Dual-power switching circuit and device

Abstract

The utility model discloses a dual power supply switching circuit and device, and relates to the technical field of dual power supply switching, and the circuit comprises an external power supply connecting end which is used for being connected with an external power supply so as to supply power to a load and charge a battery; the detection circuit is used for detecting the power supply state of the external power connection end. The controlled end of the switching circuit is electrically connected with the detection circuit, and the input end and the output end of the switching circuit are arranged on a line between the battery and the load; when the detection circuit detects that an external power supply is connected to the external power supply connecting end, the detection circuit controls the switching circuit to cut off a line between the battery and the load. And when it is detected that the external power supply connection end is not connected to the external power supply, the battery is controlled to supply power to the load, so that when the detection circuit detects that the external power supply is connected, the circuit between the battery and the load is cut off, the battery is charged, and the external power supply is controlled to supply power to the load, thereby improving the charging efficiency and the service life of the battery. And power loss is reduced.

Description

Technical Field

[0001] The utility model relates to the technical field of dual - power switching, and particularly relates to a dual - power switching circuit and device. Background Art

[0002] In the prior art, when powering the inside of a device, if no external power supply is connected externally, the device often powers itself through a battery inside the device. When an external power supply is connected, the external power supply not only powers the load inside the device but also charges the battery inside the device. However, at this time, the battery often also powers the load inside the device. With such a setting, not only the charging efficiency of the battery is reduced and the battery life is shortened, but also the external power supply loss is increased. Summary of the Utility Model

[0003] The main object of the utility model is to propose a dual - power switching circuit and device, aiming to improve the charging efficiency and life of the battery and reduce the external power supply loss.

[0004] To achieve the above object, the utility model proposes a dual - power switching circuit. The dual - power switching circuit includes a battery and an external power supply connection terminal, and the dual - power switching circuit includes:

[0005] An external power supply connection terminal for connecting to an external power supply to power a load and charge the battery;

[0006] A detection circuit electrically connected to the external power supply connection terminal for detecting the power supply state of the external power supply connection terminal;

[0007] A switching circuit, the controlled end of the switching circuit is electrically connected to the detection circuit, the input end of the switching circuit is connected to the battery, and the output end of the switching circuit is connected to the load; wherein, when the detection circuit detects that an external power supply is connected to the external power supply connection terminal, it controls the switching circuit to cut off the line between the battery and the load; when it detects that no external power supply is connected to the external power supply connection terminal, it controls the switching circuit to conduct the line between the battery and the load to control the battery to power the load.

[0008] In an embodiment, the switching circuit is specifically a PMOS transistor, the gate of the PMOS transistor is electrically connected to the detection circuit, the drain of the PMOS transistor is electrically connected to the power output terminal of the battery, and the source of the PMOS transistor is electrically connected to the load.

[0009] In one embodiment, the detection circuit specifically includes a first voltage-dividing resistor and a second voltage-dividing resistor. The first end of the first voltage-dividing resistor is electrically connected to the external power supply connection end. The second end of the first voltage-dividing resistor is respectively electrically connected to the first end of the second voltage-dividing resistor and the controlled end of the switch circuit. The second end of the second voltage-dividing resistor is grounded.

[0010] In one embodiment, the dual-power supply switching circuit further includes:

[0011] An anti-reverse connection circuit, which is arranged on the line between the external power supply connection end and the load, and is used to prevent the current from flowing reversely through the external power supply connection end and clamp the voltage supplied to the external power supply.

[0012] In one embodiment, the dual-power supply switching circuit further includes:

[0013] A surge protection circuit, which is arranged in parallel on the line between the battery and the electrical load, and is used to limit the instantaneous overvoltage of the battery and guide and discharge the surge current, so as to protect the switching circuit from being damaged.

[0014] In one embodiment, the dual-power supply switching circuit further includes:

[0015] A freewheeling circuit, which is electrically connected to the switch circuit, and is used to prevent the high-voltage impact from damaging the switch circuit when the switch circuit cuts off the line between the battery and the load.

[0016] The present utility model also provides a dual-power supply switching device, which includes a charging circuit for charging the battery and the dual-power supply switching circuit as described above.

[0017] The technical solution of the present utility model adopts the dual - power - supply switching circuit including a battery and an external power - supply connection terminal. The dual - power - supply switching circuit includes: an external power - supply connection terminal for connecting an external power supply to supply power to a load and charge the battery; a detection circuit electrically connected to the external power - supply connection terminal for detecting the power - supply state of the external power - supply connection terminal; a switching circuit, the controlled end of the switching circuit is electrically connected to the detection circuit, the input end of the switching circuit is connected to the battery, and the output end of the switching circuit is connected to the load. Wherein, when the detection circuit detects that an external power supply is connected to the external power - supply connection terminal, it controls the switching circuit to cut off the line between the battery and the load; when it detects that no external power supply is connected to the external power - supply connection terminal, it controls the switching circuit to conduct the line between the battery and the load to control the battery to supply power to the load. With such a setting, when the detection circuit detects the access of an external power supply, the dual - power - supply switching circuit can control the switching circuit to cut off the line between the battery and the load, charge the battery, and control the external power supply to supply power to the load, thereby improving the charging efficiency and service life of the battery and reducing the loss of the external power supply. Brief Description of the Drawings

[0018] In order to more clearly illustrate the technical solutions in the embodiments of the present utility model or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the following - described drawings are only some embodiments of the present utility model. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on the structures shown in these drawings.

[0019] Figure 1 It is a schematic circuit structure diagram of an embodiment of the dual - power - supply switching circuit provided by the present utility model;

[0020] Figure 2 It is a schematic circuit structure diagram of another embodiment of the dual - power - supply switching circuit provided by the present utility model.

[0021] Explanation of the Reference Numerals in the Drawings:

[0022] 1 - External power - supply connection terminal; 2 - Detection circuit; 3 - Switching circuit; 4 - Battery; 5 - Load; 6 - Surge - protection circuit; 7 - Reverse - connection prevention circuit; 8 - Free - wheeling circuit; R1 - First voltage - dividing resistor; R2 - Second voltage - dividing resistor; D1 - First diode; D2 - Schottky diode; TVS - TVS diode; C1 - First capacitor; Q1 - PMOS transistor.

[0023] The realization, functional characteristics and advantages of the object of the present utility model will be further described in conjunction with the embodiments with reference to the drawings. Detailed Embodiments

[0024] The following will clearly and completely describe the technical solutions in the embodiments of the present utility model with reference to the accompanying drawings in the embodiments of the present utility model. Obviously, the described embodiments are only a part of the embodiments of the present utility model, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present utility model without creative efforts belong to the scope of protection of the present utility model.

[0025] It should be noted that if there are directional indications (such as up, down, left, right, front, back,...) involved in the embodiments of the present utility model, the directional indications are only used to explain the relative positional relationship and movement conditions between components in a specific posture. If the specific posture changes, the directional indications will also change accordingly.

[0026] In addition, if there are descriptions involving "first", "second", etc. in the embodiments of the present utility model, the descriptions of "first", "second", etc. are only for descriptive purposes and cannot be understood as indicating or implying their relative importance or implicitly indicating the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include at least one such feature. In addition, if "and / or" or "and / or" appears throughout the text, its meaning includes three parallel solutions. Taking "A and / or B" as an example, it includes solution A, solution B, or a solution where A and B are satisfied simultaneously. In addition, the technical solutions between the various embodiments can be combined with each other, but it must be based on the ability of those of ordinary skill in the art to implement. When the combination of technical solutions results in contradictions or cannot be implemented, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection required by the present utility model.

[0027] The present utility model provides a dual - power - supply switching circuit. Please refer to Figure 1 and Figure 2 , the dual - power - supply switching circuit includes a battery 4 and an external power connection terminal 1. The dual - power - supply switching circuit includes:

[0028] The external power connection terminal 1 is used to connect to an external power supply to supply power to a load 5 and charge the battery 4;

[0029] A detection circuit 2, the detection circuit 2 is electrically connected to the external power connection terminal 1 and is used to detect the power supply state of the external power connection terminal 1;

[0030] A switch circuit 3, the controlled end of the switch circuit 3 is electrically connected to the detection circuit 2, the input end of the switch circuit 3 is connected to the battery 4, and the output end of the switch circuit 3 is connected to the load 5; wherein, when the detection circuit 2 detects that an external power supply is connected to the external power supply connection end 1, it controls the switch circuit 3 to cut off the line between the battery 4 and the load 5; when it detects that no external power supply is connected to the external power supply connection end 1, it controls the switch circuit 3 to conduct the line between the battery 4 and the load 5, so as to control the battery 4 to supply power to the load 5.

[0031] In this embodiment, the external power supply can be selected to provide wireless charging or USB cable charging for the dual-power switching circuit. The detection circuit 2 can be realized by directly monitoring whether the external power supply is connected through a voltage divider (voltage dividing resistor) or a voltage monitoring chip, or by detecting the detection pin of the battery 4 management IC to detect the connection of the external power supply. The switch circuit 3 can be realized by a mechanical switch, a tube switch or an optocoupler.

[0032] Specifically, the switch circuit 3 is set as a PMOS transistor Q1. The gate of the PMOS transistor Q1 is electrically connected to the detection circuit 2. The drain of the PMOS transistor Q1 is electrically connected to the power output end of the battery 4. The source of the PMOS transistor Q1 is electrically connected to the load 5. In this way, when the detection circuit 2 detects an external power supply and sends a high level to the gate of the PMOS transistor Q1, it controls the PMOS transistor Q1 to cut off the line between the battery 4 and the load 5.

[0033] Specifically, the detection circuit 2 is specifically a first voltage dividing resistor R1 and a second voltage dividing resistor R2. The second end of the first voltage dividing resistor R1 is respectively electrically connected to the first end of the second voltage dividing resistor R2 and the controlled end of the switch circuit 3 (i.e., the gate of the PMOS transistor). The second end of the second voltage dividing resistor R2 is grounded. With such a setting, when an external power supply is connected to the external power supply connection end 1, the first voltage dividing resistor R1 and the second voltage dividing resistor R2 detect the voltage input by the external power supply, and can divide the voltage output by the external power supply and limit it to a cut-off voltage and output it to the gate of the PMOS transistor Q1, controlling the PMOS transistor Q1 to cut off the line between the source and the drain of the PMOS transistor Q1, thereby cutting off the line between the battery 4 and the load 5, so that when the dual-power switching circuit is connected to an external power supply, it can supply power to the load through the external power supply and control the battery to stop supplying power to the load.

[0034] In one embodiment, the dual-power switching circuit further includes:

[0035] The reverse connection prevention circuit 7 is arranged on the line between the external power connection terminal 1 and the load 5, and is used to prevent the current from flowing reversely through the external power connection terminal 1 and clamp the voltage supplied to the external power source.

[0036] Specifically, the reverse connection prevention circuit 7 is specifically arranged as a first diode D1. The anode of the first diode D1 is electrically connected to the external power connection terminal 1, and the cathode of the first diode D1 is electrically connected to the load 5. In this connection manner, the first diode D1 can allow the current to flow from the external power connection terminal 1 to the load 5. However, when the current attempts to flow reversely, the first diode D1 will block this reverse current, thereby protecting the safety of the entire circuit. This design not only improves the reliability of the circuit but also ensures the stable power supply of the external power source and avoids potential damage caused by reverse current.

[0037] In an embodiment, the dual-power switching circuit further includes:

[0038] A surge protection circuit 6 is arranged in parallel on the line between the battery 4 and the electrical load 5, and is used to limit the instantaneous overvoltage of the battery 4 and guide and discharge the surge current to protect the switching circuit from being damaged.

[0039] Specifically, the surge protection circuit 6 can be arranged on the line between the battery 4 and the switching circuit 3, or can be arranged on the line between the switching circuit 3 and the load 5. The surge protection circuit 6 is arranged as a TVS diode TVS and a capacitor C1. The first end of the TVS diode TVS and the first end of the capacitor C1 are arranged in parallel on the line between the source electrode of the PMOS transistor Q1 and the load 5, and the second end of the TVS diode TVS is electrically connected to the second end of the capacitor C1. In this connection manner, when an instantaneous high voltage or surge appears in the circuit, the TVS diode TVS can quickly respond and limit the voltage increase, while the capacitor C1 can absorb a part of the surge energy, thereby ensuring the safe operation of the entire switching circuit.

[0040] In an embodiment, the dual-power switching circuit further includes:

[0041] A freewheeling circuit 8 is electrically connected to the switching circuit 3, and is used to prevent high-voltage impact from damaging the switching circuit 3 when the switching circuit 3 cuts off the line between the battery 4 and the load 5.

[0042] Specifically, the freewheeling circuit 8 is set as a Schottky diode D2. The anode of the Schottky diode D2 is electrically connected to the drain of the PMOS transistor and the power output terminal of the battery 4, and the cathode of the Schottky diode D2 is electrically connected to the source of the PMOS transistor Q1 and the load 5. With such a setting, the Schottky diode D2 can enable the switching circuit 3 to quickly release the stored energy, accelerate the switching speed, improve the overall efficiency, and can also prevent high-voltage impact from damaging the switching circuit 3. And in the dual-power switching circuit, when the Schottky diode is used in combination with the PMOS transistor Q1 serving as the switching circuit 3, since the voltage of the battery 4 can be output to the load 5 through the parasitic diode of the PMOS transistor Q1 and the Schottky diode D1, when the load 5 using electricity uses the voltage provided by the external power supply, it will force the parasitic diode of the PMOS transistor Q1 and the Schottky diode D2 to stop outputting voltage to the load 5 due to the pressure difference. With such a setting, the device of the dual-power switching circuit will not lose power instantaneously, that is, it will not cause the situation of lamp flashing between the power-off of the chip to the reset due to the power switching.

[0043] The present invention also proposes a dual-power switching device, and the dual-power switching device includes a charging circuit for charging the battery 4 and the dual-power switching circuit as described above.

[0044] The technical solution of the present invention adopts that the dual-power switching circuit includes a battery 4 and an external power supply connection terminal 1. The dual-power switching circuit includes: an external power supply connection terminal 1 for connecting an external power supply to supply power to the load 5 and charge the battery 4; a detection circuit 2 electrically connected to the external power supply connection terminal 1 for detecting the power supply state of the external power supply connection terminal 1; a switching circuit 3, the controlled end of the switching circuit 3 is electrically connected to the detection circuit 2, the input end of the switching circuit 3 is connected to the battery 4, and the output end of the switching circuit 3 is connected to the load 5. Wherein, when the detection circuit 2 detects that an external power supply is connected to the external power supply connection terminal 1, it controls the switching circuit 3 to cut off the line between the battery 4 and the load 5; when it detects that no external power supply is connected to the external power supply connection terminal 1, it controls the switching circuit 3 to conduct the line between the battery 4 and the load 5 to control the battery 4 to supply power to the load 5. With such a setting, when the detection circuit 2 detects the access of an external power supply, the dual-power switching circuit can control the switching circuit 3 to cut off the line between the battery 4 and the load 5 and charge the battery 4, and control the external power supply to supply power to the load 5, so as to improve the charging efficiency and life of the battery 4 and reduce the external power supply loss.

[0045] The present utility model also provides a dual-power switching device, which includes a charging circuit for charging the battery and the dual-power switching circuit as described above. The specific structure of the dual-power switching circuit refers to the above embodiments. Since this dual-power switching device adopts all the technical solutions of the above embodiments, it has at least all the beneficial effects brought by the technical solutions of the above embodiments, which will not be elaborated here one by one.

[0046] The above is only an exemplary embodiment of the present utility model, and does not limit the patent scope of the present utility model. Any equivalent structural transformation made under the technical concept of the present utility model by using the content of the specification and drawings of the present utility model, or directly / indirectly applied to other related technical fields, is included in the patent protection scope of the present utility model.

Claims

1. A dual power switching circuit, comprising a battery and an external power connection terminal, characterized in that: The dual power switching circuit comprises: An external power connection terminal is used to connect an external power source to supply power to the load and charge the battery; a detection circuit, the detection circuit being electrically connected to the external power connection terminal and used for detecting a power supply state of the external power connection terminal; A switch circuit, wherein a controlled end of the switch circuit is electrically connected to the detection circuit, an input end of the switch circuit is connected to the battery, and an output end of the switch circuit is connected to the load; wherein when the detection circuit detects that an external power supply connection end is connected to an external power supply, the switch circuit is controlled to cut off the line between the battery and the load; when the detection circuit detects that an external power supply connection end is not connected to an external power supply, the switch circuit is controlled to conduct the line between the battery and the load, so as to control the battery to supply power to the load.

2. The dual power switching circuit according to claim 1, characterized in that: The switch circuit is specifically a PMOS tube, the gate of the PMOS tube is electrically connected to the detection circuit, the drain of the PMOS tube is electrically connected to the power output end of the battery, and the source of the PMOS tube is electrically connected to the load.

3. The dual power switching circuit according to claim 1, characterized in that: The detection circuit is specifically a first voltage-dividing resistor and a second voltage-dividing resistor, the first end of the first voltage-dividing resistor is electrically connected to the external power supply connection end, the second end of the first voltage-dividing resistor is electrically connected to the first end of the second voltage-dividing resistor and the controlled end of the switching circuit respectively, and the second end of the second voltage-dividing resistor is grounded.

4. The dual power switching circuit according to claim 1, wherein: The dual power switching circuit also includes: The anti-reverse connection circuit is arranged on the line between the external power connection terminal and the load, and is used to prevent the current from flowing in reverse through the external power connection terminal and to clamp the voltage supplied by the external power supply.

5. The dual power switching circuit according to claim 1, wherein: The dual power switching circuit also includes: A surge protection circuit is arranged in parallel on the line between the battery and the power load, and is used to limit the instantaneous overvoltage of the battery and guide the discharge surge current to protect the switching circuit from damage.

6. The dual power switching circuit according to claim 1, wherein: The dual power switching circuit also includes: The freewheeling circuit and the switch circuit are arranged in parallel on the line between the battery and the power load, and are used to prevent high-voltage shock from damaging the switch circuit when the switch circuit cuts off the line between the battery and the load.

7. A dual power switching device, characterized in that: The dual power switching device comprises a charging circuit for charging the battery and a dual power switching circuit as claimed in any one of claims 1 to 6.

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