Power switching circuit, power supply device and downhole instrument

Abstract

The utility model discloses a power switching circuit, power supply device and downhole instrument relates to power supply technical field. Power switching circuit includes: first power supply electronic circuit and second power supply electronic circuit, and first power supply electronic circuit includes first control unit and first switch tube, and second power supply electronic circuit includes second control unit, second switch tube and third switch tube, the first end of first control unit is connected the first end of first switch tube, the control end of second switch tube, first power, and the second end of first control unit is connected with the control end of first switch tube, and the second end of first switch tube is connected the first end of second switch tube, the load of using electricity, the first end of third switch tube, second end is connected the second end of second switch tube, second power respectively, and the first end, the second end, the third end of second control unit is connected the control end of third switch tube, second power, first power respectively. The circuit can realize the switching between first power and second power, and the power consumption is low.

Description

Technical Field

[0001] This utility model relates to the field of power supply technology, and in particular to a power switching circuit, a power supply device, and a downhole instrument. Background Technology

[0002] In related technologies, power switching circuits typically include a PMOS (Positive Channel Metal Oxide Semiconductor) transistor Q, a Schottky diode D1, and a pull-down resistor R, such as... Figure 1 As shown, when the battery voltage VBAT is greater than the external power supply voltage VIN, the circuit cannot function properly, and the external power supply voltage VIN will reverse charge the battery through the body diode D2 of the PMOS transistor. Simultaneously, due to the voltage drop across the Schottky diode D1 (approximately 0.15V), the output voltage VCC cannot reach the actual value of the external power supply voltage VIN, resulting in significant power loss. Utility Model Content

[0003] This invention proposes a power switching circuit, a power supply device, and a downhole instrument to achieve switching between a first power supply and a second power supply with low power consumption.

[0004] In a first aspect, this utility model proposes a power switching circuit, the circuit comprising: a first power supply circuit and a second power supply circuit, the first power supply circuit comprising a first control unit and a first switching transistor, the second power supply circuit comprising a second control unit, a second switching transistor, and a third switching transistor; wherein, a first terminal of the first control unit is connected to a first terminal of the first switching transistor and a control terminal of the second switching transistor respectively, and is adapted to connect to a first power supply; a second terminal of the first control unit is connected to the control terminal of the first switching transistor; a second terminal of the first switching transistor is connected to a first terminal of the second switching transistor, and is adapted to connect to an electrical load; a second terminal of the second switching transistor is connected to a first terminal of the third switching transistor, and the second terminal of the third switching transistor is adapted to connect to a second power supply; a first terminal of the second control unit is connected to the control terminal of the third switching transistor, and the second terminal of the second control unit is adapted to connect to the second power supply; and a third terminal of the second control unit is adapted to connect to the first power supply.

[0005] In some examples, the first control unit includes a first transistor and a first resistor, the base of the first transistor being connected to a first terminal of the first resistor, a first terminal of the first switching transistor, and a control terminal of the second switching transistor, the second terminal of the first resistor being grounded, the emitter of the first transistor being grounded, and the collector of the first transistor being connected to the control terminal of the first switching transistor.

[0006] In some examples, the first control unit further includes a second resistor connected between the control terminal and the second terminal of the first switching transistor.

[0007] In some examples, the second control unit includes: a second transistor, a third transistor, a third resistor, and a fourth resistor. The collector of the second transistor is connected to the control terminal of the third transistor, the emitter of the second transistor is grounded, the base of the second transistor is connected to the first terminal of the third resistor and the collector of the third transistor, the second terminal of the third resistor is adapted to be connected to the second power supply, the emitter of the third transistor is grounded, the base of the third transistor is adapted to be connected to the first power supply, and the fourth resistor is connected between the control terminal and the second terminal of the third transistor.

[0008] In some examples, the second control unit further includes a sixth resistor and a fifth resistor, wherein a first end of the sixth resistor is connected to the base of the third transistor, a second end of the sixth resistor is adapted to be connected to the first power supply, a first end of the fifth resistor is connected to the base of the second transistor, and a second end of the fifth resistor is connected to the first end of the third resistor and the collector of the third transistor, respectively.

[0009] In some examples, the second control unit further includes a seventh resistor and an eighth resistor, the seventh resistor being connected between the base and emitter of the second transistor, and the eighth resistor being connected between the base and emitter of the third transistor.

[0010] In some examples, the first switch, the second switch, and the third switch are all MOSFETs.

[0011] In some examples, the first power source is an external power source, and the second power source is a battery.

[0012] Secondly, this utility model proposes a power supply device, comprising: a battery and the power switching circuit described in the first aspect, wherein the battery is connected to the second terminal of the second control unit in the power switching circuit.

[0013] Thirdly, this utility model proposes a downhole instrument, including: an electrical load and the power supply device described in the second aspect.

[0014] The power switching circuit, power supply device, and downhole instrument of this utility model embodiment, when only the first power supply is available, control the first switching transistor to conduct through the first control unit, enabling the first power supply to power the electrical load; when only the second power supply is available, control the third switching transistor to conduct through the second control unit, and control the second switching transistor to conduct through the first control unit, enabling the second power supply to power the electrical load; when both the first and second power supplies are available, control the third switching transistor to cut off through the second control unit, and control the first switching transistor to conduct through the first control unit, enabling the second power supply to power the electrical load. Thus, switching between the first and second power supplies is achieved, and power is supplied through the conduction of the switching transistors, resulting in low power consumption.

[0015] Additional aspects and advantages of this invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Attached Figure Description

[0016] Figure 1 This is a topology diagram of a power switching circuit in related technologies;

[0017] Figure 2 This is a schematic diagram of the power switching circuit according to an embodiment of the present invention;

[0018] Figure 3 This is a schematic diagram of the power switching circuit of the first specific embodiment of this utility model;

[0019] Figure 4 This is a schematic diagram of the power switching circuit of the second specific embodiment of this utility model;

[0020] Figure 5 This is a schematic diagram of the power switching circuit of the third specific embodiment of this utility model;

[0021] Figure 6 This is a schematic diagram of the power switching circuit according to the fourth specific embodiment of this utility model;

[0022] Figure 7 This is a schematic diagram of the power switching circuit according to the fifth specific embodiment of this utility model;

[0023] Figure 8 This is a structural block diagram of the power supply device according to an embodiment of the present utility model;

[0024] Figure 9 This is a structural block diagram of a downhole instrument according to an embodiment of the present invention.

[0025] Figure label:

[0026] 10,000 downhole instruments, 1,000 power supply units, 2,000 electrical loads, 100 power switching circuits, and 200 batteries;

[0027] First power supply circuit 10, second power supply circuit 20, first control unit 11, second control unit 21;

[0028] First switch M1, second switch M2, third switch M3, first transistor Q1, second transistor Q2, third transistor Q3, first resistor R1, third resistor R3, fourth resistor R4, fifth resistor R5, sixth resistor R6, seventh resistor R7, eighth resistor R8. Detailed Implementation

[0029] The embodiments of this utility model are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain this utility model, and should not be construed as limiting this utility model.

[0030] The power switching circuit, power supply device, and downhole instrument of this utility model are described below with reference to the accompanying drawings.

[0031] like Figure 1 As shown, power switching circuits in related technologies typically include a PMOS (Positive Channel Metal Oxide Semiconductor) transistor Q, a Schottky diode D1, and a pull-down resistor R. When the battery voltage is higher than the external power supply voltage, the circuit cannot function properly, and the external power supply voltage will reverse charge the battery through the body diode D2 of the PMOS transistor. Simultaneously, the Schottky diode D1 has a voltage drop of approximately 0.15V, and due to this voltage drop, the output voltage VCC does not reach the actual value of the external power supply voltage, resulting in significant power loss. Therefore, this invention proposes a power switching circuit that can reduce power consumption.

[0032] Figure 2 This is a schematic diagram of the power switching circuit according to an embodiment of the present invention.

[0033] like Figure 2As shown, the power switching circuit 100 includes: a first power supply circuit 10 and a second power supply circuit 20. The first power supply circuit 10 includes a first control unit 11 and a first switching transistor M1. The second power supply circuit 20 includes a second control unit 21, a second switching transistor M2, and a third switching transistor M3. The first terminal of the first control unit 11 is connected to the first terminal of the first switching transistor M1 and the control terminal of the second switching transistor M2, and is adapted to connect to a first power supply. The second terminal of the first control unit 11 is connected to the control terminal of the first switching transistor M1. The second terminal of the first switching transistor M1 is connected to the first terminal of the second switching transistor M2, and is adapted to connect to an electrical load. The second terminal of the second switching transistor M2 is connected to the first terminal of the third switching transistor M3, and the second terminal of the third switching transistor M3 is adapted to connect to a second power supply. The first terminal of the second control unit 21 is connected to the control terminal of the third switching transistor M3, and the second terminal of the second control unit 21 is adapted to connect to a second power supply. The third terminal of the second control unit 21 is adapted to connect to a first power supply.

[0034] For example, the first power source is an external power source, and the second power source is a battery.

[0035] In this embodiment, see Figure 2 When only the first power supply is available, the first control unit 11 controls the first switching transistor M1 to turn on, enabling the first power supply to power the load. When only the second power supply is available, the second control unit 21 controls the third switching transistor M3 to turn on, and the first control unit 11 controls the second switching transistor M2 to turn on, enabling the second power supply to power the load. When both the first and second power supplies are available, the second control unit 21 controls the third switching transistor M3 to turn off, and the first control unit 11 controls the first switching transistor M1 to turn on, enabling the second power supply to power the load. This achieves switching between the first and second power supplies, and the power supply is achieved through the conduction of the switching transistors, resulting in low power consumption.

[0036] For example, the first switch M1, the second switch M2 and the third switch M3 can all be PMOS (Metal Oxide Semiconductor) transistors.

[0037] In some embodiments of this utility model, such as Figure 3 As shown, the first control unit 11 includes: a first transistor Q1 and a first resistor R1. The base of the first transistor Q1 is connected to the first terminal of the first resistor R1, the first terminal of the first switch M1, and the control terminal of the second switch M2, respectively. The second terminal of the first resistor R1 is grounded. The emitter of the first transistor Q1 is grounded. The collector of the first transistor Q1 is connected to the control terminal of the first switch M1.

[0038] See Figure 3When the first power supply is in operation, the voltage VIN provided by the first power supply exists. The voltage VIN is supplied to the load through the output voltage VCC of the body diode of the first switching transistor M1. At the same time, the first transistor Q1 is turned on, and the gate of the first switching transistor M1 is pulled down to 0V. At this time, the first switching transistor M1 is turned on, and VIN is supplied to the load through the output voltage VCC of the first switching transistor M1.

[0039] For example, such as Figure 4 As shown, the first control unit 11 further includes a second resistor R2, which is connected between the control terminal and the second terminal of the first switching transistor M1.

[0040] By setting the second resistor R2, the first switching transistor M1 can be reliably turned off and the anti-interference capability can be improved.

[0041] In some embodiments of this utility model, such as Figure 5 As shown, the second control unit 21 includes: a second transistor Q2, a third transistor Q3, a third resistor R3, and a fourth resistor R4. The control terminal of the third switch M3 is connected to the collector of the second transistor Q2. The emitter of the second transistor Q2 is grounded. The base of the second transistor Q2 is connected to the first terminal of the third resistor R3 and the collector of the third transistor Q3. The second terminal of the third resistor R3 is adapted to be connected to a second power supply. The emitter of the third transistor Q3 is grounded. The base of the third transistor Q3 is adapted to be connected to a first power supply. The fourth resistor R4 is connected between the control terminal and the second terminal of the third switch M3.

[0042] See Figure 5 When both the first and second power supplies are operating simultaneously, the third transistor Q3 is turned on, and the second transistor Q2 is turned off. The gate and source voltages of the third switch M3 are both equal to the voltage VBAT provided by the second power supply, and the third switch M3 is turned off. Voltage VIN is supplied to the load through the body diode of the first switch M1, providing the output voltage VCC. Simultaneously, the first transistor Q1 is turned on, pulling the gate of the first switch M1 down to 0V. At this time, the first switch M1 is turned on, and VIN is supplied to the load through the output voltage VCC of the first switch M1.

[0043] When only the second power supply is applied, the third transistor Q3 is off, and the second transistor Q2 is on. The gate voltage of the third switching transistor M3 is 0V, and the gate-source voltage is less than 0V, so the third switching transistor M3 is on. The voltage VBAT reaches the output terminal through the body diodes of the third switching transistor M3 and the second switching transistor M2, resulting in the output voltage VCC. Simultaneously, the gate of the second switching transistor M2 is connected to ground through the first resistor R1, which is a low level, so the second switching transistor M2 is on. The voltage VBAT is then output as VCC through the third switching transistor M3 and the second switching transistor M2.

[0044] By setting the fourth resistor R4, the reliable turn-off of the third switch M3 can be ensured, and the anti-interference capability can be improved.

[0045] For example, such as Figure 6 As shown, the second control unit 21 further includes: a sixth resistor R6 and a fifth resistor R5. The first end of the sixth resistor R6 is connected to the base of the third transistor Q3, and the second end of the sixth resistor R6 is adapted to be connected to the first power supply. The first end of the fifth resistor R5 is connected to the base of the second transistor Q2, and the second end of the fifth resistor R5 is connected to the first end of the third resistor R3 and the collector of the third transistor Q3, respectively.

[0046] By setting the sixth resistor R6, the third transistor Q3 can be reliably switched, preventing the base of the third transistor Q3 from breaking down; by setting the fifth resistor R5, the second transistor Q2 can be reliably switched, preventing the base of the second transistor Q2 from breaking down.

[0047] For example, such as Figure 7 As shown, the second control unit 21 also includes a seventh resistor R7 and an eighth resistor R8. The seventh resistor R7 is connected between the base and emitter of the second transistor Q2, and the eighth resistor R8 is connected between the base and emitter of the third transistor Q3.

[0048] By setting the seventh resistor R7 and the eighth resistor R8, the reliable turn-off of the second transistor Q2 and the third transistor Q3 can be ensured, and the anti-interference capability can be improved.

[0049] The following is combined with Figure 7 The working principle of the power switching circuit of this utility model embodiment is described as follows:

[0050] See Figure 7 When only the first power supply is in operation, the voltage VIN is supplied to the load through the body diode of the first switching transistor M1 and the output voltage VCC. At the same time, the first transistor Q1 is turned on, the first switching transistor M1 is turned on, and VIN is supplied to the load through the output voltage VCC of the first switching transistor M1.

[0051] When the first and second power supplies are operating simultaneously, the third transistor Q3 is turned on, the second transistor Q2 is turned off, and the third switch M3 is turned off. The voltage VIN is supplied to the load through the body diode of the first switch M1, outputting voltage VCC. At the same time, the first transistor Q1 is turned on, the first switch M1 is turned on, and VIN is supplied to the load through the first switch M1, outputting voltage VCC.

[0052] When only the second power supply is in operation, the third transistor Q3 is off, the second transistor Q2 is on, and the third switch M3 is on. The voltage VBAT reaches the output terminal through the body diodes of the third switch M3 and the second switch M2, resulting in the output voltage VCC. Simultaneously, the gate of the second switch M2 is connected to ground through the first resistor R1, which is a low level. The second switch M2 is on, and the voltage VBAT outputs the voltage VCC through the third switch M3 and the second switch M2.

[0053] Since the voltage drop across the transistor after it is turned on is less than that of a Schottky diode, the conduction loss is low; furthermore, the power consumption is also reduced as the transistor operates in the saturation region.

[0054] Figure 8 This is a structural block diagram of the power supply device according to an embodiment of the present utility model.

[0055] like Figure 8 As shown, the power supply device 1000 includes a battery 200 and a power switching circuit 100 as described in the above embodiment. The battery 200 is connected to the second end of the second control unit 21 in the power switching circuit 100.

[0056] Figure 9 This is a structural block diagram of the downhole instrument of this utility model.

[0057] like Figure 9 As shown, the downhole instrument 10000 includes an electrical load 2000 and a power supply device 1000 as described in the above embodiment.

[0058] In the embodiments of this utility model, the downhole instrument can be used in oil drilling operations. To ensure the normal operation of the downhole instrument downhole, in addition to mud pulse power generation as the first voltage power supply, a battery 200 (such as a lithium battery) will be added for power supply to prevent the downhole instrument from stopping operation due to power supply problems in case of unexpected situations.

[0059] In summary, the power switching circuit, power supply device, and downhole instrument of this utility model embodiment can realize the switching between the first power supply and the second power supply, and the power supply is powered by the conduction of the switching transistor, resulting in low power consumption.

[0060] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0061] In the description of this utility model, it should be understood that the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc., indicating the orientation or positional relationship are based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this utility model and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this utility model.

[0062] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this utility model, "a plurality of" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0063] In this utility model, unless otherwise explicitly specified and limited, the terms "installation," "connection," "joining," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise explicitly limited. Those skilled in the art can understand the specific meaning of the above terms in this utility model according to the specific circumstances.

[0064] In this utility model, unless otherwise explicitly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "on top of," and "over" the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0065] Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of the present invention.

Claims

1. A power switching circuit (100), characterized by The circuit (100) includes: a first power supply circuit (10) and a second power supply circuit (20). The first power supply circuit (10) includes a first control unit (11) and a first switch (M1). The second power supply circuit (20) includes a second control unit (21), a second switch (M2) and a third switch (M3). Wherein, the first end of the first control unit (11) is connected to the first end of the first switch (M1) and the control end of the second switch (M2) respectively, and is adapted to be connected to the first power supply; the second end of the first control unit (11) is connected to the control end of the first switch (M1); the second end of the first switch (M1) is connected to the first end of the second switch (M2) and is adapted to be connected to the electrical load; the second end of the second switch (M2) is connected to the first end of the third switch (M3); the second end of the third switch (M3) is adapted to be connected to the second power supply; the first end of the second control unit (21) is connected to the control end of the third switch (M3); the second end of the second control unit (21) is adapted to be connected to the second power supply; the third end of the second control unit (21) is adapted to be connected to the first power supply. The first control unit (11) includes: a first transistor (Q1) and a first resistor (R1). The base of the first transistor (Q1) is connected to the first terminal of the first resistor (R1), the first terminal of the first switch (M1), and the control terminal of the second switch (M2). The second terminal of the first resistor (R1) is grounded. The emitter of the first transistor (Q1) is grounded. The collector of the first transistor (Q1) is connected to the control terminal of the first switch (M1). The second control unit (21) includes: a second transistor (Q2), a third transistor (Q3), a third resistor (R3), and a fourth resistor (R4). The collector of the second transistor (Q2) is connected to the control terminal of the third switch (M3). The emitter of the second transistor (Q2) is grounded. The base of the second transistor (Q2) is connected to the first terminal of the third resistor (R3) and the collector of the third transistor (Q3). The second terminal of the third resistor (R3) is adapted to be connected to the second power supply. The emitter of the third transistor (Q3) is grounded. The base of the third transistor (Q3) is adapted to be connected to the first power supply. The fourth resistor (R4) is connected between the control terminal and the second terminal of the third switch (M3).

2. The power switching circuit (100) according to claim 1, characterized in that The first control unit (11) further includes a second resistor (R2), which is connected between the control terminal and the second terminal of the first switching transistor (M1).

3. The power switching circuit (100) according to claim 1, characterized in that The second control unit (21) further includes a fifth resistor (R5) and a sixth resistor (R6). The first end of the sixth resistor (R6) is connected to the base of the third transistor (Q3), and the second end of the sixth resistor (R6) is adapted to be connected to the first power supply. The first end of the fifth resistor (R5) is connected to the base of the second transistor (Q2), and the second end of the fifth resistor (R5) is connected to the first end of the third resistor (R3) and the collector of the third transistor (Q3), respectively.

4. The power switching circuit (100) according to claim 1, characterized in that The second control unit (21) further includes a sixth resistor (R6), a seventh resistor (R7) and an eighth resistor (R8), wherein the seventh resistor (R7) is connected between the base and emitter of the second transistor (Q2) and the eighth resistor (R8) is connected between the base and emitter of the third transistor (Q3).

5. The power switching circuit (100) according to claim 1, characterized in that The first switch (M1), the second switch (M2), and the third switch (M3) are all MOSFETs.

6. The power switching circuit (100) according to any one of claims 1-5, characterized by The first power source is an external power source, and the second power source is a battery.

7. A power supply device (1000), characterized by, include: The battery (200) and the power switching circuit (100) as claimed in any one of claims 1-6, wherein the battery (200) is connected to the second end of the second control unit (21) in the power switching circuit (100).

8. A downhole instrument (10000) characterized by, include: Electrical load (2000) and power supply device (1000) as described in claim 7.

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