A power adapter

Abstract

The application discloses a power adapter, and relates to the technical field of power supply, which comprises a shell, an input terminal, a switch assembly and an input circuit arranged in the shell, wherein the input circuit comprises a safety X capacitor. The switch assembly is connected in series in a charging loop of the safety X capacitor. The switch assembly is linked with the plugging action of the power adapter, and is turned on when the input terminal is connected with an external power supply device, so that the safety X capacitor can normally work; and the switch assembly is turned off when the input terminal is separated from the external power supply device. Through the design, when the adapter is unplugged, the switch assembly can instantaneously cut off the electrical connection between the safety X capacitor and the input terminal, so that the residual charge of the safety X capacitor cannot be discharged to the outside, thereby ensuring the safety without relying on a discharging resistor. Since the discharging resistor which continuously generates loss is completely removed, the power adapter of the application reduces the overall standby power consumption, and realizes the dual goals of safety and energy saving.

Description

Technical Field

[0001] This application relates to the field of power supply technology, and in particular to a power adapter. Background Technology

[0002] Power adapters, as common and widely used electronic devices, primarily function to convert AC mains power into low-voltage DC power required by electronic products. In a typical power adapter input circuit, a safety X capacitor is usually connected in parallel between the live wire (L) and the neutral wire (N) to suppress differential-mode and common-mode electromagnetic interference. This X capacitor is crucial for ensuring the product meets electromagnetic compatibility (EMC) standards. However, the presence of the X capacitor also presents a safety hazard. When the power adapter finishes charging and is unplugged, a high voltage remains inside the X capacitor. If a user touches the adapter's input pins at this time, the residual charge will be released through the human body, potentially causing an electric shock risk.

[0003] To meet this safety standard, the industry standard practice is to connect a high-resistance discharge resistor (also known as a bleed resistor) in parallel across the X capacitor. When the adapter is disconnected from the power supply, the charge stored on the X capacitor can be slowly released through this discharge resistor. Although this design effectively solves the safety issue, because this discharge resistor is always connected in parallel with the AC input circuit, it continuously consumes power as long as the adapter is plugged in, regardless of whether it is charging the load device (i.e., including both operating and idle standby states), generating unnecessary static power consumption. Therefore, how to effectively eliminate or significantly reduce the static power consumption caused by the discharge resistor while ensuring the safe discharge of the X capacitor is a pressing technical problem to be solved in the current power adapter design field. Utility Model Content

[0004] This application aims to address at least one of the technical problems existing in the prior art. To this end, this application proposes a power adapter that can eliminate or reduce standby power consumption caused by the discharge of the X capacitor, while ensuring user safety and meeting safety regulations.

[0005] A power adapter according to an embodiment of this application includes: a housing with an internal cavity; an input terminal disposed on the housing for connecting to an external power supply device, including at least one first terminal and at least one second terminal; an input circuit disposed within the cavity, including a power conversion circuit and a safety X capacitor, wherein a first input terminal and a second input terminal of the power conversion circuit are respectively connected to the first terminal and the second terminal, and the safety X capacitor is connected in parallel between the first terminal and the second terminal; and a switching assembly connected in series between the first terminal and the safety X capacitor, or connected in series between the second terminal and the safety X capacitor, wherein the on state of the switching assembly switches in response to the connection state between the input terminal and the external power supply device.

[0006] The power adapter according to the embodiments of this application has at least the following beneficial effects: The power adapter of the embodiment solves the contradiction between safety and power consumption in the prior art by connecting a special switching component in series in the charging circuit of the safety X capacitor and configuring it to be linked to the plugging and unplugging action of the power adapter. That is, it closes when the input terminal is plugged into the external power supply device and opens when the two are separated. Specifically, when the power adapter is plugged into the power supply device and is working normally, the switching component closes, and the safety X capacitor can be normally connected to the circuit, performing its existing function of suppressing electromagnetic interference and ensuring the electromagnetic compatibility performance of the power adapter. When the power adapter is unplugged from the power supply device, the switching component opens simultaneously, physically cutting off the electrical connection between the safety X capacitor and at least one input terminal. In this way, even if there is residual charge on the safety X capacitor, it cannot form a discharge circuit outward through the input terminal, thereby eliminating the risk of electric shock that may occur when the user touches the plug pins and meeting the requirements of safety regulations. More importantly, since the safety guarantee is achieved through the physical isolation of the switching component, the power adapter of the embodiment no longer needs to connect a discharge resistor in parallel across the safety X capacitor for discharging charge, as is the case in the prior art. By completely removing the discharge resistor, the continuous static power loss it generates during adapter standby or operation is eliminated, reducing the overall power consumption of the power adapter.

[0007] According to some embodiments of this application, the switch assembly is provided with a movable actuator, which is at least partially exposed outside the housing, and the movable actuator can control the switch assembly to be turned on or off under the action of external force.

[0008] According to some embodiments of this application, the movable actuator of the switch assembly is disposed on the insertion surface of the housing; the insertion surface represents the side of the housing where the input terminal is provided.

[0009] According to some embodiments of this application, the movable actuator is a pressure rod that can be movably inserted through the insertion surface.

[0010] According to some embodiments of this application, the switch assembly includes a spring switch disposed within the housing, and one end of the pressure rod located within the housing abuts against the spring switch.

[0011] According to some embodiments of this application, the spring switch includes a fixed contact, a spring, and a movable contact. The movable contact is disposed at one end of the spring. One end of the pressure rod abuts against the end of the spring on which the movable contact is disposed. When the pressure rod moves toward the interior of the housing, it drives the spring so that the movable contact contacts the fixed contact to conduct electricity.

[0012] According to some embodiments of this application, the switch assembly further includes a reset elastic element for providing a reset force for the lever to extend out of the housing.

[0013] According to some embodiments of this application, the input circuit further includes a common-mode inductor, the first input terminal and the second input terminal of the common-mode inductor being connected to the first terminal and the second terminal respectively, and the first output terminal and the second output terminal of the common-mode inductor being connected to the first input terminal and the second input terminal of the power conversion circuit respectively.

[0014] According to some embodiments of this application, the power conversion circuit includes a bridge rectifier circuit, wherein the AC input terminal of the bridge rectifier circuit is connected to the first terminal and the second terminal respectively.

[0015] According to some embodiments of this application, a fuse is also connected in series at one end of the first terminal or the second terminal. Attached Figure Description

[0016] The present application will be further described below with reference to the accompanying drawings and embodiments, wherein: Figure 1 This is a schematic diagram of the circuit topology of the power adapter in the embodiment; Figure 2 This is a schematic diagram of the external structure of the power adapter in the embodiment; Figure 3 This is a schematic diagram of the spring switch in an embodiment.

[0017] Figure label: Housing 100; plug-in surface 110; input terminal 200; movable actuator 310. Detailed Implementation

[0018] The embodiments of this application are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain this application, and should not be construed as limiting this application.

[0019] In the description of this application, it should be understood that the orientation descriptions, such as up, down, front, back, left, right, etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application.

[0020] In the description of this application, "several" means one or more, "multiple" means two or more, "greater than," "less than," and "exceeding" are understood to exclude the stated number, while "above," "below," and "within" are understood to include the stated number. The use of "first" and "second" in the description is merely for distinguishing technical features and should not be construed as indicating or implying relative importance, or implicitly indicating the number of indicated technical features, or implicitly indicating the order of the indicated technical features.

[0021] In the description of this application, unless otherwise expressly defined, terms such as "setup," "installation," and "connection" should be interpreted broadly, and those skilled in the art can reasonably determine the specific meaning of the above terms in this application in conjunction with the specific content of the technical solution.

[0022] In the description of this application, the terms "one embodiment," "some embodiments," "illustrative embodiment," "example," "specific example," or "some examples," etc., refer to specific features, structures, materials, or characteristics described in connection with that embodiment or example, which are included in at least one embodiment or example of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0023] The power adapter includes a housing, input terminals, input circuitry, and a switching assembly. An internal cavity is formed within the housing to accommodate electronic components. Figure 2As shown, an input terminal for connecting to an external power supply (e.g., a mains outlet) is provided on one side of the housing. The input terminal can be a standard plug, including a first terminal (e.g., neutral N pin) and a second terminal (e.g., live L pin). An input circuit is housed within the housing cavity. This input circuit includes a power conversion circuit and a safety X capacitor CX1. The power conversion circuit converts the input AC power into the DC power required by the electronic device; for example, it can be a bridge rectifier circuit. The first and second input terminals of the power conversion circuit are electrically connected to the first and second terminals respectively via a circuit. The safety X capacitor CX1 filters differential-mode interference and is configured in parallel between the first and second terminals in the circuit.

[0024] The core of the power adapter embodiment lies in the fact that the circuit also includes a switching component S1. For example... Figure 1 As shown, the switch assembly S1 is connected in series between the first terminal (N line) and the safety X capacitor CX1. (Of course, in other embodiments, the switch assembly S1 can also be connected in series between the second terminal (L line) and the safety X capacitor CX1, which can also achieve the beneficial effects of the power adapter in the embodiment). The core function of the switch assembly S1 is defined as follows: when the input terminal of the power adapter is connected to the external power supply device, it must be in a closed state to ensure that the safety X capacitor CX1 can be connected to the circuit and function; when the input terminal of the power adapter is disconnected from the external power supply device (i.e., unplugged), it must be in a disconnected state to cut off the electrical connection between the safety X capacitor CX1 and the input terminal.

[0025] To achieve the aforementioned functions of the switch assembly, the switch assembly S1 can have various specific structural forms. For example, in one embodiment, the switch assembly S1 can be an automatic switch mechanically linked to the insertion and removal action. For instance, a movable actuator can be provided; when the power adapter is inserted into an external socket, the physical structure of the socket pushes the actuator, thereby closing the internal contacts of the switch; when the power adapter is removed, the actuator automatically resets after the external force is removed, causing the switch to open. In another embodiment, the switch assembly S1 can be a switch requiring manual operation by the user. For example, a push-button switch or toggle switch can be provided on the adapter housing. After inserting the adapter into the socket, the user manually presses or toggles the switch to close it; before removing the adapter, the user manually opens it. In yet another embodiment, the switch assembly S1 can also be a non-mechanical electronic switch. For example, it can be a sensor-controlled switch; the sensor can be an optical sensor, a capacitive proximity sensor, or a Hall effect sensor, used to detect whether the adapter is inserted into a specific position in the socket. When the sensor detects an "inserted" state, it outputs a signal to control a relay or solid-state switch (such as a thyristor) to close; conversely, when it detects a "disconnected" state, it controls it to open. Furthermore, the electronic switch can also determine whether to close by detecting whether the power conversion circuit has started operating (e.g., detecting its input current or voltage), and open when it detects that the main circuit has stopped operating.

[0026] Regardless of the specific form of the switching assembly S1—whether it's a mechanical or electronic switch, automatic or manual—as long as the switching assembly can achieve the core function of "closing when inserted and opening when removed," the safety capacitor X can be reliably isolated from the circuit when needed (in the working state) and when not needed (in the idle or unplugged state). This allows the power adapter in this embodiment to eliminate the reliance on traditional discharge resistors without affecting the normal function of the safety capacitor X, thereby eliminating the resulting static power consumption and ensuring electrical safety after unplugging.

[0027] In some embodiments, the switch assembly includes a movable actuator. For example... Figure 2As shown, at least a portion of the movable actuator is exposed outside the power adapter housing, or in other words, it can be accessed or driven from outside the housing. This arrangement allows the movable actuator to receive forces (i.e., "external forces") from outside the adapter and, under the action of these forces, control the switching assembly to turn on (close) or off. For example, depending on the source of the external force received by the movable actuator, two main approaches can be distinguished: In one approach, the movable actuator is a component manually operated by the user. For example, it can be a push-button switch, toggle switch, or slide switch mounted on the housing surface. After the user inserts the power adapter into an external power supply device (e.g., a socket), they actively press or toggle the movable actuator by hand, applying an "external force" that closes the switching assembly and activates the safety capacitor X. Before unplugging the adapter, the user reverses the operation of the movable actuator to reset it, causing the switching assembly to open, and then unplugs the adapter from the socket. This approach ensures the correct switching of the switching assembly state through active user operation. In a more preferred embodiment, the movable actuator can be a component that mechanically interacts with an external power supply. This means that the switch action is automatically completed during the insertion and removal process, without additional user intervention. For example, the movable actuator can be a lever, pin, or slider, with part of its structure slightly protruding from the housing surface. When the power adapter is inserted into the socket, the socket's panel or internal structure surface naturally becomes a force source, generating a thrust or pressure on the movable actuator as an "external force," causing it to displace and thus driving the switch assembly from the open state to the closed state. Conversely, when the adapter is removed from the socket, this "external force" disappears, and the movable actuator returns to its initial position under the action of a reset mechanism, synchronously causing the switch assembly to open.

[0028] Furthermore, in some embodiments, the movable actuator is disposed on the plug surface of the power adapter of the embodiment. For example... Figure 2 As shown, the "plug surface" defined here refers to the side of the housing where the input terminal (pin) is located. In other words, the movable actuator and the input terminal are located on the same functional plane. This layout allows the operation of the switch assembly to be automatically linked to the insertion and removal process of the adapter. Specifically, when the user inserts the input terminal of the power adapter into an external power supply device (such as a wall socket), the plug surface of the adapter will face and eventually fit against the surface of the socket. Since the movable actuator is located on this plug surface, the housing surface of the external power supply device (i.e., the socket panel) will inevitably contact and push the movable actuator, thereby responding to external force, causing it to displace, and ultimately driving the switch assembly S1 to close. The entire process occurs automatically along with the normal insertion action, requiring no additional operation from the user.

[0029] Preferably, to achieve the above functions, in some embodiments, the movable actuator can be designed as a lever. One end of the lever passes through an opening in the housing and protrudes slightly from the insertion surface. Its other end, inside the housing, is linked to a corresponding part of the switch assembly. When the power adapter is pushed into the socket, the end of the lever protruding from the insertion surface contacts the socket panel first or simultaneously. As the insertion process continues, the socket panel exerts a continuous pushing force on the lever, forcing it to overcome its reset force and move inward toward the housing. This inward displacement of the lever is the direct power driving the switch assembly S1 from the open state to the closed state. When the power adapter is pulled out of the socket, the pushing force from the socket panel disappears, and the lever automatically pops outward under the action of its internal reset mechanism, restoring its initial state of protruding from the insertion surface, and the switch assembly S1 is simultaneously disconnected.

[0030] More specifically, in some embodiments, the switch assembly S1 mainly consists of two parts: the aforementioned pressure rod and a spring switch located inside the housing. The spring switch is fixedly installed in a suitable position inside the housing, while the pressure rod can reciprocate inside and outside the housing, with its end inside the housing abutting against the spring switch to transmit power. For example, as... Figure 3 As shown, the internal structure of the spring switch includes a fixed contact, a resilient spring, and a movable contact located at the free end of the spring. The fixed contact is mounted on a fixed bracket inside the housing, while the fixed end of the spring is fixed elsewhere. The end of the lever inside the housing abuts against the spring at the end closest to the movable contact. To ensure the lever automatically resets after the loss of external force, the switch assembly also includes a reset spring. This spring continuously provides a pushing force (i.e., a reset force) towards the outside of the housing to the lever, maintaining its extended position outside the housing in its natural state.

[0031] When the power adapter is not inserted into the socket, the reset force of the reset elastic element (e.g., a coil spring) keeps the lever in its outermost position, with its end protruding from the insertion surface. At this time, the lever does not apply pressure to the spring contact, which is in a naturally extended state, maintaining a preset gap between the movable and fixed contacts, and switch S1 is in the open state. When the adapter is inserted into the socket, the socket panel pushes the lever into the housing and compresses the reset elastic element. The inner end of the lever then pushes the spring contact near the movable contact. When the displacement of the lever is large enough, its thrust will drive the spring contact to bend, causing the movable contact on the spring contact to move downward and finally reliably contact the fixed contact below. At this point, switch S1 is closed and the circuit of safety capacitor CX1 is connected. When the adapter is pulled out of the socket, the thrust from the socket panel disappears. The compressed reset elastic element instantly releases its stored elastic energy, and the reset force it provides pushes the lever quickly outward from the housing, returning it to its initial extended position. As the lever retracts, the pushing force on the spring disappears. The spring, with its inherent elasticity, returns to its original shape, causing the moving contact to quickly separate from the fixed contact, thus disconnecting switch S1.

[0032] Understandably, in some embodiments, the power conversion circuit may employ a topology commonly found in the art, including a bridge rectifier circuit BD1. The two AC input terminals of the bridge rectifier circuit BD1 are connected to the first terminal and the second terminal (or via other components), respectively, to convert the input AC power into pulsating DC power. In some embodiments, a common-mode inductor L1 may also be connected in series in the input circuit. This common-mode inductor L1 is located between the input terminals and the bridge rectifier circuit BD1, and is used to filter out common-mode interference signals, ensuring that the power adapter meets electromagnetic compatibility standards. In some embodiments, a fuse F1 may also be connected in series in the path of the first or second terminal. When an abnormal condition such as a short circuit occurs, causing excessive current, the fuse F1 will blow, thereby cutting off the power input and protecting the safety of subsequent circuits and the user.

[0033] The embodiments of this application have been described in detail above with reference to the accompanying drawings. However, this application is not limited to the above embodiments. Within the scope of knowledge possessed by those skilled in the art, various changes can be made without departing from the spirit of this application. Furthermore, unless otherwise specified, the embodiments and features described in the embodiments of this application can be combined with each other.

Claims

1. A power adapter, characterized in that, include: The housing (100) has an internal accommodating cavity; An input terminal (200) is disposed on the housing (100) for connecting to an external power supply device, and includes at least one first terminal and at least one second terminal; An input circuit, disposed within the accommodating cavity, includes a power conversion circuit and a safety X capacitor. The first and second input terminals of the power conversion circuit are respectively connected to the first terminal and the second terminal, and the safety X capacitor is connected in parallel between the first terminal and the second terminal. A switching assembly is connected in series between the first terminal and the safety X capacitor, or connected in series between the second terminal and the safety X capacitor. The conducting state of the switching assembly switches in response to the connection state between the input terminal and the external power supply device.

2. The power adapter according to claim 1, characterized in that, The switch assembly is provided with a movable actuator (310), which is at least partially exposed outside the housing (100). The movable actuator (310) can control the switch assembly to be turned on or off under the action of external force.

3. The power adapter according to claim 2, characterized in that, The movable actuator (310) of the switch assembly is disposed on the insertion surface (110) of the housing (100); the insertion surface (110) represents the side of the housing (100) where the input terminal (200) is provided.

4. The power adapter according to claim 3, characterized in that, The movable actuator (310) is a pressure rod that can be movably inserted through the insertion surface (110).

5. The power adapter according to claim 4, characterized in that, The switch assembly includes a spring switch, which is disposed inside the housing (100), and one end of the pressure rod located inside the housing (100) abuts against the spring switch.

6. The power adapter according to claim 5, characterized in that, The spring switch includes a fixed contact, a spring, and a movable contact. The movable contact is located at one end of the spring. One end of the pressure rod abuts against the end of the spring on which the movable contact is located. When the pressure rod moves toward the interior of the housing (100), it drives the spring so that the movable contact contacts the fixed contact to conduct electricity.

7. The power adapter according to claim 6, characterized in that, The switch assembly further includes a reset elastic element for providing a reset force for the lever to extend out of the housing (100).

8. The power adapter according to any one of claims 1-7, characterized in that, The input circuit further includes a common-mode inductor, the first input terminal and the second input terminal of the common-mode inductor are respectively connected to the first terminal and the second terminal, and the first output terminal and the second output terminal of the common-mode inductor are respectively connected to the first input terminal and the second input terminal of the power conversion circuit.

9. The power adapter according to any one of claims 1-7, characterized in that, The power conversion circuit includes a bridge rectifier circuit, and the AC input terminal of the bridge rectifier circuit is connected to the first terminal and the second terminal respectively.

10. The power adapter according to any one of claims 1-7, characterized in that, A fuse is connected in series at one end of the first terminal or the second terminal.

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