Reverse connection prevention circuit for redundant power supply and industrial equipment

Abstract

The utility model discloses a redundant power supply reverse connection prevention circuit and industrial equipment, the redundant power supply reverse connection prevention circuit comprises a loop control module and a voltage comparison module, the loop control module is connected between an external power supply and a post-stage circuit, and the voltage comparison module is connected with the loop control module and the external power supply; the voltage comparison module is used for comparing voltage signals of a first input end, a second input end and a third input end of the voltage comparison module, and outputting a switching signal to the loop control module according to the voltage signals; and the loop control module is used for controlling the on-off of a loop between the first external power supply and the post-stage circuit and a loop between the second external power supply and the post-stage circuit according to the switching signal. The redundant power supply reverse connection prevention circuit is built by adopting common devices, a special redundant power supply control chip circuit is not needed, the circuit is easy to implement, the cost is low, the response speed is high, the voltage input by the power supply can be accurately detected, and the accuracy of power supply switching is ensured.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of power management, in particular to a redundant power supply anti-reverse connection circuit and an industrial device. BACKGROUND

[0002] In order to improve the reliability and stability of the system, especially in some critical equipment and high reliability occasions, a redundant power supply design is usually adopted to ensure that the backup power supply can be immediately put into work when the main power supply fails, so as to ensure the continuous operation of the equipment.

[0003] In the prior art, a MOS (Metal-Oxide-Semiconductor Field-Effect Transistor, MOSFET) is used to realize the redundant power supply anti-reverse connection circuit. Two power supplies are connected to the MOS in parallel and output to the power bus. A redundant power supply control chip is used to detect the output state of the power supply. The opening and closing of the MOS are controlled by the redundant power supply control chip. One power supply can work alone, and multiple power supplies can work simultaneously. When one of the power supplies fails or is connected in reverse, it will not affect the output of the power bus. Since this method requires a professional chip for control, not only is the cost high, but also external interference pulses can easily cause false detection, making it difficult to ensure the accuracy of power switching. CONTENT OF THE UTILITY MODEL

[0004] The main purpose of the present application is to provide a redundant power supply anti-reverse connection circuit and an industrial device, which aims to solve the problem of high cost and difficulty in ensuring the accuracy of power switching of the existing redundant power supply anti-reverse connection circuit.

[0005] In order to achieve the above purpose, the present application provides a redundant power supply anti-reverse connection circuit, which comprises a loop control module and a voltage comparison module. The loop control module is connected between an external power supply and a rear circuit. The first input end of the voltage comparison module is used to connect with the voltage input end of the rear circuit. The second input end of the voltage comparison module is used to connect with the negative electrode of the first external power supply. The third input end of the voltage comparison module is used to connect with the negative electrode of the second external power supply. The output end of the voltage comparison module is connected with the controlled end of the loop control module.

[0006] The voltage comparison module is used to compare the voltage signals of the first input end, the second input end and the third input end, and output a switching signal to the loop control module according to the voltage signals.

[0007] The loop control module is configured to control on-off of loops between the first external power supply and the post-stage circuit and between the second external power supply and the post-stage circuit according to the switch signal.

[0008] In an embodiment, the loop control module comprises a first switch tube and a second switch tube, and the output end of the voltage comparison module comprises a first output end and a second output end, the first output end is connected with a controlled end of the first switch tube, and the second output end is connected with a controlled end of the second switch tube.

[0009] One of the first switch tube and the second switch tube is located in the loop between the first external power supply and the post-stage circuit, and the other is located in the loop between the second external power supply and the post-stage circuit.

[0010] In an embodiment, the voltage comparison module comprises a first comparator and a second comparator, a non-inverting end of the first comparator, an inverting end of the first comparator and a non-inverting end of the second comparator are configured to be connected with the voltage input end, the non-inverting end of the first comparator is configured to be connected with a negative electrode of the first external power supply, the inverting end of the first comparator and the non-inverting end of the second comparator are configured to be connected with a negative electrode of the second external power supply, an output end of the first comparator is connected with a controlled end of the first switch tube and an inverting end of the second comparator respectively, and an output end of the second comparator is connected with a controlled end of the second switch tube.

[0011] In an embodiment, the anti-reverse connection circuit of the redundant power supply further comprises a voltage reduction module, an input end of the voltage reduction module is connected with the voltage input end, and output ends of the voltage reduction module are connected with a power supply end of the first comparator and a power supply end of the second comparator respectively.

[0012] The voltage reduction module is configured to perform voltage reduction processing on the voltage of the voltage input end and output to the first comparator and the second comparator.

[0013] In an embodiment, the voltage comparison module comprises a first resistor, a second resistor, a third resistor, a sixth resistor, a seventh resistor, a ninth resistor, a first diode and a second diode.

[0014] The inverting terminal of the first comparator is connected with the first terminal of the first resistor and the first terminal of the seventh resistor, the second terminal of the first resistor is connected with the voltage input terminal, the non-inverting terminal of the first comparator is connected with the first terminal of the second resistor and the first terminal of the third resistor, the second terminal of the second resistor is connected with the voltage input terminal, the second terminal of the third resistor is connected with the anode of the first diode, the cathode of the first diode is connected with the negative electrode of the first external power supply, and the output terminal of the first comparator is connected with the controlled terminal of the first switch tube.

[0015] The inverting terminal of the second comparator is connected with the first terminal of the sixth resistor, the second terminal of the sixth resistor is connected with the output terminal of the first comparator, the non-inverting terminal of the second comparator is connected with the second terminal of the seventh resistor and the first terminal of the ninth resistor, the second terminal of the ninth resistor is connected with the anode of the second diode, the cathode of the second diode is connected with the negative electrode of the second external power supply, and the output terminal of the second comparator is connected with the controlled terminal of the second switch tube.

[0016] In an embodiment, the voltage comparison module further comprises a tenth resistor, the first terminal of the tenth resistor is connected with the output terminal of the second comparator, and the second terminal of the tenth resistor is connected with the first terminal of the ninth resistor.

[0017] In an embodiment, the voltage comparison module further comprises a fifth resistor and an eighth resistor, the first terminal of the fifth resistor is connected with the output terminal of the first comparator, the second terminal of the fifth resistor is connected with the working power supply of the first comparator, the first terminal of the eighth resistor is connected with the output terminal of the second comparator, and the second terminal of the eighth resistor is connected with the working power supply of the second comparator.

[0018] In an embodiment, the voltage reduction module comprises a transistor, a voltage stabilizing tube, an eleventh resistor, a twelfth resistor, a first capacitor and a second capacitor.

[0019] The collector of the transistor is connected with the first terminal of the eleventh resistor and the first terminal of the twelfth resistor, the emitter of the transistor is connected with the output terminal of the voltage reduction module, the base of the transistor is connected with the cathode of the voltage stabilizing tube, the reference terminal of the voltage stabilizing tube is connected with the second terminal of the twelfth resistor, the anode of the voltage stabilizing tube is grounded, the second terminal of the eleventh resistor is connected with the voltage input terminal, the first terminal of the first capacitor is connected with the second terminal of the eleventh resistor, the second terminal of the first capacitor is grounded, the first terminal of the second capacitor is connected with the emitter of the transistor, and the second terminal of the second capacitor is grounded.

[0020] In an embodiment, the anti-reverse connection circuit of the redundant power supply further comprises a filtering module, a first input end of the filtering module is connected with the positive pole of the first external power supply, a second input end of the filtering module is connected with the positive pole of the second external power supply, and an output end of the filtering module is connected with the voltage input end.

[0021] In addition, to achieve the above-mentioned purpose, the application further provides an industrial equipment comprising the anti-reverse connection circuit of the redundant power supply.

[0022] The anti-reverse connection circuit of the redundant power supply comprises a loop control module and a voltage comparison module, the loop control module is connected between an external power supply and a subsequent circuit, a first input end of the voltage comparison module is used to be connected with a voltage input end of the subsequent circuit, a second input end of the voltage comparison module is used to be connected with a negative pole of the first external power supply, a third input end of the voltage comparison module is used to be connected with a negative pole of the second external power supply, and an output end of the voltage comparison module is connected with a controlled end of the loop control module; the voltage comparison module is used to compare voltage signals of the first input end, the second input end and the third input end, and output a switching signal to the loop control module according to the voltage signals; and the loop control module controls on-off of loops between the first external power supply and the subsequent circuit and between the second external power supply and the subsequent circuit according to the switching signal. The application adopts common devices to build the anti-reverse connection circuit of the redundant power supply, does not need to rely on a special redundant power supply control chip circuit, and has the advantages of simple circuit implementation, low cost, fast response speed, accurate detection of voltage of a power supply input and ensured accuracy of power supply switching. BRIEF DESCRIPTION OF DRAWINGS

[0023] In order to more clearly illustrate the technical solutions in the embodiments of the application or the prior art, the following will briefly introduce the drawings needed to be used in the embodiments or prior art description. Obviously, the drawings in the following description only constitute some embodiments of the application, and for those skilled in the art, other drawings can also be obtained according to the structures shown in these drawings without any creative effort.

[0024] Figure 1 The functional module schematic diagram of an embodiment of the anti-reverse connection circuit of the redundant power supply provided by the application;

[0025] Figure 2 The circuit structure schematic diagram of an embodiment of the anti-reverse connection circuit of the redundant power supply provided by the application;

[0026] Figure 3 The current flow direction schematic diagram of the voltage comparison module in an embodiment of the anti-reverse connection circuit of the redundant power supply provided by the application;

[0027] Figure 4 The current flow direction schematic diagram of the voltage comparison module in an embodiment of the redundant power supply reverse connection prevention circuit provided in the present application is shown in the following figure:

[0028] Figure 5 The current flow direction schematic diagram of the voltage comparison module in an embodiment of the redundant power supply reverse connection prevention circuit provided in the present application is shown in the following figure:

[0029] Figure 6 The current flow direction schematic diagram of the voltage comparison module in an embodiment of the redundant power supply reverse connection prevention circuit provided in the present application is shown in the following figure.

[0030] The implementation, functional features and advantages of the present application will be further described with reference to the embodiments and the accompanying drawings. DETAILED DESCRIPTION

[0031] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only some of the embodiments of the present application, but not all the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative work fall within the scope of the present application.

[0032] It should be noted that if the directionality indication (such as up, down, left, right, front, back, etc.) is involved in the embodiments of the present application, the directionality indication is only used to explain the relative position relationship, movement condition, etc. between the components in a certain specific posture, and if the specific posture changes, the directionality indication also changes accordingly.

[0033] In addition, the description such as “first”, “second” and the like in the embodiments of the present application is only for the purpose of description, and cannot be understood as indicating or implying the relative importance of the technical features indicated or the number of the technical features indicated. Therefore, the features limited by “first”, “second” can explicitly or implicitly include at least one of the features. In the description of the embodiments of the present application, the meaning of “plurality” is at least two, such as two, three, etc., unless otherwise specifically limited.

[0034] In the embodiments of the present application, unless otherwise specifically defined and limited, the terms “connection”, “fixation” and the like should be understood in a broad sense, for example, “fixation” can be fixed connection, or detachable connection, or integral; can be mechanical connection, or electrical connection; can be direct connection, or indirect connection through an intermediate medium; can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise specifically limited. For those skilled in the art, the specific meaning of the above terms in the embodiments of the present application can be understood according to the specific circumstances.

[0035] In addition, the technical solutions among the various embodiments of the present application can be combined with each other, but it must be based on the implementation by the ordinary skilled in the art, when the combination of technical solutions appears contradictory or unachievable, it should be considered that the combination of technical solutions does not exist, nor within the protection scope claimed by the embodiments of the present application.

[0036] In order to better understand the above technical solutions, the above technical solutions are described in detail below in combination with the drawings.

[0037] In order to solve the problem of high cost and low precision caused by the control of a special redundant power supply control chip in the prior art, the present application provides a redundant power supply anti-reverse connection circuit and an industrial equipment.

[0038] In an embodiment of the present application, as shown in Figure 1 The present application provides a redundant power supply anti-reverse connection circuit, which comprises a loop control module 10 and a voltage comparison module 20, the loop control module 10 is connected between an external power supply and a post-stage circuit 30, a first input end of the voltage comparison module 20 is used to be connected with a voltage input end Vin of the post-stage circuit 30, a second input end of the voltage comparison module 20 is used to be connected with a negative electrode V1- of a first external power supply, a third input end of the voltage comparison module 20 is used to be connected with a negative electrode V2- of a second external power supply, and an output end of the voltage comparison module 20 is connected with a controlled end of the loop control module.

[0039] In the embodiment, the external power supply is connected with the post-stage circuit 30 to supply power to the post-stage circuit 30, wherein the external power supply comprises a first external power supply and a second external power supply, and the first external power supply and the second external power supply are redundant power supplies to each other, so that when one of the power supplies is suspended, or reversed or other faults, the other power supply can normally supply power to the post-stage circuit 30. The post-stage circuit 30 can be a back-end circuit in the same device, or can be another separate post-stage equipment.

[0040] For example, the external power supply is a direct current power supply. Normally, the positive pole of the first external power supply and the positive pole of the second external power supply are connected to the voltage input end Vin of the subsequent circuit 30, and the voltage input end Vin can be regarded as the positive connection end of the subsequent circuit 30. Meanwhile, the negative pole of the first external power supply and the negative pole of the second external power supply are connected to the negative connection end of the subsequent circuit 30. When the power supply is reversely connected, for example, when the first external power supply is reversely connected, the negative pole of the first external power supply will be incorrectly connected to the voltage input end Vin of the subsequent circuit 30, and the positive pole of the first external power supply will be incorrectly connected to the negative connection end of the subsequent circuit 30. At this time, the first external power supply cannot normally supply power to the subsequent circuit 30. The same is true when the second external power supply is reversely connected. When the positive pole and / or the negative pole of the power supply is suspended, for example, when the positive pole and / or the negative pole of the first external power supply is not connected to the corresponding terminal of the subsequent circuit 30, it will also cause the first external power supply to be unable to normally supply power to the subsequent circuit 30. The same is true when the second external power supply is suspended.

[0041] The voltage comparison module 20 is configured to compare voltage signals of the first input end, the second input end and the third input end, and output a switching signal to the loop control module 10 according to the voltage signals.

[0042] The loop control module 10 is configured to control the on-off of the loop between the first external power supply and the subsequent circuit 30 and the loop between the second external power supply and the subsequent circuit 30 according to the switching signal.

[0043] In this embodiment, the voltage comparison module 20 is a device with voltage comparison function, such as an operational amplifier, a comparator, etc. The first external power supply and the second external power supply are monitored by the voltage comparison module 20. The voltage comparison module 20 outputs a corresponding switching signal according to the state of the first external power supply and the second external power supply. The loop control module 10 controls the on-off of the loop between the first external power supply and the subsequent circuit 30 and the loop between the second external power supply and the subsequent circuit 30 according to the switching signal. For example, when the positive and negative poles of the first external power supply are reversely connected or suspended, and the positive and negative poles of the second external power supply are normally connected, the voltage comparison module 20 outputs a switching signal according to the voltage signal of the first input end, the voltage signal of the second input end and the voltage signal of the third input end. The loop control module 10 turns off the loop between the first external power supply and the subsequent circuit 30 and turns on the loop between the second external power supply and the subsequent circuit 30 according to the received switching signal.

[0044] The embodiment utilizes the comparison function of the voltage comparison module 20 to replace the special control chip of the current redundant power supply, has simple circuit, low cost, can accurately detect the voltage input by the external power supply, has fast response speed, can detect the power supply abnormality in a short time and realize switching, and ensures the accuracy of power supply switching.

[0045] In an embodiment of the present application, referring to Figure 2 As shown in the figure, the loop control module 10 includes a first switch tube and a second switch tube, the output end of the voltage comparison module 20 includes a first output end and a second output end, the first output end is connected with the controlled end of the first switch tube, and the second output end is connected with the controlled end of the second switch tube.

[0046] One of the first switch tube and the second switch tube is located in the loop between the first external power supply and the rear-stage circuit 30, and the other is located in the loop between the second external power supply and the rear-stage circuit 30. For example, the first switch tube can be arranged in the loop between the second external power supply and the rear-stage circuit 30, the second switch tube is arranged in the loop between the first external power supply and the rear-stage circuit 30, the first switch tube opens or closes the loop between the second external power supply and the rear-stage circuit 30 according to the switching signal of the first output end, and the second switch tube opens or closes the loop between the first external power supply and the rear-stage circuit 30 according to the switching signal of the second output end.

[0047] In the embodiment, the first switch tube and the second switch tube are devices with switching function, such as MOS tube (Metal-Oxide-Semiconductor Field-Effect Transistor, MOSFET), IGBT (Insulate-Gate Bipolar Transistor), triode, etc., which are not limited here.

[0048] In the technical scheme provided by the embodiment, the opening and closing of the loop between the external power supply and the rear-stage circuit are realized by the first switch tube and the second switch tube, the anti-reverse connection protection of the redundant power supply is realized, and the fast switching function of the redundant power supply is realized.

[0049] In an embodiment of the present application, as Figure 2As shown, the voltage comparison module 20 includes a first comparator U1A and a second comparator U1B, the non-inverting terminal of the first comparator U1A, the inverting terminal of the first comparator U1A and the non-inverting terminal of the second comparator U1B are connected with the voltage input terminal Vin, the non-inverting terminal of the first comparator U1A is connected with the negative pole V1- of the first external power supply, the inverting terminal of the first comparator U1A and the non-inverting terminal of the second comparator U1B are connected with the negative pole V2- of the second external power supply, the output terminal of the first comparator U1A is connected with the controlled terminal of the first switch tube and the inverting terminal of the second comparator U1B respectively, and the output terminal of the second comparator U1B is connected with the controlled terminal of the second switch tube.

[0050] In the embodiment, when the first external power supply and the second external power supply are reversely connected or suspended, the first comparator U1A or the second comparator U1B can output a switch signal to turn off the switch tube in the circuit, so as to realize the fast switching of the circuit.

[0051] In an embodiment of the present application, as shown in Figure 2 The redundancy power supply reverse connection prevention circuit further includes a voltage reduction module 40, the input terminal of the voltage reduction module 40 is connected with the voltage input terminal Vin, and the output terminal of the voltage reduction module 40 is connected with the power supply terminal of the first comparator U1A and the power supply terminal of the second comparator U1B respectively.

[0052] The voltage reduction module 40 is used for reducing the voltage of the voltage input terminal Vin and then outputting the voltage to the first comparator U1A and the second comparator U1B.

[0053] In the embodiment, when one of the first external power supply and the second external power supply is connected in positive direction, the voltage reduction module 40 can normally work and output the power supply +VCC to the comparator for power supply, at this time, the first comparator U1A and the second comparator U1B can normally work, and then control the first switch tube and the second switch tube to be turned on or turned off, when the first external power supply and the second external power supply are reversely connected or suspended, the voltage reduction module 40 cannot normally work because the first switch tube and the second switch tube are in reverse blocking state, at this time, the first comparator U1A and the second comparator U1B do not work, so the first switch tube and the second switch tube are in turned-off state, and then the subsequent circuit 30 is protected.

[0054] In an embodiment of the present application, as shown in Figure 2As shown, the first switching transistor is a first NMOS transistor Q1, and the second switching transistor is a second NMOS transistor Q2; the gate G of the first NMOS transistor Q1 is connected to the output terminal of the first comparator U1A, the drain D of the first NMOS transistor Q1 is connected to the negative terminal V2- of the second external power supply, and the source S of the first NMOS transistor Q1 is connected to the subsequent circuit 30; the gate G of the second NMOS transistor Q2 is connected to the output terminal of the second comparator U1B, the drain D of the second NMOS transistor Q2 is connected to the negative terminal V1- of the first external power supply, and the source S of the second NMOS transistor Q2 is connected to the subsequent circuit 30.

[0055] In this embodiment, when the first external power supply is connected in the positive direction and the second external power supply is connected in the positive direction, reversed, or floating, the output of the first comparator U1A outputs a low level, the first NMOS transistor Q1 is turned off, the loop between the second external power supply and the subsequent circuit 30 is broken, the output of the second comparator U1B outputs a high level, the second NMOS transistor Q2 is turned on, and the loop between the first external power supply and the subsequent circuit 30 is connected.

[0056] When the second external power supply is connected in the positive direction and the first external power supply is connected in the reverse direction or floating, the output of the first comparator U1A outputs a high level, the first NMOS transistor Q1 is turned on, the loop between the second external power supply and the subsequent circuit 30 is connected, the output of the second comparator U1B outputs a low level, the second NMOS transistor Q2 is turned off, and the loop between the first external power supply and the subsequent circuit 30 is disconnected.

[0057] When both the first external power supply and the second external power supply are reverse-connected or floating, the first NMOS transistor Q1 and the second NMOS transistor Q2 are both in the reverse cutoff state. The buck module 40 cannot work normally and cannot supply power to the first comparator U1A and the second comparator U1B. At this time, neither the first comparator U1A nor the second comparator U1B works. Therefore, the first NMOS transistor Q1 and the second NMOS transistor Q2 are both in the off state, and the loop between the first external power supply, the second external power supply and the subsequent circuit 30 is disconnected.

[0058] Specifically, such as Figure 2 As shown, the voltage comparison module 20 includes a first resistor R1, a second resistor R2, a third resistor R3, a sixth resistor R6, a seventh resistor R7, a ninth resistor R9, a first diode D1, and a second diode D2.

[0059] The inverting terminal of the first comparator U1A is connected with the first terminal of the first resistor R1 and the first terminal of the seventh resistor R7, the second terminal of the first resistor R1 is connected with the voltage input terminal Vin, the non-inverting terminal of the first comparator U1A is connected with the first terminal of the second resistor R2 and the first terminal of the third resistor R3, the second terminal of the second resistor R2 is connected with the voltage input terminal Vin, the second terminal of the third resistor R3 is connected with the anode of the first diode D1, the cathode of the first diode D1 is connected with the negative pole V1- of the first external power supply, and the output terminal of the first comparator U1A is connected with the controlled terminal of the first switch tube.

[0060] The inverting terminal of the second comparator U1B is connected with the first terminal of the sixth resistor R6, the second terminal of the sixth resistor R6 is connected with the output terminal of the first comparator U1A, the non-inverting terminal of the second comparator U1B is connected with the second terminal of the seventh resistor R7 and the first terminal of the ninth resistor R9, the second terminal of the ninth resistor R9 is connected with the anode of the second diode D2, the cathode of the second diode D2 is connected with the negative pole V2- of the second external power supply, and the output terminal of the second comparator U1B is connected with the controlled terminal of the second switch tube.

[0061] In the embodiment, the first comparator U1A and the second comparator U1B are used for comparison, the first diode D1 and the second diode D2 are used for unidirectional conduction, the first external power supply and the second external power supply are monitored, the first comparator U1A and the second comparator U1B can accurately detect the voltage input by the power supply, and the accuracy of power supply switching is ensured.

[0062] Further, as shown in Figure 2 The voltage comparison module 20 further includes a tenth resistor R10, the first terminal of the tenth resistor R10 is connected with the output terminal of the second comparator U1B, and the second terminal of the tenth resistor R10 is connected with the first terminal of the ninth resistor R9.

[0063] In the embodiment, in order to avoid the ringing effect, the second comparator U1B adopts the connection mode of a hysteresis comparator, the tenth resistor R10 and the second comparator U1B constitute a hysteresis comparator, the anti-interference ability is enhanced, and the unstable state caused by noise is avoided.

[0064] Further, the voltage comparison module 20 further comprises a fifth resistor R5 and an eighth resistor R8; a first end of the fifth resistor R5 is connected with an output end of the first comparator U1A, and a second end of the fifth resistor R5 is connected with a working power supply +VCC of the first comparator U1A; a first end of the eighth resistor R8 is connected with an output end of the second comparator U1B, and a second end of the eighth resistor R8 is connected with a working power supply +VCC of the second comparator U1B.

[0065] In the embodiment, the fifth resistor R5 and the eighth resistor R8 are respectively used as pull-up resistors of the first comparator U1A and the second comparator U1B, so as to improve the driving capability of the first comparator U1A and the second comparator U1B, and ensure that the signal can reach the power supply voltage level when outputting a high level.

[0066] In the embodiment, the first resistor R1, the second resistor R2, the third resistor R3, the sixth resistor R6, the seventh resistor R7 and the ninth resistor R9 meet the following conditions:

[0067] As shown in Figure 3 when the first external power supply and the second external power supply are both connected, the voltage input end Vin passes through the second resistor R2, the third resistor R3, the first diode D1, and the first resistor R1, the seventh resistor R7, the ninth resistor R9 and the second diode D2 in sequence.

[0068] At this time, the voltage at the non-inverting end of the first comparator U1A is the voltage at the inverting end of the first comparator U1A is

[0069] Since V ②＜ V ① at this time, the voltage at the output end of the first comparator U1A is ③ 0V, and the first NMOS tube Q1 is turned off.

[0070] the voltage at the non-inverting end of the second comparator U1B is the voltage at the inverting end of the second comparator U1B is ④ V ③ = 0V.

[0071] Since ⑤＞ V ④ at this time, the output voltage at the output end of the second comparator U1B is V ⑥ greater than the GS end voltage V GS2 (th) of the second NMOS tube Q2, and the second NMOS tube Q2 is turned on.

[0072] In the embodiment, when both the first external power supply and the second external power supply are connected in positive, only the second NMOS Q2 is turned on, so that only the first external power supply works and the second external power supply does not work, which can prevent the occurrence of current imbalance.

[0073] As shown in Figure 4 When the first external power supply is connected in reverse or suspended and the second external power supply is connected in positive, the voltage input terminal Vin passes through the first resistor R1, the seventh resistor R7, the ninth resistor R9, and the second diode D2 in sequence.

[0074] At this time, the voltage at the inverting terminal of the first comparator U1A is Since the first external power supply is connected in reverse or suspended, the voltage at the non-inverting terminal of the first comparator U1A is ② = Vin, at this time V ② > V ① , the voltage at the output terminal of the first comparator U1A is ③ = +vcc, V ③ is greater than the GS voltage V GS1 (th) of the first NMOS Q1, so the second NMOS Q2 is turned on.

[0075] For the second comparator U1B, the voltage at the non-inverting terminal of the second comparator U1B is The voltage at the inverting terminal of the second comparator U1B is ④ = V ③ = +VCC > V ⑤ , at this time the voltage at the output terminal of the second comparator U1B is 0V, and the second NMOS Q2 is turned off. ⑥

[0076] In the embodiment, when the first external power supply is connected in reverse or suspended and the second external power supply is connected in positive, through the comparison function of the first comparator U1A and the first comparator U1B, the second NMOS Q2 is turned off, so that the loop between the first external power supply and the subsequent circuit 30 is turned off, the first NMOS Q1 is turned on, so that the loop between the second external power supply and the subsequent circuit 30 is turned on, and the fast switching of the redundant power supply is realized.

[0077] As shown in Figure 5 When the first external power supply is connected in positive and the second external power supply is connected in reverse or suspended, the voltage input terminal Vin passes through the second resistor R2, the third resistor R3, and the first diode D1 in sequence.

[0078] At this time, the voltage at the non-inverting terminal of the first comparator U1A is ​Because the second external power supply is reversed or floating, the voltage V at the inverting terminal of the first comparator U1A is... ① =Vin, because the voltage V at the non-inverting input of the first comparator U1A ② Less than the voltage at the inverting terminal V ① At this time, the voltage V at the output terminal of the first comparator U1A is ③ The voltage is 0V, so the first NMOS transistor Q1 is turned off.

[0079] For the second comparator U1B, the voltage V at the non-inverting input of the second comparator U1B at this time ⑤ =Vin, the voltage V at the inverting input of the second comparator U1B ④ =0V, because V ⑤＞ V ④ Therefore, the voltage V at the output of the second comparator U1B ⑥ =+vcc, the second NMOS transistor Q2 turns on.

[0080] In this embodiment, when the second external power supply is reverse-connected or floating, and the first external power supply is connected in the correct direction, the comparison function of the first comparator U1A and the first comparator U1B can turn off the first NMOS transistor Q1, turn off the loop between the second external power supply and the subsequent circuit 30, turn on the second NMOS transistor Q2, and turn on the loop between the first external power supply and the subsequent circuit 30, thereby realizing the rapid switching of redundant power supplies.

[0081] like Figure 6 As shown, when both the first external power supply and the second external power supply are reverse-connected or floating, the body diodes of the first NMOS transistor Q1 and the second NMOS transistor Q2 are both in the reverse cutoff state, and there is no voltage input terminal Vin output. The buck module 40 does not work and cannot provide the working power supply +VCC to the first comparator U1A and the second comparator U1B. At this time, both the first NMOS transistor Q1 and the second NMOS transistor Q2 are in the off state, thereby protecting the subsequent circuit 30.

[0082] In another embodiment of the present application, the first switch tube is a first PMOS tube, the second switch tube is a second PMOS tube, and the voltage comparison module 20 further comprises a first inverter and a second inverter; the input end of the first inverter is connected with the output end of the first comparator U1A, the output end of the first inverter is connected with the gate of the first PMOS tube, the drain of the first PMOS tube is connected with the positive pole of the second external power supply, the source of the first PMOS tube is connected with the rear-stage circuit 30; the input end of the second inverter is connected with the output end of the second comparator U1B, the output end of the second inverter is connected with the gate of the second PMOS tube, the drain of the second PMOS tube is connected with the positive pole of the first external power supply, and the source of the second PMOS tube is connected with the rear-stage circuit 30.

[0083] In the embodiment, the PMOS tube is arranged at the input side of the loop control module 10, and the level of the output end of the comparator is inverted by using the inverter, thereby realizing the anti-reverse connection and fast switching function of the redundant power supply as in the foregoing embodiment, and the specific control logic can refer to the foregoing embodiment, which will not be described herein.

[0084] Further, as shown in Figure 2 The voltage input end Vin is connected with the second end of the eleventh resistor R11, the first end of the first capacitor C1 is connected with the second end of the eleventh resistor R11, and the second end of the first capacitor C1 is grounded; the first end of the second capacitor C2 is connected with the emitter of the triode Q3, and the second end of the second capacitor C2 is grounded.

[0085] In the embodiment, when one of the first external power supply and the second external power supply is connected in positive, the voltage input end Vin is stepped down by the triode Q3 and the voltage stabilizing tube D3, and the stepped-down +VCC power supply is supplied to the first comparator U1A and the second comparator U1B as the working power supply of the first comparator U1A and the second comparator U1B, so that the comparators are powered and operated, and the first switch tube and the second switch tube are controlled to be turned on or turned off.

[0086] In an embodiment of the present application, as shown in Figure 2As shown, the reverse connection prevention circuit of the redundant power supply further comprises a filtering module 50; a first input terminal of the filtering module 50 is connected with the positive pole of the first external power supply, a second input terminal of the filtering module 50 is connected with the positive pole of the second external power supply, and an output terminal of the filtering module 50 is connected with the voltage input terminal.

[0087] In the embodiment, the filtering module 50 is used for electromagnetic compatibility filtering, specifically, the filtering module 50 comprises a filter, through which the conduction of the interference signal of the external power supply can be reduced, the sensitive circuit inside the post-stage circuit 30 is protected, the influence of the high-frequency interference signal is prevented, the electromagnetic compatibility (EMC) of the power supply is ensured to meet the standard, and other electronic devices are avoided from being interfered.

[0088] The application further provides an industrial device comprising the reverse connection prevention circuit of the redundant power supply in any of the above embodiments, and the specific structure of the reverse connection prevention circuit of the redundant power supply is referred to the above embodiments. Since the industrial device adopts all the technical solutions of the above embodiments, it at least has all the beneficial effects brought by the technical solutions of the above embodiments, which will not be repeated here.

[0089] The corresponding technical features in the above embodiments can be used with each other on the premise that they do not cause contradictory or unimplementable schemes.

[0090] It should be noted that in this document, the term "comprising" or "including" or any other variant thereof is intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements not only includes those elements, but also includes other elements not explicitly listed or inherent to such a process, method, article or device. Without more limitations, the element defined by the statement "comprising a" does not exclude the presence of additional identical elements in the process, method, article or device including the element.

[0091] The embodiments of the application are described above in combination with the drawings, but the application is not limited to the above specific embodiments, which are only illustrative rather than limiting, and those of ordinary skill in the art can make many forms under the inspiration of the application without departing from the scope of the application and the protection scope of the claims.

Claims

1. A redundant power supply reverse connection protection circuit, characterized in that, The redundant power supply anti-reverse connection circuit comprises a loop control module and a voltage comparison module, the loop control module is connected between an external power supply and a subsequent circuit, the external power supply comprises a first external power supply and a second external power supply, a first input end of the voltage comparison module is used for being connected with a voltage input end of the subsequent circuit, a second input end of the voltage comparison module is used for being connected with a negative electrode of the first external power supply, a third input end of the voltage comparison module is used for being connected with a negative electrode of the second external power supply, and an output end of the voltage comparison module is connected with a controlled end of the loop control module; The voltage comparison module is used for comparing voltage signals of the first input end, the second input end and the third input end, and outputting a switching signal to the loop control module according to the voltage signals. The loop control module is used for controlling on-off of loops between the first external power supply and the subsequent circuit and between the second external power supply and the subsequent circuit according to the switching signal.

2. The reverse connection prevention circuit for redundant power supply according to claim 1, wherein The loop control module comprises a first switch tube and a second switch tube, the output end of the voltage comparison module comprises a first output end and a second output end, the first output end is connected with a controlled end of the first switch tube, and the second output end is connected with a controlled end of the second switch tube. One of the first switch tube and the second switch tube is located in the loop between the first external power supply and the subsequent circuit, and the other is located in the loop between the second external power supply and the subsequent circuit.

3. The reverse connection prevention circuit for redundant power supply according to claim 2, wherein The voltage comparison module comprises a first comparator and a second comparator, a non-inverting end of the first comparator, an inverting end of the first comparator and a non-inverting end of the second comparator are used for being connected with the voltage input end, the non-inverting end of the first comparator is used for being connected with the negative electrode of the first external power supply, the inverting end of the first comparator and the non-inverting end of the second comparator are used for being connected with the negative electrode of the second external power supply, an output end of the first comparator is connected with the controlled end of the first switch tube and an inverting end of the second comparator respectively, and an output end of the second comparator is connected with the controlled end of the second switch tube.

4. The reverse connection prevention circuit for redundant power supply according to claim 3, wherein The redundant power supply anti-reverse connection circuit further comprises a voltage reduction module, an input end of the voltage reduction module is connected with the voltage input end, and output ends of the voltage reduction module are connected with a power supply end of the first comparator and a power supply end of the second comparator respectively. The voltage reduction module is used for performing voltage reduction processing on a voltage of the voltage input end and outputting the voltage to the first comparator and the second comparator.

5. The reverse connection prevention circuit for redundant power supply according to claim 3, wherein The voltage comparison module comprises a first resistor, a second resistor, a third resistor, a sixth resistor, a seventh resistor, a ninth resistor, a first diode and a second diode. The inverting terminal of the first comparator is connected with the first terminal of the first resistor and the first terminal of the seventh resistor, the second terminal of the first resistor is connected with the voltage input terminal, the non-inverting terminal of the first comparator is connected with the first terminal of the second resistor and the first terminal of the third resistor, the second terminal of the second resistor is connected with the voltage input terminal, the second terminal of the third resistor is connected with the anode of the first diode, the cathode of the first diode is connected with the negative electrode of the first external power supply, and the output terminal of the first comparator is connected with the controlled terminal of the first switch tube. The inverting terminal of the second comparator is connected with the first terminal of the sixth resistor, the second terminal of the sixth resistor is connected with the output terminal of the first comparator, the non-inverting terminal of the second comparator is connected with the second terminal of the seventh resistor and the first terminal of the ninth resistor, the second terminal of the ninth resistor is connected with the anode of the second diode, the cathode of the second diode is connected with the negative electrode of the second external power supply, and the output terminal of the second comparator is connected with the controlled terminal of the second switch tube.

6. The reverse connection prevention circuit for redundant power supplies according to claim 5, wherein The voltage comparison module further comprises a tenth resistor, the first terminal of the tenth resistor is connected with the output terminal of the second comparator, and the second terminal of the tenth resistor is connected with the first terminal of the ninth resistor.

7. The reverse connection prevention circuit for redundant power supplies according to claim 5, wherein The voltage comparison module further comprises a fifth resistor and an eighth resistor, the first terminal of the fifth resistor is connected with the output terminal of the first comparator, the second terminal of the fifth resistor is connected with the working power supply of the first comparator, the first terminal of the eighth resistor is connected with the output terminal of the second comparator, and the second terminal of the eighth resistor is connected with the working power supply of the second comparator.

8. The reverse connection prevention circuit for redundant power supply as claimed in claim 4, wherein, The voltage comparison module further comprises a fifth resistor and an eighth resistor, the first terminal of the fifth resistor is connected with the output terminal of the first comparator, the second terminal of the fifth resistor is connected with the working power supply of the first comparator, the first terminal of the eighth resistor is connected with the output terminal of the second comparator, and the second terminal of the eighth resistor is connected with the working power supply of the second comparator. The voltage comparison module further comprises a fifth resistor and an eighth resistor, the first terminal of the fifth resistor is connected with the output terminal of the first comparator, the second terminal of the fifth resistor is connected with the working power supply of the first comparator, the first terminal of the eighth resistor is connected with the output terminal of the second comparator, and the second terminal of the eighth resistor is connected with the working power supply of the second comparator.

9. The reverse connection prevention circuit for redundant power supplies according to claim 1, wherein, The voltage comparison module further comprises a fifth resistor and an eighth resistor, the first terminal of the fifth resistor is connected with the output terminal of the first comparator, the second terminal of the fifth resistor is connected with the working power supply of the first comparator, the first terminal of the eighth resistor is connected with the output terminal of the second comparator, and the second terminal of the eighth resistor is connected with the working power supply of the second comparator. The voltage comparison module further comprises a fifth resistor and an eighth resistor, the first terminal of the fifth resistor is connected with the output terminal of the first comparator, the second terminal of the fifth resistor is connected with the working power supply of the first comparator, the first terminal of the eighth resistor is connected with the output terminal of the second comparator, and the second terminal of the eighth resistor is connected with the working power supply of the second comparator.

10. An industrial plant, characterized in that, The voltage comparison module further comprises a fifth resistor and an eighth resistor, the first terminal of the fifth resistor is connected with the output terminal of the first comparator, the second terminal of the fifth resistor is connected with the working power supply of the first comparator, the first terminal of the eighth resistor is connected with the output terminal of the second comparator, and the second terminal of the eighth resistor is connected with the working power supply of the second comparator. The voltage comparison module further comprises a fifth resistor and an eighth resistor, the first terminal of the fifth resistor is connected with the output terminal of the first comparator, the second terminal of the fifth resistor is connected with the working power supply of the first comparator, the first terminal of the eighth resistor is connected with the output terminal of the second comparator, and the second terminal of the eighth resistor is connected with the working power supply of the second comparator. The voltage comparison module further comprises a fifth resistor and an eighth resistor, the first terminal of the fifth resistor is connected with the output terminal of the first comparator, the second terminal of the fifth resistor is connected with the working power supply of the first comparator, the first terminal of the eighth resistor is connected with the output terminal of the second comparator, and the second terminal of the eighth resistor is connected with the working power supply of the second comparator. The voltage comparison module further comprises a fifth resistor and an eighth resistor, the first terminal of the fifth resistor is connected with the output terminal of the first comparator, the second terminal of the fifth resistor is connected with the working power supply of the first comparator, the first terminal of the eighth resistor is connected with the output terminal of the second comparator, and the second terminal of the eighth resistor is connected with the working power supply of the second comparator. The voltage comparison module further comprises a fifth resistor and an eighth resistor, the first terminal of the fifth resistor is connected with the output terminal of the first comparator, the second terminal of the fifth resistor is connected with the working power supply of the first comparator, the first terminal of the eighth resistor is connected with the output terminal of the second comparator, and the second terminal of the eighth resistor is connected with the working power supply of the second comparator. The voltage comparison module further comprises a fifth resistor and an eighth resistor, the first terminal of the fifth resistor is connected with the output terminal of the first comparator, the second terminal of the fifth resistor is connected with the working power supply of the first comparator, the first terminal of the eighth resistor is connected with the output terminal of the second comparator, and the second terminal of the eighth resistor is connected with the working power supply of the second comparator. The voltage comparison module further comprises a fifth resistor and an eighth resistor, the first terminal of the fifth resistor is connected with the output terminal of the first comparator, the second terminal of the fifth resistor is connected with the working power supply of the first comparator, the first terminal of the eighth resistor is connected with the output terminal of the second comparator, and the second terminal of the eighth resistor is connected with the working power supply of the second comparator. The voltage comparison module further comprises a fifth resistor and an eighth resistor, the first terminal of the fifth resistor is connected with the output terminal of the first comparator, the second terminal of the fifth resistor is connected with the working power supply of the first comparator, the first terminal of the eighth resistor is connected with the output terminal of the second comparator, and the second terminal of the eighth resistor is connected with the working power supply of the second comparator. The voltage comparison module further comprises a fifth resistor and an eighth resistor, the first terminal of the fifth resistor is connected with the output terminal of the first comparator, the second terminal of the fifth resistor is connected with the working power supply of the first comparator, the first terminal of the eighth resistor is connected with the output terminal of the second comparator, and the second terminal of the eighth resistor is connected with the working power supply of the second comparator. The voltage comparison module further comprises a fifth resistor and an eighth resistor, the first terminal of the fifth resistor is connected with the output terminal of the first comparator, the second terminal of the fifth resistor is connected with the working power supply of the first comparator, the first terminal of the eighth resistor is connected with the output terminal of the second comparator, and the second terminal of the eighth resistor is connected with the working power supply of the second comparator. The voltage comparison module further comprises a fifth resistor and an eighth resistor, the first terminal of the fifth resistor is connected with the output terminal of the first comparator, the second terminal of the fifth resistor is connected with the working power supply of the first comparator, the first terminal of the eighth resistor is connected with the output terminal of the second comparator, and the second terminal of the eighth resistor is connected with the working power supply of the second comparator. The voltage comparison module further comprises a fifth resistor and an eighth resistor, the first terminal of the fifth resistor is connected with the output terminal of the first comparator, the second terminal of the fifth resistor is connected with the working power supply of the first comparator, the first terminal of the eighth resistor is connected with the output terminal of the second comparator, and the second terminal of the eighth resistor is connected with the working power supply of the second comparator. The voltage comparison module further comprises a fifth resistor and an eighth resistor, the first terminal of the fifth resistor is connected with the output terminal of the first comparator, the second terminal of the fifth resistor is connected with the working power supply of the first comparator, the first terminal of the eighth resistor is connected with the output terminal of the second comparator, and the second terminal of the eighth resistor is connected with the working power supply of the second comparator. The voltage comparison module further comprises a fifth resistor and an eighth resistor, the first terminal of the fifth resistor is connected with the output terminal of the first comparator, the second terminal of the fifth resistor is connected with the working power supply of the first comparator, the first terminal of the eighth resistor is connected with the output terminal of the second comparator, and the second terminal of the eighth resistor is connected with the working power supply of the second comparator. The voltage comparison module further comprises a fifth resistor and an eighth resistor, the first terminal of the fifth resistor is connected with the output terminal of the first comparator, the second terminal of the fifth resistor is

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