Anti-backflow circuit and power supply module

Abstract

The utility model provides an anti-backflow circuit and a power supply module, comprising at least two circuits which form the same power supply circuit, the input end of each power supply circuit is electrically connected with a first DC power supply, and the output end of each power supply circuit outputs a second DC power supply and supplies power to the outside; the power supply circuit comprises a first control triode and a first MOS tube, a base electrode of the first control triode is electrically connected with a first divider resistor and then is connected to a first direct current power supply, the base electrode of the first control triode is also electrically connected with a second divider resistor and then is grounded, and an emitting electrode of the first control triode is grounded; the collector is electrically connected with the first control resistor and then connected to the grid of the first MOS tube, the drain of the first MOS tube is electrically connected with the first direct-current power supply, and the source outputs a second direct-current power supply. According to the utility model, the anti-backflow circuit can be extended to a plurality of power supply circuits, so that the plurality of power supply circuits can supply power to the same load or different loads. The circuit is low in cost, solves the heating problem of a conventional anti-backflow circuit, and improves the reliability of a product.

Description

Technical Field

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

[0002] Traditional power supply circuits generally have a single power input. The disadvantage of this single power supply is that if the power supply fails, the entire system will not work properly, which has a greater impact on some equipment that requires long-term uninterrupted operation.

[0003] At present, some high-end equipment often designs dual power supply or multi-power supply redundancy function in the power supply system. When the main power supply fails, the redundant power supply can be immediately switched to power the system to ensure the normal operation of the equipment. Figure 1 As shown, when two DC lines supply power to the load at the same time, Schottky diodes are usually used as isolation circuits. However, Schottky diodes have leakage current problems. When the input current is large, the temperature of the Schottky diode rises, the loss rate is large, and there will be serious heating problems. It is not suitable for application in actual circuits. Utility Model Content

[0004] In order to solve the above technical problems, a technical solution adopted by the utility model is to provide an anti-backflow circuit, including at least two power supply circuits with the same circuit composition, the input end of each power supply circuit is electrically connected to a first DC power supply, the output end outputs a second DC power supply, and supplies power to the outside; the power supply circuit includes a first control transistor and a first MOS tube, the base of the first control transistor is electrically connected to a first voltage-dividing resistor and then connected to the first DC power supply, and the base of the first control transistor is also electrically connected to the second voltage-dividing resistor and then grounded, the emitter of the first control transistor is grounded, the collector is electrically connected to the first control resistor and then connected to the gate of the first MOS tube, the drain of the first MOS tube is electrically connected to the first DC power supply, and the source outputs the second DC power supply.

[0005] In some embodiments, the first DC power supply is also electrically connected to a first filter capacitor and then grounded, a second control resistor is also arranged between the source and the gate of the first MOS tube, a second filter capacitor is also connected in parallel at both ends of the second control resistor, and the source of the first MOS tube is electrically connected to a third filter capacitor and then grounded.

[0006] In some embodiments, the first control transistor is a chip L8050QLT1 G, and the first MOS transistor is a chip AET3152AS.

[0007] In some embodiments, the voltage of the first DC power supply and the second DC power supply are both +5V.

[0008] In some embodiments, the resistance value of the first voltage-dividing resistor is 3K ohms, and the resistance value of the second voltage-dividing resistor is 2K ohms.

[0009] In some embodiments, the resistance value of the first control resistor is 10K ohms, and the resistance value of the second control resistor is 100K ohms.

[0010] The utility model also provides a power supply module, and the alarm device has the anti-backflow circuit as described above.

[0011] The beneficial effects of the utility model are as follows: the utility model provides an anti-backflow circuit, including a power supply circuit with the same circuit composition of at least two circuits, the input end of each power supply circuit is electrically connected to a first DC power supply, and the output end outputs a second DC power supply and supplies power to the outside; the power supply circuit includes a first control transistor and a first MOS tube, the base of the first control transistor is electrically connected to the first voltage-dividing resistor and then connected to the first DC power supply, and the base of the first control transistor is also electrically connected to the second voltage-dividing resistor and then grounded, the emitter of the first control transistor is grounded, the collector is electrically connected to the first control resistor and then connected to the gate of the first MOS tube, the drain of the first MOS tube is electrically connected to the first DC power supply, and the source outputs the second DC power supply. The anti-backflow circuit in the utility model can be extended to a multi-way power supply circuit, so that the multi-way power supply circuit can supply power to the same load or different loads. The circuit cost is low, the heating problem of the traditional anti-backflow circuit is solved, and the reliability of the product is improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 It is a schematic diagram of two direct currents supplying power to a load simultaneously in the prior art;

[0013] Figure 2 It is a schematic diagram of a power supply circuit in the anti-backflow circuit according to the utility model;

[0014] Figure 3 It is a schematic diagram of another power supply circuit of the backflow prevention circuit according to the utility model. DETAILED DESCRIPTION

[0015] In order to facilitate the understanding of the present invention, the present invention is described in more detail below in conjunction with the accompanying drawings and specific embodiments. The accompanying drawings provide preferred embodiments of the present invention. However, the present invention can be implemented in many different forms and is not limited to the embodiments described in this specification. On the contrary, the purpose of providing these embodiments is to make the understanding of the disclosure of the present invention more thorough and comprehensive.

[0016] It should be noted that, unless otherwise defined, all technical and scientific terms used in this specification have the same meaning as those commonly understood by those skilled in the art in the technical field of the present invention. The terms used in the specification of the present invention are only for the purpose of describing specific embodiments and are not intended to limit the present invention. The term "and / or" used in this specification includes any and all combinations of one or more related listed items.

[0017] like Figure 2 and Figure 3 As shown, the utility model provides an anti-backflow circuit, which includes at least two circuits forming the same power supply circuit, such as Figure 2 and Figure 3 The two power supply circuits shown in FIG. 1 are connected to a first DC power supply at the input end of each power supply circuit, and a second DC power supply is output at the output end of each power supply circuit and supplies power to the outside. Figure 2 Taking the power supply circuit shown as an example, the power supply circuit includes a first control transistor Q3 and a first MOS tube Q1. The base of the first control transistor Q3 is electrically connected to the first voltage-dividing resistor R3 and then connected to the first DC power supply USB_5V, and the base of the first control transistor Q3 is also electrically connected to the second voltage-dividing resistor R7 and then grounded. The emitter of the first control transistor Q3 is grounded, the collector is electrically connected to the first control resistor R4 and then connected to the gate of the first MOS tube Q1, the drain of the first MOS tube Q1 is electrically connected to the first DC power supply USB_5V, and the source outputs the second DC power supply 5V0.

[0018] like Figure 3 The power supply circuit shown is Figure 2 The power supply circuit shown has the same composition, the difference is Figure 3 The power supply circuit in the circuit is input with another first direct current power supply DC_5V.

[0019] In this embodiment, when only the first DC power source USB_5V is input to Figure 2 When the power supply circuit shown in the figure is used, the base of the first control transistor Q3 is at a high level, the first control transistor Q3 is turned on, the first MOS transistor Q1 is turned on, and the source of the first MOS transistor Q1 outputs the second DC power supply 5V0 to supply power to the load; at the same time, due to Figure 3 The power supply circuit shown in the figure has no input of the first DC power supply DC_5V, the first control transistor Q4 and the first MOS transistor Q2 are both turned off, Figure 2 The second DC power 5V0 output by the middle power circuit will not flow back to the first DC power DC_5V.

[0020] Similarly, when only the first DC power supply DC_5V is input to Figure 3When the power supply circuit shown in the figure is used, the base of the first control transistor Q4 is at a high level, the first control transistor Q4 is turned on, the first MOS transistor Q2 is turned on, and the source of the first MOS transistor Q2 outputs the second DC power supply 5V0 to supply power to the load; at the same time, due to Figure 2 The power supply circuit shown in the figure does not have the first DC power supply USB_5V input, the first control transistor Q3 and the first MOS transistor Q1 are both turned off, Figure 3 The second DC power 5V0 output by the middle power circuit will not flow back to the first DC power USB_5V.

[0021] Furthermore, the anti-backflow circuit in this embodiment can be extended to a multi-way power supply circuit, so that the multi-way power supply circuit can supply power to the same load or different loads.

[0022] like Figure 2 As shown, in this embodiment, the first DC power supply USB_5V is also electrically connected to the first filter capacitor C1 and then grounded, a second control resistor R1 is also arranged between the source and the gate of the first MOS tube Q1, and a second filter capacitor C2 is also connected in parallel at both ends of the second control resistor R1, and the source of the first MOS tube Q1 is electrically connected to the third filter capacitor C3 and then grounded.

[0023] In this embodiment, the first control transistor Q3 is a chip L8050QLT1G, and the first MOS tube Q1 is a chip AET3152AS (PMOS tube). The first control transistor Q3 and the first MOS tube Q1 can realize the function of dual-channel input anti-backflow. At the same time, the chip AET3152AS in SOP8 package has a large power dissipation, which solves the heat dissipation problem caused by large input current and excessive input loss, and improves the reliability of the product. The resistance of the first voltage-dividing resistor R3 is 3K ohms, and the resistance of the second voltage-dividing resistor R7 is 2K ohms. The resistance of the first control resistor R4 is 10K ohms, and the resistance of the second control resistor R1 is 100K ohms.

[0024] In this embodiment, the voltages of the first DC power supply USB_5V and the second DC power supply 5V0 are both +5V. In some embodiments, the voltage values ​​of the first DC power supply and the second DC power supply can be other voltages, such as +3.3V, 12V, 24V, etc., and the corresponding first control transistor, first MOS tube and other electronic components are selected according to the needs. In some embodiments, the voltage values ​​of the first DC power supply and the second DC power supply are equal.

[0025] In the present application, the anti-backflow circuit uses a MOS tube combined with a triode and a number of resistors and capacitors. The circuit cost is low, which solves the heating problem of the traditional anti-backflow circuit and improves the reliability of the product.

[0026] The utility model also provides a power supply module, which has the anti-backflow circuit as described above.

[0027] It can be seen that the utility model provides an anti-backflow circuit, including at least two power supply circuits with the same circuit composition, the input end of each power supply circuit is electrically connected to a first DC power supply, and the output end outputs a second DC power supply and supplies power to the outside; the power supply circuit includes a first control transistor and a first MOS tube, the base of the first control transistor is electrically connected to the first voltage-dividing resistor and then connected to the first DC power supply, and the base of the first control transistor is also electrically connected to the second voltage-dividing resistor and then grounded, the emitter of the first control transistor is grounded, the collector is electrically connected to the first control resistor and then connected to the gate of the first MOS tube, the drain of the first MOS tube is electrically connected to the first DC power supply, and the source outputs the second DC power supply. The anti-backflow circuit in the utility model can be extended to multiple power supply circuits to realize that multiple power supply circuits supply power to the same load or different loads. The circuit cost is low, solves the heating problem of traditional anti-backflow circuits, and improves the reliability of the product.

[0028] The above description is only an embodiment of the present invention, and does not limit the patent scope of the present invention. Any equivalent structural transformation made using the contents of the specification and drawings of the present invention, or directly or indirectly applied in other related technical fields, is also included in the patent protection scope of the present invention.

Claims

1. A backflow prevention circuit, characterized in that: The invention comprises a power supply circuit with at least two circuits having the same circuit composition, wherein the input end of each power supply circuit is respectively electrically connected to a first DC power supply, and the output end respectively outputs a second DC power supply and supplies power to the outside; the power supply circuit comprises a first control transistor and a first MOS transistor, wherein the base of the first control transistor is electrically connected to a first voltage-dividing resistor and then connected to the first DC power supply, and the base of the first control transistor is also electrically connected to a second voltage-dividing resistor and then grounded, the emitter of the first control transistor is grounded, the collector is electrically connected to the first control resistor and then connected to the gate of the first MOS transistor, the drain of the first MOS transistor is electrically connected to the first DC power supply, and the source outputs the second DC power supply.

2. The anti-backflow circuit according to claim 1, characterized in that: The first DC power supply is also electrically connected to the first filter capacitor and then grounded, a second control resistor is also arranged between the source and the gate of the first MOS tube, a second filter capacitor is also connected in parallel at both ends of the second control resistor, and the source of the first MOS tube is electrically connected to the third filter capacitor and then grounded.

3. The anti-backflow circuit according to claim 2, characterized in that: The first control transistor is a chip L8050QLT1 G, and the first MOS transistor is a chip AET3152AS.

4. The anti-backflow circuit according to claim 3, characterized in that: The voltage of the first DC power supply and the second DC power supply are both +5V.

5. The anti-backflow circuit according to claim 4, characterized in that: The resistance value of the first voltage-dividing resistor is 3K ohms, and the resistance value of the second voltage-dividing resistor is 2K ohms.

6. The anti-backflow circuit according to claim 5, characterized in that: The resistance value of the first control resistor is 10K ohms, and the resistance value of the second control resistor is 100K ohms.

7. A power module, characterized in that: The power module has the anti-backflow circuit as claimed in any one of claims 1 to 6.

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