Simple dual-power switching circuit

Abstract

The utility model provides a simple dual-power switching circuit, and belongs to the technical field of switching circuits. Comprising a diode D1, a diode D2 and a diode U1, the diode D1 and the diode D2 are connected in parallel, the cathodes of the diode D1 and the diode D2 are connected with the diode U1, VCC is connected with the cathodes of the diode D1 and the diode D2, the anodes of the diode D1 and the diode D2 are connected with a PowerIN-1 and a PowerIN-2 respectively, and dual-power-supply switching is achieved through the one-way conduction characteristic of the diode. The two diodes D1 and D2 are matched with the low-dropout linear voltage regulator U1, dual-power-supply switching is achieved by means of the unidirectional conduction characteristic of the diodes, compact circuit design is achieved by means of the diodes D1 and D2, the resistors R1-R5, the low-dropout linear voltage regulator U1 and a simple connecting line, and on the basis of the unidirectional conduction of the diodes D1 and D2, the dual-power-supply switching circuit is simple in structure and convenient to use. A power supply control and detection circuit formed by a key SW1, resistors R2, R3, R4 and R5, diodes D3, D4 and D5 and the like is combined to form a clear and understandable circuit logic.

Description

Technical Field

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

[0002] With the continuous development of electronic technology, various electronic devices have been widely used in people's lives and work, and the demand for power supply has become increasingly diversified and complex. In many scenarios, electronic devices need to have the ability to be powered by dual power sources to ensure the continuous and stable operation of the devices in different environments or conditions. For example, some rechargeable devices can be powered by an external power adapter, or they can be powered by a built-in battery when no external power source is available.

[0003] However, existing dual power switching technologies typically employ complex circuit structures. A common approach is to use multiple MOSFETs and transistors, requiring precise connections and intricate control logic. This not only increases the difficulty and complexity of circuit design but also leads to higher costs due to the large number of components. Alternatively, some solutions utilize dedicated power switching integrated circuits (ICs). While this method offers a certain degree of integration, dedicated ICs are often expensive and may require a large area on a printed circuit board (PCB), which is not ideal for electronic devices with strict cost and PCB space constraints. Utility Model Content

[0004] The technical problem to be solved by this utility model is to provide a simple dual power supply switching circuit, which solves the technical problems of high cost, large PCB circuit design area and design difficulty caused by the use of multiple field-effect transistors and transistors or dedicated power switching ICs in the existing dual power supply switching circuits.

[0005] Technical Solution: To achieve the above objectives, this utility model is implemented through the following technical solution: A simple dual power supply switching circuit, including: D1, D2 and U1, D1 and D2 are connected in parallel, and the cathodes of D1 and D2 are connected to U1. At the same time, VCC is connected to the cathodes of D1 and D2, and the anodes of D1 and D2 are connected to Power_IN-1 and Power_IN-2 respectively. It utilizes the unidirectional conduction characteristics of diodes to achieve dual power supply switching.

[0006] In a further embodiment, the cathodes of D1 and D2 are connected to the IN pin of U1 for inputting the selected power supply into U1.

[0007] In a further embodiment, a power control circuit is included, comprising R5, SW1, and D3. The EN pin of U1 is connected to one end of R5, the other end of R5 is grounded, and a resistor R2 is connected in parallel on the connection line between R5 and the EN pin. The other end of R2 is connected to the cathode of D3, the anode of D3 is connected to SW1, and SW1 is also connected to POWER_IN-1. The connection between SW1 and R5 and D3 is used for manual control of the operating state of U1.

[0008] In a further embodiment, R1 and GPIO_2 are connected. One end of resistor R1 is connected to the connection line between D3 and SW1, and the other end of R1 is connected to GPIO_2 to provide additional detection or control signal input for the power control circuit and to assist in the intelligent management and stable operation of the circuit.

[0009] In a further embodiment, a power supply detection circuit is included, which includes R3 and D4. One end of R3 is connected to the EN pin of U1, and the other end is connected to the cathode of the diode D4. The anode of D4 is connected to GPIO_1. Through the connection of R3, diode D4 and GPIO_1, the status of one of the power supplies in the circuit can be detected.

[0010] In another embodiment, R4 and D5 are connected. One end of R4 is connected to the EN pin of U1, and the other end is connected to the cathode of diode D5. The anode of D5 is connected to POWER_IN-2. The detection of the status of another power supply is achieved through the connection of resistor R4, diode D5 and POWER_IN-2.

[0011] In a further embodiment, the MCU control system has its internal POWER_OUT pin connected to the OUT pin of U1, so that the power supply after being regulated by U1 is output to the MCU control system.

[0012] In a further embodiment, the load, whose internal POWER_OUT is connected to the internal POWER_OUT of the MCU control system, further transfers the stable power output from U1 to the load, so that the load can work normally under a stable power supply.

[0013] In a further embodiment, an output filtering circuit is provided, which includes C1. One end of C1 is connected to the connection line between U1 and the MCU control system, and the other end of C1 is grounded, for preliminary filtering of the power supply output by U1.

[0014] In a further embodiment, D1, D2, D3, D4, and D5 are all semiconductor devices with suitable forward conduction voltage and reverse breakdown voltage, and their electrical parameters are adapted to the power supply voltage range in the circuit.

[0015] Beneficial effects: 1. By using two diodes D1 and D2 in conjunction with a low-dropout linear regulator U1, dual power supply switching is achieved by utilizing the unidirectional conduction characteristics of diodes; this simple structure replaces complex multi-tube combinations or expensive dedicated ICs, reducing the number of components and costs, thus achieving the effect of reducing circuit costs.

[0016] 2. By utilizing diodes D1 and D2, resistors R1-R5, a low-dropout linear regulator U1, and simple connection lines, a compact circuit design was achieved. For example, the direct connection between the diodes and U1, as well as the orderly distribution of the resistors in the control and detection circuits, avoided excessive wiring and component space occupation, thus saving PCB circuit design area and effectively reducing the size of the PCB board.

[0017] 3. Based on the unidirectional conduction of diodes D1 and D2, and combined with the power control and detection circuit consisting of button SW1, resistors R2, R3, R4, R5, and diodes D3, D4, D5, a clear and easy-to-understand circuit logic is formed. For example, button SW1 controls the working state of U1 through resistors and diodes, and the power detection circuit connects to the GPIO port through resistors and diodes to realize power status detection. This makes the entire circuit design simple and clear, easy to understand and implement, reduces the design difficulty, and improves the design efficiency. Attached Figure Description

[0018] To more clearly illustrate the technical solutions in this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0019] Figure 1 This is a schematic diagram of the structure of this utility model. Detailed Implementation

[0020] To make the objectives, technical solutions, and advantages of this utility model clearer, the technical solutions in this utility model are described clearly and completely. Obviously, the described embodiments are only some, not all, of the embodiments in this utility model. All other embodiments obtained by those skilled in the art based on the embodiments in this utility model without creative effort are within the scope of protection of this utility model.

[0021] This application provides a simplified dual-power switching circuit, solving the technical problems of high cost, large PCB area, and design difficulties caused by the use of multiple MOSFETs and transistors or dedicated power switching ICs in existing dual-power switching circuits. In practical use, it achieves the goals of significantly reducing circuit cost, significantly reducing PCB area, and simplifying circuit design process.

[0022] To better understand the above technical solutions, the following will provide a detailed explanation of the technical solutions in conjunction with the accompanying drawings and specific implementation methods.

[0023] Reference Figure 1 A simple dual power supply switching circuit includes D1, D2 and U1. D1 and D2 are connected in parallel, and the cathodes of D1 and D2 are connected to U1. VCC is connected to the cathodes of D1 and D2. The anodes of D1 and D2 are connected to Power_IN-1 and Power_IN-2 respectively. It utilizes the unidirectional conduction characteristics of diodes to achieve dual power supply switching.

[0024] By connecting D1 and D2 in parallel, with their cathodes connected to U1 and their anodes connected to Power_IN-1 and Power_IN-2 respectively, and utilizing the unidirectional conduction characteristic of diodes, a simple and effective dual power supply switching mechanism is achieved. When both Power_IN-1 and Power_IN-2 are input, diode D1 or D2 will conduct according to their voltage level, while the other will be cut off, thus automatically selecting the higher voltage power input to provide power to subsequent circuits. This avoids the traditional complex power switching circuit structure, reduces circuit complexity and cost, and provides basic power selection functionality for devices with dual power inputs.

[0025] The cathodes of D1 and D2 are connected to the IN pin of U1 to input the selected power supply into U1.

[0026] Connecting the cathodes of D1 and D2 to the IN pin of U1 clarifies the power transmission path, enabling the power selected by diodes D1 or D2 to be accurately input into the low-dropout linear regulator U1. This ensures reliable power transmission from the dual power input terminals to U1, preparing for subsequent voltage regulation and ensuring the continuity and stability of the subsequent processing flow after power switching.

[0027] The power control circuit includes R5, SW1, and D3. The EN pin of U1 is connected to one end of R5, and the other end of R5 is grounded. A resistor R2 is connected in parallel on the connection line between R5 and the EN pin. The other end of R2 is connected to the cathode of D3. The anode of D3 is connected to SW1, and SW1 is also connected to POWER_IN-1. The connection between SW1, R5, and D3 is used for manual control of the operating state of U1.

[0028] By utilizing the connection relationships of R5, SW1, and D3 in the power control circuit, where the EN pin of U1 is grounded to R5, R2 is connected in parallel on the connection line between R5 and the EN pin, the other end of R2 is connected to the cathode of D3, the anode of D3 is connected to SW1, and SW1 is connected to POWER_IN-1, the manual control function of the working state of U1 is realized. Users can change the connection state of the circuit by operating the button SW1, thereby changing the enable signal of U1 and controlling whether U1 works. This allows users to manually turn the power output of the entire circuit on or off according to actual needs, increasing the flexibility and controllability of circuit operation.

[0029] R1 and GPIO_2: One end of resistor R1 is connected to the connection line between D3 and SW1, and the other end of R1 is connected to GPIO_2, so as to provide additional detection or control signal input for the power control circuit and assist in realizing intelligent management and stable operation of the circuit.

[0030] One end of resistor R1 is connected to the connection line between D3 and SW1, and the other end is connected to GPIO_2, introducing an additional detection or control signal input source for the power control circuit. This structure realizes the monitoring and information feedback of the power control circuit status. GPIO_2 can obtain the real-time status information of the circuit, providing more control signal inputs to the system, assisting in the intelligent management and stable operation of the circuit, and improving the intelligence and operational stability of the circuit. For example, the validity of the circuit operation can be judged based on the signal of GPIO_2 or a basis can be provided for other control logic.

[0031] The power supply detection circuit includes R3 and D4. One end of R3 is connected to the EN pin of U1, and the other end is connected to the cathode of diode D4. The anode of D4 is connected to GPIO_1. Through the connection of R3, diode D4 and GPIO_1, the status of one of the power supplies in the circuit can be detected.

[0032] By utilizing the connection relationship between R3 and D4 in the power supply detection circuit, one end of R3 is connected to the EN pin of U1, and the other end is connected to the cathode of D4. The anode of D4 is connected to GPIO_1, thus realizing the status detection function of one of the power supplies in the circuit. Through this connection method, the status information of this power supply can be fed back to the system via GPIO_1, allowing the system to monitor the operating status of this power supply in real time, such as whether the power supply is working normally and whether the voltage is stable. This provides important information for the system's power management and control, enabling appropriate protection or adjustment measures to be taken when power supply abnormalities occur.

[0033] R4 and D5, one end of R4 is connected to the EN pin of U1, and the other end is connected to the cathode of diode D5. The anode of D5 is connected to POWER_IN-2. Through the connection of resistor R4, diode D5 and POWER_IN-2, the status of another power supply can be detected.

[0034] In the power detection circuit, R4 and D5 are connected as follows: one end of R4 is connected to the EN pin of U1, and the other end is connected to the cathode of D5. The anode of D5 is connected to POWER_IN-2, which realizes the detection of the status of the other power supply (POWER_IN-2). Through the cooperation of resistors and diodes, the status information of POWER_IN-2 is fed back to the system through the corresponding connection, so that the system can fully grasp the working status of the dual power supply and ensure that the circuit can perform reasonable power switching and management operations according to the power supply status when there is a dual power supply input.

[0035] The MCU control system has its internal POWER_OUT pin connected to the OUT pin of U1 so that the power supply after being regulated by U1 is output to the MCU control system.

[0036] Connecting the POWER_OUT pin of the MCU control system to the OUT pin of U1 enables the power supply after being regulated by U1 to be output to the MCU control system, providing a stable operating voltage for the MCU control system and ensuring its normal operation. This allows the MCU to work stably and thus perform its control and processing functions, providing a stable power supply guarantee for the intelligent control and coordinated operation of the entire circuit system.

[0037] The load, whose internal POWER_OUT is connected to the internal POWER_OUT of the MCU control system, further transfers the stable power output from U1 to the load, so that the load can work normally under a stable power supply.

[0038] By connecting the load's POWER_OUT to the POWER_OUT inside the MCU control system, the regulated and controlled power output from U1 is further transferred to the load, ensuring that the load operates normally under a stable power supply. This connection ensures a complete power transmission link from the voltage regulator and control components to the load, guaranteeing stable operation of the load and preventing performance degradation or failure due to power fluctuations or instability. This improves the overall system reliability and load operation stability.

[0039] An output filtering circuit is provided, which includes C1. One end of C1 is connected to the connection line between U1 and the MCU control system, and the other end of C1 is grounded. It is used to perform preliminary filtering on the power supply output by U1.

[0040] In the output filtering circuit, capacitor C1 is used. One end of C1 is connected to the connection line between U1 and the MCU control system, and the other end is grounded, which realizes the initial filtering of the power supply output by U1. Through the filtering effect of capacitor C1, high-frequency noise and ripple in the power supply can be filtered out, providing a cleaner and more stable power supply for the subsequent MCU control system and load, reducing interference components in the power supply, improving the electromagnetic compatibility and power quality of the entire circuit system, and ensuring the stability and reliability of the system.

[0041] D1, D2, D3, D4, and D5 are all semiconductor devices with suitable forward conduction voltage and reverse breakdown voltage, and their electrical parameters are adapted to the power supply voltage range in the circuit.

[0042] By selecting semiconductor devices D1, D2, D3, D4, and D5 with suitable forward conduction voltage and reverse breakdown voltage, and ensuring that their electrical parameters are matched with the power supply voltage range in the circuit, the normal operation of the diodes in the circuit is guaranteed. This ensures that these diodes will not break down due to excessive reverse voltage when the circuit is operating normally, and that they can effectively conduct current during forward conduction, thereby improving the safety and reliability of the circuit and avoiding circuit failures or performance degradation caused by unsuitable diode parameters.

[0043] During operation, in the initial state, if button SW1 is not pressed, the LDO (U1) does not output power, the MCU control system is in a non-operating state, and GPIO-1 and GPIO-2 are both low. When button SW1 is pressed, the EN pin of the LDO becomes high, the LDO starts working, and Power_OUT outputs power to the MCU control system to enable it to operate. The MCU detects that GPIO-2 is high and controls GPIO-1 to output a high level, keeping the LDO continuously working. At this time, the MCU control system and the load are powered by Power_IN-1. Regarding power input, when Power_IN-2 is powered and its voltage is greater than Power_IN-1, because the VCC voltage is greater than Power_IN-1, D1 cannot conduct to supply power to the LDO, while D2 conducts to supply power to the LDO, thus switching the LDO input power from Power_IN-1 to Power_IN-2. When Power_IN-2 is powered off, D2 does not conduct, the VCC voltage drops, causing D1 to conduct, and the LDO returns to being powered by Power_IN-1. During circuit operation, R3, D4, and GPIO_1 in the power detection circuit work together to accurately detect the status of one power supply. R4 and D5, connected to the relevant power supply, can effectively detect the status of the other power supply, laying a solid foundation for stable circuit operation. Simultaneously, capacitor C1 in the output filter circuit optimizes the filtering of the U1 output power supply, effectively ensuring the stability of the output power supply and driving the load to work normally. Furthermore, resistor R1, along with D3, SW1, and GPIO_2, cooperate to deliver crucial detection or control signals to the power control circuit.

[0044] The figures shown in the accompanying drawings are illustrative and are intended only to more intuitively demonstrate the key structure and connection relationships of a simple dual-power switching circuit of this utility model. In practical applications, the appearance and size of the device can be adjusted and optimized according to specific needs.

[0045] This utility model encompasses any substitutions, modifications, equivalent methods, and solutions made within the spirit and scope of this utility model. To provide the public with a thorough understanding of this utility model, specific details have been described in detail in the above preferred embodiments; however, those skilled in the art can fully understand this utility model even without these detailed descriptions. Furthermore, to avoid unnecessary confusion regarding the essence of this utility model, well-known methods, processes, procedures, components, and circuits have not been described in detail.

[0046] The above description is only a preferred embodiment of the present utility model. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present utility model, and these improvements and modifications should also be considered within the protection scope of the present utility model.

Claims

1. A simple dual power switching circuit comprising, D1, D2 and U1, characterized in that: The cathodes of D1 and D2 are connected to U1, and VCC is connected to the cathodes of D1 and D2, and the anodes of D1 and D2 are connected to Power_IN-1 and Power_IN-2 respectively, which realizes double power supply switching by using the unidirectional conduction characteristic of diode.

2. The simple dual power switching circuit according to claim 1, characterized in that: The cathodes of D1 and D2 are connected to the IN pin of U1 for inputting the selected power supply into U1.

3. The simple dual power supply switching circuit according to claim 1, wherein, Further comprising: A power supply control circuit, which contains R5, SW1 and D3, the EN pin of U1 is connected to one end of R5, the other end of R5 is grounded, and R2 is connected in parallel on the connection line between R5 and the EN pin, the other end of R2 is connected to the cathode of D3, the anode of D3 is connected to SW1, and SW1 is also connected to Power_IN-1, and the connection between SW1, R5 and D3 is used for manual control of the working state of U1.

4. The simple dual power supply switching circuit according to claim 3, wherein Further comprising: R1 and GPIO_2, one end of R1 is connected to the connection line between D3 and SW1, and the other end of R1 is connected to GPIO_2, so as to provide additional detection or control signal input for the power supply control circuit, and assist in realizing intelligent management and stable operation of the circuit.

5. The simple dual power supply switching circuit according to claim 4, wherein, Further comprising: A power supply detection circuit, which contains R3 and D4, one end of R3 is connected to the EN pin of U1, and the other end is connected to the cathode of D4, the anode of D4 is connected to GPIO_1, and the connection between R3, diode D4 and GPIO_1 realizes the state detection of one of the power supplies in the circuit.

6. The simple dual power supply switching circuit according to claim 5, wherein The power supply detection circuit further comprises R4 and D5, one end of R4 is connected to the EN pin of U1, and the other end is connected to the cathode of diode D5, the anode of D5 is connected to Power_IN-2, and the connection between resistor R4, diode D5 and Power_IN-2 realizes the detection of the state of the other power supply.

7. The simple dual power supply switching circuit according to claim 1, wherein Further comprising: A MCU control system, the POWER_OUT inside the MCU control system is connected to the OUT pin of U1, so that the stabilized power supply output from U1 is output to the MCU control system.

8. The simple dual power switching circuit according to claim 7, wherein, Further comprising: A load, the POWER_OUT inside the load is connected to the POWER_OUT inside the MCU control system, so that the stabilized power supply output from U1 is further transmitted to the load, so that the load can work normally under the stable power supply.

9. The simple dual power switching circuit according to claim 7, wherein, Further comprising: An output filter circuit, which contains C1, one end of C1 is connected to the connection line between U1 and the MCU control system, and the other end of C1 is grounded, which is used for preliminary filtering of the power supply output by U1.

10. The simple dual power switching circuit according to claim 1, characterized in that: The D1, D2, D3, D4 and D5 are all semiconductor devices with appropriate forward conduction voltage and reverse breakdown voltage, and their electrical parameters are adapted to the range of power supply voltage in the circuit.

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