Reverse connection prevention circuit

Abstract

The utility model discloses an anti-reverse-connection circuit, and the circuit comprises wiring terminals which comprise a positive wiring terminal and a negative wiring terminal; the positive electrode end of the photoelectric coupler is electrically connected with the positive electrode terminal, and the negative electrode end of the photoelectric coupler is electrically connected with the negative electrode terminal; the input end of the post-stage circuit is electrically connected with the photoelectric coupler; and the bidirectional silicon controlled rectifier is arranged at a circuit connection point between the output end of the post-stage circuit and the photoelectric coupler, and the bidirectional silicon controlled rectifier is also electrically connected with the positive terminal. When the wiring is correct, the photoelectric coupler is opened to trigger the bidirectional silicon controlled rectifier, so that the bidirectional silicon controlled rectifier is conducted to supply power to a post-stage circuit, the power loss is reduced, and the heating value of the element can also be reduced; and when the wiring is reversely connected, as no current passes through the photoelectric coupler, the bidirectional silicon controlled rectifier cannot be opened and cannot supply power to a post-stage circuit, so that the effect of protecting the post-stage circuit is achieved.

Description

Technical Field

[0001] This utility model relates to the technical field of reverse connection circuits, and in particular to a circuit for preventing reverse connection. Background Technology

[0002] Traditional reverse connection protection circuits use diodes connected in series in the circuit to prevent reverse connection. This solution is generally used in power supply systems with low current. However, when used in power supply systems with high current, the diode has a forward voltage drop. According to the formula power = voltage x current, the higher the current, the greater the power loss generated in the diode. This can easily lead to overheating and damage of the diode, resulting in high power loss and heat generation in the components. Utility Model Content

[0003] In order to overcome the shortcomings of the existing technical solutions, this utility model embodiment provides a circuit to prevent reverse connection.

[0004] The technical solution adopted by this utility model to solve its technical problem is:

[0005] A reverse connection protection circuit, the circuit comprising:

[0006] The terminal block includes a positive terminal block and a negative terminal block;

[0007] An optocoupler, wherein the positive terminal of the optocoupler is electrically connected to the positive terminal, and the negative terminal of the optocoupler is electrically connected to the negative terminal;

[0008] The input terminal of the subsequent circuit is electrically connected to the optocoupler;

[0009] A bidirectional thyristor is provided at the circuit connection point between the output terminal of the subsequent circuit and the optocoupler, and the bidirectional thyristor is also electrically connected to the positive terminal.

[0010] As a preferred technical solution of this utility model, the optocoupler includes a photosensitive bidirectional thyristor, and the photosensitive bidirectional thyristor is electrically connected to the control terminal of the bidirectional thyristor.

[0011] As a preferred embodiment of this invention, the optocoupler further includes a light-emitting diode (LED), the positive terminal of which is electrically connected to the positive terminal, and the negative terminal of which is electrically connected to the negative terminal.

[0012] As a preferred embodiment of the present invention, the circuit further includes a first resistor, the input terminal of which is electrically connected to the photosensitive bidirectional thyristor, and the output terminal of which is electrically connected to the bidirectional thyristor.

[0013] As a preferred embodiment of this invention, the circuit further includes a diode, the input terminal of which is electrically connected to the positive terminal, and the output terminal of which is electrically connected to the positive terminal of the optocoupler.

[0014] As a preferred embodiment of the present invention, the circuit further includes a second resistor, the input terminal of which is electrically connected to the output terminal of the diode, and the output terminal of which is electrically connected to the positive terminal of the optocoupler.

[0015] As a preferred technical solution of this utility model, the subsequent circuit is electrically connected to the peripheral device.

[0016] Compared with the prior art, the beneficial effects of this utility model are:

[0017] When the wiring is correct, the optocoupler is turned on to trigger the bidirectional thyristor, which then conducts to supply power to the subsequent circuit, reducing power loss and heat generation of the components themselves. When the wiring is reversed, no current flows through the optocoupler, so the bidirectional thyristor cannot be turned on and cannot supply power to the subsequent circuit, thus protecting the subsequent circuit. Attached Figure Description

[0018] To more clearly illustrate the technical solutions of the embodiments of this utility model, the drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0019] Figure 1 This is a circuit diagram of an embodiment of the present invention.

[0020] Figure 2 This is a circuit diagram of the optocoupler according to an embodiment of the present invention.

[0021] Numbers in the diagram

[0022] 1. Positive terminal;

[0023] 2. Negative terminal;

[0024] 3. Optocoupler; 31. Photosensitive bidirectional thyristor; 32. Light-emitting diode;

[0025] 4. Subsequent stage circuit;

[0026] 5. Bidirectional thyristor;

[0027] 6. First resistor;

[0028] 7. Diode;

[0029] 8. Second resistor. Detailed Implementation

[0030] To make the technical problems, technical solutions and beneficial effects to be solved by this application clearer, the following describes this application in further detail with reference to the accompanying drawings and embodiments.

[0031] It should be understood that the specific embodiments described herein are merely illustrative of this application and are not intended to limit this application.

[0032] It should be noted that when a component is referred to as "fixed to" or "set on" another component, it can be directly on the other component or indirectly on that other component.

[0033] When a component is said to be "connected to" another component, it can be directly connected to the other component or indirectly connected to that other component.

[0034] It should be understood that the terms "length", "width", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application.

[0035] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined with "first" or "second" may explicitly or implicitly include one or more of that feature.

[0036] In the description of this application, "multiple" means two or more, unless otherwise expressly and specifically defined.

[0037] To address the technical problems of high power loss and heat generation of components in existing power supply systems with high current, this utility model provides a reverse connection protection circuit.

[0038] The following describes in detail the specific structure of the reverse connection protection circuit provided by the embodiments of this utility model, according to the appendix. Figure 1 and Figure 2 As shown, the specific structure of the reverse connection protection circuit includes a terminal block, an optocoupler 3, a subsequent circuit 4, a diode 7, and a bidirectional thyristor 5.

[0039] The terminals include a positive terminal 1 and a negative terminal 2. Specifically, the positive terminal 1 is used to connect to the high-potential end of the power supply or equipment. In the circuit, current flows out from the positive terminal of the power supply and connects to the electrical equipment or circuit board through the positive terminal 1 to provide the required power. The positive terminal 1 is usually electrically connected to the positive terminal of the power supply or equipment to ensure that the current can flow smoothly into the equipment. The negative terminal 2 is used to connect to the low-potential end of the power supply or equipment. After the current passes through the equipment, it flows back to the negative terminal of the power supply through the negative terminal 2, thus completing the current loop. The negative terminal 2 ensures that the current can smoothly return to the power supply to maintain the normal operation of the circuit.

[0040] The positive terminal of optocoupler 3 is electrically connected to positive terminal 1, and the negative terminal of optocoupler 3 is electrically connected to negative terminal 2.

[0041] Specifically, the optocoupler 3 is an electrical conversion device that uses light as a medium to transmit electrical signals. It is used to convert weak input electrical signals into optical signals for transmission, and then convert the optical signals back into electrical signals for output. This conversion method can realize long-distance signal transmission, thereby avoiding signal attenuation or distortion caused by excessively long cables or electromagnetic interference. It also has excellent electrical isolation performance, which can block the direct connection between input and output circuits and avoid faults or safety hazards caused by mutual influence between circuits.

[0042] In actual operation, the signal is coupled from one circuit to another to achieve electrical isolation while allowing electrical energy to pass through. Specifically, the signal is converted into an optical signal. When the optocoupler 3 receives enough light, it generates a current or voltage output, thereby transmitting the input signal to another circuit.

[0043] The input terminal of the subsequent circuit 4 is electrically connected to the optocoupler 3.

[0044] Specifically, when the current at the positive terminal 1 passes through the optocoupler 3, an optical signal is generated. The generated optical signal is output from the photodetector to achieve the conversion between electricity and light. When current flows through the optocoupler 3, it is turned on, and the bidirectional thyristor 5 is triggered and turned on to supply power to the subsequent circuit 4. Conversely, if the wiring is reversed, that is, the current at the positive terminal 1 cannot pass through the optocoupler 3, the bidirectional thyristor 5 cannot be turned on and cannot supply power to the subsequent circuit 4, thus protecting the subsequent circuit 4.

[0045] It should be noted that the optocoupler 3 is also used to detect the input current, ensuring that it conducts when there is current and disconnects in time when there is no current, thereby protecting the downstream circuit 4.

[0046] The bidirectional thyristor 5 is located at the circuit connection point between the output terminal of the subsequent circuit 4 and the optocoupler 3. The bidirectional thyristor 5 is also electrically connected to the positive terminal 1.

[0047] Specifically, when the electrically triggered bidirectional thyristor 5 is in the on-state, it generates a voltage on the control electrode, causing the subsequent circuit 4 to start supplying power and achieve normal operation. More specifically, the internal structure of the bidirectional thyristor 5 differs from that of a typical unidirectional thyristor. It has three electrodes: a control electrode (G), an anode (A), and a cathode (K). When a suitable positive trigger signal is applied to the control electrode G, the two PN junctions are in a forward biased state, allowing current to flow from the anode to the cathode. Similarly, when a suitable shunt signal or reverse trigger signal is applied to the control electrode G, the two PN junctions are in a reverse biased state, allowing current to flow from the cathode to the anode. Thus, the bidirectional thyristor 5 can withstand higher forward voltages and currents, and can also perform reverse conduction in some operating environments.

[0048] For example, when a forward voltage (anode voltage higher than cathode voltage) is applied between the anode and cathode, and an appropriate trigger signal is applied to the control electrode, the bidirectional thyristor 5 will conduct. This trigger signal is a small pulse signal that causes a slight breakdown in the PN junction inside the bidirectional thyristor 5, thereby allowing a large current to flow. Once conducted, the bidirectional thyristor 5 will remain in the conducting state even if the trigger signal is removed, until the current decreases below a certain value and then turns off. Once the normal operating current no longer flows through the bidirectional thyristor 5 (i.e., the current decreases below the arc extinction threshold), the current will dissipate naturally due to the internal voltage drop, eventually turning the bidirectional thyristor 5 off.

[0049] It should be noted that the bidirectional thyristor 5 can also be triggered to conduct under reverse voltage. When the anode voltage is lower than the cathode voltage, a trigger signal still needs to be applied to the control electrode to start conduction.

[0050] In summary, during forward conduction, optocoupler 3 is powered on and receives a forward current, amplifying the output current and triggering the triac 5 to conduct. When the triac 5 is conducting, a voltage is generated on its control electrode, supplying power to the subsequent circuit 4 and enabling normal operation. If the wiring is reversed, optocoupler 3 cannot receive a forward current, causing the phototransistor to not conduct. This prevents the triac 5 from being triggered, thus failing to generate voltage to power the subsequent circuit 4. Therefore, the subsequent circuit 4 cannot be powered. This design serves as a protection mechanism, preventing circuit damage due to incorrect power supply.

[0051] In some specific embodiments, the optocoupler 3 includes a photosensitive bidirectional thyristor 31, which is electrically connected to the control terminal of the bidirectional thyristor 5.

[0052] Specifically, the photosensitive bidirectional thyristor 31 is a semiconductor device whose conduction and blocking are controlled by optical signals. When irradiated by light of a specific wavelength and intensity, the internal structure of the photosensitive bidirectional thyristor 31 changes, thereby altering its electrical characteristics and causing it to transition from a high-resistance state to a low-resistance state, thus enabling current conduction. When the photosensitive bidirectional thyristor 31 receives light from an external light source (such as light emitted by an LED) and converts it into an electrical signal, which is a change in current or voltage, the converted electrical signal is transmitted through the circuit to the control electrode of the bidirectional thyristor 5. This electrical signal is used to trigger the bidirectional thyristor 5 to transition from a high-resistance state to a low-resistance state, thereby enabling current conduction. Once the bidirectional thyristor 5 is triggered and conducts, current in the external circuit can flow through the bidirectional thyristor 5, thereby realizing functions such as circuit on / off control or dimming.

[0053] In the above embodiment, the photosensitive bidirectional thyristor 31 internally includes one or more photodiodes 7 and a bidirectional thyristor 5. The photodiode 7 is located inside the package, and its two ends are the positive and negative terminals of the photodiode 7, respectively. When external light shines on the photodiode 7, the light energy is converted into electrical energy, thereby generating a photocurrent, which is used to drive the internal amplifier circuit, thereby controlling the conduction of the bidirectional thyristor 5. When there is no light, the photosensitive bidirectional thyristor 31 is in a blocking state. When light occurs, the photocurrent is large enough to trigger the bidirectional thyristor 5 to conduct, and the current can pass through the anode of the bidirectional thyristor 5. Thus, the photosensitive bidirectional thyristor 31 converts the light signal into an electrical signal and uses the electrical signal to control the conduction and blocking of the bidirectional thyristor 5. Due to the electrical isolation between the photodiode 7 and the bidirectional thyristor 5, the photosensitive bidirectional thyristor 31 can realize signal transmission, and at the same time, it can also be used to protect the rest of the circuit from interference and damage.

[0054] In a further embodiment, the optocoupler 3 also includes a light-emitting diode 32, the positive terminal of which is electrically connected to the positive terminal 1, and the negative terminal of which is electrically connected to the negative terminal 2.

[0055] Specifically, the light-emitting diode 32 (LED) is the main active element in the optocoupler 3, used to realize the conversion between light energy and electrical energy. When current passes through the light-emitting diode 32, it turns on the light-emitting diode 32 and emits light. When current passes through the input terminal of the light-emitting diode 32 (generally a switching signal), the light-emitting diode 32 emits a light signal. Since the light intensity of the light-emitting diode 32 is proportional to the input current and has a good linear relationship, it can convert the electrical signal into a light signal.

[0056] In the above embodiment, more specifically, the light-emitting diode 32 emits light when a certain current flows through it, and this light illuminates the adjacent photosensitive bidirectional thyristor 31. Since the photosensitive bidirectional thyristor 31 can be controlled by light signals, when illuminated by specific light, the switching state of the photosensitive bidirectional thyristor 31 changes, causing the circuit to conduct or disconnect, allowing current to flow freely in both directions of alternating current. When the current through the light-emitting diode 32 is strong enough (reaching the trigger current), the photosensitive bidirectional thyristor 31 is turned on, allowing current to flow to the subsequent circuit 4. Conversely, when the wiring is reversed, the light-emitting diode 32 does not receive a positive current stimulus and cannot emit enough light to trigger the conduction of the photosensitive bidirectional thyristor 31. In this case, the photosensitive bidirectional thyristor 31 remains in the off state, thereby preventing current from flowing to the subsequent circuit 4.

[0057] In some specific embodiments, the circuit further includes a first resistor 6, the input terminal of which is electrically connected to the photosensitive bidirectional thyristor 31, and the output terminal of which is electrically connected to the bidirectional thyristor 5.

[0058] Specifically, the first resistor 6 is used to adjust the current input to the optocoupler 3, thereby controlling the light output intensity of the optocoupler 3 and further affecting the switching state of the bidirectional thyristor 5 connected to it. The resistor also limits and divides the current, ensuring that the current flows along a predetermined path and preventing damage to the circuit or devices due to excessive current. Furthermore, the resistor acts as a voltage divider, ensuring that the signal output from the optocoupler 3 is correctly transmitted to the bidirectional thyristor 5. In addition, the first resistor 6 reduces common-mode interference of the input signal, improving the circuit's anti-interference capability.

[0059] In some specific embodiments, the circuit also includes a diode 7, the input terminal of which is electrically connected to the positive terminal 1, and the output terminal of which is electrically connected to the positive terminal of the optocoupler 3.

[0060] Specifically, since diode 7 has unidirectional conductivity, meaning that current can only flow in from the positive terminal and out from the negative terminal, when it is forward-biased, the current can flow normally; when it is reverse-biased, the potential barrier inside diode 7 prevents the current from flowing, thus blocking the current.

[0061] Because diode 7 exhibits unidirectional conductivity, its forward conduction and reverse blocking characteristics are based on its unique PN structure. Specifically, diode 7 is formed by the contact of P-type and N-type semiconductors to create a PN junction. Due to the difference in charge distribution between the P-type and N-type semiconductors on both sides of the PN junction, a space charge region is formed. When a forward voltage is applied to diode 7 (i.e., the positive terminal is connected to the P-region and the negative terminal to the N-region), the direction of the applied electric field is opposite to the direction of the electric field within the PN junction. This weakens the electric field within the PN junction, narrowing the space charge region and allowing majority carriers (electrons or holes) to flow from the high-concentration region to the low-concentration region, forming a forward current and causing diode 7 to conduct. When a reverse voltage is applied to diode 7 (i.e., the positive terminal is connected to the N-region and the negative terminal to the P-region), the direction of the applied electric field is the same as the direction of the electric field within the PN junction. Under the influence of the electric field, the flow of majority carriers from the low-concentration region to the high-concentration region is hindered. At this time, the width of the space charge region expands, making it so that almost no current can pass through diode 7; that is, diode 7 is in a blocking state.

[0062] In some specific embodiments, the circuit further includes a second resistor 8, the input terminal of which is electrically connected to the output terminal of the diode, and the output terminal of the second resistor 8 is electrically connected to the positive terminal of the optocoupler 3.

[0063] Specifically, the second resistor 8 serves to limit current and divide voltage, ensuring that the current flows as needed and protecting the subsequent circuit from excessive current. The output terminal of the second resistor 8 is electrically connected to the positive terminal of the optocoupler 3 to adjust the magnitude of the current entering the optocoupler 3 to meet the current requirements of the optocoupler 3.

[0064] The subsequent circuit 4 is electrically connected to an external device, for example, a motor drive board. The current and voltage output by the subsequent circuit 4 are converted into specifications that the motor drive board can accept through a suitable interface circuit (such as a voltage regulator or current amplifier), ensuring that the subsequent circuit 4 can provide sufficient current to the motor drive board.

[0065] The above description is merely a specific embodiment of this utility model, but the protection scope of this utility model is not limited thereto. Any person skilled in the art can easily conceive of various equivalent modifications or substitutions within the technical scope disclosed in this utility model, and these modifications or substitutions should all be covered within the protection scope of this utility model. Therefore, the protection scope of this utility model should be determined by the scope of the claims.

Claims

1. A reverse connection prevention circuit, characterized by comprising: The circuit comprises: a terminal, the terminal comprising a positive terminal and a negative terminal; a photoelectric coupler, a positive terminal of the photoelectric coupler being electrically connected with the positive terminal, and a negative terminal of the photoelectric coupler being electrically connected with the negative terminal; a post-stage circuit, an input terminal of the post-stage circuit being electrically connected with the photoelectric coupler; a bidirectional thyristor, the bidirectional thyristor being arranged at a circuit connection point between an output terminal of the post-stage circuit and the photoelectric coupler, and the bidirectional thyristor being further electrically connected with the positive terminal.

2. The reverse-connection-proof circuit according to claim 1, characterized in that, The photoelectric coupler comprises a photosensitive bidirectional thyristor, the photosensitive bidirectional thyristor being electrically connected with a control terminal of the bidirectional thyristor.

3. The reverse-connection-proof circuit according to claim 2, characterized in that, The photoelectric coupler further comprises a light-emitting diode, a positive terminal of the light-emitting diode being electrically connected with the positive terminal, and a negative terminal of the light-emitting diode being electrically connected with the negative terminal.

4. The reverse-connection-proof circuit according to claim 2, wherein The circuit further comprises a first resistor, an input terminal of the first resistor being electrically connected with the photosensitive bidirectional thyristor, and an output terminal of the first resistor being electrically connected with the bidirectional thyristor.

5. The reverse-connection-preventive circuit according to claim 1, wherein The circuit further comprises a diode, an input terminal of the diode being electrically connected with the positive terminal, and an output terminal of the diode being electrically connected with the positive terminal of the photoelectric coupler.

6. The reverse-connection-proof circuit according to claim 5, wherein The circuit further comprises a second resistor, an input terminal of the second resistor being electrically connected with the output terminal of the diode, and an output terminal of the second resistor being electrically connected with the positive terminal of the photoelectric coupler.

7. The reverse-connection-preventive circuit according to claim 1, wherein The post-stage circuit is electrically connected with an external device.

Images