Power supply anti-reverse circuit and power supply module

Abstract

The utility model discloses a power anti-reverse circuit and a power module, the power anti-reverse circuit comprising: a power input module, a loop switching module, a first power supply loop and a second power supply loop; the power input module comprises a first power access port and a second power access port; the loop switching module comprises a first voltage division switching unit and a second voltage division switching unit; the first power supply loop comprises a first voltage division unit, a first switch tube and a second switch tube; the second power supply loop comprises a second voltage division unit, a third switch tube and a fourth switch tube. The power anti-reverse circuit of the utility model embodiment can pass a large current and has low power loss. While improving the reverse connection protection capability of the power anti-reverse circuit for the load, it also controls the loss of power resources, so that the power anti-reverse circuit can realize reverse connection protection efficiently and energy-savingly.

Description

Technical Field

[0001] The utility model relates to the technical field of circuits, in particular to a power supply anti-reverse circuit and a power supply module. Background Art

[0002] The input part of the power supply is generally protected by fuses, diodes, field effect transistors (MOS), etc. in order to prevent erroneous operation such as connecting the positive and negative poles of the battery to the opposite circuit and causing damage.

[0003] A power reverse protection circuit in the prior art uses a Schottky diode as a switching element of the power reverse protection circuit, but the forward conduction voltage drop of the Schottky diode is about 0.3V, which will cause power loss, and the forward conduction current that the diode can tolerate is small and cannot pass large current. Utility Model Content

[0004] The utility model provides a power supply anti-reverse circuit and a power supply module, which can pass a large current with low power loss, and at the same time improves the reverse connection protection capability of the power supply anti-reverse circuit for the load, and also controls the loss of power supply resources, so that the power supply anti-reverse circuit can realize reverse connection protection efficiently and energy-savingly.

[0005] In a first aspect, an embodiment of the utility model provides a power supply anti-reverse circuit, comprising: a power supply input module, a circuit switching module, a first power supply circuit, and a second power supply circuit;

[0006] The power input module includes a first power access port and a second power access port; the circuit switching module includes a first voltage division switching unit and a second voltage division switching unit; the first power supply circuit includes a first voltage division unit, a first switch tube and a second switch tube; the second power supply circuit includes a second voltage division unit, a third switch tube and a fourth switch tube;

[0007] The first voltage division switching unit is connected to the second power supply inlet, the first voltage division unit and the gate of the first switch tube, the source of the first switch tube is connected to the load, the drain of the first switch tube is connected to the first power supply inlet, the gate of the second switch tube is connected to the first power supply inlet, the source of the second switch tube is connected to the load, and the drain of the second switch tube is connected to the second power supply inlet;

[0008] The second voltage division switching unit is connected to the first power access port, the second voltage division unit and the gate of the third switch tube, the source of the third switch tube is connected to the load, the drain of the third switch tube is connected to the second power access port, the gate of the fourth switch tube is connected to the second power access port, the source of the fourth switch tube is connected to the load, and the drain of the fourth switch tube is connected to the first power access port.

[0009] Optionally, the direction of current in the first power supply circuit is opposite to the direction of current in the second power supply circuit, and the direction in which the current in the first power supply circuit flows into the load is the same as the direction in which the current in the second power supply circuit flows into the load.

[0010] Optionally, the first voltage dividing unit includes a first resistor and a second resistor, and the second voltage dividing unit includes a third resistor and a fourth resistor;

[0011] One end of the first resistor is connected to the first power supply inlet, the other end of the first resistor is connected to one end of the second resistor and the first voltage division switching unit, and the other end of the second resistor is grounded;

[0012] One end of the third resistor is connected to the second power supply inlet, the other end of the third resistor is connected to one end of the fourth resistor and the second voltage division switching unit, and the other end of the fourth resistor is grounded.

[0013] Optionally, the first voltage division switching unit includes a fifth switch tube and a first relay; the second voltage division switching unit includes a sixth switch tube and a second relay; the first power supply circuit also includes a third voltage division unit, and the second power supply circuit also includes a fourth voltage division unit;

[0014] The fourth voltage dividing unit includes a fifth resistor and a sixth resistor, and the third voltage dividing unit includes a seventh resistor and an eighth resistor;

[0015] The gate of the fifth switch tube is connected between the seventh resistor and the eighth resistor, the source of the fifth switch tube is grounded, and the drain of the fifth switch tube is connected to the control end of the first relay;

[0016] The gate of the sixth switch tube is connected between the fifth resistor and the sixth resistor, the source of the sixth switch tube is grounded, and the drain of the sixth switch tube is connected to the control end of the second relay.

[0017] Optionally, the first voltage division switching unit further includes a first diode, and the second voltage division switching unit further includes a second diode;

[0018] The anode of the first diode is connected to the drain of the fifth switch tube, and the cathode of the first diode is connected to the control end of the first relay;

[0019] The anode of the second diode is connected to the drain of the sixth switch tube, and the cathode of the second diode is connected to the control end of the second relay.

[0020] Optionally, it also includes: a voltage regulating module;

[0021] The voltage regulating module includes a third diode and a fourth diode;

[0022] The anode of the third diode is connected to the drain of the first switch tube, and the cathode of the third diode is connected to the source of the first switch tube;

[0023] An anode of the fourth diode is connected to a drain of the third switch tube, and a cathode of the fourth diode is connected to a source of the third switch tube.

[0024] Optionally, both the first switch tube and the third switch tube are PMOS tubes;

[0025] The second switch tube and the fourth switch tube are both NMOS tubes.

[0026] Optionally, the fifth switch tube and the sixth switch tube are both NMOS tubes.

[0027] Optionally, the third diode and the fourth diode are both Schottky diodes.

[0028] In a second aspect, an embodiment of the utility model further provides a power supply module, wherein the power supply module is provided with a power supply anti-reverse circuit as in the first aspect.

[0029] The utility model embodiment provides a power anti-reverse circuit and a power module, including: a power input module, a loop switching module, a first power supply loop and a second power supply loop; the power input module includes a first power access port and a second power access port; the loop switching module includes a first voltage division switching unit and a second voltage division switching unit; the first power supply loop includes a first voltage division unit, a first switch tube and a second switch tube; the second power supply loop includes a second voltage division unit, a third switch tube and a fourth switch tube; the first voltage division switching unit is connected to the second power access port, the first voltage division unit and the gate of the first switch tube, and the The source of a switch tube is connected to the load, the drain of the first switch tube is connected to the first power access port, the gate of the second switch tube is connected to the first power access port, the source of the second switch tube is connected to the load, and the drain of the second switch tube is connected to the second power access port; the second voltage division switching unit is connected to the first power access port, the second voltage division unit and the gate of the third switch tube, the source of the third switch tube is connected to the load, the drain of the third switch tube is connected to the second power access port, the gate of the fourth switch tube is connected to the second power access port, the source of the fourth switch tube is connected to the load, and the drain of the fourth switch tube is connected to the first power access port. The power anti-reverse circuit provided by the embodiment of the utility model can pass a large current and has low power loss. While improving the reverse connection protection capability of the power anti-reverse circuit for the load, it also controls the loss of power resources, so that the power anti-reverse circuit can achieve reverse connection protection efficiently and energy-savingly.

[0030] It should be understood that the contents described in this section are not intended to identify the key or important features of the embodiments of the present utility model, nor are they intended to limit the scope of the present utility model. Other features of the present utility model will become easily understood through the following description. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0032] Figure 1 A circuit diagram of a power supply anti-reverse circuit provided in an embodiment of the utility model;

[0033] Figure 2 A circuit diagram of another power supply anti-reverse circuit provided in an embodiment of the utility model;

[0034] Figure 3 A circuit diagram of another power supply anti-reverse circuit provided in an embodiment of the utility model;

[0035] Figure 4 A circuit diagram of another power supply anti-reverse circuit provided in an embodiment of the utility model. DETAILED DESCRIPTION

[0036] In order to enable those skilled in the art to better understand the solution of the utility model, the technical solution in the embodiment of the utility model will be clearly and completely described below in conjunction with the drawings in the embodiment of the utility model. Obviously, the described embodiment is only a part of the embodiment of the utility model, not all of the embodiments. Based on the embodiment of the utility model, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of the utility model.

[0037] It should be noted that the terms "first", "second", etc. in the specification and claims of the utility model and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the data used in this way can be interchanged where appropriate, so that the embodiments of the utility model described here can be implemented in an order other than those illustrated or described here. In addition, the terms "including" and "having" and any of their variations are intended to cover non-exclusive inclusions, for example, a process, method, system, product or device that includes a series of steps or units is not necessarily limited to those steps or units clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0038] Figure 1 A circuit diagram of a power supply anti-reverse circuit provided by an embodiment of the utility model, referring to Figure 1 The circuit includes: a power input module 110, a circuit switching module 120, a first power supply circuit 130 and a second power supply circuit 140. The power input module 110 includes a first power access port 111 and a second power access port 112. The circuit switching module 120 includes a first voltage division switching unit 121 and a second voltage division switching unit 122. The first power supply circuit 130 includes a first voltage division unit 131, a first switch tube Q1 and a second switch tube Q2. The second power supply circuit 140 includes a second voltage division unit 141, a third switch tube Q3 and a fourth switch tube Q4.

[0039] Continue to refer Figure 1The first voltage division switching unit 121 is connected to the second power supply inlet 112, the first voltage division unit 131, and the gate of the first switch tube Q1. The source of the first switch tube Q1 is connected to the load, the drain of the first switch tube Q1 is connected to the first power supply inlet 111, the gate of the second switch tube Q2 is connected to the first power supply inlet 111, the source of the second switch tube Q2 is connected to the load, and the drain of the second switch tube Q2 is connected to the second power supply inlet 112. The second voltage division switching unit 122 is connected to the first power supply inlet 111, the second voltage division unit 141, and the gate of the third switch tube Q3. The source of the third switch tube Q3 is connected to the load, the drain of the third switch tube Q3 is connected to the second power supply inlet 112, the gate of the fourth switch tube Q4 is connected to the second power supply inlet 112, the source of the fourth switch tube Q4 is connected to the load, and the drain of the fourth switch tube Q4 is connected to the first power supply inlet 111.

[0040] Continue to refer Figure 1 , the first power access port 111 is connected to the positive power electrode P, and the second power access port 112 is connected to the negative power electrode N. It should be noted that when the first power access port 111 and the second power access port 112 are not connected to the power supply, the first power access port 111 is grounded by the first voltage divider unit 131, and the second power access port 112 is grounded by the second voltage divider unit 141.

[0041] The power anti-reverse circuit provided by the embodiment of the utility model is provided with a first voltage dividing unit 131 and a second voltage dividing unit 141 to achieve voltage reduction, and adopts MOSFET as a switch tube, which can pass a large current with low power loss. The embodiment of the utility model improves the reverse connection protection capability of the power anti-reverse circuit for the load, and also controls the loss of power resources, so that the power anti-reverse circuit can achieve reverse connection protection efficiently and energy-savingly.

[0042] Optionally, based on the above embodiment, the current direction in the first power supply circuit 130 is opposite to the current direction in the second power supply circuit 140, and the direction in which the current in the first power supply circuit 130 flows into the load is the same as the direction in which the current in the second power supply circuit 140 flows into the load.

[0043] Optionally, based on the above embodiment, continue to refer to Figure 1, the first voltage dividing unit 131 includes a first resistor R1 and a second resistor R2, and the second voltage dividing unit 141 includes a third resistor R3 and a fourth resistor R4. One end of the first resistor R1 is connected to the first power supply inlet 111, the other end of the first resistor R1 is connected to one end of the second resistor R2 and the first voltage dividing switching unit 121, and the other end of the second resistor R2 is grounded. One end of the third resistor R3 is connected to the second power supply inlet 112, the other end of the third resistor R3 is connected to one end of the fourth resistor R4 and the second voltage dividing switching unit 122, and the other end of the fourth resistor R4 is grounded.

[0044] In the embodiment of the present invention, the first voltage dividing unit 131 includes a first resistor R1 and a second resistor R2, and the second voltage dividing unit 141 includes a third resistor R3 and a fourth resistor R4, for achieving voltage reduction.

[0045] Figure 2 A circuit diagram of another power supply anti-reverse circuit provided by an embodiment of the utility model, specifically: Figure 1 Partial circuit diagram of the power supply anti-reverse circuit in the figure. Figure 2 The specific structures of the first voltage division switching unit 121 and the second voltage division switching unit 122 are shown. Figure 1-2 , the first voltage division switching unit 121 includes a fifth switch tube Q5 and a first relay Relay1. The second voltage division switching unit 122 includes a sixth switch tube Q6 and a second relay Relay2. The first power supply circuit 130 also includes a third voltage division unit 132, and the second power supply circuit 140 also includes a fourth voltage division unit 142. The third voltage division unit 132 includes a fifth resistor R5 and a sixth resistor R6, and the fourth voltage division unit 142 includes a seventh resistor R7 and an eighth resistor R8.

[0046] Continue to refer Figure 2 The gate of the fifth switch tube Q5 is connected between the seventh resistor R7 and the eighth resistor R8, the source of the fifth switch tube Q5 is grounded, and the drain of the fifth switch tube Q5 is connected to the control end of the first relay Relay1. The gate of the sixth switch tube Q6 is connected between the fifth resistor R5 and the sixth resistor R6, the source of the sixth switch tube Q6 is grounded, and the drain of the sixth switch tube Q6 is connected to the control end of the second relay Relay2.

[0047] Optionally, based on the above embodiment, continue to refer to Figure 1One end of the fifth resistor R5 is connected to the first power supply inlet 111, the other end of the fifth resistor R5 is connected to one end of the sixth resistor R6 and the gate of the second switch tube Q2, and the other end of the sixth resistor R6 is grounded. One end of the seventh resistor R7 is connected to the second power supply inlet 112, the other end of the seventh resistor R7 is connected to one end of the eighth resistor R8 and the gate of the fourth switch tube Q4, and the other end of the eighth resistor R8 is grounded.

[0048] In the embodiment of the utility model, the first relay Relay1 and the second relay Relay2 are used as switching switches for switching voltages. The fifth switch tube Q5 is used to control the first relay Relay1, and the sixth switch tube Q6 is used to control the second relay Relay2.

[0049] Figure 3 Another circuit diagram of a power supply anti-reverse circuit provided by the embodiment of the utility model is shown in FIG. Figure 3 ,and Figure 1 The power anti-reverse circuit in is different in that: Figure 3 The first power inlet 111 is connected to the negative pole N of the power supply, and the second power inlet 112 is connected to the positive pole P of the power supply for power supply. For the convenience of description, this connection relationship is called reverse power connection. Figure 4 A circuit diagram of another power supply anti-reverse circuit provided by an embodiment of the utility model, specifically: Figure 3 Partial circuit diagram of the power supply anti-reverse circuit in the figure. Figure 4 The specific structures of the first voltage division switching unit 121 and the second voltage division switching unit 122 are shown.

[0050] In the embodiment of the utility model, when the fifth switch tube Q5 is turned off, the upper contact of the first relay Relay1 is connected, and when the fifth switch tube Q5 is turned on, the lower contact of the first relay Relay1 is connected. When the sixth switch tube Q6 is turned off, the upper contact of the second relay Relay2 is connected, and when the sixth switch tube Q6 is turned on, the lower contact of the second relay Relay2 is connected.

[0051] Continue to refer Figure 1-2 The upper contact of the first relay Relay1 is connected between the first resistor R1 and the second resistor R2 , and the lower contact of the first relay Relay1 is connected to the second power inlet 112 . Figure 1 The contact of the first relay Relay1 in the circuit is connected. Figure 2 The fifth switch tube Q5 in is turned off.

[0052] Continue to refer Figure 1-2 , an upper contact of the second relay Relay2 is connected between the fifth resistor R5 and the sixth resistor R6 , and a lower contact of the second relay Relay2 is connected to the first power inlet 111 . Figure 1The lower contact of the second relay Relay2 in the Figure 2 The sixth switch tube Q6 in is turned on.

[0053] Figure 3 The upper and lower contacts of the first relay Relay1 in the circuit are connected. Figure 4 The fifth switch tube Q5 in is turned on. Figure 3 The contact of the second relay Relay2 in the circuit is connected. Figure 4 The sixth switch tube Q6 in is turned off.

[0054] Optionally, based on the above embodiment, continue to refer to Figure 2 The first voltage division switching unit 121 further includes a first diode D1, and the second voltage division switching unit 122 further includes a second diode D2. The anode of the first diode D1 is connected to the drain of the fifth switch tube Q5, and the cathode of the first diode D1 is connected to the control end of the first relay Relay1. The anode of the second diode D2 is connected to the drain of the sixth switch tube Q6, and the cathode of the second diode D2 is connected to the control end of the second relay Relay2.

[0055] In the embodiment of the utility model, the first diode D1 and the second diode D2 are used as freewheeling diodes to respond to the induced electromotive force when the relay coil is powered off.

[0056] Optionally, based on the above embodiment, continue to refer to Figure 1 , the circuit further includes: a voltage regulating module 150. The voltage regulating module 150 includes a third diode D3 and a fourth diode D4. The anode of the third diode D3 is connected to the drain of the first switch tube Q1, and the cathode of the third diode D3 is connected to the source of the first switch tube Q1. The anode of the fourth diode D4 is connected to the drain of the third switch tube Q3, and the cathode of the fourth diode D4 is connected to the source of the third switch tube Q3.

[0057] In the embodiment of the utility model, the third diode D3 is connected in parallel with the parasitic diode in the first switch tube Q1, and the fourth diode D4 is connected in parallel with the parasitic diode in the third switch tube Q3, which can reduce the forward conduction voltage of the first switch tube Q1 and the third switch tube Q3, so that the forward conduction voltage of the parasitic diode in the first switch tube Q1 is clamped at the same voltage as the forward conduction voltage of the third diode D3, and the forward conduction voltage of the parasitic diode in the third switch tube Q3 is clamped at the same voltage as the forward conduction voltage of the fourth diode D4.

[0058] Optionally, based on the above embodiment, the forward conduction voltages of the third diode D3 and the fourth diode D4 are both 0.3V.

[0059] Exemplarily, the forward conduction voltage of the parasitic diodes in the first switch tube Q1 and the third switch tube Q3 can both be 0.7V. When the third diode D3 is connected in parallel with the parasitic diode in the first switch tube Q1 and the fourth diode D4 is connected in parallel with the parasitic diode in the third switch tube Q3, the forward conduction voltage of the parasitic diode in the first switch tube Q1 is clamped at 0.3V, and the forward conduction voltage of the parasitic diode in the third switch tube Q3 is also clamped at 0.3V.

[0060] Optionally, based on the above embodiment, continue to refer to Figure 1 , the power anti-reverse circuit also includes: a ninth resistor R9, a tenth resistor R10, an eleventh resistor R11 and a twelfth resistor R12. One end of the ninth resistor R9 is connected to the control end of the first relay Relay1, and the other end of the ninth resistor R9 is connected to the gate of the first switch tube Q1. One end of the tenth resistor R10 is connected between the third resistor R3 and the fourth resistor R4, and the other end of the tenth resistor R10 is connected to the gate of the second switch tube Q2. One end of the eleventh resistor R11 is connected to the control end of the second relay Relay2, and the other end of the eleventh resistor R11 is connected to the gate of the third switch tube Q3. One end of the twelfth resistor R12 is connected between the seventh resistor R7 and the eighth resistor R8, and the other end of the twelfth resistor R12 is connected to the gate of the fourth switch tube Q4.

[0061] In the embodiment of the utility model, the ninth resistor R9, the tenth resistor R10, the eleventh resistor R11 and the twelfth resistor R12 are provided to play a protective role and prevent excessive transient current from impacting the switch tube.

[0062] Optionally, based on the above embodiment, the first switch tube Q1 and the third switch tube Q3 are both PMOS tubes, and the second switch tube Q2 and the fourth switch tube Q4 are both NMOS tubes.

[0063] Optionally, based on the above embodiment, the fifth switch tube and the sixth switch tube are both NMOS tubes.

[0064] Optionally, based on the above embodiment, the third diode and the fourth diode are both Schottky diodes.

[0065] In the present utility model embodiment, reference Figure 1-2When the power supply is positively connected, at the moment of power-on, the first resistor R1 and the second resistor R2 are connected in series, the fifth resistor R5 and the sixth resistor R6 are connected in series, the first voltage dividing unit 131 and the third voltage dividing unit 132 are connected in parallel, the third resistor R3 and the fourth resistor R4 are connected in series, the seventh resistor R7 and the eighth resistor R8 are connected in series, and the second voltage dividing unit 141 and the fourth voltage dividing unit 142 are connected in parallel. After the first voltage dividing unit 131 and the third voltage dividing unit 132 and the second voltage dividing unit 141 and the fourth voltage dividing unit 142 divide the voltage, the channels of the first switch tube Q1, the second switch tube Q2 and the sixth switch tube Q6 are turned on, and the channels of the third switch tube Q3, the fourth switch tube Q4 and the fifth switch tube Q5 are turned off. In the steady state process, because the channel of the second switch tube Q2 is turned on, the negative electrode N of the power supply is grounded, and the power supply voltage changes. At this time, the channels of the first switch tube Q1, the second switch tube Q2 and the sixth switch tube Q6 are turned on, and the channels of the third switch tube Q3, the fourth switch tube Q4 and the fifth switch tube Q5 are turned off. In summary, Figure 1-2 In the power reverse protection circuit of the embodiment, at the power-on instant and in the steady state, the channels of the first switch tube Q1, the second switch tube Q2 and the sixth switch tube Q6 are turned on, and the channels of the third switch tube Q3, the fourth switch tube Q4 and the fifth switch tube Q5 are turned off.

[0066] In order to facilitate understanding of the scheme of the embodiment of the utility model, illustratively, when the power supply is positively connected, when the power supply voltage is 5V, the resistance values ​​of the first resistor R1, the second resistor R2, the third resistor R3, the fourth resistor R4, the fifth resistor R5, the sixth resistor R6, the seventh resistor R7 and the eighth resistor R8 are all equal, and the forward conduction voltages of the third diode D3 and the fourth diode D4 are both 0.3V. At the moment of power-on, the voltage between the positive electrode P of the power supply and the ground is 2.5V, the voltage between the negative electrode N of the power supply and the ground is -2.5V, and the upper contact of the first relay Relay1 is connected. At this time, the voltage between the gate of the first switch tube Q1 and the ground is 1.25V, and the voltage between the gate source of the first switch tube Q1 is 1.25-(2.5-0.3)=-0.95V, so the channel of the first switch tube Q1 is turned on. The voltage between the second switch tube Q2 and the ground is 1.25V, the voltage between the gate and source of the second switch tube Q2 is 1.25-0=1.25V, the channel of the second switch tube Q2 is turned on, the channel of the sixth switch tube Q6 is turned on, and the lower contact of the second relay Relay2 is turned on. The voltage between the third switch tube Q3 and the ground is -1.25V. Since the lower contact of the second relay Relay2 is turned on, the voltage between the gate and source of the third switch tube Q3 is 2.5-2.5=0V, and the channel of the third switch tube Q3 is turned off. The voltage between the fourth switch tube Q4 and the ground is -1.25V, the voltage between the gate and source of the fourth switch tube Q4 is -1.25-0=-1.25V, the channel of the fourth switch tube Q4 is turned off, the channel of the fifth switch tube Q5 is turned off, and the upper contact of the first relay Relay1 is turned on.

[0067] When the power supply is positively connected, in the steady state process, after the channel of the second switch tube Q2 is turned on, the negative electrode N of the power supply is grounded. At this time, the voltage between the negative electrode N of the power supply and the ground is 0V, the voltage between the positive electrode P of the power supply and the ground is 5V, and the voltage between the gate of the first switch tube Q1 and the ground is 2.5V. Because the upper contact of the first relay Relay1 is connected, the voltage between the gate source of the first switch tube Q1 is 2.5-(5-0.3)=-2.2V, and the channel of the first switch tube Q1 is turned on. The voltage between the second switch tube Q2 and the ground is 2.5V, the voltage between the gate source of the second switch tube Q2 is 2.5-0=2.5V, the channel of the second switch tube Q2 is turned on, the channel of the sixth switch tube Q6 is turned on, and the lower contact of the second relay Relay2 continues to be connected. The voltage between the third switch tube Q3 and the ground is 0V. Since the lower contact of the second relay Relay2 is still connected, the voltage between the gate and source of the third switch tube Q3 is 5-5=0V, and the channel of the third switch tube Q3 is cut off. The voltage between the fourth switch tube Q4 and the ground is 0V, the voltage between the gate and source of the fourth switch tube Q4 is 0-0=0V, the channel of the fourth switch tube Q4 is cut off, the channel of the fifth switch tube Q5 is cut off, and the upper contact of the first relay Relay1 is connected.

[0068] In the present utility model embodiment, reference Figure 3-4 When the power supply is reversed, at the moment of power-on, the first resistor R1 and the second resistor R2 are connected in series, the fifth resistor R5 and the sixth resistor R6 are connected in series, the first voltage dividing unit 131 and the third voltage dividing unit 132 are connected in parallel, the third resistor R3 and the fourth resistor R4 are connected in series, the seventh resistor R7 and the eighth resistor R8 are connected in series, and the second voltage dividing unit 141 and the fourth voltage dividing unit 142 are connected in parallel. After the first voltage dividing unit 131 and the third voltage dividing unit 132 are divided by the second voltage dividing unit 141 and the fourth voltage dividing unit 142, the channels of the third switch tube Q3, the fourth switch tube Q4 and the fifth switch tube Q5 are turned on, and the channels of the first switch tube Q1, the second switch tube Q2 and the sixth switch tube Q6 are turned off. In the steady state process, because the channel of the fourth switch tube Q4 is turned on, the negative electrode N of the power supply is grounded, and the power supply voltage changes. At this time, the channels of the third switch tube Q3, the fourth switch tube Q4 and the fifth switch tube Q5 are turned on, and the channels of the first switch tube Q1, the second switch tube Q2 and the sixth switch tube Q6 are turned off. In summary, Figure 3-4 In the power reverse protection circuit of the embodiment, the channels of the third switch tube Q3, the fourth switch tube Q4 and the fifth switch tube Q5 are turned on, and the channels of the first switch tube Q1, the second switch tube Q2 and the sixth switch tube Q6 are turned off during the power-on instant and the steady state process. Since the operating principle of the circuit is the same when the power is clean and when the power is reversed, the analysis process of the circuit when the power is reversed will not be repeated here.

[0069] The embodiment of the utility model further provides a power supply module, and the power supply module is provided with the power supply anti-reverse circuit provided in the above embodiment.

[0070] The above specific implementations do not constitute a limitation on the protection scope of the present utility model. It should be understood by those skilled in the art that various modifications, combinations, sub-combinations and substitutions can be made according to design requirements and other factors. Any modification, equivalent substitution and improvement made within the spirit and principle of the present utility model shall be included in the protection scope of the present utility model.

Claims

1. A power supply anti-reverse circuit, characterized in that: include: A power input module, a circuit switching module, a first power supply circuit and a second power supply circuit; The power input module includes a first power access port and a second power access port; the circuit switching module includes a first voltage division switching unit and a second voltage division switching unit; the first power supply circuit includes a first voltage division unit, a first switch tube and a second switch tube; the second power supply circuit includes a second voltage division unit, a third switch tube and a fourth switch tube; The first voltage division switching unit is connected to the second power supply inlet, the first voltage division unit and the gate of the first switch tube, the source of the first switch tube is connected to the load, the drain of the first switch tube is connected to the first power supply inlet, the gate of the second switch tube is connected to the first power supply inlet, the source of the second switch tube is connected to the load, and the drain of the second switch tube is connected to the second power supply inlet; The second voltage division switching unit is connected to the first power access port, the second voltage division unit and the gate of the third switch tube, the source of the third switch tube is connected to the load, the drain of the third switch tube is connected to the second power access port, the gate of the fourth switch tube is connected to the second power access port, the source of the fourth switch tube is connected to the load, and the drain of the fourth switch tube is connected to the first power access port.

2. The power supply anti-reverse circuit according to claim 1, characterized in that: The direction of the current in the first power supply circuit is opposite to the direction of the current in the second power supply circuit, and the direction in which the current in the first power supply circuit flows into the load is the same as the direction in which the current in the second power supply circuit flows into the load.

3. The power anti-reverse circuit according to claim 1, characterized in that: The first voltage dividing unit includes a first resistor and a second resistor, and the second voltage dividing unit includes a third resistor and a fourth resistor; One end of the first resistor is connected to the first power supply inlet, the other end of the first resistor is connected to one end of the second resistor and the first voltage division switching unit, and the other end of the second resistor is grounded; One end of the third resistor is connected to the second power supply inlet, the other end of the third resistor is connected to one end of the fourth resistor and the second voltage division switching unit, and the other end of the fourth resistor is grounded.

4. The power anti-reverse circuit according to claim 3, characterized in that: The first voltage division switching unit includes a fifth switch tube and a first relay; the second voltage division switching unit includes a sixth switch tube and a second relay; the first power supply circuit also includes a third voltage division unit, and the second power supply circuit also includes a fourth voltage division unit; The fourth voltage dividing unit includes a fifth resistor and a sixth resistor, and the third voltage dividing unit includes a seventh resistor and an eighth resistor; The gate of the fifth switch tube is connected between the seventh resistor and the eighth resistor, the source of the fifth switch tube is grounded, and the drain of the fifth switch tube is connected to the control end of the first relay; The gate of the sixth switch tube is connected between the fifth resistor and the sixth resistor, the source of the sixth switch tube is grounded, and the drain of the sixth switch tube is connected to the control end of the second relay.

5. The power anti-reverse circuit according to claim 4, characterized in that: The first voltage division switching unit further includes a first diode, and the second voltage division switching unit further includes a second diode; The anode of the first diode is connected to the drain of the fifth switch tube, and the cathode of the first diode is connected to the control end of the first relay; The anode of the second diode is connected to the drain of the sixth switch tube, and the cathode of the second diode is connected to the control end of the second relay.

6. The power supply anti-reverse circuit according to claim 1, characterized in that: Also includes: Voltage regulating module; The voltage regulating module includes a third diode and a fourth diode; The anode of the third diode is connected to the drain of the first switch tube, and the cathode of the third diode is connected to the source of the first switch tube; An anode of the fourth diode is connected to a drain of the third switch tube, and a cathode of the fourth diode is connected to a source of the third switch tube.

7. The power anti-reverse circuit according to claim 1, characterized in that: The first switch tube and the third switch tube are both PMOS tubes; The second switch tube and the fourth switch tube are both NMOS tubes.

8. The power supply anti-reverse circuit according to claim 4, characterized in that: The fifth switch tube and the sixth switch tube are both NMOS tubes.

9. The power supply anti-reverse circuit according to claim 6, characterized in that: The third diode and the fourth diode are both Schottky diodes.

10. A power module, characterized in that: The power module is provided with a power anti-reverse circuit according to any one of claims 1 to 9.

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