Quick-response short-circuit protection circuit
By designing a fast-responsive short-circuit protection circuit, using the current detection unit and the switch control unit, the existing short-circuit protection solution is solved, and the low-cost and efficient short-circuit protection effect is achieved. It is suitable for educational and teaching environments and low-power electronic equipment.
Patent Information
- Application Number
- CN202421263390.7
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-06-04
- Publication Date
- 2025-03-25
- Estimated Expiration
- 2034-06-04
AI Technical Summary
The existing short-circuit protection solutions have problems such as slow response and high cost, and are not suitable for educational and teaching environments.
A fast-responsive short-circuit protection circuit is designed, including a current detection unit and a switch control unit. The switching speed is accelerated by using thyristors and Darlington tubes to realize the function of responding to short circuits within tens of microseconds.
The circuit can respond to short circuits within tens of microseconds, with an output current as low as 1uA, effectively protecting sensitive circuits, and inexpensive, suitable for teaching environments and low-power electronic devices.
Smart Images
Figure CN222673902U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to the technical field of protection circuits, in particular to a fast-response short-circuit protection circuit. Background Art
[0002] Short circuit failures in electronic circuits are a common and dangerous problem that can cause equipment damage, fire, or even threaten life. Especially in the field of education, it is not uncommon for students to cause short circuits due to careless operation during circuit experiments.
[0003] At present, the main short-circuit protection solutions on the market include air switches, fuses, resettable fuses or isolated power modules. Air switches and fuses are widely used in high-power electrical appliances, but they are slow to protect the small-power circuits commonly seen in laboratories and cannot effectively prevent short-circuit accidents that occur quickly. Although resettable fuses are suitable for small circuits, their working method of increasing the resistance by heating the resistor results in a long short-circuit disconnection reaction time, and the protection effect is limited for sensitive circuits that require immediate protection. In addition, although some isolated power modules have short-circuit protection functions, they are expensive and usually lack immediate prompt functions for short-circuit events, which are not suitable for the needs of teaching environments. Although high-end power supply equipment provides short-circuit shutdown functions, their high cost limits their popularity.
[0004] In the process of implementing the utility model, the applicant found that there are at least the following problems in the prior art:
[0005] The current short-circuit protection scheme has problems such as slow response and high cost, and is not suitable for educational teaching environments. Utility Model Content
[0006] The purpose of the utility model is to provide a fast-response short-circuit protection circuit to solve the technical problems that the current short-circuit protection solutions in the prior art are slow to respond, expensive, and unsuitable for educational environments. The preferred technical solutions among the many technical solutions provided by the utility model can produce many technical effects as described below.
[0007] In order to achieve the above purpose, the utility model provides the following technical solutions:
[0008] The utility model provides a fast-response short-circuit protection circuit, which is connected between a power supply and a load and is used for protecting the short-circuit circuit. The utility model comprises a current detection unit and a switch control unit; the current detection unit is used for detecting whether a short circuit occurs between the power supply and the load, and when a short circuit occurs, sends a short-circuit signal to the switch control unit; the switch control unit is used for cutting off the power supply of the power supply to the load when receiving the short-circuit signal; the switch control unit comprises a thyristor and a Darlington tube; the thyristor is respectively connected to the Darlington tube and the current detection unit and is used for controlling the disconnection and conduction between the power supply and the load; the Darlington tube is used for accelerating the switching speed.
[0009] Preferably, the current detection unit includes a second resistor R2, a third resistor R3, a fifth resistor R5, a sixth resistor R6 and a fourth transistor Q4; the base of the fourth transistor Q4 is connected to the sixth resistor R6, the emitter is respectively connected to the positive electrode of the power supply and one end of the fifth resistor R5, and the collector is respectively connected to the negative electrode of the power supply and the positive electrode of the load through the second resistor R2 and the third resistor R3; the other end of the fifth resistor is connected to the negative electrode of the load; the sixth resistor R6 is also connected in parallel to both ends of the fifth resistor R5.
[0010] Preferably, the circuit also includes a short circuit reminder unit, which is used to light up a light to remind that a short circuit occurs in the circuit; the short circuit reminder unit includes an active buzzer H, a first light-emitting diode D1 and a first resistor R1; the cathode of the first light-emitting diode D1 is connected to pin 2 of the active buzzer H and a switch control unit, and the anode is connected to the positive pole of the power supply through the first resistor R1.
[0011] Preferably, the short circuit reminder unit also includes a second light emitting diode D2 and a seventh resistor R7; the cathode of the second light emitting diode D2 is connected between the negative electrode of the power supply and the positive electrode of the load, and the anode is connected to the negative electrode of the load through the seventh resistor R7.
[0012] Preferably, the circuit also includes a manual reset unit, which is used to manually turn on the power supply to supply power to the load after the short circuit fault is eliminated; the manual reset unit includes a key switch KEY and a second capacitor C2; pin 1 and pin 2 of the key switch KEY are both connected between the negative electrode of the power supply and the positive electrode of the load, and pin 3 and pin 4 are both connected to the switch control unit; the second capacitor C2 is connected in parallel at both ends of the key switch KEY.
[0013] Preferably, the circuit also includes a short-circuit simulation unit for causing a short circuit in the circuit; the short-circuit simulation unit includes a microswitch SW1 and a first capacitor C1; one end of the microswitch SW1 is connected between the positive pole of the power supply and the negative pole of the load, and the other end is connected between the negative pole of the power supply and the positive pole of the load; the first capacitor C1 is connected in parallel at both ends of the microswitch SW1.
[0014] Preferably, the thyristor includes a first transistor Q1 and a third transistor Q3; the base of the first transistor Q1 is connected to the current detection unit, the emitter is connected between the negative electrode of the power supply and the positive electrode of the load, and the collector is connected to the base of the third transistor Q3; the collector of the third transistor Q3 is connected to the base of the first transistor Q1, and the emitter is connected to the Darlington transistor.
[0015] Preferably, the Darlington transistor includes a second transistor Q2 and a fifth transistor Q5; the base of the second transistor Q2 is connected to the emitter of the third transistor Q3, the collector is respectively connected to the positive electrode of the power supply and the collector of the fifth transistor Q5, and the emitter is connected to the base of the fifth transistor Q5; the emitter of the fifth transistor Q5 is connected to the negative electrode of the load.
[0016] Preferably, the switch control unit further includes a fourth resistor R4 for limiting the current of the thyristor; one end of the fourth resistor R4 is connected to the base of the first transistor Q1, and the other end is connected to the current detection unit.
[0017] Preferably, the circuit also includes a first connector J1, a second connector J2, a third connector J3 and a fourth connector J4, all of which are HDR-M-2.54 models; the circuit is connected to the positive pole of the power supply, the negative pole of the power supply, the positive pole of the load and the negative pole of the load through the first connector J1, the second connector J2, the third connector J3 and the fourth connector J4 respectively.
[0018] Implementing one of the above technical solutions of the utility model has the following advantages or beneficial effects:
[0019] The utility model detects whether a short circuit occurs in the circuit by setting a current detection unit. If a short circuit occurs, the power connection is cut off by a switch control unit, and short-circuit protection can be achieved through simple and low-cost components; the circuit can respond to a short circuit and implement protection measures within tens of microseconds, and the output current is as low as below 1uA during a short circuit, which can effectively protect sensitive circuits such as chips; the circuit has low cost and low operating energy consumption, ensuring that the equipment can maintain its efficient short-circuit protection function with the lowest energy consumption while running for a long time. Its low cost and low energy consumption characteristics are not only suitable for teaching environments such as school laboratories, but also suitable for low-power electronic equipment. BRIEF DESCRIPTION OF THE DRAWINGS
[0020] In order to more clearly illustrate the technical solutions of the embodiments of the present utility model, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present utility model. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work. In the drawings:
[0021] Figure 1 It is a circuit diagram of a fast-response short-circuit protection circuit of an embodiment of the utility model;
[0022] In the figure: 1. Current detection unit; 2. Switch control unit; 21. Thyristor; 22. Darlington tube; 3. Short circuit reminder unit; 4. Manual reset unit; 5. Short circuit simulation unit. DETAILED DESCRIPTION
[0023] In order to make the purpose, technical solutions and advantages of the utility model clearer, the various exemplary embodiments to be described below will refer to the corresponding drawings, which constitute a part of the exemplary embodiments, wherein various exemplary embodiments that may be used to implement the utility model are described. Unless otherwise indicated, the same numbers in different drawings represent the same or similar elements. The implementation methods described in the following exemplary embodiments do not represent all implementation methods consistent with the present disclosure. It should be understood that they are only examples of processes, methods, and devices that are consistent with some aspects of the utility model disclosed as detailed in the attached claims, and other embodiments may also be used, or the embodiments listed herein may be modified in structure and function without departing from the scope and essence of the utility model.
[0024] In the description of the present utility model, it should be understood that the terms "center", "longitudinal", "lateral", etc. indicate the orientation or position relationship based on the drawings, which is only for the convenience of describing the utility model and simplifying the description, rather than indicating or implying that the elements referred to must have a specific orientation, be constructed and operated in a specific orientation. The terms "first", "second", etc. are only used for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. The term "multiple" means two or more. The terms "connected" and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, an integral connection, a mechanical connection, an electrical connection, a communication connection, a direct connection, an indirect connection through an intermediate medium, and can be the internal connection of two elements or the interaction relationship between two elements. The term "and / or" includes any and all combinations of one or more related listed items. For those of ordinary skill in the art, the specific meanings of the above terms in the present utility model can be understood according to the specific circumstances.
[0025] In order to illustrate the technical solution of the present invention, a specific embodiment is provided below, in which only the parts related to the embodiment of the present invention are shown.
[0026] Embodiment 1:
[0027] like Figure 1 As shown, the utility model provides a fast-response short-circuit protection circuit, which is connected between a power supply and a load and is used to protect the short-circuit circuit, and includes a current detection unit 1 and a switch control unit 2; the current detection unit 1 is used to detect whether a short circuit occurs between the power supply and the load, and when a short circuit occurs, sends a short-circuit signal to the switch control unit; the switch control unit 2 is used to cut off the power supply to the load when receiving the short-circuit signal; the switch control unit 2 includes a thyristor 21 and a Darlington tube 22; the thyristor 21 is respectively connected to the Darlington tube 22 and the current detection unit 1, and is used to control the shutdown and conduction between the power supply and the load; the Darlington tube 22 is used to speed up the switching speed.
[0028] The short-circuit protection circuit of this embodiment is suitable for circuit experiment teaching in various schools and educational institutions. By setting a current detection unit 1 to detect whether a short circuit occurs in the circuit, if a short circuit occurs, the thyristor 21 of the switch control unit 2 can respond quickly to cut off the power connection, and short-circuit protection can be achieved through simple and low-cost components; the circuit can respond to a short circuit and implement protection measures within tens of microseconds. When a short circuit occurs, the output current is as low as less than 1uA, which can effectively protect sensitive circuits such as chips; the circuit is low-cost and has low operating energy consumption, ensuring that the equipment can maintain its efficient short-circuit protection function with the lowest energy consumption while running for a long time. Its low cost and low energy consumption are not only suitable for teaching environments such as school laboratories, but also for low-power electronic equipment.
[0029] As an optional implementation, the current detection unit 1 includes a second resistor R2, a third resistor R3, a fifth resistor R5, a sixth resistor R6 and a fourth transistor Q4; the base of the fourth transistor Q4 is connected to the sixth resistor R6, the emitter is respectively connected to the positive electrode of the power supply and one end of the fifth resistor R5, and the collector is respectively connected to the negative electrode of the power supply and the positive electrode of the load through the second resistor R2 and the third resistor R3; the other end of the fifth resistor is connected to the negative electrode of the load; the sixth resistor R6 is also connected in parallel to both ends of the fifth resistor R5. The fifth resistor R5 is a measuring resistor, which can convert the current into a voltage signal (i.e., a short-circuit signal), and can determine whether the circuit is short-circuited by the voltage signal. The sixth resistor R6 is a sliding rheostat, which is connected in parallel with the fifth resistor R5. By adjusting the resistance value of the sixth resistor R6, the current limiting value of the short-circuit protection can be changed (if the current exceeds the current limiting value, it means that the circuit is short-circuited, and the connection between the power supply and the load needs to be cut off as soon as possible). After finding a suitable current limiting value through multiple simulation experiments, the sixth resistor R6 can be replaced with a fixed resistor to reduce the circuit cost. The second resistor R2 and the third resistor R3 can divide the voltage signal, and after the voltage division, the voltage signal is controlled via the fourth resistor R4 to control the thyristor 21 .
[0030] As an optional embodiment, the circuit also includes a short circuit reminder unit 3, which is used to light up to remind the circuit of a short circuit; the short circuit reminder unit 3 includes an active buzzer H, a first light emitting diode D1 and a first resistor R1; the cathode of the first light emitting diode D1 is connected to the pin 2 of the active buzzer H and the switch control unit 2, and the anode is connected to the positive pole of the power supply through the first resistor R1. The short circuit reminder unit 3 also includes a second light emitting diode D2 and a seventh resistor R7; the cathode of the second light emitting diode D2 is connected between the negative pole of the power supply and the positive pole of the load, and the anode is connected to the negative pole of the load through the seventh resistor R7. When the circuit is working normally, the second light emitting diode D2 will light up a green light. Once a short circuit occurs, the second light emitting diode D2 will not light up, and the first light emitting diode D1 will light up a red light accompanied by a chirp from the active buzzer H to remind the staff that the circuit is short-circuited. The first resistor R1 and the second resistor R2 are used to limit the current of the first light emitting diode D1 and the second light emitting diode D2.
[0031] As an optional implementation, the circuit also includes a manual reset unit 4, which is used to manually turn on the power supply to the load after the short circuit fault is eliminated; the manual reset unit 4 includes a key switch KEY and a second capacitor C2; the key switch KEY pins 1 and 2 are connected between the negative pole of the power supply and the positive pole of the load, and the pins 3 and 4 are connected to the switch control unit 2; the second capacitor C2 is connected in parallel to both ends of the key switch KEY. After the short circuit, the protection circuit will disconnect the power supply from the load. After the short circuit fault is eliminated, the key switch KEY can be pressed to restart the power supply to the load. When a switch containing mechanical contacts such as the key switch KEY is disconnected or closed, due to the elastic effect of the mechanical contacts, a key switch will not be immediately and stably connected when closed, and will not be disconnected all at once when disconnected, so there is a series of jitters at the moment of closing and disconnecting. Therefore, the second capacitor C2 is set to eliminate this jitter. The use of a reset mechanism can enhance the interactivity and practicality of teaching, and combines automatic and manual reset options to adapt to different scene requirements, which is particularly suitable for teaching environments.
[0032] As an optional implementation, the circuit also includes a short-circuit simulation unit 5, which is used to short-circuit the circuit; the short-circuit simulation unit 5 includes a micro switch SW1 and a first capacitor C1; one end of the micro switch SW1 is connected between the positive pole of the power supply and the negative pole of the load, and the other end is connected between the negative pole of the power supply and the positive pole of the load; the first capacitor C1 is connected in parallel to both ends of the micro switch SW1. When the micro switch SW1 is pressed, the circuit will short-circuit, and the performance of the short-circuit protection circuit can be tested by this unit to test whether the protection circuit can cut off the power supply in time when a short circuit occurs, so as to achieve the purpose of short-circuit protection. The first capacitor C1 is also used for key debounce.
[0033] As an optional implementation, the thyristor 21 includes a first triode Q1 and a third triode Q3; the base of the first triode Q1 is connected to the current detection unit 1, the emitter is connected between the negative pole of the power supply and the positive pole of the load, and the collector is connected to the base of the third triode Q3; the collector of the third triode Q3 is connected to the base of the first triode Q1, and the emitter is connected to the Darlington transistor 22. The Darlington transistor 22 includes a second triode Q2 and a fifth triode Q5; the base of the second triode Q2 is connected to the emitter of the third triode Q3, the collector is connected to the positive pole of the power supply and the collector of the fifth triode Q5, and the emitter is connected to the base of the fifth triode Q5; the emitter of the fifth triode Q5 is connected to the negative pole of the load. The thyristor 21 is formed by the first triode Q1 and the third triode Q3, which has no contact, fast response speed, low power consumption, high reliability, and can react quickly after a short circuit occurs in the circuit to protect the load from damage. The second transistor Q2 and the fifth transistor Q5 form a Darlington transistor 22, which can not only speed up the turning-off and turning-on speed of the thyristor 21, but also increase the driving capability. The switch control unit 2 also includes a fourth resistor R4, which is used to limit the current of the thyristor 21; one end of the fourth resistor R4 is connected to the base of the first transistor Q1, and the other end is connected to the current detection unit 1.
[0034] As an optional implementation, the circuit also includes a first connector J1, a second connector J2, a third connector J3 and a fourth connector J4, all of which are HDR-M-2.54 models; the circuit is connected to the positive pole of the power supply, the negative pole of the power supply, the positive pole of the load and the negative pole of the load through the first connector J1, the second connector J2, the third connector J3 and the fourth connector J4 respectively.
[0035] The following combination Figure 1The working principle of the short-circuit protection circuit of this embodiment is explained as follows: when the circuit works normally and there is no short circuit phenomenon, the voltage on the sixth resistor R6 of the current detection unit 1 is small and does not exceed the base turn-on voltage of the fourth transistor Q4, and the collector and emitter of the fourth transistor Q4 are cut off. The base of the first transistor Q1 of the switch control unit 2 is at a low level, the collector and emitter of the first transistor Q1 are cut off, the first transistor Q1 and the third transistor Q3 in the thyristor 21 are not turned on, and the second transistor Q2 and the fifth transistor Q5 in the Darlington tube 22 are turned on. At this time, the power supply is normal, and the second light-emitting diode D2 lights up green. When a short circuit occurs in the circuit, the current of the fifth resistor R5 as a measuring resistor increases, generating a high level, exceeding the turn-on voltage of the fourth transistor Q4, and the collector and emitter of the fourth transistor Q4 are turned on. After the second resistor R2 and the third resistor R3 divide the voltage, the high level is applied to the base of the first transistor Q1, and the collector and emitter of the first transistor Q1 are turned on, so that the base of the third transistor Q3 is at a low level, and the collector and emitter of the third transistor Q3 are turned on. At this time, the voltage of the base of the second transistor Q2 is instantly pulled down, the second transistor Q2 is turned off, and the fifth transistor Q5 is also turned off, so that the power supply is cut off. At the same time, the second light-emitting diode D2 is extinguished, the first light-emitting diode D1 lights up red, and the active buzzer H sounds, reminding the staff that a short circuit has occurred.
[0036] The present embodiment is applicable to the circuit experiment teaching of educational institutions at all levels, and can immediately indicate the short-circuit fault to students, and realize short-circuit protection through simple low-cost components such as resistors, capacitors, and triodes. After testing, the circuit can respond to short circuits and implement protection measures within tens of microseconds, and realize the output current as low as 1uA or less when short circuit occurs, effectively protecting sensitive circuits such as chips. For example, the short-circuit protection current threshold is set to 200mA, and even if it is reset without eliminating the short-circuit source, it can still be effectively protected, showing a high degree of reliability and robustness. Due to the design of the measuring resistor, a voltage drop of about 0.3V will appear under normal working conditions, which is equivalent to increasing the internal resistance of the power supply, which has a practical auxiliary effect on the teaching of circuit internal resistance in secondary and higher education, and enhances the measurement accuracy and teaching value of the experiment.
[0037] The embodiment is only a special case and does not indicate that the present invention is implemented in such a way.
[0038] The above description is only the preferred embodiment of the present invention. Those skilled in the art will appreciate that various changes or equivalent substitutions may be made to these features and embodiments without departing from the spirit and scope of the present invention. In addition, under the guidance of the present invention, these features and embodiments may be modified to adapt to specific circumstances and materials without departing from the spirit and scope of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed herein, and all embodiments falling within the scope of the claims of this application belong to the protection scope of the present invention.
Claims
1. A fast-response short-circuit protection circuit, characterized in that: It is connected between a power supply and a load and is used for protecting a short circuit, and comprises a current detection unit and a switch control unit; the current detection unit is used for detecting whether a short circuit occurs between the power supply and the load, and when a short circuit occurs, sends a short circuit signal to the switch control unit; the switch control unit is used for cutting off the power supply of the power supply to the load when receiving the short circuit signal; the switch control unit comprises a thyristor and a Darlington tube; the thyristor is respectively connected to the Darlington tube and the current detection unit and is used for controlling the disconnection and conduction between the power supply and the load; the Darlington tube is used for accelerating the switching speed.
2. A fast-response short-circuit protection circuit according to claim 1, characterized in that: The current detection unit includes a second resistor R2, a third resistor R3, a fifth resistor R5, a sixth resistor R6 and a fourth transistor Q4; the base of the fourth transistor Q4 is connected to the sixth resistor R6, the emitter is respectively connected to the positive electrode of the power supply and one end of the fifth resistor R5, and the collector is respectively connected to the negative electrode of the power supply and the positive electrode of the load through the second resistor R2 and the third resistor R3; the other end of the fifth resistor is connected to the negative electrode of the load; the sixth resistor R6 is also connected in parallel to both ends of the fifth resistor R5.
3. A fast-response short-circuit protection circuit according to claim 1, characterized in that: The circuit also includes a short circuit reminder unit, which is used to light up a light to remind the circuit of a short circuit; the short circuit reminder unit includes an active buzzer H, a first light-emitting diode D1 and a first resistor R1; the cathode of the first light-emitting diode D1 is connected to pin 2 of the active buzzer H and the switch control unit, and the anode is connected to the positive electrode of the power supply through the first resistor R1.
4. A fast-response short-circuit protection circuit according to claim 3, characterized in that: The short circuit reminder unit further includes a second light emitting diode D2 and a seventh resistor R7; the cathode of the second light emitting diode D2 is connected between the negative electrode of the power supply and the positive electrode of the load, and the anode is connected to the negative electrode of the load through the seventh resistor R7.
5. A fast-response short-circuit protection circuit according to claim 1, characterized in that: The circuit also includes a manual reset unit, which is used to manually turn on the power supply to supply power to the load after the short circuit fault is eliminated; the manual reset unit includes a key switch KEY and a second capacitor C2; pins 1 and 2 of the key switch KEY are both connected between the negative electrode of the power supply and the positive electrode of the load, and pins 3 and 4 are both connected to the switch control unit; the second capacitor C2 is connected in parallel at both ends of the key switch KEY.
6. A fast-response short-circuit protection circuit according to claim 1, characterized in that: The circuit also includes a short-circuit simulation unit for causing a short circuit in the circuit; the short-circuit simulation unit includes a micro switch SW1 and a first capacitor C1; one end of the micro switch SW1 is connected between the positive electrode of the power supply and the negative electrode of the load, and the other end is connected between the negative electrode of the power supply and the positive electrode of the load; the first capacitor C1 is connected in parallel to both ends of the micro switch SW1.
7. A fast-response short-circuit protection circuit according to claim 1, characterized in that: The thyristor includes a first transistor Q1 and a third transistor Q3; the base of the first transistor Q1 is connected to the current detection unit, the emitter is connected between the negative electrode of the power supply and the positive electrode of the load, and the collector is connected to the base of the third transistor Q3; the collector of the third transistor Q3 is connected to the base of the first transistor Q1, and the emitter is connected to the Darlington transistor.
8. A fast-response short-circuit protection circuit according to claim 7, characterized in that: The Darlington transistor includes a second transistor Q2 and a fifth transistor Q5; the base of the second transistor Q2 is connected to the emitter of the third transistor Q3, the collector is respectively connected to the positive electrode of the power supply and the collector of the fifth transistor Q5, and the emitter is connected to the base of the fifth transistor Q5; the emitter of the fifth transistor Q5 is connected to the negative electrode of the load.
9. A fast-response short-circuit protection circuit according to claim 8, characterized in that: The switch control unit further includes a fourth resistor R4 for limiting the current of the thyristor; one end of the fourth resistor R4 is connected to the base of the first transistor Q1, and the other end is connected to the current detection unit.
10. A fast-response short-circuit protection circuit according to claim 1, characterized in that: The circuit also includes a first connector J1, a second connector J2, a third connector J3 and a fourth connector J4, all of which are HDR-M-2.54; the circuit is connected to the positive pole of the power supply, the negative pole of the power supply, the positive pole of the load and the negative pole of the load through the first connector J1, the second connector J2, the third connector J3 and the fourth connector J4 respectively.