Power switching circuit and electronic equipment

Abstract

A power switching circuit and an electronic device belong to the technical field of power supply, a first switching circuit transmits a first voltage in response to the first voltage being greater than or equal to a preset threshold; the second switching circuit transmits a second voltage in response to the first voltage smaller than a preset threshold value, and disconnects the output of the second voltage in response to the first voltage larger than or equal to the preset threshold value; the selection circuit transmits a first voltage in response to the first voltage transmitted by the first switching circuit being greater than or equal to a preset threshold value, and transmits a second voltage in response to the first voltage transmitted by the first switching circuit being less than the preset threshold value; short circuit caused by simultaneous access of the first voltage and the second voltage and abnormal power failure of subsequent equipment are avoided, the reliability and safety of the power supply switching circuit are improved, and the possibility that the action time sequence of the selection circuit is disordered during voltage switching is reduced; the power switching circuit is only composed of the first switching circuit, the second switching circuit and the selection circuit, a control logic unit and a microprocessor are not needed, the circuit is simple, and the cost is low.

Description

Technical Field

[0001] This application belongs to the technical field of power supply, and particularly relates to a power supply switching circuit and an electronic device. Background Art

[0002] In recent years, with the increasing requirements for the reliability of the power distribution system, higher requirements have also been put forward for the power supply reliability of secondary equipment. In addition to being equipped with a backup battery, two sets of AC power supply inputs, namely the main and backup ones, are also required so that the backup power supply can seamlessly switch to maintain the normal operation of the equipment after the main power supply loses power, thereby improving the safety level of the power system.

[0003] In the prior art, the following two technical solutions are usually adopted to achieve power supply switching: 1. Use power electronic devices (such as thyristors, field effect transistors, etc.) to construct a voltage switching circuit; 2. Adopt a relay containing two single-pole double-throw nodes or two relays each containing a single-pole double-throw node.

[0004] However, in the above solutions, the power electronic devices in Technical Solution 1 have weak anti-interference ability and are easily burned out when used in high-voltage electricity. Moreover, the core unit of this solution includes a power detection unit, a control logic unit, and a switching execution unit, and some even need to be paired with a microprocessor. This makes the system contain both high-voltage and low-voltage electricity, and circuit design needs to consider issues such as safety isolation between high-voltage and low-voltage electricity. Therefore, this solution requires many components, has a complex circuit design, a high failure rate of the entire system, low reliability, and high cost. In Technical Solution 2, due to the synchronism during the relay switching process and the relay contact bounce, there will be a phenomenon that the new power supply switches in while the original power supply has not been completely disconnected during the power supply switching process, resulting in a short circuit between the two power supplies, causing a strong short-term impact on the equipment and the power supply system. In severe cases, it will even lead to a short circuit between the two power supplies, not only affecting the service life of the power supply system, but also causing the two power supply systems to trigger short-circuit protection simultaneously and lose power at the same time, unable to supply power to the subsequent equipment, resulting in abnormal power-off of the subsequent equipment, with low reliability and safety.

[0005] Therefore, there is an urgent need for a power supply switching circuit with a simple circuit, low cost, high reliability, and high safety. Summary of the Utility Model

[0006] The purpose of this application is to provide a power supply switching circuit and an electronic device, aiming to solve the problems of complex design, high cost, low reliability, and low safety of the existing power supply switching circuit.

[0007] An embodiment of this application provides a power supply switching circuit, including:

[0008] A first switch circuit, configured to connect to a first voltage, transmit the first voltage in response to the first voltage being greater than or equal to a preset threshold, and stop transmitting the first voltage in response to the first voltage being less than the preset threshold;

[0009] A second switch circuit, connected to the first switch circuit, configured to access the first voltage and the second voltage, transmit the second voltage in response to the first voltage being less than a preset threshold, and disconnect the output of the second voltage in response to the first voltage being greater than or equal to the preset threshold;

[0010] A selection circuit, connected to the first switch circuit and the second switch circuit, configured to transmit the first voltage in response to the first voltage transmitted by the first switch circuit being greater than or equal to a preset threshold, and transmit the second voltage in response to the first voltage transmitted by the first switch circuit being less than the preset threshold.

[0011] In one embodiment, the power supply switching circuit further includes:

[0012] A first delay circuit, connected to the first switch circuit and the second switch circuit, configured to delay the first voltage;

[0013] The first switch circuit is specifically configured to transmit the first voltage in response to the delayed first voltage being greater than or equal to a preset threshold, and stop transmitting the first voltage in response to the delayed first voltage being less than the preset threshold;

[0014] A second delay circuit, connected to the second switch circuit, configured to delay the first voltage;

[0015] The second switch circuit is specifically configured to transmit the second voltage in response to the delayed first voltage being less than a preset threshold, and disconnect the output of the second voltage in response to the delayed first voltage being greater than or equal to the preset threshold;

[0016] A third delay circuit, connected to the first switch circuit and the selection circuit, configured to delay the first voltage;

[0017] The selection circuit is specifically configured to transmit the first voltage in response to the first voltage transmitted by the first switch circuit after delay being greater than or equal to a preset threshold, and transmit the second voltage in response to the first voltage transmitted by the first switch circuit after delay being less than the preset threshold.

[0018] In one embodiment, the first delay circuit includes a first capacitor;

[0019] A first end and a second end of the first capacitor jointly serve as a first voltage input end of the first delay circuit and a delayed first voltage output end of the first delay circuit, and are connected to the first switch circuit and the second switch circuit to input a first voltage and output a delayed first voltage;

[0020] The second delay circuit includes a second capacitor;

[0021] A first end and a second end of the second capacitor jointly serve as a first voltage input terminal and a first voltage output terminal after delay of the second delay circuit, and are connected to the second switching circuit to input a first voltage and output a first voltage after delay;

[0022] The third delay circuit includes a third capacitor;

[0023] A first end and a second end of the third capacitor jointly serve as a first voltage input terminal and a first voltage output terminal after delay of the third delay circuit, and are connected to the first switching circuit and the selection circuit to input a first voltage and output a first voltage after delay.

[0024] In one embodiment, the power supply switching circuit further includes:

[0025] A first overvoltage protection circuit, connected to the first switching circuit and the second switching circuit, configured to perform overvoltage protection on the first voltage;

[0026] The first switching circuit is specifically configured to transmit the first voltage in response to the first voltage after overvoltage protection, and stop transmitting the first voltage in response to the first voltage after overvoltage protection being less than a preset threshold;

[0027] A second overvoltage protection circuit, connected to the second switching circuit, configured to perform overvoltage protection on the first voltage;

[0028] The second switching circuit is specifically configured to transmit the second voltage in response to the first voltage after overvoltage protection being less than a preset threshold, and disconnect the output of the second voltage in response to the first voltage after overvoltage protection being greater than or equal to the preset threshold;

[0029] A third overvoltage protection circuit, connected to the first switching circuit and the selection circuit, configured to perform overvoltage protection on the first voltage;

[0030] The selection circuit is specifically configured to transmit the first voltage in response to the first voltage transmitted by the first switching circuit after overvoltage protection being greater than or equal to a preset threshold, and transmit the second voltage in response to the first voltage transmitted by the first switching circuit after overvoltage protection being less than the preset threshold.

[0031] In one embodiment, the power supply switching circuit further includes:

[0032] The first protection circuit, connected to the first switch circuit and the second switch circuit, is configured to protect the first voltage;

[0033] The second protection circuit, connected to the second switch circuit, is configured to protect the second voltage.

[0034] In one embodiment, the first protection circuit includes:

[0035] The first overcurrent protection circuit, configured to perform overcurrent protection on the first voltage;

[0036] The first differential-mode interference suppression circuit, connected to the first overcurrent protection circuit, is configured to suppress differential-mode interference on the first voltage after overcurrent protection;

[0037] The first common-mode interference suppression circuit, connected to the first overcurrent protection circuit, the first differential-mode interference suppression circuit, the first switch circuit, and the second switch circuit, is configured to suppress common-mode interference on the first voltage after differential-mode interference suppression;

[0038] The second protection circuit includes:

[0039] The second overcurrent protection circuit, configured to perform overcurrent protection on the second voltage;

[0040] The second differential-mode interference suppression circuit, connected to the second overcurrent protection circuit, is configured to suppress differential-mode interference on the second voltage after overcurrent protection;

[0041] The second common-mode interference suppression circuit, connected to the second overcurrent protection circuit, the second differential-mode interference suppression circuit, and the second switch circuit, is configured to suppress common-mode interference on the second voltage after differential-mode interference suppression.

[0042] In one embodiment, the first switch circuit includes a first relay;

[0043] The first common terminal of the first relay, the second common terminal of the first relay, the first end of the coil of the first relay, and the second end of the coil of the first relay together serve as the first voltage input terminal of the first switch circuit to input the first voltage; the first normally open contact of the first relay and the second normally open contact of the first relay together serve as the first voltage output terminal of the first switch circuit, connected to the selection circuit to output the first voltage.

[0044] In one embodiment, the second switch circuit includes a second relay;

[0045] The first end of the coil of the second relay and the second end of the coil of the second relay together serve as the first voltage input terminal of the second switching circuit to input the first voltage; the first common terminal of the second relay and the second common terminal of the second relay together serve as the second voltage input terminal of the second switching circuit to input the second voltage; the first normally closed contact of the second relay and the second normally closed contact of the second relay together serve as the second voltage output terminal of the second switching circuit and are connected to the selection circuit to output the second voltage.

[0046] In one embodiment, the selection circuit includes a third relay;

[0047] The first normally open contact of the third relay, the second normally open contact of the third relay, the first end of the coil of the third relay and the second end of the coil of the third relay together serve as the first voltage input terminal of the selection circuit and are connected to the first switching circuit to input the first voltage; the first normally closed contact of the third relay and the second normally closed contact of the third relay together serve as the second voltage input terminal of the selection circuit and are connected to the second switching circuit to input the second voltage; the first common terminal of the third relay and the second common terminal of the third relay together serve as the first voltage output terminal and the second voltage output terminal of the selection circuit to output the first voltage and the second voltage.

[0048] An embodiment of the present application further provides an electronic device, and the electronic device includes the above-mentioned power supply switching circuit.

[0049] The beneficial effects of the embodiment of the present application compared with the prior art are as follows: Only one of the first switching circuit and the second switching circuit is turned on, so that only one of the first voltage and the second voltage is transmitted to the selection circuit, and the selection circuit responds to the first voltage transmitted by the first switching circuit and performs corresponding actions. Thereby, the short circuit caused by the simultaneous access of the first voltage and the second voltage and the abnormal power-off of the subsequent device are avoided, the reliability and safety of the power supply switching circuit are improved, and the possibility of the action timing disorder of the selection circuit during voltage switching is reduced; and the power supply switching circuit is only composed of the first switching circuit, the second switching circuit and the selection circuit, without a control logic unit and a microprocessor, the circuit is simple and the cost is low. Description of the Drawings

[0050] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings required for the description of the embodiments will be briefly introduced below. Obviously, the drawings in the following description are only some embodiments of the present application. For those of ordinary skill in the art, other drawings can be obtained according to these drawings without creative efforts.

[0051] Figure 1 A schematic structural diagram of a power supply switching circuit provided by an embodiment of the present application;

[0052] Figure 2 Another schematic structural diagram of a power supply switching circuit provided by an embodiment of the present application;

[0053] Figure 3 Another schematic structural diagram of a power supply switching circuit provided by an embodiment of the present application;

[0054] Figure 4 Another schematic structural diagram of a power supply switching circuit provided by an embodiment of the present application;

[0055] Figure 5 Another schematic structural diagram of a power supply switching circuit provided by an embodiment of the present application;

[0056] Figure 6 A partial example circuit schematic diagram of a power supply switching circuit provided by an embodiment of the present application. Detailed implementation manners

[0057] In order to make the technical problems, technical solutions and beneficial effects to be solved by the present application clearer and more understandable, the present application will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and are not used to limit the present application.

[0058] It should be noted that when an element is referred to as "fixed to" or "disposed on" another element, it can be directly on the other element or indirectly on the other element. When an element is referred to as "connected to" another element, it can be directly connected to the other element or indirectly connected to the other element.

[0059] It should be understood that the orientation or positional relationship indicated by the terms "length", "width", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc. is based on the orientation or positional relationship shown in the accompanying drawings. It is only for the convenience of describing the present application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation to the present application.

[0060] In addition, the terms "first" and "second" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include one or more of such features. In the description of the present application, "a plurality" means two or more unless otherwise specifically defined.

[0061] Figure 1 The figure shows a schematic structural diagram of a power supply switching circuit provided by an embodiment of the present application. For the sake of convenience of description, only the parts related to this embodiment are shown and are described in detail as follows:

[0062] The above power supply switching circuit includes a first switch circuit 10, a second switch circuit 20, and a selection circuit 30.

[0063] The first switch circuit 10 is configured to connect to a first voltage, and in response to the first voltage being greater than or equal to a preset threshold, transmit the first voltage, and in response to the first voltage being less than the preset threshold, stop transmitting the first voltage.

[0064] The second switch circuit 20 is connected to the first switch circuit 10, and is configured to connect to the first voltage and a second voltage. In response to the first voltage being less than the preset threshold, transmit the second voltage, and in response to the first voltage being greater than or equal to the preset threshold, disconnect the output of the second voltage.

[0065] The selection circuit 30 is connected to the first switch circuit 10 and the second switch circuit 20, and is configured to, in response to the first voltage transmitted by the first switch circuit 10 being greater than or equal to the preset threshold, transmit the first voltage, and in response to the first voltage transmitted by the first switch circuit 10 being less than the preset threshold, transmit the second voltage.

[0066] In a specific implementation, the first voltage and the second voltage may be alternating current. At this time, the first voltage may be output from the live wire L1 of the first AC bus and the neutral wire N1 of the first AC bus, and the second voltage may be output from the live wire L2 of the second AC bus and the neutral wire N2 of the second AC bus. At this time, the first voltage may supply power to the main power supply, and the second voltage may supply power to the backup power supply.

[0067] In a specific implementation, the first voltage and the second voltage may be direct current. At this time, the first voltage may be output from the positive electrode of the first DC bus and the negative electrode of the first DC bus, and the second voltage may be output from the positive electrode of the second DC bus and the negative electrode of the second DC bus (not shown in the figure).

[0068] In a specific implementation, at this time, if the first voltage is greater than or equal to the preset threshold, it proves that the main power supply is working properly. The first switch circuit 10 transmits the first voltage to the selection circuit 30, the second switch circuit 20 disconnects the output of the second voltage, and the selection circuit 30 outputs the first voltage to supply power to the load; if the first voltage is less than the preset threshold, it proves that the main power supply has lost power. At this time, the second switch circuit 20 transmits the second voltage to the selection circuit 30, and the selection circuit 30 outputs the second voltage to supply power to the load.

[0069] When the first voltage is normally powered, the first switch circuit 10 responds to the first voltage being greater than or equal to a preset threshold, transmits the first voltage to the selection circuit 30, the second switch circuit 20 responds to the first voltage being greater than or equal to the preset threshold, disconnects the output of the second voltage, and the selection circuit 30 responds to the first voltage being greater than or equal to the preset threshold, transmits the first voltage for power supply; when the first voltage loses power, it is powered by the second voltage. At this time, the first switch circuit 10 stops transmitting the first voltage, the second switch circuit 20 responds to the first voltage being less than the preset threshold, transmits the second voltage to the selection circuit 30, and the selection circuit 30 responds to the first voltage being less than the preset threshold, transmits the second voltage for power supply; thus, when switching from power supply by the first voltage to power supply by the second voltage, both the first switch circuit 10 and the second switch circuit 20 will operate only after the first voltage loses power, and only one path of voltage is transmitted to the selection circuit 30. After both the first switch circuit 10 and the second switch circuit 20 operate, the selection circuit 30 performs a selection switch to stop transmitting the first voltage and transmit the second voltage; when switching from power supply by the second voltage to power supply by the first voltage, both the first switch circuit 10 and the second switch circuit 20 will operate only after the first voltage is powered on, and only one path of voltage is transmitted to the selection circuit 30. After both the first switch circuit 10 and the second switch circuit 20 operate, the selection circuit 30 performs a selection switch to stop transmitting the second voltage and transmit the first voltage; from this, it can be seen that when switching between power supply by the first voltage and the second voltage, the first switch circuit 10 and the second switch circuit 20 act first, and the selection circuit 30 acts later. Therefore, there is a time interval when switching between the first voltage and the second voltage, avoiding short circuits caused by the simultaneous connection of the first voltage and the second voltage and abnormal power-off of the subsequent devices, improving the reliability and safety of the power supply switching circuit; and this power supply switching circuit is only composed of the first switch circuit 10, the second switch circuit 20 and the selection circuit 30, without a control logic unit and a microprocessor, the circuit is simple and the cost is low.

[0070] By way of example and not limitation, as Figure 2 shown, the power supply switching circuit further includes a first delay circuit 40, a second delay circuit 50 and a third delay circuit 60.

[0071] The first delay circuit 40, connected to the first switch circuit 10 and the second switch circuit 20, is configured to delay the first voltage.

[0072] The first switch circuit 10 is specifically configured to transmit the first voltage in response to the delayed first voltage being greater than or equal to a preset threshold, and stop transmitting the first voltage in response to the delayed first voltage being less than the preset threshold.

[0073] The second delay circuit 50, connected to the second switch circuit 20, is configured to delay the first voltage.

[0074] The second switch circuit 20 is specifically configured to transmit a second voltage in response to the delayed first voltage being less than a preset threshold, and to disconnect the output of the second voltage in response to the delayed first voltage being greater than or equal to the preset threshold.

[0075] A third delay circuit 60, connected to the first switch circuit 10 and the selection circuit 30, is configured to delay the first voltage transmitted by the first switch circuit 10.

[0076] The selection circuit 30 is specifically configured to transmit the first voltage in response to the delayed first voltage transmitted by the first switch circuit 10 being greater than or equal to the preset threshold, and to transmit the second voltage in response to the delayed first voltage transmitted by the first switch circuit 10 being less than the preset threshold.

[0077] Through the first delay circuit 40, the response time of the first switch circuit 10 to transmit the first voltage can be adjusted according to actual requirements. Through the second delay circuit 50, the response time of the second switch circuit 20 to transmit the second voltage can be adjusted according to actual requirements. Through the third delay circuit 60, the response time of the selection circuit 30 to transmit the first voltage or the second voltage can be adjusted according to actual requirements. Thus, it not only avoids the short circuit caused by the simultaneous access of the first voltage and the second voltage and the abnormal power-off of the subsequent devices, but also reduces the possibility that the action time intervals of the first switch circuit 10, the second switch circuit 20, and the selection circuit 30 are too long, resulting in too long a switching time interval between the first voltage and the second voltage and bringing a large voltage drop impact to the subsequent stage, further improving the reliability and safety of the circuit.

[0078] As an example rather than a limitation, as Figure 3 shown, the power supply switching circuit further includes a first overvoltage protection circuit 70, a second overvoltage protection circuit 80, and a third overvoltage protection circuit 90.

[0079] The first overvoltage protection circuit 70, connected to the first switch circuit 10 and the second switch circuit 20, is configured to perform overvoltage protection on the first voltage.

[0080] The first switch circuit 10 is specifically configured to transmit the first voltage in response to the first voltage after overvoltage protection, and to stop transmitting the first voltage in response to the first voltage after overvoltage protection being less than the preset threshold.

[0081] The second overvoltage protection circuit 80, connected to the second switch circuit 20, is configured to perform overvoltage protection on the first voltage.

[0082] The second switch circuit 20 is specifically configured to transmit the second voltage in response to the first voltage after overvoltage protection being less than the preset threshold, and to disconnect the output of the second voltage in response to the first voltage after overvoltage protection being greater than or equal to the preset threshold.

[0083] The third overvoltage protection circuit 90, connected to the first switching circuit 10 and the selection circuit 30, is configured to perform overvoltage protection on the first voltage.

[0084] The selection circuit 30 is specifically configured to transmit the first voltage in response to the first voltage transmitted by the first switching circuit 10 after overvoltage protection being greater than or equal to a preset threshold, and transmit the second voltage in response to the first voltage transmitted by the first switching circuit 10 after overvoltage protection being less than the preset threshold.

[0085] The possibility of overvoltage damage to the first switching circuit 10 is reduced by the first overvoltage protection circuit 70, the possibility of overvoltage damage to the second switching circuit 20 is reduced by the second overvoltage protection circuit 80, and the possibility of overvoltage damage to the selection circuit 30 is reduced by the third overvoltage protection circuit 90, improving the safety of the power supply switching circuit.

[0086] By way of example and not limitation, as Figure 4 shown, the power supply switching circuit further includes a first protection circuit 100 and a second protection circuit 110.

[0087] The first protection circuit 100, connected to the first switching circuit 10 and the second switching circuit 20, is configured to protect the first voltage.

[0088] The second protection circuit 110, connected to the second switching circuit 20, is configured to protect the second voltage.

[0089] The first voltage input to the power supply switching circuit is protected by the first protection circuit 100, and the second voltage input to the power supply switching circuit is protected by the second protection circuit 110, further improving the safety of the power supply switching circuit.

[0090] By way of example and not limitation, as Figure 4 shown, the first protection circuit 100 includes a first overcurrent protection circuit 101, a first common-mode interference suppression circuit 103, and a first differential-mode interference suppression circuit 102.

[0091] The first overcurrent protection circuit 101 is configured to perform overcurrent protection on the first voltage.

[0092] The first differential-mode interference suppression circuit 102, connected to the first overcurrent protection circuit 101, is configured to suppress differential-mode interference on the first voltage after overcurrent protection.

[0093] The first common-mode interference suppression circuit 103, connected to the first overcurrent protection circuit 101, the first differential-mode interference suppression circuit 102, the first switching circuit 10, and the second switching circuit 20, is configured to suppress common-mode interference on the first voltage after differential-mode interference suppression.

[0094] The second protection circuit 110 includes a second overcurrent protection circuit 111, a second common-mode interference suppression circuit 113, and a second differential-mode interference suppression circuit 112.

[0095] The second overcurrent protection circuit 111 is connected to the second switch circuit 20 and is configured to perform overcurrent protection on the second voltage.

[0096] The second differential-mode interference suppression circuit 112 is connected to the second overcurrent protection circuit 111 and is configured to perform differential-mode interference suppression on the second voltage after overcurrent protection.

[0097] The second common-mode interference suppression circuit 113 is connected to the second overcurrent protection circuit 111, the second differential-mode interference suppression circuit 112, and the second switch circuit 20, and is configured to perform common-mode interference suppression on the second voltage after differential-mode interference suppression.

[0098] Through the first overcurrent protection circuit 101, overcurrent protection is quickly performed when the first voltage has a short circuit or is overloaded, reducing the possibility of the main power supply being burned out and the further expansion of faults in the subsequent circuit. Through the second overcurrent protection circuit 111, overcurrent protection is quickly performed when the second voltage has a short circuit or is overloaded, reducing the possibility of the backup power supply being burned out and the further expansion of faults in the subsequent circuit, thereby improving the safety of the power supply switching circuit; the anti-interference ability of the power supply switching circuit is improved by two common-mode interference suppression circuits and two differential-mode interference suppression circuits.

[0099] Figure 6 A partial example circuit structure of the power supply switching circuit provided by the embodiment of the present application is shown. For the convenience of description, only the parts related to the embodiment of the present application are shown and are described in detail as follows:

[0100] The first delay circuit 40 includes a first capacitor C1.

[0101] The first end and the second end of the first capacitor C1 jointly serve as the first voltage input terminal of the first delay circuit 40 and the first voltage output terminal after delay of the first delay circuit 40, and are connected to the first switch circuit 10 and the second switch circuit 20 to input the first voltage and output the first voltage after delay.

[0102] The second delay circuit 50 includes a second capacitor C2.

[0103] The first end and the second end of the second capacitor C2 jointly serve as the first voltage input terminal of the second delay circuit 50 and the first voltage output terminal after delay of the second delay circuit 50, and are connected to the second switch circuit 20 to input the first voltage and output the first voltage after delay.

[0104] The third delay circuit 60 includes a third capacitor C3.

[0105] The first end and the second end of the third capacitor C3 jointly serve as the first voltage input terminal and the delayed first voltage output terminal of the third delay circuit 60, and are connected to the first switch circuit 10 and the selection circuit 30 to input the first voltage and output the delayed first voltage.

[0106] Each delay circuit element is simple and easy to obtain, and has a low cost.

[0107] The first switch circuit 10 includes a first relay RLY1.

[0108] The first common terminal, the second common terminal, the first end of the coil, and the second end of the coil of the first relay RLY1 jointly serve as the first voltage input terminal of the first switch circuit 10 to input the first voltage; the first normally open contact and the second normally open contact of the first relay RLY1 jointly serve as the first voltage output terminal of the first switch circuit 10 and are connected to the selection circuit 30 to output the first voltage.

[0109] The first relay RLY1 is a high-immunity device for high-voltage electricity, with a low failure rate and high reliability.

[0110] The second switch circuit 20 includes a second relay RLY2.

[0111] The first end of the coil and the second end of the coil of the second relay RLY2 jointly serve as the first voltage input terminal of the second switch circuit 20 to input the first voltage; the first common terminal and the second common terminal of the second relay RLY2 jointly serve as the second voltage input terminal of the second switch circuit 20 to input the second voltage; the first normally closed contact and the second normally closed contact of the second relay RLY2 jointly serve as the second voltage output terminal of the second switch circuit 20 and are connected to the selection circuit 30 to output the second voltage.

[0112] The second relay RLY2 is a high-immunity device for high-voltage electricity, with a low failure rate and high reliability.

[0113] The selection circuit 30 includes a third relay RLY3.

[0114] The first normally open contact of the third relay RLY3, the second normally open contact of the third relay RLY3, the first end of the coil of the third relay RLY3, and the second end of the coil of the third relay RLY3 together serve as the first voltage input terminal of the selection circuit 30 and are connected to the first switch circuit 10 to input the first voltage; the first normally closed contact of the third relay RLY3 and the second normally closed contact of the third relay RLY3 together serve as the second voltage input terminal of the selection circuit 30 and are connected to the second switch circuit 20 to input the second voltage; the first common terminal of the third relay RLY3 and the second common terminal of the third relay RLY3 together serve as the first voltage output terminal of the selection circuit 30 and the second voltage output terminal of the selection circuit 30 to output the first voltage and the second voltage.

[0115] In a specific implementation, the power supply switching circuit may further include a first resistor R1, a second resistor R2, and a third resistor R3.

[0116] The first end of the first resistor R1 is connected to the first end of the coil of the first relay RLY1, and the second end of the first resistor R1 and the second end of the coil of the first relay RLY1 together input the first voltage; the first end of the second resistor R2 is connected to the first end of the coil of the second relay RLY2, and the second end of the second resistor R2 and the second end of the coil of the second relay RLY2 together input the first voltage; the first end of the third resistor R3 is connected to the first end of the coil of the third relay RLY3, and the second end of the third resistor R3 and the second end of the coil of the third relay RLY3 together input the first voltage.

[0117] In a specific implementation, the first resistor R1 may be a current limiting resistor, and the first resistor R1 may cooperate with the first delay circuit 40 to improve the accuracy of the delay; the second resistor R2 may be a current limiting resistor, and the second resistor R2 may cooperate with the second delay circuit 50 to improve the accuracy of the delay; the third resistor R3 may be a current limiting resistor, and the third resistor R3 may cooperate with the third delay circuit 60 to improve the accuracy of the delay.

[0118] The third relay RLY3 is a high immunity device for high voltage electricity, with low failure rate and high reliability.

[0119] The first overvoltage protection circuit 70 includes a first varistor MY1.

[0120] The first end of the first varistor MY1 and the second end of the first varistor MY1 together serve as the first voltage input terminal of the first overvoltage protection circuit 70 and the first voltage output terminal after overvoltage protection of the first overvoltage protection circuit 70, and are connected to the first switch circuit 10 and the second switch circuit 20 to input the first voltage and output the first voltage after overvoltage protection.

[0121] It can be understood that the first varistor MY1 can provide a freewheeling circuit for the coil of the first relay RLY1 when power is cut off, thereby protecting the first relay RLY1.

[0122] The second overvoltage protection circuit 80 includes a second varistor MY2.

[0123] The first end and the second end of the second varistor MY2 jointly serve as the first voltage input terminal of the second overvoltage protection circuit 80 and the first voltage output terminal after overvoltage protection of the second overvoltage protection circuit 80, and are connected to the second switch circuit 20 to input the first voltage and output the first voltage after overvoltage protection.

[0124] It can be understood that the second varistor MY2 can provide a freewheeling circuit for the coil of the second relay RLY2 when power is cut off, thereby protecting the second relay RLY2.

[0125] The third overvoltage protection circuit 90 includes a third varistor MY3.

[0126] The first end and the second end of the third varistor MY3 jointly serve as the first voltage input terminal of the third overvoltage protection circuit 90 and the first voltage output terminal after overvoltage protection of the third overvoltage protection circuit 90, and are connected to the first switch circuit 10 and the selection circuit 30 to input the first voltage and output the first voltage after overvoltage protection.

[0127] It can be understood that the third varistor MY3 can provide a freewheeling circuit for the coil of the third relay RLY3 when power is cut off, thereby protecting the third relay RLY3.

[0128] The first overcurrent protection circuit 101 includes a first fuse F1 and a second fuse F2.

[0129] The first end of the first fuse F1 and the first end of the second fuse F2 serve as the first voltage input terminal of the first overcurrent protection circuit 101 to input the first voltage; the second end of the first fuse F1 and the second end of the second fuse F2 serve as the first voltage output terminal after overcurrent protection of the first overcurrent protection circuit 101, and are connected to the first differential-mode interference suppression circuit 102 and the first common-mode interference suppression circuit 103 to output the first voltage after overcurrent protection.

[0130] The first differential-mode interference suppression circuit 102 includes a sixth capacitor C6 and a sixth varistor MY6.

[0131] The first terminal of the sixth capacitor C6, the second terminal of the sixth capacitor C6, the first terminal of the sixth varistor MY6, and the second terminal of the sixth varistor MY6 together serve as the first voltage input terminal after overcurrent protection of the first differential-mode interference suppression circuit 102 and the first voltage output terminal after common-mode interference suppression of the first differential-mode interference suppression circuit 102, and are connected to the first overcurrent protection circuit 101 and the first common-mode interference suppression circuit 103 to input the first voltage after overcurrent protection and output the first voltage after differential-mode interference suppression.

[0132] Among them, the sixth capacitor C6 can be a safety capacitor.

[0133] The first common-mode interference suppression circuit 103 includes a first common-mode inductor T1, a fourth capacitor C4, a fifth capacitor C5, a fourth varistor MY4, a fifth varistor MY5, and a first gas discharge tube DS1.

[0134] The first terminal of the fourth capacitor C4, the first terminal of the fifth capacitor C5, the first terminal of the fourth varistor MY4, the first terminal of the fifth varistor MY5, the first input terminal of the first common-mode inductor T1, and the second input terminal of the first common-mode inductor T1 together serve as the first voltage input terminal after differential-mode interference suppression of the first common-mode interference suppression circuit 103 and are connected to the first overcurrent protection circuit 101 and the first differential-mode interference suppression circuit 102 to input the first voltage after differential-mode interference suppression; the second terminal of the fourth varistor MY4 and the second terminal of the fifth varistor MY5 and the first terminal of the first gas discharge tube DS1 are connected, and the first output terminal of the first common-mode inductor T1 and the second output terminal of the first common-mode inductor T1 together serve as the first voltage output terminal after common-mode interference suppression of the first common-mode interference suppression circuit 103 and are connected to the first switch circuit 10 and the second switch circuit 20 to output the first voltage after common-mode interference suppression; the second terminal of the fourth capacitor C4, the second terminal of the fifth capacitor C5, and the second terminal of the first gas discharge tube DS1 are commonly connected to the chassis ground.

[0135] Among them, the fourth capacitor C4 and the fifth capacitor C5 can be safety capacitors.

[0136] The second overcurrent protection circuit 111 includes a third fuse F3 and a fourth fuse F4.

[0137] The first terminal of the third fuse F3 and the first terminal of the fourth fuse F4 serve as the second voltage input terminal of the second overcurrent protection circuit 111 to input the second voltage; the second terminal of the third fuse F3 and the second terminal of the fourth fuse F4 serve as the second voltage output terminal after overcurrent protection of the second overcurrent protection circuit 111 and are connected to the second differential-mode interference suppression circuit 112 and the second common-mode interference suppression circuit 113 to output the second voltage after overcurrent protection.

[0138] The second differential-mode interference suppression circuit 112 includes a ninth capacitor C9 and a ninth varistor MY9.

[0139] The first end of the ninth capacitor C9, the second end of the ninth capacitor C9, the first end of the ninth varistor MY9, and the second end of the ninth varistor MY9 jointly serve as the second voltage input end after overcurrent protection of the second differential-mode interference suppression circuit 112 and the second voltage output end after common-mode interference suppression of the second differential-mode interference suppression circuit 112, and are connected to the second overcurrent protection circuit 111 and the second common-mode interference suppression circuit 113 to input the second voltage after overcurrent protection and output the second voltage after differential-mode interference suppression.

[0140] Among them, the ninth capacitor C9 can be a safety capacitor.

[0141] The second common-mode interference suppression circuit 113 includes a second common-mode inductor T2, a seventh capacitor C7, an eighth capacitor C8, a seventh varistor MY7, an eighth varistor MY8, and a second gas discharge tube DS2.

[0142] The first end of the seventh capacitor C7, the first end of the eighth capacitor C8, the first end of the seventh varistor MY7, the first end of the eighth varistor MY8, the first input end of the second common-mode inductor T2, and the second input end of the second common-mode inductor T2 jointly serve as the second voltage input end after differential-mode interference suppression of the second common-mode interference suppression circuit 113, and are connected to the second overcurrent protection circuit 111 and the second differential-mode interference suppression circuit 112 to input the second voltage after differential-mode interference suppression; the second end of the seventh varistor MY7 and the second end of the eighth varistor MY8 and the first end of the second gas discharge tube DS2 are connected, and the first output end of the second common-mode inductor T2 and the second output end of the second common-mode inductor T2 jointly serve as the second voltage output end after common-mode interference suppression of the second common-mode interference suppression circuit 113, and are connected to the second switch circuit 20 to output the second voltage after common-mode interference suppression; the second end of the seventh capacitor C7, the second end of the eighth capacitor C8, and the second end of the second gas discharge tube DS2 are jointly connected to the chassis ground.

[0143] Among them, the seventh capacitor C7 and the eighth capacitor C8 can be safety capacitors.

[0144] The following further explains with the working principle Figure 6 as shown:

[0145] The first ends of the first fuse F1 and the second fuse F2 are connected to a first voltage. The first fuse F1 and the second fuse F2 perform overcurrent protection on the first voltage, and output the first voltage after overcurrent protection from the second ends of the first fuse F1 and the second fuse F2; the first end of the sixth capacitor C6, the second end of the sixth capacitor C6, the first end of the sixth varistor MY6, and the second end of the sixth varistor MY6 input the first voltage. The sixth capacitor C6 and the sixth varistor MY6 perform differential-mode interference suppression on the first voltage, and output the first voltage after differential-mode interference suppression from the first end of the sixth capacitor C6, the second end of the sixth capacitor C6, the first end of the sixth varistor MY6, and the second end of the sixth varistor MY6; the first end of the fourth capacitor C4, the first end of the fifth capacitor C5, the first end of the fourth varistor MY4, the first end of the fifth varistor MY5, the first input end of the first common-mode inductor T1, and the second input end of the first common-mode inductor T1 input the first voltage. The first common-mode inductor T1, the fourth capacitor C4, the fifth capacitor C5, the fourth varistor MY4, the fifth varistor MY5, and the first gas discharge tube DS1 perform common-mode interference suppression on the first voltage, and output the first voltage after common-mode interference suppression from the first output end of the first common-mode inductor T1 and the second output end of the first common-mode inductor T1; the first ends of the third fuse F3 and the fourth fuse F4 are connected to the first voltage. The third fuse F3 and the fourth fuse F4 perform overcurrent protection on the first voltage, and output the second voltage after overcurrent protection from the second ends of the third fuse F3 and the fourth fuse F4; the first end of the ninth capacitor C9, the second end of the ninth capacitor C9, the first end of the ninth varistor MY9, and the second end of the ninth varistor MY9 are connected to the second voltage. The ninth capacitor C9 and the ninth varistor MY9 perform differential-mode interference suppression on the second voltage, and output the second voltage after differential-mode interference suppression from the first end of the ninth capacitor C9, the second end of the ninth capacitor C9, the first end of the ninth varistor MY9, and the second end of the ninth varistor MY9. The first end of the seventh capacitor C7, the first end of the eighth capacitor C8, the first end of the seventh varistor MY7, the first end of the eighth varistor MY8, the first input end of the second common-mode inductor T2, and the second input end of the second common-mode inductor T2 input the second voltage. The second common-mode inductor T2, the seventh capacitor C7, the eighth capacitor C8, the seventh varistor MY7, the eighth varistor MY8, and the second gas discharge tube DS2 perform common-mode interference suppression on the second voltage, and output the second voltage after common-mode interference suppression from the first output end of the second common-mode inductor T2 and the second output end of the second common-mode inductor T2.

[0146] When switching from power supply by the backup power source to power supply by the main power source, the first end of the coil of the second relay RLY2 and the second end of the coil of the second relay RLY2 are jointly connected to the first voltage after overcurrent protection, differential-mode interference suppression, and common-mode interference suppression. The first common end of the second relay RLY2 and the second common end of the second relay RLY2 input the second voltage. The second relay RLY2 operates, the normally closed contact disconnects, and the normally open contact closes, thereby disconnecting the output of the second voltage. The first common end of the first relay RLY1, the second common end of the first relay RLY1, the first end of the coil of the first relay RLY1, and the second end of the coil of the first relay RLY1 are jointly connected to the first voltage after overcurrent protection, differential-mode interference suppression, and common-mode interference suppression. The first resistor R1 limits the current of the first voltage. The first relay RLY1 operates, the normally closed contact disconnects, and the normally open contact closes, so that the first normally open contact of the first relay RLY1 and the second normally open contact of the first relay RLY1 output the first voltage to the first normally open contact of the third relay RLY3, the second normally open contact of the third relay RLY3, the first end of the third resistor R3, and the second end of the coil of the third relay RLY3. The third resistor R3 limits the current of the first voltage. The third relay RLY3 operates, the normally closed contact disconnects, and the normally open contact closes, so that the first voltage is output from the first common end and the second common end of the third relay RLY3 to the load for power supply.

[0147] Therefore, when switching from power supply by the main power source to power supply by the backup power source, all three relays lose power. Therefore, the first relay RLY1 stops transmitting the first voltage. The first common end of the second relay RLY2 and the second common end of the second relay RLY2 input the second voltage. The normally closed contact of the second relay RLY2 closes, and the normally open contact disconnects, so that the first normally closed contact of the second relay RLY2 and the second normally closed contact of the second relay RLY2 output the second voltage to the first normally closed contact of the third relay RLY3 and the second normally closed contact of the third relay RLY3. The normally closed contact of the third relay RLY3 closes, and the normally open contact disconnects, so that the second voltage is output from the common end of the third relay RLY3, the first common end and the second common end of the third relay RLY3 to the load for power supply.

[0148] The embodiment of the present application further provides an electronic device, and the electronic device includes the above power supply switching circuit.

[0149] It should be understood that the magnitudes of the sequence numbers of the steps in the above embodiments do not mean the order of execution. The order of execution of each process should be determined according to its function and internal logic, and should not constitute any limitation to the implementation process of the embodiments of the present application.

[0150] The embodiments described above are only used to illustrate the technical solutions of the present application, rather than to limit it; although the present application has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions described in the foregoing embodiments, or perform equivalent replacements on some of the technical features; and these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present application, and should all be included in the protection scope of the present application.

Claims

1. A power switching circuit, characterized in that: include: A first switch circuit is configured to connect to a first voltage, transmit the first voltage in response to the first voltage being greater than or equal to a preset threshold, and stop transmitting the first voltage in response to the first voltage being less than the preset threshold; a second switch circuit, connected to the first switch circuit, configured to access the first voltage and the second voltage, transmit the second voltage in response to the first voltage being less than a preset threshold, and disconnect the output of the second voltage in response to the first voltage being greater than or equal to the preset threshold; A selection circuit is connected to the first switching circuit and the second switching circuit, and is configured to transmit the first voltage in response to the first voltage transmitted by the first switching circuit being greater than or equal to a preset threshold, and to transmit the second voltage in response to the first voltage transmitted by the first switching circuit being less than the preset threshold.

2. The power switching circuit according to claim 1, wherein: Also includes: A first delay circuit, connected to the first switch circuit and the second switch circuit, configured to delay the first voltage; The first switch circuit is specifically configured to transmit the first voltage in response to the first voltage after the delay being greater than or equal to a preset threshold, and to stop transmitting the first voltage in response to the first voltage after the delay being less than the preset threshold; a second delay circuit, connected to the second switch circuit and configured to delay the first voltage; The second switch circuit is specifically configured to transmit the second voltage in response to the first voltage after the delay being less than a preset threshold, and disconnect the output of the second voltage in response to the first voltage after the delay being greater than or equal to the preset threshold; a third delay circuit, connected to the first switch circuit and the selection circuit, and configured to delay the first voltage transmitted by the first switch circuit; The selection circuit is specifically configured to transmit the first voltage in response to the first voltage transmitted by the first switching circuit after a delay being greater than or equal to a preset threshold, and to transmit the second voltage in response to the first voltage transmitted by the first switching circuit after a delay being less than the preset threshold.

3. The power switching circuit according to claim 2, wherein: The first delay circuit includes a first capacitor; The first end of the first capacitor and the second end of the first capacitor serve together as a first voltage input end of the first delay circuit and a delayed first voltage output end of the first delay circuit, and are connected to the first switch circuit and the second switch circuit to input a first voltage and output a delayed first voltage; The second delay circuit includes a second capacitor; The first end of the second capacitor and the second end of the second capacitor serve together as the first voltage input end of the second delay circuit and the delayed first voltage output end of the second delay circuit, and are connected to the second switch circuit to input the first voltage and output the delayed first voltage; The third delay circuit includes a third capacitor; The first end of the third capacitor and the second end of the third capacitor together serve as the first voltage input end of the third delay circuit and the first voltage output end after delay of the third delay circuit, and are connected to the first switching circuit and the selection circuit to input the first voltage and output the first voltage after delay.

4. The power switching circuit according to claim 1, wherein: Also includes: A first overvoltage protection circuit, connected to the first switch circuit and the second switch circuit, configured to perform overvoltage protection on the first voltage; The first switch circuit is specifically configured to transmit the first voltage in response to the first voltage after overvoltage protection, and stop transmitting the first voltage in response to the first voltage after overvoltage protection being less than a preset threshold; a second overvoltage protection circuit, connected to the second switch circuit, and configured to perform overvoltage protection on the first voltage; The second switch circuit is specifically configured to transmit the second voltage in response to the first voltage after overvoltage protection being less than a preset threshold, and disconnect the output of the second voltage in response to the first voltage after overvoltage protection being greater than or equal to the preset threshold; a third overvoltage protection circuit, connected to the first switch circuit and the selection circuit, and configured to perform overvoltage protection on the first voltage; The selection circuit is specifically configured to transmit the first voltage in response to the first voltage transmitted by the first switching circuit after overvoltage protection being greater than or equal to a preset threshold, and to transmit the second voltage in response to the first voltage transmitted by the first switching circuit after overvoltage protection being less than the preset threshold.

5. The power switching circuit according to claim 1, wherein: Also includes: a first protection circuit, connected to the first switch circuit and the second switch circuit, and configured to protect the first voltage; The second protection circuit is connected to the second switch circuit and is configured to protect the second voltage.

6. The power switching circuit according to claim 5, characterized in that: The first protection circuit comprises: a first overcurrent protection circuit, configured to perform overcurrent protection on the first voltage; A first differential mode interference suppression circuit, connected to the first overcurrent protection circuit, configured to perform differential mode interference suppression on the first voltage after overcurrent protection; A first common-mode interference suppression circuit is connected to the first overcurrent protection circuit, the first differential-mode interference suppression circuit, the first switch circuit, and the second switch circuit, and is configured to perform common-mode interference suppression on the first voltage after differential-mode interference suppression; The second protection circuit comprises: a second overcurrent protection circuit, configured to perform overcurrent protection on the second voltage; A second differential mode interference suppression circuit is connected to the second overcurrent protection circuit and is configured to perform differential mode interference suppression on the second voltage of the overcurrent protection; The second common-mode interference suppression circuit is connected to the second overcurrent protection circuit, the second differential-mode interference suppression circuit and the second switch circuit, and is configured to perform common-mode interference suppression on the second voltage after differential-mode interference suppression.

7. The power switching circuit according to claim 1, wherein: The first switch circuit includes a first relay; The first common end of the first relay, the second common end of the first relay, the first end of the coil of the first relay and the second end of the coil of the first relay are used together as a first voltage input end of the first switch circuit to input the first voltage; The first normally open contact of the first relay and the second normally open contact of the first relay serve together as a first voltage output terminal of the first switch circuit, and are connected to the selection circuit to output the first voltage.

8. The power switching circuit according to claim 1, wherein: The second switch circuit includes a second relay; The first end of the coil of the second relay and the second end of the coil of the second relay are used together as the first voltage input end of the second switch circuit to input the first voltage; The first common terminal of the second relay and the second common terminal of the second relay serve together as the second voltage input terminal of the second switch circuit to input the second voltage; the first normally closed contact of the second relay and the second normally closed contact of the second relay serve together as the second voltage output terminal of the second switch circuit, which are connected to the selection circuit to output the second voltage.

9. The power switching circuit according to claim 1, wherein: The selection circuit includes a third relay; The first normally open contact of the third relay, the second normally open contact of the third relay, the first end of the coil of the third relay and the second end of the coil of the third relay are used together as the first voltage input end of the selection circuit, connected to the first switch circuit to input the first voltage; the first normally closed contact of the third relay and the second normally closed contact of the third relay are used together as the second voltage input end of the selection circuit, connected to the second switch circuit to input the second voltage; The first common terminal of the third relay and the second common terminal of the third relay serve together as the first voltage output terminal of the selection circuit and the second voltage output terminal of the selection circuit to output the first voltage and the second voltage.

10. An electronic device, characterized in that: Comprising the power switching circuit as claimed in any one of claims 1 to 9.

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