Extension socket with USB charging circuit

Abstract

The utility model provides an extension socket with a USB charging circuit, and aims to improve charging stability and realize energy-saving management. According to the extension socket, alternating current is converted into stable low-voltage direct current through the AD / DC conversion circuit so as to be used for charging the USB interface. The power supply conversion part comprises a synchronous rectification module, a transformer, a primary side feedback control module and an optocoupler feedback module circuit, and can effectively filter high-frequency noise and stabilize output voltage. The charging control circuit comprises an infrared sensor, a current detection module and a switch unit, so as to achieve the functions of automatically starting a charging function when a user approaches and automatically disconnecting a line when no charging current exists, thereby reducing the standby power consumption. The USB charging circuit comprises a direct current step-down converter and a charging protocol management module, supports multiple USB protocols, and provides two modes of common charging and PD fast charging to adapt to the requirements of different devices. The beneficial effects of the design are that power supply stability is improved, energy consumption is reduced, and diversified charging demands of users are satisfied.

Description

TECHNICAL FIELD

[0001] The utility model relates to the technical field of row plug, especially to a row plug with USB charging circuit. BACKGROUND

[0002] With the popularization and diversification of electronic devices, especially the widespread use of mobile devices such as smartphones, tablets, etc., users' functional requirements for row plugs are no longer limited to AC interfaces, but hope that row plugs can have DC power supply functions at the same time, especially providing convenient charging services for USB interfaces and Type-C interfaces. This demand has prompted the emergence of row plugs with USB charging ports on the market. However, the existing row plugs with USB charging function generally have the following shortcomings in design:

[0003] Poor charging interface compatibility: the existing row plugs with USB charging function usually only support a single or limited charging protocol, which cannot meet the needs of different devices for fast charging protocols, resulting in that some devices cannot achieve fast charging and the use experience is not good.

[0004] Insufficient stability of power conversion design: the USB charging circuit part of the traditional USB interface row plug adopts a simple step-down method, which is insufficient in stability. When the load device fails or is short-circuited, it may cause power transient disturbance or even damage the internal circuit of the row plug.

[0005] Lack of power saving management: many charging devices remain on for a long time, even when there is no charging demand, still consuming power, and the existing charging devices lack a management mechanism that can perceive user behavior and achieve energy saving through an automatic start-stop mechanism. SUMMARY

[0006] In view of the deficiencies in the prior art, the utility model provides a row plug with USB charging circuit, mainly solving the following problems: the USB charging circuit of the existing charging row plug lacks stable power conversion and automatic energy-saving design.

[0007] To achieve the above purpose, the utility model adopts the following technical solutions:

[0008] A row plug with USB charging circuit, comprising a row plug body, further comprising an AD / DC conversion circuit, a charging control circuit, a USB charging circuit and a USB charging interface.

[0009] The input end of the power strip body is electrically connected with the input end of the AC / DC conversion circuit, the output end of the AC / DC conversion circuit is connected with the input end of the charging control circuit, the output end of the charging control circuit is connected with the input end of the USB charging circuit, and the output end of the USB charging circuit is connected with the USB charging interface; the charging control circuit comprises an infrared sensor, a current detection module, a controller and a switching unit; the output end of the infrared sensor is connected with the input end of the controller, and is used for detecting the action of the user approaching the USB interface; the detection end of the current detection module is connected with the current detection end of the USB charging circuit, and the output end of the current detection module is connected with the input end of the controller; the output end of the controller is connected with the control end of the switching unit, the input end of the switching unit is connected with the output end of the AC / DC conversion circuit, and the output end of the switching unit is connected with the input end of the USB charging circuit.

[0010] Further, the USB charging circuit comprises a direct-current voltage reduction converter and a charging protocol management module.

[0011] The input end of the direct-current voltage reduction converter is connected with the output end of the charging control circuit, the output end of the direct-current voltage reduction converter is connected with the input end of the charging protocol management module, the output end of the charging protocol management module is connected with the input end of the USB charging interface, and the output end of the charging protocol management module is connected with the detection end of the charging control circuit as a current detection end.

[0012] Further, the AC / DC conversion circuit comprises a synchronous rectification module, a transformer, a primary side feedback control module and an optical coupling feedback module.

[0013] The input end of the primary side feedback control module is connected with the input end of the power strip body, and the input alternating current is rectified and converted into direct current and output to the primary side of the transformer; the secondary side of the transformer is connected with the input end of the synchronous rectification module, the output end of the synchronous rectification module is connected with the input end of the charging control circuit and the input end of the optical coupling feedback module; and the output end of the optical coupling feedback module is connected with the feedback end of the primary side feedback control module, and is used for maintaining the stable voltage of the primary side of the transformer.

[0014] Preferably, the current detection module comprises one of a current detection resistor, a Hall sensor or a current transformer.

[0015] Further, the USB charging interface comprises at least one group of USB interfaces and TypeC interfaces, and each TypeC interface and USB interface is connected in series with a charging protocol management module corresponding to the TypeC interface and the USB interface.

[0016] Further, the power strip body comprises an overload protector and a socket hole position; the input end of the overload protector is connected with the alternating current input, and the output end of the overload protector is connected with the socket hole position and the input end of the AC / DC conversion circuit.

[0017] Further, the utility model still includes a circuit board, the circuit board is integrated with AD / DC conversion circuit, charge control circuit, USB charging circuit and USB charging interface.

[0018] Beneficial effect: the extension socket with USB charging circuit provided by the utility model, the charging protocol management module included in the USB charging circuit realizes the universal compatibility of multiple charging equipment;Adopt two-stage rectification and filter structure, the first rectification circuit is responsible for rectifying high voltage alternating current into direct current, then eliminate high frequency noise through the first filter circuit;The secondary side after the isolation transformer further passes through the second rectification circuit and filter circuit, voltage is smoothed to low voltage direct current output that meets the USB power supply requirement, this multistage rectification filter design ensures the stability of voltage;Through the charge control circuit, the user charging behavior is perceived and the switch of charging circuit is automatically controlled, effectively reduces standby power consumption. BRIEF DESCRIPTION OF DRAWINGS

[0019] Figure 1 It is extension socket structure diagram of an embodiment of the utility model;

[0020] Figure 2 It is USB charging circuit and USB charging interface connection diagram of an embodiment of the utility model;

[0021] Figure 3 It is USB charging circuit and USB charging interface principle diagram of an embodiment of the utility model;

[0022] Figure 4 It is AC / DC conversion circuit principle diagram of an embodiment of the utility model;

[0023] Figure 5 It is current sensing resistor layout diagram of an embodiment of the utility model;

[0024] Figure 6 It is extension socket body circuit diagram of an embodiment of the utility model;

[0025] Figure 7 It is extension socket physical object diagram of an embodiment of the utility model.

[0026] In the above drawing:

[0027] 1, the plug body; 2, AC / DC conversion circuit; 3, charging control circuit; 4, USB charging circuit; 5, USB charging interface; 6, infrared sensor; 7, current detection module; 8, controller; 9, switch unit; 10, USB interface; 11, TypeC interface; 12, the first DC voltage converter; 13, charging protocol management module; 14, the second DC voltage converter; 15, fast charging protocol management module; 16, synchronous rectification module; 17, transformer; 18, primary side feedback control module; 19, optocoupler feedback module; 20, current detection resistor; 21, MOSFET; 22, overload protector; 23, socket hole; 24, circuit board. DETAILED DESCRIPTION

[0028] The embodiments of the present application will be described in detail below, examples of which are shown in the drawings, example embodiments can be implemented in various forms, and should not be understood as being limited to the examples set forth herein; on the contrary, these embodiments are provided so that the present application will be more comprehensive and complete, and the concepts of example embodiments will be fully conveyed to those skilled in the art. In the description of the present application, it should be noted that unless otherwise specifically defined and limited, the terms "mounting", "connecting", "connecting" should be understood broadly, for example, it can be fixedly connected, or it can be detachably connected, or integrally connected; it can be mechanically connected, or it can be electrically connected; it can be directly connected, or it can be indirectly connected through an intermediate medium; it can be the communication between two elements. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0029] The plug structure of the embodiment is shown in Figure 1 It comprises a plug body 1, and also comprises an AC / DC conversion circuit 2, a charging control circuit 3, a USB charging circuit 4 and a USB charging interface 5.

[0030] The input end of the plug body 1 is electrically connected with the input end of the AC / DC conversion circuit 2, and the AC / DC conversion circuit 2 converts alternating current into direct current and then outputs to the charging control circuit 3; the output end of the charging control circuit 3 is connected with the input end of the USB charging circuit 4, for detecting the USB charging state and switching the USB charging circuit 4; the output end of the USB charging circuit 4 is connected with the input end of the USB charging interface 5.

[0031] The charging control circuit 3 comprises an infrared sensor 6, a current detection module 7, a controller 8 and a switching unit 9; the output end of the infrared sensor 6 is connected to the input end of the controller 8, for detecting the action of the user approaching the USB charging interface 5; the detection end of the current detection module 7 is connected to the current detection end of the USB charging circuit 4, and the output end of the current detection module 7 is connected to the input end of the controller 8; the output end of the controller 8 is connected to the control end of the switching unit 9, the input end of the switching unit 9 is connected to the output end of the AC / DC conversion circuit 2, and the output end of the switching unit 9 is connected to the input end of the USB charging circuit 4.

[0032] The USB charging circuit and the USB charging interface connection diagram of the embodiment are shown in Figure 2 The USB charging interface 5 in the embodiment comprises two groups of USB interfaces 10 (USB1, USB2) and TypeC interfaces 11 (USB3, USB4), wherein the TypeC interface 11 is a charging interface supporting the USB PD fast charging protocol, therefore, in order to avoid affecting the charging performance and efficiency due to interference between lines, the charging lines in the embodiment are divided into two branches, namely a USB charging branch and a TypeC charging branch, each branch is independently stepped down and selects a charging protocol.

[0033] In the USB charging branch, the output end of the first direct-current step-down converter 12 is connected to the input end of the charging protocol management module 13, the charging protocol management module 13 is used for identifying and providing specific voltages and currents required by different USB protocols, and outputting to the input end of the USB interface 10; in the TypeC charging branch, the output end of the second direct-current step-down converter 14 is connected to the input end of the fast charging protocol management module 15, and the output end of the fast charging protocol management module 15 is connected to the TypeC interface 11, and the corresponding principle diagram is shown in Figure 3 .

[0034] The AC / DC conversion circuit 2 comprises a synchronous rectification module 16, a transformer 17, a primary side feedback control module 18 and an optical coupling feedback module 19. The principle diagram of the AC / DC conversion circuit of the embodiment is shown in Figure 4As shown, the input end of the primary side feedback control module 18 is connected with two input ends of the power strip body 1, the two end input ends of the primary side feedback control module 18 are respectively provided with a fuse F1 and a thermistor NTC1, which are respectively used for overcurrent protection and surge current suppression, two coil windings of the common mode inductor CM1 are respectively connected with the fuse F1 and the thermistor NTC1, and are coupled through a magnetic core to suppress electromagnetic interference, and the output end of the common mode inductor CM1 is connected to the rectifier bridge BR1. In the embodiment, the primary side feedback control module 18 uses the rectifier bridge BR1 to convert alternating current into direct current, the rectified direct current is filtered through a filter circuit including capacitors C1, C2 and an inductor L2 to reduce high-frequency interference and voltage ripple, and stable direct current output is formed to the primary side of the transformer 17, the secondary side of the transformer 17 is connected with the input end of the synchronous rectification module 16, the transformer 17 reduces high-voltage direct current to low-voltage direct current and transfers from the primary side to the secondary side, and the synchronous rectification module 16 outputs the low-voltage direct current after secondary rectification and filtering to the optocoupler feedback module 19 and the charging control circuit 3. The output end of the optocoupler feedback module 19 is connected with the feedback end of the primary side feedback control module 18, and in the embodiment, the primary side feedback control module 18 further includes a PWM control circuit, the PWM control circuit receives optocoupler feedback, controls the on-off of the primary side coil of the transformer 17 through a built-in switch tube, and maintains the stable voltage of the primary side of the transformer 17 through adjustment of the switching frequency, and the PWM control circuit used in the embodiment is an integrated PWM current control chip OB273x.

[0035] The working process of the charging control circuit 3 in the embodiment is as follows: in the embodiment, the infrared sensor 6 continuously detects whether there is hand movement close to the charging interface, and sends an opening signal to the controller 8 to open the switch unit 9 to supply power to the USB charging circuit 4 when detecting that the user is close, and the switch unit 9 used in the embodiment is an N-type MOSFET 21.

[0036] The current detection module 7 used in the embodiment is a current detection resistor 20, and the layout of the current detection resistor is as shown in Figure 5As shown, the current detection module 7 can also be replaced by one of a Hall sensor or a current transformer. The input end of each USB charging interface 5 is connected in series with a current detection resistor 20, and the two ends (RS+, RS-) of the current detection resistor 20 are connected to the controller 8 of the charging control circuit 3 as current detection ends, and the current state of the USB charging interface 5 is detected in real time. After the device is fully charged, the USB charging interface 5 will generally enter a very low current state, but the current will not stop completely, so the current detection module 7 in this embodiment sets a 10mA threshold, so that the controller 8 judges as "not in use" state. When the controller 8 detects that all charging interface currents are less than 10mA, all meet the "not in use" state, a low level is applied to the gate of the MOSFET 21 to turn off the MOSFET 21, and if the controller 8 detects that any charging interface current is greater than 10mA, a high level is continuously applied to the gate of the MOSFET 21 to supply power to the USB charging circuit 4.

[0037] The circuit diagram of the power strip body of the embodiment is shown in Figure 6 The corresponding physical diagram of the power strip is shown in Figure 7 As shown, it includes an overload protector 22, a socket hole 23 and a circuit board 24; in this embodiment, the AC output is divided into two output lines, and three socket holes are evenly distributed on each line. An overload protector 22 is connected in series at the input end of each output line, which is used to automatically cut off the power when the load current exceeds 1.5 times of 20A. The input end of the overload protector 22 is connected to the AC input, and the output end of the overload protector 22 is connected to the socket hole 23 and the input end of the AC / DC conversion circuit 2. The circuit board 24 is used to set the AC / DC conversion circuit 2, the charging control circuit 3, the USB charging circuit 4 and the USB charging interface 5.

[0038] Finally, it should be pointed out that the above embodiments are only used to illustrate the technical solutions of the present application and are not limiting. Although the present application has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solutions of the present application can be modified or replaced by equivalents without departing from the purpose and scope of the present application, and all should be covered in the scope of the claims of the present application.

Claims

1. A power strip with USB charging circuit, comprising a power strip body, characterized in that, The AC / DC conversion circuit, the charging control circuit, the USB charging circuit and the USB charging interface are further included. The input end of the power strip body is electrically connected with the input end of the AC / DC conversion circuit, the output end of the AC / DC conversion circuit is connected with the input end of the charging control circuit, the output end of the charging control circuit is connected with the input end of the USB charging circuit, and the output end of the USB charging circuit is connected with the USB charging interface. The charging control circuit comprises an infrared sensor, a current detection module, a controller and a switching unit. The output end of the infrared sensor is connected with the input end of the controller, and the infrared sensor is used for detecting the action of the user approaching the USB interface. The detection end of the current detection module is connected with the current detection end of the USB charging circuit, and the output end of the current detection module is connected with the input end of the controller. The output end of the controller is connected with the control end of the switching unit, the input end of the switching unit is connected with the output end of the AC / DC conversion circuit, and the output end of the switching unit is connected with the input end of the USB charging circuit.

2. The USB charging circuit-equipped power strip of claim 1, wherein, The USB charging circuit comprises a direct-current voltage reduction converter and a charging protocol management module. The input end of the direct-current voltage reduction converter is connected with the output end of the charging control circuit, the output end of the direct-current voltage reduction converter is connected with the input end of the charging protocol management module, the output end of the charging protocol management module is connected with the input end of the USB charging interface, and the output end of the charging protocol management module is connected with the detection end of the charging control circuit as the current detection end.

3. The USB charging circuit-equipped power strip of claim 2, wherein, The current detection module comprises one of a current detection resistor, a Hall sensor or a current transformer.

4. The USB charging circuit-equipped power strip of claim 1, wherein, The AC / DC conversion circuit comprises a synchronous rectification module, a transformer, a primary side feedback control module and an optical coupling feedback module. The input end of the primary side feedback control module is connected with the input end of the power strip body, and the primary side feedback control module converts the input alternating current into direct current and outputs the direct current to the primary side of the transformer. The secondary side of the transformer is connected with the input end of the synchronous rectification module, the output end of the synchronous rectification module is connected with the input end of the charging control circuit and the input end of the optical coupling feedback module. The output end of the optical coupling feedback module is connected with the feedback end of the primary side feedback control module, and the optical coupling feedback module is used for maintaining the stable voltage of the primary side of the transformer.

5. The USB charging circuit-equipped power strip of claim 1, wherein, The USB charging interface comprises at least one group of USB interfaces and Type C interfaces, and each Type C interface and USB interface is connected with a corresponding charging protocol management module in series.

6. The USB charging circuit-equipped power strip of claim 1, wherein, The power strip body comprises an overload protector and a socket hole position. The input end of the overload protector is connected with the alternating current input, and the output end of the overload protector is connected with the socket hole position and the input end of the AC / DC conversion circuit.

7. The USB charging circuit-equipped power strip of claim 1, wherein, The circuit board is further included, and the circuit board is integrated with the AD / DC conversion circuit, the charging control circuit, the USB charging circuit and the USB charging interface.

Images