Trip unit testing device

Abstract

This invention provides a trip unit testing device, including a DC power supply module, a first switching device, and a control module. The DC power supply module and the first switching device are connected in series with the trip unit under test. The DC power supply module outputs a target DC power signal, the amplitude of which is variable and is one of multiple preset amplitudes. The control module is electrically connected to the first switching device and outputs a target control PWM signal to the first switching device to control its switching state. The duty cycle of the target control PWM signal is variable and is one of multiple preset duty cycles. The first switching device controls the switching of the target DC power signal based on the input target control PWM signal to output a test PWM signal to the trip unit. This invention can output test PWM signals with different amplitudes and duty cycles to the trip unit, expanding the testing range and improving the testing effect.

Description

Technical Field

[0001] This utility model relates to the field of electrical testing technology, specifically to a trip unit testing device. Background Technology

[0002] Trip units are crucial protective devices in power systems, primarily used to detect overloads, short circuits, or other abnormal conditions in circuits and prevent equipment damage or fires by disconnecting the circuit. Trip unit testing is a process used to evaluate and verify the performance of trip units, thereby verifying whether the trip unit can correctly respond to overload or short-circuit currents, ultimately ensuring that the sensitivity and reliability of the trip unit meet design requirements.

[0003] However, traditional trip unit testing devices can usually only perform partial testing on the trip unit. They can only provide a single test signal to test whether the trip unit can respond correctly under this single test signal, which makes the test range insufficient and results in poor test results. Utility Model Content

[0004] In view of the shortcomings of the existing technology, this utility model provides a trip unit testing device.

[0005] In one embodiment, the present invention provides a trip unit testing device, which includes a DC power supply module, a first switching device, and a control module;

[0006] The DC power supply module and the first switching device are used in series with the trip unit device under test;

[0007] The DC power supply module is used to output a target DC power signal, the amplitude of which is variable and can be one of a number of preset amplitudes;

[0008] The control module is electrically connected to the first switching device and is used to output a target control PWM signal to the first switching device to control the switching state of the first switching device. The duty cycle of the target control PWM signal is variable and is one of multiple preset duty cycles.

[0009] The first switching device is used to control the switching of the target DC power supply signal based on the accessed target control PWM signal, so as to output a test PWM signal to the trip unit.

[0010] In one embodiment, the DC power supply module includes a second switching device, a first DC power supply, and a second DC power supply, and the plurality of preset amplitudes include a first preset amplitude and a second preset amplitude;

[0011] The first DC power supply is electrically connected to the first input terminal of the second switching device, and is used to output a first DC power supply signal with a first preset amplitude to the first input terminal of the second switching device.

[0012] The second DC power supply is electrically connected to the second input terminal of the second switching device, and is used to output a second DC power supply signal with a second preset amplitude to the second input terminal of the second switching device.

[0013] The output terminal of the second switching device is used for electrical connection with the trip unit;

[0014] The second switching device is used to control the first input terminal or the second input terminal to connect with the trip unit device, so as to output the first DC power signal or the second DC power signal to the trip unit device based on the first DC power signal and the second DC power signal received.

[0015] The first DC power supply signal or the second DC power supply signal is used as the target DC power supply signal.

[0016] In one embodiment, the second switching device includes a first toggle switch.

[0017] In one embodiment, the control module includes a main control unit, a first input unit, and a second input unit, and the multiple preset duty cycles include a first preset duty cycle and a second preset duty cycle;

[0018] The first input unit is electrically connected to the first input terminal of the main control unit and is used to output a first duty cycle indication signal to the first input terminal of the main control unit.

[0019] The second input unit is electrically connected to the second input terminal of the main control unit and is used to output a second duty cycle indication signal to the second input terminal of the main control unit.

[0020] The output terminal of the main control unit is electrically connected to the first switching device, and is used to output a first control PWM signal with a first preset duty cycle to the first switching device according to the first duty cycle indication signal, or to output a second control PWM signal with a second preset duty cycle to the first switching device according to the second duty cycle indication signal.

[0021] The first control PWM signal or the second control PWM signal is used as the target control PWM signal.

[0022] In one embodiment, the master control unit includes a Bluetooth SoC.

[0023] In one embodiment, the first input unit includes a third switching device and a first pull-up resistor;

[0024] The input terminal of the third switching device is electrically connected to the first input terminal of the main control unit and is used to access the working voltage through the first pull-up resistor. The output terminal of the third switching device is used for grounding.

[0025] In one embodiment, the third switching device includes a first push-button switch.

[0026] In one embodiment, the first input unit includes a fourth switching device and a second pull-up resistor;

[0027] The input terminal of the fourth switching device is electrically connected to the second input terminal of the main control unit and is used to access the working voltage through the second pull-up resistor. The output terminal of the fourth switching device is used for grounding.

[0028] In one embodiment, the fourth switching device includes a second push-button switch.

[0029] In one embodiment, the trip unit device includes a first trip unit module and a second trip unit module, and the trip unit testing device further includes a fifth switching device;

[0030] The input terminal of the fifth switching device is electrically connected to the DC power supply module, the first output terminal of the fifth switching device is electrically connected to the first trip unit module, and the second output terminal of the fifth switching device is electrically connected to the second trip unit module.

[0031] The fifth switching device is used to connect the control input terminal to the first trip unit module or the second trip unit module, so as to output the test PWM signal to the first trip unit module or the second trip unit module.

[0032] In one embodiment, the fifth switching device includes a second toggle switch.

[0033] The aforementioned trip unit testing device includes a DC power supply module, a first switching device, and a control module. The DC power supply module can provide DC power signals of different amplitudes. The first switching device can control the on / off state of the DC power signal and, under the switching control of the control module, can adjust the DC power signal to different duty cycles. Ultimately, it can output test PWM signals of different amplitudes and duty cycles to the trip unit, thus expanding the testing range and improving the testing effect. Attached Figure Description

[0034] To more clearly illustrate the technical solutions in the embodiments of this utility model, the drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0035] Figure 1 This is a schematic diagram of the trip unit testing device in one embodiment of the present invention;

[0036] Figure 2 This is a schematic diagram of the specific structure of the trip unit testing device including the DC power supply module in one embodiment of the present invention;

[0037] Figure 3 This is a schematic diagram of the specific structure of the control module included in one embodiment of the trip unit testing device of this utility model;

[0038] Figure 4 This is a schematic diagram of the specific structure of the first input unit and the second input unit in one embodiment of the present invention;

[0039] Figure 5 This is a schematic diagram of a trip unit device including a first trip unit module and a second trip unit module in one embodiment of the present invention;

[0040] Figure 6 This is a schematic diagram of the specific structure of the trip unit testing device including the first switching device in one embodiment of the present invention. Detailed Implementation

[0041] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of the present utility model.

[0042] In the description of this utility model, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicating orientation or positional relationships based on the orientation or positional relationships shown in the accompanying drawings, are only for the convenience of describing this utility model 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, and therefore should not be construed as a limitation of this utility model. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, features defined with "first" and "second" may explicitly or implicitly include one or more of the stated features. In the description of this application, "a plurality of" means two or more, unless otherwise explicitly specified. In this application, the term "exemplary" is used to mean "used as an example, illustration, or description." Any embodiment described as "exemplary" in this application is not necessarily to be construed as being more preferred or advantageous than other embodiments. The following description is provided to enable any person skilled in the art to implement and use this invention. Details are set forth in the following description for purposes of explanation. It should be understood that those skilled in the art will recognize that this invention can be implemented without using these specific details. In other instances, well-known structures and processes will not be described in detail to avoid obscuring the description of this invention with unnecessary detail. Therefore, this invention is not intended to be limited to the embodiments shown, but is consistent with the broadest scope of the principles and features disclosed in this application.

[0043] Firstly, such as Figure 1 As shown, in one embodiment, the present invention provides a trip unit testing device, which includes a DC power supply module, a first switching device, and a control module.

[0044] The DC power supply module and the first switching device are used in series with the trip unit device under test.

[0045] Among them, Figure 1 In this embodiment, the trip unit is connected in series between the DC power module and the first switching device. Of course, in other embodiments, the first switching device may also be connected in series between the DC power module and the trip unit.

[0046] The DC power supply module is used to output a target DC power signal, the amplitude of which is variable and can be one of a number of preset amplitudes.

[0047] Specifically, the multiple preset amplitudes may include a first preset amplitude and a second preset amplitude, enabling the DC power module to output a first DC power signal VCC1 with the first preset amplitude and a second DC power signal VCC2 with the second preset amplitude. Either the first DC power signal VCC1 or the second DC power signal VCC2 can be used as the target DC power signal output by the DC power module.

[0048] The control module is electrically connected to the first switching device and is used to output a target control PWM signal to the first switching device to control the switching state of the first switching device. The duty cycle of the target control PWM signal is variable and is one of multiple preset duty cycles.

[0049] Among them, the target DC power supply signal mentioned above, the multiple preset duty cycles may specifically include a first preset duty cycle and a second preset duty cycle, so that the control module can output a first control PWM signal PWM1 with the first preset duty cycle and a second control PWM signal PWM2 with the second preset duty cycle. Any one of the first control PWM signal PWM1 and the second control PWM signal PWM2 can be used as the target control PWM signal output by the control module.

[0050] The first switching device is used to control the switching of the target DC power supply signal based on the accessed target control PWM signal, so as to output a test PWM signal PWM0 to the trip unit.

[0051] The DC power supply module can control the amplitude of the test PWM signal PWM0, and the control module can control the duty cycle of the test PWM signal PWM0 through the first switching device, so that the test PWM signal PWM0 can have different amplitudes and different duty cycles.

[0052] Specifically, if the first preset amplitude is 4V, the second preset amplitude is 7.8V, the high-level duration in one cycle represented by the first preset duty cycle is 4ms, and the high-level duration in one cycle represented by the second preset duty cycle is 100ms, then the test PWM signal PWM0 is any one of "amplitude of 4V and high level for 4ms", "amplitude of 4V and high level for 100ms", "amplitude of 7.8V and high level for 4ms" and "amplitude of 7.8V and high level for 100ms".

[0053] The aforementioned trip unit testing device includes a DC power supply module, a first switching device, and a control module. The DC power supply module can provide DC power signals of different amplitudes. The first switching device can control the on / off state of the DC power signal and, under the switching control of the control module, can adjust the DC power signal to different duty cycles. Ultimately, it can output test PWM signals of different amplitudes and duty cycles to the trip unit, thus expanding the testing range and improving the testing effect.

[0054] like Figure 2 As shown, in one embodiment, the DC power supply module includes a second switching device, a first DC power supply, and a second DC power supply.

[0055] The first DC power supply is electrically connected to the first input terminal of the second switching device, and is used to output a first DC power supply signal VCC1 with a first preset amplitude to the first input terminal of the second switching device.

[0056] The second DC power supply is electrically connected to the second input terminal of the second switching device, and is used to output a second DC power supply signal VCC2 with a second preset amplitude to the second input terminal of the second switching device.

[0057] The output of the second switching device is used for electrical connection with the trip unit.

[0058] The second switching device is used to control the connection between the first input terminal or the second input terminal and the trip unit, so as to output the first DC power signal VCC1 or the second DC power signal VCC2 to the trip unit based on the input first DC power signal VCC1 and the second DC power signal VCC2.

[0059] In this embodiment, by providing a second switching device with a selection function, two independent first DC power supplies and a second DC power supply can be directly connected. When the first DC power supply is needed, the second switching device connects the line between the first DC power supply and the trip unit, thereby outputting the first DC power supply signal VCC1; when the second DC power supply is needed, the second switching device connects the line between the second DC power supply and the trip unit, thereby outputting the second DC power supply signal VCC2.

[0060] In one embodiment, the second switching device includes a first toggle switch.

[0061] The first toggle switch has a first state and a second state, which can be switched manually. When the user operates the first toggle switch to the first state, the first toggle switch connects the line between the first DC power supply and the trip unit, thereby outputting the first DC power supply signal VCC1; when the user operates the first toggle switch to the second state, the first toggle switch connects the line between the second DC power supply and the trip unit, thereby outputting the second DC power supply signal VCC2.

[0062] like Figure 3 As shown, in one embodiment, the control module includes a main control unit, a first input unit, and a second input unit.

[0063] The first input unit is electrically connected to the first input terminal of the main control unit and is used to output the first duty cycle indication signal ctrl1 to the first input terminal of the main control unit.

[0064] The first duty cycle indicator signal ctrl1 output by the first input unit can be of various signal types. Its purpose is to instruct the main control unit to output a PWM signal with a first preset duty cycle, while the first duty cycle indicator signal ctrl itself does not need to be a PWM signal.

[0065] The second input unit is electrically connected to the second input terminal of the main control unit and is used to output the second duty cycle indication signal ctrl2 to the second input terminal of the main control unit.

[0066] Similarly, the second duty cycle indicator signal ctrl2 output by the second input unit can be of various signal types. Its purpose is to instruct the main control unit to output a PWM signal with a second preset duty cycle, while the second duty cycle indicator signal ctrl2 itself does not need to be a PWM signal.

[0067] The output terminal of the main control unit is electrically connected to the first switching device, and is used to output a first control PWM signal PWM1 with a first preset duty cycle to the first switching device according to the first duty cycle indication signal ctrl1, or to output a second control PWM signal PWM2 with a second preset duty cycle to the first switching device according to the second duty cycle indication signal ctrl2.

[0068] Since the first input unit and the second input unit are electrically connected to different input terminals of the main control unit, the main control unit can determine the preset duty cycle represented by the duty cycle indicator signal based on the input terminal that receives the duty cycle indicator signal. If the first input terminal is connected, the duty cycle indicator signal is determined to represent the first preset duty cycle; similarly, if the second input terminal is connected, the duty cycle indicator signal is determined to represent the second preset duty cycle.

[0069] In other words, in this embodiment, the first duty cycle indication signal output by the first input unit and the second duty cycle indication signal output by the second input unit only need to ensure their signal validity (e.g., high level), without needing to include duty cycle related information.

[0070] The power supply to the main control unit can be indicated by corresponding indicator lights. For example, the operating voltage is connected to the anode of the LED, and the cathode of the LED is connected to the input terminal of the main control unit, which is then grounded. When an operating voltage is input, the LED illuminates to indicate this.

[0071] The operating voltage of the main control unit can be generated by the corresponding power processing module. The power processing module can directly draw power from the DC power module mentioned above. By configuring filter capacitors and step-down regulator chips, the DC power output from the DC power module is filtered, stepped down, and regulated to provide the main control unit with an operating voltage that meets the power supply requirements.

[0072] The main control unit includes, but is not limited to, a Bluetooth SoC (System on Chip). A Bluetooth SoC is an integrated circuit specifically designed to support Bluetooth communication functions. It integrates a Bluetooth radio, microcontroller, memory, and other necessary components onto a single chip to achieve low-power and efficient wireless communication. When a Bluetooth SoC is used as the main control unit, in addition to wired access to the first duty cycle indicator signal ctrl1 output from the first input unit and the second duty cycle indicator signal ctrl2 output from the second input unit, it can also wirelessly access other indicator signals via Bluetooth, thereby enhancing the richness of duty cycle control.

[0073] like Figure 4 As shown, in one embodiment, the first input unit includes a third switching device and a first pull-up resistor R1.

[0074] The input terminal of the third switching device is electrically connected to the first input terminal of the main control unit to output a first duty cycle indication signal ctrl1 to the first input terminal of the main control unit. The input terminal of the third switching device is used to connect to the working voltage VCC through the first pull-up resistor R1, and the output terminal of the third switching device is used to ground.

[0075] As mentioned in the above embodiments, the first duty cycle indicator signal ctrl1 output to the main control unit must be valid. In this embodiment, the first duty cycle indicator signal ctrl1 is valid when it is low.

[0076] Specifically, when the third switching device is off, the first duty cycle indicator signal ctrl1 is at a high level, the first input terminal of the main control unit is connected to a high level, and it is determined to be invalid based on preset logic, so the first control PWM signal PWM1 with the first preset duty cycle is not output; when the third switching device is on, the first duty cycle indicator signal ctrl1 is at a low level, the first input terminal of the main control unit is connected to a low level, it is determined to be valid based on preset logic, and the first control PWM signal PWM1 with the first preset duty cycle is output.

[0077] In one embodiment, the third switching device includes a first push-button switch.

[0078] Reference Figure 4 When the first button switch is used as the third switching device and is not manually pressed by the user, the first duty cycle indicator signal ctrl1 is at a high level; when the first button switch is used as the third switching device and is manually pressed by the user, the first duty cycle indicator signal ctrl1 is at a low level.

[0079] like Figure 4 As shown, in one embodiment, the first input unit includes a fourth switching device and a second pull-up resistor R2.

[0080] The input terminal of the fourth switching device is electrically connected to the second input terminal of the main control unit to output a second duty cycle indication signal ctrl2 to the second input terminal of the main control unit. The input terminal of the fourth switching device is used to connect to the working voltage VCC through the second pull-up resistor R1, and the output terminal of the fourth switching device is used to ground.

[0081] As in the above embodiment, the second duty cycle indicator signal ctrl2 is effective when it is low.

[0082] Specifically, when the fourth switching device is off, the second duty cycle indicator signal ctrl2 is at a high level, the second input terminal of the main control unit is connected to a high level, and it is determined to be invalid based on preset logic, so the second control PWM signal PWM2 with the second preset duty cycle is not output; when the fourth switching device is on, the second duty cycle indicator signal ctrl2 is at a low level, the second input terminal of the main control unit is connected to a low level, it is determined to be valid based on preset logic, and the second control PWM signal PWM2 with the second preset duty cycle is output.

[0083] In one embodiment, the fourth switching device includes a second push-button switch.

[0084] Reference Figure 4 When the second button switch is used as the fourth switching device and is not manually pressed by the user, the second duty cycle indicator signal ctrl2 is at a high level; when the second button switch is used as the fourth switching device and is manually pressed by the user, the second duty cycle indicator signal ctrl2 is at a low level.

[0085] like Figure 5 As shown, in one embodiment, the trip unit device includes a first trip unit module and a second trip unit module, and the trip unit testing device further includes a fifth switching device.

[0086] The input terminal of the fifth switching device is electrically connected to the DC power supply module to receive the first DC power supply signal VCC1 or the second DC power supply signal VCC2. The first output terminal of the fifth switching device is used to be electrically connected to the first trip unit module, and the second output terminal of the fifth switching device is used to be electrically connected to the second trip unit module.

[0087] The fifth switching device is used to connect the control input terminal to the first trip unit module or the second trip unit module, so as to output the test PWM signal PWM0 to the first trip unit module or the second trip unit module.

[0088] Similar to the second switching device described above, this embodiment incorporates a fifth switching device with a selection function, enabling direct electrical connection to two independent first and second trip unit modules. When testing the first trip unit module, the fifth switching device connects the DC power supply module and the first trip unit module, thereby outputting the test PWM signal PWM0 to the first trip unit module. Similarly, when testing the second trip unit module, the fifth switching device connects the DC power supply module and the second trip unit module, thereby outputting the test PWM signal PWM0 to the second trip unit module.

[0089] In one embodiment, the fifth switching device includes a second toggle switch.

[0090] The second toggle switch has a first state and a second state, which can be switched manually. When the user operates the second toggle switch to the first state, the second toggle switch connects the DC power supply module and the first trip unit module, thereby outputting the test PWM signal PWM0 to the first trip unit module; when the user operates the second toggle switch to the second state, the second toggle switch connects the DC power supply module and the second trip unit module, thereby outputting the test PWM signal PWM0 to the second trip unit module.

[0091] like Figure 6 As shown, in one embodiment, the first switching device includes a MOSFET Q1.

[0092] The drain of MOSFET Q1 is electrically connected to the first trip unit module and the second trip unit module, respectively. The gate of MOSFET Q1 is electrically connected to the first terminal of capacitor C1 and the first terminal of resistor R4, respectively, and is electrically connected to the control module through resistor R3, so as to receive the first control PWM signal PWM1 or the second control PWM signal PWM2. The source of MOSFET Q1, the second terminal of capacitor C1 and the second terminal of resistor R4 are respectively used for grounding.

[0093] Specifically, when the first control PWM signal PWM1 or the second control PWM signal PWM2 is high, the MOSFET Q1 is turned on, and the first trip module or the second trip module is at a high level; when the first control PWM signal PWM1 or the second control PWM signal PWM2 is low, the MOSFET Q1 is turned off, and the first trip module or the second trip module is at a low level; the high and low levels on the first trip module or the second trip module alternate cyclically, thereby generating the test PWM signal PMW0.

[0094] In the above embodiments, the descriptions of each embodiment have different focuses. For parts not described in detail in a certain embodiment, please refer to the detailed descriptions of other embodiments above, which will not be repeated here.

[0095] The trip unit testing device provided by this utility model has been described in detail above. Specific examples have been used to illustrate the principle and implementation of this utility model. The description of the above embodiments is only for the purpose of helping to understand the method and core idea of ​​this utility model. At the same time, for those skilled in the art, there will be changes in the specific implementation and application scope based on the idea of ​​this utility model. Therefore, the content of this specification should not be construed as a limitation of this utility model.

[0096] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

Claims

1. A trip unit testing device, characterized in that, The trip unit testing device includes a DC power supply module, a first switching device, and a control module; The DC power supply module and the first switching device are connected in series with the trip unit device under test. The DC power module is used to output a target DC power signal, the amplitude of which is variable and is one of a plurality of preset amplitudes; The control module is electrically connected to the first switching device and is used to output a target control PWM signal to the first switching device to control the switching state of the first switching device. The duty cycle of the target control PWM signal is variable and is one of a plurality of preset duty cycles. The first switching device is used to control the switching of the target DC power supply signal based on the accessed target control PWM signal, so as to output a test PWM signal to the trip unit.

2. The trip unit testing device according to claim 1, characterized in that, The DC power supply module includes a second switching device, a first DC power supply, and a second DC power supply, and the plurality of preset amplitudes include a first preset amplitude and a second preset amplitude; The first DC power supply is electrically connected to the first input terminal of the second switching device, and is used to output a first DC power supply signal of the first preset amplitude to the first input terminal of the second switching device; The second DC power supply is electrically connected to the second input terminal of the second switching device, and is used to output a second DC power supply signal with the second preset amplitude to the second input terminal of the second switching device; The output terminal of the second switching device is used for electrical connection with the trip unit. The second switching device is used to control the first input terminal or the second input terminal to connect with the trip unit device, so as to output the first DC power signal or the second DC power signal to the trip unit device based on the first DC power signal and the second DC power signal received; Wherein, the first DC power signal or the second DC power signal serves as the target DC power signal.

3. The trip unit testing device according to claim 2, characterized in that, The second switching device includes a first toggle switch.

4. The trip unit testing device according to claim 1, characterized in that, The control module includes a main control unit, a first input unit, and a second input unit, and the plurality of preset duty cycles include a first preset duty cycle and a second preset duty cycle; The first input unit is electrically connected to the first input terminal of the main control unit and is used to output a first duty cycle indication signal to the first input terminal of the main control unit. The second input unit is electrically connected to the second input terminal of the main control unit and is used to output a second duty cycle indication signal to the second input terminal of the main control unit; The output terminal of the main control unit is electrically connected to the first switching device, and is used to output a first control PWM signal with the first preset duty cycle to the first switching device according to the first duty cycle indication signal, or to output a second control PWM signal with the second preset duty cycle to the first switching device according to the second duty cycle indication signal. Wherein, the first control PWM signal or the second control PWM signal serves as the target control PWM signal.

5. The trip unit testing device according to claim 4, characterized in that, The main control unit includes a Bluetooth SoC.

6. The trip unit testing device according to claim 4, characterized in that, The first input unit includes a third switching device and a first pull-up resistor; The input terminal of the third switching device is electrically connected to the first input terminal of the main control unit and is used to access the working voltage through the first pull-up resistor. The output terminal of the third switching device is used to ground.

7. The trip unit testing device according to claim 6, characterized in that, The third switching device includes a first push-button switch.

8. The trip unit testing device according to claim 4, characterized in that, The first input unit includes a fourth switching device and a second pull-up resistor; The input terminal of the fourth switching device is electrically connected to the second input terminal of the main control unit and is used to access the working voltage through the second pull-up resistor. The output terminal of the fourth switching device is used to ground.

9. The trip unit testing device according to claim 8, characterized in that, The fourth switching device includes a second push-button switch.

10. The trip unit testing device according to claim 1, characterized in that, The trip unit includes a first trip unit module and a second trip unit module, and the trip unit testing device further includes a fifth switching device; The input terminal of the fifth switching device is electrically connected to the DC power supply module, the first output terminal of the fifth switching device is electrically connected to the first trip unit module, and the second output terminal of the fifth switching device is electrically connected to the second trip unit module. The fifth switching device is used to control the input terminal to connect with the first trip unit module or the second trip unit module, so as to output the test PWM signal to the first trip unit module or the second trip unit module.

11. The trip unit testing device according to claim 10, characterized in that, The fifth switching device includes a second toggle switch.

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