Reverse connection prevention circuit and controller

Abstract

The invention provides an anti-reverse-connection circuit and a controller. The anti-reverse-connection circuit is connected with a power input port and a main circuit. The anti-reverse-connection circuit comprises a reverse-connection detection module and a reverse-connection correction module. The reverse connection detection module is used for detecting the voltage of the input positive electrode and the input negative electrode of the power supply input port to determine whether the power supply input port has a reverse connection problem, and controlling the connection state of the reverse connection correction module according to whether the reverse connection problem exists; and the reverse connection correction module is used for responding to the control of the reverse connection detection module and exchanging signal output of the positive output end and the negative output end when the power input port has a reverse connection problem. The reverse connection detection module is arranged to detect whether the positive electrode and the negative electrode of the power supply input port are connected reversely, and when it is detected that reverse connection exists in the power supply input port, the reverse connection correction module is controlled to exchange signal output of the positive electrode and the negative electrode, so that it can be guaranteed that the polarity of voltage output to the main circuit is correct, and the influence of reverse connection on the main circuit is avoided.

Description

Technical Field

[0001] This invention relates to the field of circuit safety, and more particularly to a reverse connection protection circuit and controller. Background Technology

[0002] With the rapid development of electronic technology, microcontrollers have been increasingly widely used in the field of frequency converter technology. Under the current technology, most controllers use DC power input. DC power input has polarity. If the positive and negative terminals are reversed, it may burn out the power supply device, or even burn out the controller's main chip and other core components. Summary of the Invention

[0003] The main objective of this invention is to provide a reverse connection protection circuit and controller, which aims to solve the problem of how to avoid reverse connection of the controller in the prior art.

[0004] To achieve the above objectives, the present invention provides a reverse connection protection circuit, which is connected to the power input port and the main circuit respectively; the reverse connection protection circuit includes a reverse connection detection module and a reverse connection correction module. The detection terminal of the reverse connection detection module is connected between the positive and negative input terminals of the power input port. The positive input terminal of the reverse connection correction module is connected to the positive input terminal of the power input port, and the negative input terminal of the reverse connection correction module is connected to the negative input terminal of the power input port. The positive output terminal of the reverse connection correction module is connected to the positive power supply terminal of the main circuit, and the negative output terminal of the reverse connection correction module is connected to the negative power supply terminal of the main circuit. The control terminal of the reverse connection correction module is connected to the output terminal of the reverse connection detection module. Wherein: The reverse connection detection module is used to detect the voltage between the positive and negative input terminals of the power input port to determine whether there is a reverse connection problem at the power input port, and to control the connection status of the reverse connection correction module based on whether there is a reverse connection problem. The reverse connection correction module is used to respond to the control of the reverse connection detection module and, when there is a reverse connection problem at the power input port, swap the signal outputs of the positive and negative output terminals.

[0005] Optionally, the reverse connection detection module includes a detection unit and a switching unit. The detection terminal of the detection unit is connected between the positive and negative input terminals of the power input port. The output terminal of the detection unit is connected to the control terminal of the switching unit, and the output terminal of the switching unit is connected to the control terminal of the reverse connection correction module. Wherein: The detection unit is used to detect the voltage between the positive and negative terminals of the power input port to determine whether there is a reverse connection problem at the power input port, and to send a control signal to the switching unit according to whether there is a reverse connection problem. The switching unit is used to control the reverse connection correction module to switch the signal outputs of the positive and negative output terminals when there is a reverse connection problem at the power input port, according to the control signal.

[0006] Optionally, the detection unit includes a first resistor, a second resistor, and a first diode; wherein: The first end of the first resistor is connected to the negative input terminal of the power input port, the second end of the first resistor is connected to the control terminal of the switching unit as the output terminal of the detection unit, the second end of the first resistor is also connected to the first end of the second resistor, the second end of the second resistor is connected to the positive terminal of the first diode, and the negative terminal of the first diode is connected to the positive input terminal of the power input port.

[0007] Optionally, the first diode is a light-emitting diode.

[0008] Optionally, the switching unit includes a first switching transistor and a second switching transistor, wherein: The gate of the first switching transistor is connected to the output terminal of the detection unit as the control terminal of the switching unit. The drain of the first switching transistor is connected to the positive input terminal of the power input port. The source of the first switching transistor is connected to the source of the second switching transistor. The drain of the second switching transistor is connected to the control terminal of the reverse connection correction module as the output terminal of the switching unit. The gate of the second switching transistor is connected to the first switching transistor.

[0009] Optionally, the detection unit further includes a detection control unit, which includes a first switch and a second switch; the first switch is connected between the detection terminal of the detection unit and the negative input terminal of the power input port, the first terminal of the second switch is connected to the positive input terminal of the power input port, and the second terminal of the second switch is connected between the output terminal of the switch unit and the control terminal of the reverse calibration module; wherein: The first switch is used to close when the reverse connection protection circuit is effective and to open when the reverse connection protection circuit is ineffective. The second switch is used to open when the reverse connection protection circuit is effective and to close when the reverse connection protection circuit is ineffective.

[0010] Optionally, the reverse connection correction module includes a first switching unit and a second switching unit; The first switching unit includes a first detection subunit and a first switching subunit, and the second switching unit includes a second detection subunit and a second switching subunit; The first detection subunit is positively connected between the positive and negative input terminals of the power input port. The output terminal of the first detection subunit is connected to the control terminal of the first switching subunit. The input terminals of the first switching subunit are respectively connected to the positive and negative input terminals of the power input port. The output terminals of the first switching subunit are respectively connected to the first input terminal of the second switching subunit. The second input terminals of the second switching subunit are respectively connected to the negative and positive input terminals of the power input port. The output terminals of the second switching subunit are respectively connected to the positive and negative power supply terminals of the main circuit. The control terminal of the second switching subunit is connected to the output terminal of the second detection subunit. The first terminal of the second detection subunit is connected to the negative input terminal of the power input port. The second terminal of the second detection subunit serves as the control terminal of the reverse connection correction module and is connected to the output terminal of the reverse connection detection module. Wherein: When the first switching unit detects that the positive input terminal and the negative input terminal of the power input port are not forward connected, it controls the input terminal and the output terminal of the first switching subunit to disconnect. When the second switching unit detects a current loop, it controls the second input terminal and the output terminal of the second switching subunit to close.

[0011] Optionally, the first switching unit includes a first relay and a second diode; wherein: The first end of the first relay coil is connected to the negative input terminal of the power input port, the second end of the first relay coil is connected to the negative terminal of the second diode, and the positive terminal of the second diode is connected to the positive input terminal of the power input port. The normally open contact of the first contact group of the first relay is connected to the positive input terminal of the power input port, and the moving contact of the first contact group of the first relay is connected to the first contact of the first input terminal of the second switching unit. The normally open contact of the second contact group of the first relay is connected to the negative input terminal of the power input port, and the moving contact of the second contact group of the first relay is connected to the second contact of the first input terminal of the second switching unit.

[0012] Optionally, the second switching unit is a second relay; wherein: The first end of the coil of the second relay is connected to the negative input terminal of the power input port, and the second end of the coil of the second relay is connected to the output terminal of the reverse connection correction module as the control terminal of the reverse connection correction module. The moving contact of the first contact group of the second relay coil is connected to the positive power supply of the main circuit, the normally closed contact of the first contact group of the second relay is connected to the first contact of the output terminal of the first switching unit, and the normally open contact of the first contact group of the second relay is connected to the negative input terminal of the power input port. The moving contact of the second contact group of the second relay coil is connected to the negative terminal of the main circuit, the normally closed contact of the second contact group of the second relay is connected to the second contact of the output terminal of the first switching unit, and the normally open contact of the second contact group of the second relay is connected to the positive terminal of the power input port.

[0013] In addition, to achieve the above objectives, the present invention also provides a controller, the controller including a reverse connection protection circuit, a power input port and a main circuit, wherein the reverse connection protection circuit is configured as described above.

[0014] This invention proposes a reverse connection protection circuit and controller. The reverse connection protection circuit is connected to both a power input port and a main circuit. The circuit includes a reverse connection detection module and a reverse connection correction module. The detection terminal of the reverse connection detection module is connected between the positive and negative input terminals of the power input port. The positive input terminal of the reverse connection correction module is connected to the positive input terminal of the power input port, and the negative input terminal is connected to the negative input terminal of the power input port. The positive output terminal of the reverse connection correction module is connected to the positive power supply terminal of the main circuit. The negative output terminal of the module is connected to the negative power supply terminal of the main circuit, and the control terminal of the reverse connection correction module is connected to the output terminal of the reverse connection detection module. The reverse connection detection module detects the voltage between the positive and negative input terminals of the power input port to determine if a reverse connection problem exists, and controls the connection state of the reverse connection correction module based on the presence of the problem. The reverse connection correction module responds to the control of the reverse connection detection module by swapping the signal outputs of the positive and negative output terminals when a reverse connection problem is detected at the power input port. By setting up a reverse connection detection module to detect whether the positive and negative terminals of the power input port are reversed, and by controlling the reverse connection correction module to swap the positive and negative signal outputs when a reverse connection is detected, the polarity of the voltage output to the main circuit is ensured to be correct, preventing the reverse connection from affecting the main circuit. Attached Figure Description

[0015] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the structures shown in these drawings without creative effort.

[0016] Figure 1 This is a functional block diagram of an embodiment of the reverse connection protection circuit of the present invention; Figure 2 This is a circuit diagram of the reverse connection protection circuit of the present invention; Figure 3 This is a flowchart illustrating the overall application of the reverse connection protection circuit of the present invention.

[0017] The realization of the objective, functional features and advantages of the present invention will be further explained in conjunction with the embodiments and with reference to the accompanying drawings.

[0018] Explanation of icon numbers: Detailed Implementation

[0019] It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

[0020] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0021] It should be noted that all directional indications (such as up, down, left, right, front, back, etc.) in the embodiments of the present invention are only used to explain the relative positional relationship and movement of each component in a certain specific posture (as shown in the figure). If the specific posture changes, the directional indication will also change accordingly.

[0022] Furthermore, the use of terms such as "first" and "second" in this invention is for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined with "first" or "second" may explicitly or implicitly include at least one of that feature. Additionally, the technical solutions of the various embodiments can be combined with each other, but only on the basis of being achievable by those skilled in the art. When the combination of technical solutions is contradictory or impossible to implement, such a combination of technical solutions should be considered non-existent and not within the scope of protection claimed by this invention.

[0023] This invention provides a reverse connection protection circuit 100, which is applied in a controller. Please refer to [link / reference]. Figure 1 , Figure 1 This is a functional block diagram of an embodiment of the reverse connection protection circuit 100 of the present invention. In this embodiment, the reverse connection protection circuit 100 is connected to the power input port 200 and the main circuit 300 respectively; the reverse connection protection circuit 100 includes a reverse connection detection module 110 and a reverse connection correction module 120; The detection terminal of the reverse connection detection module 110 is connected between the positive input terminal VIN+ and the negative input terminal VIN- of the power input port 200. The positive input terminal of the reverse connection correction module 120 is connected to the positive input terminal VIN+ of the power input port 200, and the negative input terminal of the reverse connection correction module 120 is connected to the negative input terminal VIN- of the power input port 200. The positive output terminal of the reverse connection correction module 120 is connected to the positive power supply terminal VO+ of the main circuit 300, and the negative output terminal of the reverse connection correction module 120 is connected to the negative power supply terminal VO- of the main circuit 300. The control terminal of the reverse connection correction module 120 is connected to the output terminal of the reverse connection detection module 110. The reverse connection detection module 110 is used to detect the voltage between the positive input terminal VIN+ and the negative input terminal VIN- of the power input port 200 to determine whether there is a reverse connection problem in the power input port 200, and to control the connection status of the reverse connection correction module 120 according to whether there is a reverse connection problem. The reverse connection correction module 120 is used to respond to the control of the reverse connection detection module 110 and, when there is a reverse connection problem at the power input port 200, to exchange the signal outputs of the positive output terminal and the negative output terminal.

[0024] A controller is a device in an equipment used to perform control functions. The specific type of controller can be set based on the actual application scenario. For example, the controller can be the core control unit in a frequency converter system, which typically consists of a main circuit 300 and a DC power supply, and is responsible for receiving external commands and regulating the operating status of the frequency converter. The following explanation will use a frequency converter system as an example; other scenarios can be implemented by analogy and will not be elaborated further.

[0025] The main circuit 300 is the circuit part of the frequency converter controller that directly undertakes the core functions of operation.

[0026] The power input port 200 is the connection interface for connecting to an external DC power supply.

[0027] The power input port 200 includes a positive input terminal VIN+ and a negative input terminal VIN-. The positive input terminal VIN+ is used to connect to the positive terminal of an external DC power supply, and the negative input terminal VIN- is used to connect to the negative terminal of an external DC power supply. Simultaneously, the positive input terminal VIN+ of the power input port 200 is led out and connected to the positive power supply terminal VO+ of the main circuit 300, and the negative input terminal VIN- of the power input port is led out and connected to the negative power supply terminal VO- of the main circuit 300, thus providing power to the main circuit 300. When the positive and negative terminals of the power input port 200 are reversed, the positive power supply terminal VO+ of the main circuit 300 is connected to the negative terminal of the DC power supply, and the negative power supply terminal VO- of the main circuit 300 is connected to the positive terminal of the DC power supply, causing the main circuit 300 to malfunction or even burn out.

[0028] In this embodiment, a reverse connection protection circuit 100 is provided between the power input port 200 and the main circuit 300.

[0029] The reverse connection detection module 110 is a module for detecting the positive and reverse connections of the power input port 200; the positive connection means that the positive input terminal VIN+ of the power input port 200 is connected to the positive terminal of the external DC power supply, and the negative input terminal VIN- is connected to the negative terminal of the external DC power supply; the reverse connection means that the positive input terminal VIN+ of the power input port 200 is connected to the negative terminal of the external DC power supply, and the negative input terminal VIN- is connected to the positive terminal of the external DC power supply.

[0030] The reverse connection correction module 120 is used to transmit the voltage from the power input port 200 to the main circuit 300, and also to correct the voltage polarity in reverse connection cases.

[0031] When the power input port 200 is positively connected to the external DC power supply, the reverse connection detection module 110 detects that the power input port 200 is positively connected. Therefore, it controls the reverse connection correction module 120 to maintain the original connection state, that is, to connect the positive input terminal VIN+ of the power input port 200 to the positive power supply terminal VO+ of the main circuit 300, and to connect the negative input terminal VIN- of the power input port 200 to the negative power supply terminal VO- of the main circuit 300.

[0032] When the power input port 200 is reverse-connected to an external DC power supply, the reverse connection detection module 110 detects that the power input port 200 is reverse-connected. Therefore, it controls the reverse connection correction module 120 to switch the connection state, that is, to connect the positive input terminal VIN+ of the power input port 200 to the negative power supply terminal VO- of the main circuit 300, and to connect the negative input terminal VIN- of the power input port 200 to the positive power supply terminal VO+ of the main circuit 300. This ensures that the positive and negative terminals of the power supply terminal of the main circuit 300 are still correct, and that the main circuit 300 can still achieve normal power supply when the power input port 200 is reverse-connected.

[0033] In this embodiment, a reverse connection detection module 110 is set up to detect whether the positive and negative terminals of the power input port 200 are reversed. When a reverse connection is detected in the power input port 200, the reverse connection correction module 120 is controlled to exchange the positive and negative signal outputs, so as to ensure that the polarity of the voltage output to the main circuit 300 is correct and to avoid the reverse connection from affecting the main circuit 300.

[0034] Further, the reverse connection detection module 110 includes a detection unit and a switching unit. The detection terminal of the detection unit is connected between the positive input terminal VIN+ and the negative input terminal VIN- of the power input port 200. The output terminal of the detection unit is connected to the control terminal of the switching unit, and the output terminal of the switching unit is connected to the control terminal of the reverse connection correction module 120. Wherein: The detection unit is used to detect the voltage between the positive input terminal VIN+ and the negative input terminal VIN- of the power input port 200 to determine whether there is a reverse connection problem in the power input port 200, and to send a control signal to the switching unit according to whether there is a reverse connection problem. The switching unit is used to control the reverse connection correction module 120 to switch the signal outputs of the positive and negative output terminals when there is a reverse connection problem at the power input port 200, according to the control signal.

[0035] The detection unit is used to detect the positive and negative connections of the power input port 200; The switching unit is used to control the connection status of the reverse connection correction module 120 based on the detection status of the detection unit.

[0036] When the power input port 200 is positively connected to an external DC power supply, the detection unit detects that the power input port 200 is positively connected and outputs a control signal indicating positive connection to the switching unit. Based on this control signal, the switching unit controls the reverse connection correction module 120 to maintain the original connection state, that is, to connect the positive input terminal VIN+ of the power input port 200 to the positive power supply terminal VO+ of the main circuit 300, and to connect the negative input terminal VIN- of the power input port 200 to the negative power supply terminal VO- of the main circuit 300.

[0037] When the power input port 200 is reverse-connected to an external DC power supply, the detection unit detects that the power input port 200 is reverse-connected and outputs a control signal indicating the reverse connection to the switching unit. Based on the control signal, the switching unit controls the reverse connection correction module 120 to exchange the positive and negative signal outputs, so as to ensure that the polarity of the voltage output to the main circuit 300 is correct and to avoid the reverse connection from affecting the main circuit 300.

[0038] This embodiment enables the detection of reverse connection of the power input port 200 and the control of the reverse connection correction module 120 by setting up a detection unit and a switching unit.

[0039] Furthermore, the detection unit includes a first resistor R1, a second resistor R2, and a first diode D1; wherein: The first end of the first resistor R1 is connected to the negative input terminal VIN- of the power input port 200. The second end of the first resistor R1 is connected to the control terminal of the switching unit as the output terminal of the detection unit. The second end of the first resistor R1 is also connected to the first end of the second resistor R2. The second end of the second resistor R2 is connected to the positive terminal of the first diode D1. The negative terminal of the first diode D1 is connected to the positive input terminal VIN+ of the power input port 200.

[0040] When the power input port 200 is positively connected to an external DC power supply, the positive terminal of the first diode D1 is connected to the negative input terminal VIN- of the power input port 200, i.e., the negative terminal of the DC power supply, through the second resistor R2 and the first resistor R1. The negative terminal of the first diode D1 is connected to the positive input terminal VIN+ of the power input port 200, i.e., the positive terminal of the DC power supply. At this time, the voltage at the negative terminal of the first diode D1 is greater than the voltage at the positive terminal, the first diode D1 is cut off, and there is no signal output at the connection point of the first resistor R1 and the second resistor R2, i.e., no voltage signal is output to the control terminal of the switching unit.

[0041] When the power input port 200 is reverse-connected to the external DC power supply, the positive terminal of the first diode D1 is connected to the negative input terminal VIN- of the power input port 200, i.e., the positive terminal of the DC power supply, through the second resistor R2 and the first resistor R1. The negative terminal of the first diode D1 is connected to the positive input terminal VIN+ of the power input port 200, i.e., the negative terminal of the DC power supply. At this time, the voltage at the positive terminal of the first diode D1 is greater than the voltage at the negative terminal, and the first diode D1 is turned on. The connection point of the first resistor R1 and the second resistor R2 outputs the voltage after the DC power supply is divided. That is, the voltage after the DC power supply is divided by the first resistor R1 and the second resistor R2 is output to the control terminal of the switching unit.

[0042] Furthermore, a Zener diode V1 can be provided; wherein, the positive terminal of the Zener diode V1 is connected to the second end of the second resistor R2, and the negative terminal of the Zener diode V1 is connected to the first end of the second resistor R2; the Zener diode V1 limits the gate-source voltage of the first switch Q1 and the second switch Q2 to not exceed the set voltage range, thereby protecting the gate-source voltage of the first switch Q1 and the second switch Q2 from exceeding the maximum value of the device gate-source voltage.

[0043] That is, through the structure of the detection unit in this application, different signals can be output to the control terminal of the switching unit when the power input port 200 is connected to the external DC power supply in a positive or negative direction, so that the switching unit presents different states. Therefore, it is possible to distinguish between the power input port 200 and the external DC power supply in a positive or negative direction, and thus enable the switching unit to control the reverse connection correction module 120 to achieve different connection states when the power input port 200 is connected to the external DC power supply in a positive or negative direction.

[0044] Furthermore, the first diode D1 is a light-emitting diode.

[0045] When the power input port 200 is positively connected to an external DC power supply, the positive terminal of the first diode D1 is connected to the negative input terminal VIN- of the power input port 200, i.e., the negative terminal of the DC power supply, through the second resistor R2 and the first resistor R1. The negative terminal of the first diode D1 is connected to the positive input terminal VIN+ of the power input port 200, i.e., the positive terminal of the DC power supply. At this time, the voltage at the negative terminal of the first diode D1 is greater than the voltage at the positive terminal, the first diode D1 is cut off, and the first diode D1 does not emit light.

[0046] When the power input port 200 is reverse-connected to the external DC power supply, the positive terminal of the first diode D1 is connected to the negative input terminal VIN- of the power input port 200, i.e., the positive terminal of the DC power supply, through the second resistor R2 and the first resistor R1. The negative terminal of the first diode D1 is connected to the positive input terminal VIN+ of the power input port 200, i.e., the negative terminal of the DC power supply. At this time, the voltage at the positive terminal of the first diode D1 is greater than the voltage at the negative terminal, the first diode D1 is turned on, and the first diode D1 emits light.

[0047] In this embodiment, by setting the first diode D1 as a light-emitting diode, it can present different states of not emitting light and emitting light when the power input port 200 is connected to the external DC power supply in a positive or negative direction, thereby indicating whether the power input port 200 is connected to the external DC power supply in a positive or negative direction, so that the user can understand the positive or negative connection status of the power input port 200 with the external DC power supply based on the light-emitting diode.

[0048] Furthermore, the switching unit includes a first switching transistor Q1 and a second switching transistor Q2, wherein: The gate of the first switching transistor Q1 is connected to the output terminal of the detection unit as the control terminal of the switching unit. The drain of the first switching transistor Q1 is connected to the positive input terminal VIN+ of the power input port 200. The source of the first switching transistor Q1 is connected to the source of the second switching transistor Q2. The drain of the second switching transistor Q2 is connected to the control terminal of the reverse connection correction module 120 as the output terminal of the switching unit. The gate of the second switching transistor Q2 is connected to the first switching transistor Q1.

[0049] The specific types of the first switch Q1 and the second switch Q2 can be set according to actual needs. In this embodiment, the first switch Q1 and the second switch Q2 are NMOS transistors for illustration.

[0050] When the power input port 200 is positively connected to the external DC power supply, there is no voltage signal output at the output terminal of the detection unit. At this time, the gate of the first switch Q1 is at a low level, and the first switch Q1 is turned off. The gate of the second switch Q2 is at a low level, and the second switch Q2 is turned off. The control terminal of the reverse connection correction module 120 cannot be connected to the positive input terminal VIN+ of the power interface through the switching unit.

[0051] When the power input port 200 is reverse-connected to the external DC power supply, the output terminal of the detection unit outputs a voltage signal. At this time, the gate of the first switch Q1 is at a high level, the gate-source voltage is greater than the conduction threshold of the first switch Q1, and the first switch Q1 is turned on. The gate of the second switch Q2 is at a high level, the gate-source voltage is greater than the conduction threshold of the second switch Q2, and the second switch Q2 is turned on. The control terminal of the reverse connection correction module 120 is connected to the positive input terminal VIN+ of the power interface through the switching unit.

[0052] In this embodiment, by setting a switching unit composed of the first switching transistor Q1 and the second switching transistor Q2, the connection relationship between the control terminal of the reverse connection correction module 120 and the negative input terminal VIN- of the power input port 200 is different when the power input port 200 is connected to the external DC power supply in positive or negative directions. This enables control of the reverse connection correction module 120 in different states when the power input port 200 is connected to the external DC power supply in positive or negative directions.

[0053] Furthermore, a third resistor R3 can be set. The first end of the third resistor R3 is connected to the negative input terminal of the power input port 200, and the second end of the third resistor R3 is connected between the source of the first switching transistor Q1 and the source of the second switching transistor Q2.

[0054] The third resistor, R3, is a current-limiting resistor.

[0055] Furthermore, the detection unit also includes a detection control unit, which includes a first switch S1 and a second switch S2; the first switch S1 is connected between the detection terminal of the detection unit and the negative input terminal VIN- of the power input port 200; the first terminal of the second switch S2 is connected to the positive input terminal VIN+ of the power input port 200; and the second terminal of the second switch S2 is connected between the output terminal of the switch unit and the control terminal of the reverse connection correction module 120; wherein: The first switch S1 is used to close when the reverse connection protection circuit 100 is effective, and to open when the reverse connection protection circuit 100 is ineffective; The second switch S2 is used to open when the reverse connection protection circuit 100 is effective and to close when the reverse connection protection circuit 100 is ineffective.

[0056] It is understood that the reverse connection protection circuit 100 in this application contains various components. When the reverse connection protection circuit 100 is connected to the controller, the components in the reverse connection protection circuit 100 will also cause an increase in energy consumption. However, when the user determines that the power input port 200 is connected in the correct direction, the reverse connection protection circuit 100 can be disconnected from the controller, thereby avoiding an increase in energy consumption. Therefore, in this embodiment, a detection control unit is set to control whether the reverse connection protection circuit 100 is connected to the controller.

[0057] "Reverse connection protection circuit 100 is effective" means that the reverse connection protection circuit 100 is connected to the controller and achieves the reverse connection protection effect; "reverse connection protection circuit 100 is ineffective" means that the reverse connection protection circuit 100 is not connected to the controller and does not perform the reverse connection protection function.

[0058] When the reverse connection protection circuit 100 is not required to be connected to the controller, the first switch S1 is opened and the second switch S2 is closed. At this time, the connection between the detection terminal of the detection unit and the negative input terminal VIN- of the power input port 200 is disconnected. At the same time, the switching unit is bypassed by the second switch S2 on the positive branch of the power input port 200. At this time, both the detection unit and the switching unit are disconnected from the power input port 200, thus rendering the reverse connection protection circuit 100 ineffective.

[0059] When the reverse connection protection circuit 100 needs to be connected to the controller, the first switch S1 is closed and the second switch S2 is opened. At this time, the detection terminal of the detection unit is connected to the negative input terminal VIN- of the power input port 200. At the same time, the switching unit is connected to the positive input terminal VIN+ of the power input port 200 and the control terminal of the reverse connection correction module 120, thereby invalidating the reverse connection protection circuit 100.

[0060] This embodiment allows users to select the connection of the reverse connection protection circuit 100 based on actual needs by setting a first switch S1 and a second switch S2, thereby enabling and disabling the reverse connection protection function and avoiding increased energy consumption when the reverse connection protection function is not needed.

[0061] Furthermore, the reverse connection correction module 120 includes a first switching unit and a second switching unit; The first switching unit includes a first detection subunit and a first switching subunit, and the second switching unit includes a second detection subunit and a second switching subunit; The first detection subunit is positively connected between the positive input terminal VIN+ and the negative input terminal VIN- of the power input port 200. The output terminal of the first detection subunit is connected to the control terminal of the first switching subunit. The input terminals of the first switching subunit are respectively connected to the positive input terminal VIN+ and the negative input terminal VIN- of the power input port 200. The output terminals of the first switching subunit are respectively connected to the first input terminal of the second switching subunit. The second input terminals of the second switching subunit are respectively connected to the negative input terminal VIN- and the positive input terminal VIN+ of the power input port 200. The output terminals of the second switching subunit are respectively connected to the positive power supply terminal VO+ and the negative power supply terminal VO- of the main circuit 300. The control terminal of the second switching subunit is connected to the output terminal of the second detection subunit. The first terminal of the second detection subunit is connected to the negative input terminal VIN- of the power input port 200. The second terminal of the second detection subunit serves as the control terminal of the reverse connection correction module 120 and is connected to the output terminal of the reverse connection detection module 110. When the first switching unit detects that the positive input terminal VIN+ and the negative input terminal VIN- of the power input port 200 are not forward connected, it controls the input terminal and the output terminal of the first switching subunit to disconnect. When the second switching unit detects a current loop, it controls the second input terminal and the output terminal of the second switching subunit to close.

[0062] The first switching unit is used to switch whether to output the current positive and negative connection status of the power input port 200 to the second switching unit; The second switching unit is used to output the current positive and negative terminals of the power input port 200 or the opposite positive and negative terminals of the power input port 200 to the main circuit 300.

[0063] When the power input port 200 is positively connected to an external DC power supply, the first detection subunit of the first switching unit is forward-biased and detects the positive connection state of the power input port 200. At this time, the input terminal and output terminal of the first switching subunit are connected, and the positive input terminal VIN+ and the negative input terminal VIN- of the power input port 200 are connected to the first input terminal of the second switching subunit through the first switching subunit. The second detection subunit of the second switching subunit receives the control signal from the reverse connection detection module 110 to connect the positive input terminal VIN+ of the power input port 200 to the positive power supply terminal VO+ of the main circuit 300, and connect the negative input terminal VIN- of the power input port 200 to the negative power supply terminal VO- of the main circuit 300.

[0064] When the power input port 200 is reverse-connected to an external DC power supply, the first detection subunit of the first switching unit does not conduct in reverse and detects the reverse connection state of the power input port 200. At this time, it controls the input and output terminals of the first switching subunit to disconnect. The positive input terminal VIN+ and the negative input terminal VIN- of the power input port 200 cannot be connected to the first input terminal of the second switching subunit through the first switching subunit. The second detection subunit of the second switching subunit receives the control signal from the reverse connection detection module 110 to connect the positive input terminal VIN+ of the power input port 200 to the negative power supply terminal VO- of the main circuit 300, and connect the negative input terminal VIN- of the power input port 200 to the positive power supply terminal VO+ of the main circuit 300.

[0065] In this embodiment, by setting a first switching unit and a second switching unit, it is possible to determine whether the current positive input VIN+ and negative input VIN- of the power input port 200 are connected to the main circuit 300 in the same or opposite way based on the positive or negative connection state of the power input port 200 and the external DC power supply, so that the main circuit 300 can have the correct power supply connection in both cases.

[0066] Furthermore, the first switching unit includes a first relay K1 and a second diode D2; wherein: The first end of the coil of the first relay K1 is connected to the negative input terminal VIN- of the power input port 200, the second end of the coil of the first relay K1 is connected to the negative terminal of the second diode D2, and the positive terminal of the second diode D2 is connected to the positive input terminal VIN+ of the power input port 200. The normally open contact of the first contact group of the first relay K1 is connected to the positive input VIN+ of the power input port 200, and the moving contact VIN1+ of the first contact group of the first relay K1 is connected to the first contact of the first input terminal of the second switching unit. The normally open contact of the second contact group of the first relay K1 is connected to the negative input terminal VIN- of the power input port 200, and the moving contact VIN1- of the second contact group of the first relay K1 is connected to the second contact of the first input terminal of the second switching unit.

[0067] When the power input port 200 is positively connected to an external DC power supply, the positive terminal of the second diode D2 is connected to the positive terminal of the DC power supply, and the negative terminal of the second diode D2 is connected to the negative terminal of the DC power supply through the coil of the first relay K1. The second diode D2 is forward-biased, the coil of the first relay K1 is energized, the normally open contact of the first relay K1 is closed, and the normally closed contact is open. The moving contact VIN1+ of the first contact group of the first relay K1 is connected to the positive input VIN+ of the power input port 200, and the moving contact VIN1- of the second contact group of the first relay K1 is connected to the negative input VIN- of the power input port 200. At this time, the first relay K1 connects the positive input VIN+ and the negative input VIN- of the power input port 200 to the second switching unit.

[0068] When the power input port 200 is reverse-connected to the external DC power supply, the positive terminal of the second diode D2 is connected to the negative terminal of the DC power supply, and the negative terminal of the second diode D2 is connected to the positive terminal of the DC power supply through the coil of the first relay K1. The second diode D2 is cut off, the coil of the first relay K1 is not energized, the normally open contact of the first relay K1 is open, and the normally closed contact is closed. The moving contact VIN1+ of the first contact group of the first relay K1 is connected to the empty contact, and the moving contact VIN1- of the second contact group of the first relay K1 is connected to the empty contact. At this time, the first relay K1 does not connect the positive input VIN+ and the negative input VIN- of the power input port 200 to the second switching unit.

[0069] In this embodiment, by setting the first relay K1 and the second diode D2, the positive and negative input terminals VIN+ and VIN- of the power input port 200 are controlled to be connected to the second switching unit in the positive and negative connection states of the power input port 200 and the external DC power supply, thus realizing the distinction between different states of the power input port 200.

[0070] Furthermore, the second switching unit is a second relay K2; wherein: The first end of the coil of the second relay K2 is connected to the negative input terminal VIN- of the power input port 200, and the second end VOUT2 of the coil of the second relay K2 is connected to the output terminal of the reverse connection detection module 110 as the control terminal of the reverse connection correction module 120. The moving contact of the first contact group of the second relay K2 coil is connected to the positive power supply VO+ of the main circuit 300, the normally closed contact of the first contact group of the second relay K2 is connected to the first contact of the output terminal of the first switching unit, and the normally open contact of the first contact group of the second relay K2 is connected to the negative input VIN- of the power input port 200. The moving contact of the second contact group of the second relay K2 coil is connected to the negative terminal of the main circuit 300, the normally closed contact of the second contact group of the second relay K2 is connected to the second contact of the output terminal of the first switching unit, and the normally open contact of the second contact group of the second relay K2 is connected to the positive input terminal VIN+ of the power input port 200.

[0071] When the power input port 200 is positively connected to an external DC power supply, the first terminal VOUT1 of the second relay K2 coil is connected to the negative terminal of the external DC power supply, and the second terminal VOUT2 of the second relay K2 coil cannot be connected to the positive terminal of the power input port 200 through the detection module. Therefore, the second relay K2 coil is not energized, the normally open contact of the second relay K2 is open, and the normally closed contact is closed. The moving contact of the first contact group of the second relay K2 is closed with the normally closed contact. That is, the moving contact of the second relay K2 connects the positive power supply VO+ of the main circuit 300 to the first contact of the output terminal of the first switching unit, that is, the positive input VIN+ of the power input port 200, and connects the negative power supply VO- of the main circuit 300 to the second contact of the output terminal of the first switching unit, that is, the negative input VIN- of the power input port 200. This realizes that the power input port 200 is directly connected to the main circuit 300 for power supply in the same direction.

[0072] When the power input port 200 is reverse-connected to the external DC power supply, the first terminal VOUT1 of the second relay K2 coil is connected to the positive terminal of the external DC power supply, and the second terminal VOUT2 of the second relay K2 coil can be connected to the positive terminal of the power input port 200 through the detection module, that is, connected to the negative terminal of the external DC power supply. Therefore, the second relay K2 coil is energized, the normally open contact of the second relay K2 closes, and the normally closed contact opens; the moving contact of the first contact group of the second relay K2 closes with the normally open contact, that is, the moving contact of the second relay K2 connects the positive terminal VO+ of the main circuit 300 to the negative terminal of the power input port 200, that is, the positive terminal of the external DC power supply, and connects the negative terminal VO- of the main circuit 300 to the positive terminal of the power input port 200, that is, the negative terminal of the external DC power supply; thus realizing that the power input port 200 is connected to the main circuit 300 for power supply in the opposite direction.

[0073] In this embodiment, by setting the second relay K2, the positive and negative connection between the power supply electrode of the main circuit 300 and the power input port 200 is controlled by the positive and negative connection states of the power input port 200 and the external DC power supply, so that the main circuit 300 can always be correctly connected to the DC power supply.

[0074] The overall implementation of this application is explained below: A reverse connection protection circuit 100 for DC power supplies of frequency converter controllers is mainly used for power-on testing when there is no matching power supply. Connecting the reverse connection protection circuit 100 provides reverse connection protection for the controller, preventing short circuits and other issues, thus protecting the safety of personnel and equipment at the testing site. After the test is completed, the reverse connection protection circuit 100 can be deactivated to avoid unnecessary heat generation, power consumption, and voltage drop. This circuit has a simple structure, low cost, good portability, and can be used with various types of controllers.

[0075] The existing controller lacks a reverse connection protection circuit 100; the power supply is directly connected from the 24V power input port and via internal wiring to the main circuit 300 to power the controller. (See also...) Figure 1 This application adds a reverse connection protection circuit 100, which is connected between the 24V power input port and the main circuit 300. Not only can it supply power to the main circuit 300 normally when the power supply is connected in the correct direction, but it can also automatically correct the positive and negative polarity when the positive and negative terminals are reversed. This avoids short circuit hazards and restores the power supply to the controller without requiring manual adjustment of the wiring and without causing damage to the device.

[0076] See Figure 3 The reverse connection protection circuit 100's operating procedure is as follows: Before powering on, first determine whether the reverse connection protection circuit 100 needs to be enabled based on the test environment and requirements. If not enabled, switch the first switch S1 to the off position and the second switch S2 to the closed position, then use the reverse connection protection terminal to supply power normally, and the controller will operate normally. If the reverse connection protection circuit 100 is enabled, switch the first switch S1 to the closed position and the second switch S2 to the off position, then power on. The circuit will determine whether the positive and negative terminals of the power supply are reversed. If they are not reversed, the controller will operate normally. If they are reversed, the circuit will automatically correct the positive and negative terminals, and the controller will finally operate normally.

[0077] See Figure 2 The schematic diagram of the reverse connection protection circuit 100 is shown. In the diagram, the first resistor R1 and the second resistor R2 are voltage divider resistors, the third resistor R3 is a current limiting resistor, the first switch Q1 and the second switch Q2 are two N-channel enhancement-mode MOSFETs, the first switch S1 and the second switch S2 are toggle switches, and a Zener diode V1, a first diode D1, a second diode D2, a first relay K1 and a second relay K2 are also provided.

[0078] The first resistor R1 and the second resistor R2 form a voltage divider circuit, which serves to divide the voltage. The first diode D1 serves as a reverse connection protection safety indicator. The Zener diode V1 limits the gate-source voltage of the first switch Q1 and the second switch Q2 to not exceed the set voltage range, thus protecting the gate-source voltage of the first switch Q1 and the second switch Q2 from exceeding the maximum value of the device gate-source voltage. The first switch Q1 and the second switch Q2 are two N-channel enhancement-mode MOSFETs. Their working principle is that when the gate voltage is higher than the threshold voltage, the gate electric field attracts electrons and forms an N-type conductive channel on the surface of the P-type substrate, allowing current to flow from the source to the drain; otherwise, the channel is not conducting and the current is zero.

[0079] The self-recovery function is mainly achieved through the first relay K1 and the second relay K2. The function of the relay is that when the coil is not energized, the normally closed contact is closed and the normally open contact is open. When the coil is energized, the normally closed contact is open and the normally open contact is closed.

[0080] When the first switch S1 is closed and the second switch S2 is open, the reverse connection protection circuit 100 is activated. At this time, when the input terminals are reversed, the first diode D1 illuminates to indicate that the power supply terminals are reversed. The voltage division between the first resistor R1 and the second resistor R2 ensures that the voltage between the gate and source of the first switch Q1 and the second switch Q2 is greater than the threshold voltage Vth. The drain and source of the first switch Q1 and the second switch Q2 are connected. At this time, the first terminal of the second relay K2 is connected to the negative input terminal VIN- of the power input port 200. Since the terminals are reversed, the negative input terminal VIN- of the power input port 200 is actually the positive terminal of the DC power supply. The second relay K2's... The two terminals are connected to the positive input VIN+ of the power input port 200. Since the positive and negative terminals are reversed at this time, the positive input VIN+ of the power input port 200 is actually the negative terminal of the DC power supply. There is a potential difference between the two ends of the coil of the second relay K2, which energizes and forms a current. The second relay K2 switches on, while the first relay K1 switches off. The moving contact of the second relay K2 connects the positive power supply VO+ of the main circuit 300 to the negative input VIN- of the power input port 200, which is actually the positive terminal of the DC power supply, and connects the negative power supply VO- of the main circuit 300 to the positive input VIN+ of the power input port 200, which is actually the negative terminal of the DC power supply. In this way, the positive and negative terminals of the power supply are automatically corrected, and the controller is powered normally.

[0081] When the input positive and negative terminals are connected in the correct direction, due to the unidirectional conductivity of the first diode D1, the first diode D1 does not emit light and its voltage cannot be divided by the first resistor R1 and the second resistor R2. The first resistor R1 pulls down the gate voltage of the first switch Q1 and the second switch Q2 to the input negative terminal VIN- voltage. The source of the first switch Q1 is connected to the input positive terminal VIN+ voltage. The voltage between the gate and source of the first switch Q1 is less than zero, which is less than the threshold voltage Vth of the MOSFET. The source and drain of the first switch Q1 are turned off. At this time, there is no potential difference across the coil of the second relay K2, and the contacts of the second relay K2 do not operate. The moving contact of the second relay K2 connects the positive power supply terminal VO+ of the main circuit 300 to the positive input terminal VIN+ of the power input port 200 through the contact VIN1+ of the first relay K1; and connects the negative power supply terminal VO- of the main circuit 300 to the negative input terminal VIN- of the power input port 200 through the contact VIN1- of the first relay K1. The controller can be powered on normally. When reverse connection protection is not required, switch the first switch S1 to the off position and the second switch S2 to the closed position, and the reverse connection protection circuit 100 is taken out of service.

[0082] See Figure 1 , 3 ,Will Figure 1 VIN+, VIN-, VO+, V0- and Figure 3 By connecting VIN+, VIN-, VO+, and V0- accordingly, the reverse connection protection circuit 100 can be added to the controller. That is, based on the existing controller, only the reverse connection protection circuit 100 needs to be added between the 24V power input port and the input terminal of the 24V power module in the main circuit 300 to enable the protection circuit to function. The circuit structure is simple, low in cost, and has good portability, and can be used in various types of controllers.

[0083] This invention also protects a controller, which includes a reverse connection protection circuit 100, a power input port 200, and a main circuit 300. The structure of the reverse connection protection circuit 100 can be referred to the above embodiment, and will not be repeated here. Accordingly, since the controller of this embodiment adopts the above-described reverse connection protection circuit 100 technical solution, the controller has all the beneficial effects of the above-described reverse connection protection circuit 100.

[0084] It should be noted that, in this document, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or system that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or system. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or system that includes that element. The sequence numbers of the above-described embodiments are for descriptive purposes only and do not represent the superiority or inferiority of the embodiments.

[0085] The above are merely preferred embodiments of the present invention and do not limit the scope of the patent. Any equivalent structural or procedural transformations made based on the description and drawings of the present invention, or direct or indirect applications in other related technical fields, are similarly included within the scope of patent protection of the present invention.

Claims

1. A reverse connection protection circuit, characterized in that, The reverse connection protection circuit is connected to the power input port and the main circuit respectively; the reverse connection protection circuit includes a reverse connection detection module and a reverse connection correction module. The detection terminal of the reverse connection detection module is connected between the positive and negative input terminals of the power input port. The positive input terminal of the reverse connection correction module is connected to the positive input terminal of the power input port, and the negative input terminal of the reverse connection correction module is connected to the negative input terminal of the power input port. The positive output terminal of the reverse connection correction module is connected to the positive power supply terminal of the main circuit, and the negative output terminal of the reverse connection correction module is connected to the negative power supply terminal of the main circuit. The control terminal of the reverse connection correction module is connected to the output terminal of the reverse connection detection module. Wherein: The reverse connection detection module is used to detect the voltage between the positive and negative input terminals of the power input port to determine whether there is a reverse connection problem at the power input port, and to control the connection status of the reverse connection correction module based on whether there is a reverse connection problem. The reverse connection correction module is used to respond to the control of the reverse connection detection module and, when there is a reverse connection problem at the power input port, swap the signal outputs of the positive and negative output terminals.

2. The reverse connection protection circuit as described in claim 1, characterized in that, The reverse connection detection module includes a detection unit and a switching unit. The detection terminal of the detection unit is connected between the positive and negative input terminals of the power input port. The output terminal of the detection unit is connected to the control terminal of the switching unit, and the output terminal of the switching unit is connected to the control terminal of the reverse connection correction module. Wherein: The detection unit is used to detect the voltage between the positive and negative terminals of the power input port to determine whether there is a reverse connection problem at the power input port, and to send a control signal to the switching unit according to whether there is a reverse connection problem. The switching unit is used to control the reverse connection correction module to switch the signal outputs of the positive and negative output terminals when there is a reverse connection problem at the power input port, according to the control signal.

3. The reverse connection protection circuit as described in claim 2, characterized in that, The detection unit includes a first resistor, a second resistor, and a first diode; wherein: The first end of the first resistor is connected to the negative input terminal of the power input port, the second end of the first resistor is connected to the control terminal of the switching unit as the output terminal of the detection unit, the second end of the first resistor is also connected to the first end of the second resistor, the second end of the second resistor is connected to the positive terminal of the first diode, and the negative terminal of the first diode is connected to the positive input terminal of the power input port.

4. The reverse connection circuit as described in claim 3, characterized in that, The first diode is a light-emitting diode.

5. The reverse connection protection circuit as described in claim 2, characterized in that, The switching unit includes a first switching transistor and a second switching transistor, wherein: The gate of the first switching transistor is connected to the output terminal of the detection unit as the control terminal of the switching unit. The drain of the first switching transistor is connected to the positive input terminal of the power input port. The source of the first switching transistor is connected to the source of the second switching transistor. The drain of the second switching transistor is connected to the control terminal of the reverse connection correction module as the output terminal of the switching unit. The gate of the second switching transistor is connected to the first switching transistor.

6. The reverse connection protection circuit as described in claim 2, characterized in that, The detection unit further includes a detection control unit, which includes a first switch and a second switch; the first switch is connected between the detection terminal of the detection unit and the negative input terminal of the power input port, the first terminal of the second switch is connected to the positive input terminal of the power input port, and the second terminal of the second switch is connected between the output terminal of the switch unit and the control terminal of the reverse connection correction module; wherein: The first switch is used to close when the reverse connection protection circuit is effective and to open when the reverse connection protection circuit is ineffective. The second switch is used to open when the reverse connection protection circuit is effective and to close when the reverse connection protection circuit is ineffective.

7. The reverse connection protection circuit as described in claim 1, characterized in that, The reverse connection correction module includes a first switching unit and a second switching unit; The first switching unit includes a first detection subunit and a first switching subunit, and the second switching unit includes a second detection subunit and a second switching subunit; The first detection subunit is positively connected between the positive and negative input terminals of the power input port. The output terminal of the first detection subunit is connected to the control terminal of the first switching subunit. The input terminals of the first switching subunit are respectively connected to the positive and negative input terminals of the power input port. The output terminals of the first switching subunit are respectively connected to the first input terminal of the second switching subunit. The second input terminals of the second switching subunit are respectively connected to the negative and positive input terminals of the power input port. The output terminals of the second switching subunit are respectively connected to the positive and negative power supply terminals of the main circuit. The control terminal of the second switching subunit is connected to the output terminal of the second detection subunit. The first terminal of the second detection subunit is connected to the negative input terminal of the power input port. The second terminal of the second detection subunit serves as the control terminal of the reverse connection correction module and is connected to the output terminal of the reverse connection detection module. Wherein: When the first switching unit detects that the positive input terminal and the negative input terminal of the power input port are not forward connected, it controls the input terminal and the output terminal of the first switching subunit to disconnect. When the second switching unit detects a current loop, it controls the second input terminal and the output terminal of the second switching subunit to close.

8. The reverse connection protection circuit as described in claim 7, characterized in that, The first switching unit includes a first relay and a second diode; wherein: The first end of the first relay coil is connected to the negative input terminal of the power input port, the second end of the first relay coil is connected to the negative terminal of the second diode, and the positive terminal of the second diode is connected to the positive input terminal of the power input port. The normally open contact of the first contact group of the first relay is connected to the positive input terminal of the power input port, and the moving contact of the first contact group of the first relay is connected to the first contact of the first input terminal of the second switching unit. The normally open contact of the second contact group of the first relay is connected to the negative input terminal of the power input port, and the moving contact of the second contact group of the first relay is connected to the second contact of the first input terminal of the second switching unit.

9. The reverse connection protection circuit as described in claim 7, characterized in that, The second switching unit is a second relay; wherein: The first end of the coil of the second relay is connected to the negative input terminal of the power input port, and the second end of the coil of the second relay is connected to the output terminal of the reverse connection correction module as the control terminal of the reverse connection correction module. The moving contact of the first contact group of the second relay coil is connected to the positive power supply of the main circuit, the normally closed contact of the first contact group of the second relay is connected to the first contact of the output terminal of the first switching unit, and the normally open contact of the first contact group of the second relay is connected to the negative input terminal of the power input port. The moving contact of the second contact group of the second relay coil is connected to the negative terminal of the main circuit, the normally closed contact of the second contact group of the second relay is connected to the second contact of the output terminal of the first switching unit, and the normally open contact of the second contact group of the second relay is connected to the positive terminal of the power input port.

10. A controller, characterized in that, The electronic device includes a reverse connection protection circuit, a power input port, and a main circuit, wherein the reverse connection protection circuit is configured as described in any one of claims 1-9.

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