is sized to fit standard electrical cabinet installation space. It has an independent cavity-separated DC power supply module 200, leakage detection module 300 and leakage alarm module 400 inside. Externally, it can be configured with quick-connect male and female terminals (such as plug-in terminals) to support quick connection with external electrical lines.
[0035] The DC power supply module 200 converts AC mains power into a DC voltage of a specific rating. The converted DC voltage can be used as the operating voltage for the leakage current detection module 300 and the leakage current alarm module 400. Specifically, the DC power supply module 200 may include a 220V to 24V DC switching power supply, which converts AC 220V voltage into DC 24V operating voltage.
[0036] Specifically, the DC power supply module 200 includes a transformer unit 210 and a rectifier bridge unit 220. The transformer unit is used to convert the input mains power into a preset AC voltage, and the rectifier bridge unit is used to convert the AC voltage into a DC voltage.
[0037] The transformer unit receives 220V AC mains power at its input terminal and outputs 24V AC voltage at its output terminal, which serves as the input to the rectifier bridge unit. The rectifier bridge unit 220 includes four bridged rectifier diodes (D1, D2, D3, D4) and a capacitor C1, converting AC power to DC power.
[0038] The DC power module 200 also includes a fuse unit 230, which is located at the voltage input terminal of the transformer unit 210 to prevent the equipment from burning out due to a short circuit in the 220V power supply.
[0039] In one embodiment, combined Figure 1 As shown, the leakage current alarm device also includes a backup power module 500, which is used to supply power to the leakage current detection module 300 and the leakage current alarm module 400.
[0040] When the mains power is interrupted, the backup power module 500 automatically switches to supply power to maintain the normal operation of the leakage current alarm device 100 and prevent monitoring interruption. The backup power module includes a 24V battery and a switching unit. When the DC power module 200 fails to supply power, the switching unit closes, thereby supplying power to the leakage current detection module 300 and the leakage current alarm module 400 through the 24V battery.
[0041] The leakage current detection module 300 includes an adjustable resistor 310 and a test connection component 700. The test connection component 700 is used to perform leakage current detection on the test point of the electrical circuit. The test connection component 700 is located outside the main body 100, and relevant personnel can clamp the test connection component 700 at the test point on the electrical circuit to be tested (such as any suitable point on the specific circuit to be tested). Specifically, when the test connection component 700 is clamped at the location on the electrical circuit to be tested, it clamps the electrical circuit under test, thereby generating a current signal / voltage signal within the test connection component 700. This current signal / voltage signal is transmitted to the adjustable resistor 310 through a wire, and after passing through the adjustable resistor 310, the current signal / voltage signal is transmitted to the leakage current alarm module 400.
[0042] The first end of the adjustable resistor 310 can be connected to the DC power supply module 200 via the test connection component 700 to ensure that the detection circuit obtains a stable operating voltage. The second end of the adjustable resistor 310 is electrically connected to the signal input terminal of the leakage current alarm module 400 via a wire to transmit the voltage signal to the leakage current alarm module 400.
[0043] Different electrical devices (such as transformers, cables, and distribution cabinets) have different normal leakage current values. The adjustable resistor 310 allows operators to adjust the detection threshold according to the actual scenario, avoiding false alarms. For example, for precision electronic equipment (with low normal leakage current), the resistance value can be decreased to improve sensitivity; for high-power motors (with higher normal leakage current), the resistance value can be increased to avoid false triggering. After prolonged use, the resistance value of the adjustable resistor 310 can be readjusted to recalibrate the detection threshold, ensuring measurement accuracy and extending the equipment's lifespan.
[0044] After receiving the current signal at the signal input terminal of the leakage current alarm module 400, it compares whether the current signal exceeds a preset current threshold. When the current threshold is exceeded, the leakage current alarm module 400 is activated and generates a leakage current alarm signal.
[0045] Specifically, the leakage current alarm module 400 includes a speaker and an alarm light, and the leakage current alarm signal includes an audio signal and a light signal.
[0046] The drive circuit in the leakage current alarm module can generate control signals to drive the speaker and alarm light. When the leakage current alarm signal is triggered, one or more of the sound and light signals can be activated.
[0047] The leakage current alarm module 400 includes a speaker, an alarm light, and a leakage current detection chip. The leakage current detection chip can be any suitable chip capable of implementing audible and visual alarm functions.
[0048] In one embodiment, when the current signal intensity received at the signal input terminal of the leakage current alarm module is different, different alarm signals are generated accordingly.
[0049] Specifically, the sound signal emitted by a loudspeaker can be a fixed sound signal or different sound signals; similarly, the light signal generated by an alarm light can also be a fixed signal or different signals, such as producing different colors of light, and / or producing light with different flashing frequencies.
[0050] Different alarm signals correspond to different current signal intensities, indicating different leakage conditions. For example, based on the specific alarm signal, it can be determined which electrical device under test has a leakage problem, and also the severity of the leakage.
[0051] For example, depending on the strength of the received current signal, when the current signal strength is in a state of slight leakage (e.g., the current is between 0.2mA and 1mA), the speaker (e.g., a buzzer) emits a low-frequency alarm, and the alarm light flashes at a low frequency; while when the current signal strength is in a state of severe leakage (e.g., the current exceeds 1mA), the speaker emits a high-frequency alarm, and the alarm light flashes at a higher frequency.
[0052] The leakage current alarm device in this application uses a leakage current detection module 300 to detect leakage current at the test point on the electrical circuit, measures the leakage current corresponding to the test point, and uses a leakage current alarm module 400 to alarm when the leakage current exceeds the current threshold. This enables timely and reliable detection of leakage current in the host device and provides an alarm prompt when leakage current is detected. It has the technical advantages of high accuracy, high reliability, low cost, and no impact on the normal operation of existing equipment.
[0053] This application can replace some faulty current transformers that cannot be repaired or replaced while significantly reducing costs, without affecting the operation of existing equipment. This application is applicable to existing aging equipment, eliminating the need for complete replacement of older equipment, allowing existing equipment to operate normally without interference, and improving the stability of electrical equipment in data centers without requiring power outages.
[0054] In one embodiment, the adjustable resistor 310 is a rotary resistor with multiple selectable resistance values. Relevant testers can set the specific resistance value of the rotary resistor according to the actual situation, thereby realizing the monitoring of leakage current.
[0055] The test connection component 700 can specifically be a clamp-on test mechanism, which may be a magnetoelectric current sensing clamp or a Hall effect current sensing clamp. The clamp-on test mechanism also includes an insulated handle for ease of use by relevant personnel. When its jaws are closed, it can clamp the electrical circuit under test (such as a single-core cable or busbar), thereby generating a current / voltage signal within the clamp-on test mechanism. This current / voltage signal is input to the leakage current alarm module. This application uses a clamp-on test mechanism, which has the functions of simplifying testing and effectively increasing the safety distance, ensuring personal safety.
[0056] The leakage current detection module 300 also includes a current display unit 320 connected in series with the adjustable resistor 310. The current display unit 320 can be an ammeter. By setting the current display unit, the specific current flowing through the adjustable resistor in the leakage current detection module 300 can be displayed intuitively, thereby knowing the specific leakage current or voltage at the detection point and intuitively judging whether the device function is normal.
[0057] In one embodiment, such as Figure 1 As shown, the host body 100 is connected to multiple test connection components 700. The leakage current detection module 300 includes the same number of adjustable resistors 310 as the test connection components 700. The first end of each adjustable resistor 310 can be electrically connected to the DC power supply module 200 through a corresponding test connection component 700.
[0058] In this embodiment, the host body 100 is connected to multiple test connection components 700 through multiple test connection points 600. The number of test connection points 600 can be set according to actual application requirements, such as 3, 6, 8, or any other suitable number. Each test connection point 600 is configured with an adjustable resistor 310 and a current display unit 320. One test connection component 700 is connected to one test connection point 600 to realize leakage current detection of the test point on the electrical circuit through the test connection component 700. Figure 3 As shown. Preferably, the test connection assembly 700 is detachably connected to the test connection point 600. Figure 1 The test connection point 600 shown in the figure, as well as the corresponding adjustable resistor 310 and current display unit 320, are all in the number of three. Each adjustable resistor 310 is connected in parallel to achieve independent measurement for the point to be tested.
[0059] Optionally, multiple adjustable resistors 310 can be connected in parallel. The second end of each adjustable resistor 310 (the end not connected to the test connection point 600) is connected together via copper foil traces on the circuit board, ultimately connecting to the input terminal of the leakage current alarm module. This connection method allows the signal of each test connection point 600 to be input independently without interference, and ensures that the normal operation of other detection channels is not affected when one adjustable resistor 310 fails.
[0060] To prevent signal crosstalk between different detection channels, electrical isolation measures are adopted between each adjustable resistor and its connecting lines in the circuit board design. For example, a 2mm wide grounded copper foil isolation strip is set between adjacent adjustable resistor lines, and small ferrite beads are added at the pins of the adjustable resistors for high-frequency filtering, effectively suppressing signal interference.
[0061] In one embodiment, combined Figure 1 As shown, the second ends of multiple adjustable resistors 310 are connected to the signal input terminal of the leakage current alarm module 400. When the sum of the currents in the circuits containing the multiple adjustable resistors 310 exceeds the preset current threshold, the signal input terminal of the leakage current alarm module 400 is activated.
[0062] In this embodiment, the current signal received at the signal input terminal of the leakage current alarm module 400 is the sum of the currents in the circuits containing the multiple adjustable resistors 310. When the sum of these currents exceeds a preset current threshold, an alarm signal is triggered.
[0063] In one embodiment, the leakage current alarm device has multiple leakage current alarm modules 400. The second end of each adjustable resistor 310 is connected to the signal input terminal of a leakage current alarm module 400. When the current in the circuit where one of the adjustable resistors 310 is located exceeds a preset current threshold, the signal input terminal of the corresponding leakage current alarm module 400 is activated, generating a leakage current alarm signal to indicate that leakage has occurred at the test connection point 600 corresponding to the adjustable resistor 310 that exceeds the current threshold.
[0064] Among them, such as Figure 2 As shown, the second terminal of each adjustable resistor 310 can be independently connected to a signal input terminal of the leakage current alarm module 400. Specifically, the leakage current alarm module 400 can distinguish the test connection point 600 corresponding to the received current signal. When the current signal received at any signal input terminal exceeds the corresponding set current threshold, a leakage current alarm signal corresponding to that test connection point 600 is generated. Optionally, the leakage current alarm signals corresponding to different test connection points 600 are different. By generating different leakage current alarm signals, relevant personnel can identify the test connection point 600 with leakage risk and its corresponding test point.
[0065] For example, a time-division multiplexing method can be used to connect to the signal input terminal. The leakage current alarm module 400 can connect the circuit corresponding to the different adjustable resistors 310 at different times. Based on the time of the received signal, the corresponding test connection point 600 and its corresponding test point can be located.
[0066] Different leakage current alarm signals can be different in terms of the frequency and volume of sound signals; or they can be different in terms of the brightness, color and flashing frequency of light signals.
[0067] In one embodiment, the signal input terminal of the leakage current alarm module includes multiple terminals; the second terminal of each adjustable resistor is connected to one signal input terminal of the leakage current alarm module. When the current in the circuit containing one of the adjustable resistors exceeds a preset current threshold, the corresponding signal input terminal of the leakage current alarm module is activated, generating an alarm signal corresponding to the activated signal input terminal.
[0068] Specifically, a leakage current alarm module may include one or more leakage current detection chips, such as a single leakage current detection chip, a speaker, and an alarm light. The leakage current detection chip has multiple signal input terminals. By inputting a current signal at each terminal, the corresponding detection point can be identified. Furthermore, different leakage current alarm signals are generated when different signal input terminals are activated.
[0069] Optionally, the number of leakage detection chips, speakers, and alarm lights is the same as the number of detection points. Each detection point is configured with one leakage detection chip, speaker, and alarm light, connected to the signal input terminal on the corresponding leakage detection chip. In this way, each leakage detection chip independently detects one detection point. When a leakage occurs at any detection point, the corresponding speaker and alarm light generate an alarm signal. By observing which speaker or alarm light generates the alarm signal, the specific detection point where the leakage has occurred can be located.
[0070] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this application.
[0071] Furthermore, those skilled in the art will understand that although some embodiments herein include certain features included in other embodiments but not others, combinations of features from different embodiments are meant to be within the scope of this application and form different embodiments. For example, any of the embodiments above can be used in any combination. The information disclosed in this background section is intended only to enhance the understanding of the general background of this application and should not be construed as an admission or in any way implying that such information constitutes prior art known to those skilled in the art.
Claims
1. A leakage current alarm device, characterized in that, The leakage current alarm device includes: a main unit, a DC power supply module, a leakage current detection module, and a leakage current alarm module; The DC power supply module is located inside the main unit and is used to supply power to the leakage detection module and the leakage alarm module. The leakage current detection module includes an adjustable resistor and a test connection component. The test connection component is used to detect leakage current at the test point on the electrical circuit. The first end of the adjustable resistor can be electrically connected to the DC power supply module through the test connection component, and the second end of the adjustable resistor is electrically connected to the signal input terminal of the leakage current alarm module. When the current signal received at the signal input terminal of the leakage current alarm module exceeds the preset current threshold, the leakage current alarm module is activated and generates a leakage current alarm signal.
2. The leakage current alarm device according to claim 1, characterized in that, The host body is connected to multiple test connection components. The leakage current detection module includes the same number of adjustable resistors as the test connection components. The first end of each adjustable resistor is electrically connected to a DC power supply module through a corresponding test connection component.
3. The leakage current alarm device according to claim 2, characterized in that, Multiple adjustable resistors are connected in parallel, and the second ends of the multiple adjustable resistors are connected to the signal input terminal of the leakage current alarm module. When the sum of the currents in the circuits containing the multiple adjustable resistors exceeds a preset current threshold, the signal input terminal of the leakage current alarm module is activated.
4. The leakage current alarm device according to claim 2, characterized in that, The leakage current alarm module has multiple modules, and the second end of each adjustable resistor is connected to the signal input terminal of a leakage current alarm module. When the current in the circuit where one of the adjustable resistors is located exceeds a preset current threshold, the signal input terminal of the corresponding leakage current alarm module is activated, generating a leakage current alarm signal to indicate that leakage has occurred at the detection point corresponding to the adjustable resistor that exceeds the current threshold.
5. The leakage current alarm device according to claim 2, characterized in that, The leakage current alarm module includes multiple signal input terminals; The second end of each adjustable resistor is connected to a signal input terminal of the leakage current alarm module. When the current in the circuit containing one of the adjustable resistors exceeds the preset current threshold, the corresponding signal input terminal of the leakage current alarm module is activated, generating an alarm signal corresponding to the activated signal input terminal.
6. The leakage current alarm device according to claim 1, characterized in that, The DC power supply module includes a transformer unit and a rectifier bridge unit. The transformer unit is used to convert the input AC power into a preset AC voltage, and the rectifier bridge unit is used to convert the AC voltage into a DC voltage.
7. The leakage current alarm device according to claim 1, characterized in that, The adjustable resistor is a rotary resistor; The leakage current detection module also includes a current display unit connected in series with the adjustable resistor.
8. The leakage current alarm device according to claim 1, characterized in that, When the signal input terminal of the leakage current alarm module receives a current signal of different strengths, it generates a corresponding alarm signal.
9. The leakage current alarm device according to claim 1, characterized in that, The leakage current alarm module includes a speaker and an alarm light, and the leakage current alarm signal includes an audio signal and a light signal.
10. The leakage current alarm device according to claim 1, characterized in that, The leakage current alarm device also includes a backup power module, which is used to supply power to the leakage current detection module and the leakage current alarm module.