Switching circuit of common contact of wearable electronic equipment
By designing a switch circuit for common contacts in wearable electronic devices and switching the use of D+ and D- contacts in charging and detection modes using double-biter double-throw switches, the problem of difficulty in sharing contacts in existing devices is solved, and simplified design and functional flexibility is achieved.
Patent Information
- Application Number
- CN202421727577.8
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-07-19
- Publication Date
- 2025-06-27
- Estimated Expiration
- 2034-07-19
AI Technical Summary
When implementing wear detection, existing wearable electronic devices need to add contacts in contact with the human body, resulting in inconvenient appearance and internal structure design, and the charging contacts and detection contacts cannot be shared.
A switch circuit with common contacts is designed, and VCC, D+, D-, and GND contacts are provided on the outer surface of the wearable electronic device and corresponding terminals are provided inside. The D+ and D- contacts are switched in charging mode and detection mode using a double-knife double-throw switch.
The sharing of charging contacts and detection contacts is realized, which simplifies the structural design of the equipment, reduces manufacturing costs, and improves the functional flexibility of the equipment.
Smart Images
Figure CN223040010U_ABST
Abstract
Description
Technical Field
[0001] The present application relates to a wearable electronic device, and particularly to a switching circuit that shares contacts for the charging function and the detection function of the wearable electronic device. Background Art
[0002] The functions of wearable devices represented by smart watches and smart bracelets are becoming more and more abundant, and usually include health monitoring functions. In order to improve the accuracy of health monitoring, it is necessary to accurately know whether the wearable device is in a worn state. An existing method for a smart watch or a smart bracelet to implement wearing detection is to use a human body impedance detection circuit, which has a high detection accuracy, but it is necessary to add contacts that come into contact with the human body, which brings inconvenience to the appearance and internal structure design of the smart watch or the smart bracelet.
[0003] Most existing smart watches or smart bracelets use magnetic charging, and charging contacts (also called electrodes, contacts, etc.) are provided on the surface of the smart watch or the smart bracelet. Please refer to Figure 1 . Most existing smart watches or smart bracelets are provided with four charging contacts on the outer surface (such as the back shell), namely, a VCC (power supply) contact, a GND (ground) contact, a D+ contact, and a D− contact. Correspondingly, there are also a VCC contact, a GND contact, a D+ contact, and a D− contact on the magnetic charger. The positions of the same contacts of the wearable electronic device and the charger correspond. When the wearable electronic device is connected to the charger and the charger is powered on, the wearable electronic device is in the charging mode. Summary of the Utility Model
[0004] The technical problem to be solved by the present application is how to make the charging contacts of the wearable electronic device also serve as detection contacts, that is, to achieve the sharing (reuse, sharing) of contacts, and at the same time use a switching circuit to ensure that the shared contacts can be used normally in both the charging mode and the detection mode.
[0005] To solve the above technical problems, the present application proposes a switch circuit for a common contact of a wearable electronic device. On the outer surface of the wearable electronic device, there are a VCC contact, a D+ contact, a D- contact, and a GND contact; inside the wearable electronic device, there are a VCC terminal, a D+ terminal, a detection + terminal, a D- terminal, a detection - terminal, and a GND terminal; among them, the VCC terminal, the D+ terminal, the D- terminal, and the GND terminal are connected to a USB charging circuit or a USB data transmission circuit inside the wearable electronic device; the detection + terminal and the detection - terminal are connected to a detection circuit inside the wearable electronic device. The VCC contact is directly connected to the VCC terminal, and the GND contact is directly connected to the GND terminal; the D+ contact and the D- contact are connected to the D+ terminal, the detection + terminal, the D- terminal, and the detection - terminal through a double-pole double-throw switch; the double-pole double-throw switch has at least two switch states. When the VCC terminal and the GND terminal are powered, the double-pole double-throw switch is in the first switch state; the first switch state is to connect the D+ contact and the D- contact to the D+ terminal and the D- terminal respectively, and at this time, the detection + terminal and the detection - terminal are floating. When the VCC terminal and the GND terminal are not powered, the double-pole double-throw switch is in the second switch state; the second switch state is to connect the D+ contact and the D- contact to the detection + terminal and the detection - terminal respectively, and at this time, the D+ terminal and the D- terminal are floating.
[0006] Preferably, the detection circuit includes any one of a human body impedance detection circuit and an electrocardiogram monitoring circuit.
[0007] Further, the D+ terminal, the detection + terminal, the D- terminal, and the detection - terminal inside the wearable electronic device share the D+ contact and the D- contact on the outer surface of the wearable electronic device.
[0008] Preferably, the double-pole double-throw switch is an analog switch, which is implemented by a junction field effect transistor JFET or a metal oxide semiconductor field effect transistor MOSFET.
[0009] Further, a processor is also provided inside the wearable electronic device, and the switch state of the double-pole double-throw switch is controlled by the processor.
[0010] Preferably, the processor is an application processor AP; the processor controls the double-pole double-throw switch to switch the switch state through a general-purpose input / output GPIO port.
[0011] Further, when four contacts on the outer surface of the wearable electronic device are connected to a magnetic USB charger and the magnetic USB charger is connected to a power source, the VCC terminal and GND terminal inside the wearable electronic device are connected to the magnetic USB charger through the VCC contact and GND contact on the outer surface and then connected to the power source to obtain power supply; the processor of the wearable electronic device determines whether the wearable device is in a charging mode or a USB mode by detecting the power supply status of the VCC terminal and GND terminal, and then controls the double-pole double-throw switch to switch to the first switch state through the GPIO port; the processor of the wearable electronic device continues to control the charging status through the GPIO port.
[0012] Further, when four contacts on the outer surface of the wearable electronic device are connected to a USB cable and the USB cable is connected to other electronic devices, the VCC terminal and GND terminal inside the wearable electronic device are connected to the USB cable through the VCC contact and GND contact on the outer surface and then connected to other electronic devices to obtain power supply; the processor of the wearable electronic device determines whether the wearable device is in a charging mode or a USB mode by detecting the power supply status of the VCC terminal and GND terminal, and then controls the double-pole double-throw switch to switch to the first switch state through the GPIO port; the processor of the wearable electronic device continues to control the USB cable to transmit data through the GPIO port.
[0013] Further, when the VCC terminal and GND terminal inside the wearable electronic device cannot obtain power supply, the processor of the wearable electronic device determines that the wearable device is in a detection mode by detecting the state that the VCC terminal and GND terminal do not obtain power supply, and then controls the double-pole double-throw switch to switch to the second switch state through the GPIO port; the processor of the wearable electronic device continues to control the realization of the detection function and obtain the detection result through the GPIO port.
[0014] Preferably, the human body impedance detection circuit includes a pulse width modulation (PWM) signal generator, an operational amplifier, a high-pass filter circuit, a resonant filter circuit, a current limiting circuit, and measurement electrodes; wherein, the PWM signal generator is used to generate a PWM signal as the signal source of the human body impedance detection circuit; the operational amplifier is used to pre-amplify the PWM signal; the high-pass filter circuit is used to extract the high-frequency components in the PWM signal; the resonant filter circuit is used to filter and select the frequency of the PWM signal in the high-frequency part; the current limiting circuit is used to limit the current within the range of human body safety current; the measurement electrodes are used to make contact measurements with the human skin, that is, the D+ contact and D- contact on the outer surface of the wearable electronic device.
[0015] The technical effect achieved by this application is that different terminals inside the wearable electronic device share external contacts, which simplifies the internal and external structural design of the wearable electronic device. Description of the Drawings
[0016] Figure 1 It is a schematic diagram of four conductive contacts of an existing smart watch or smart bracelet.
[0017] Figure 2 It is a schematic diagram of a switch circuit of a common contact of a wearable electronic device proposed in this application.
[0018] Figure 3 It is Figure 2 a schematic diagram when the double - pole double - throw switch in is in the first switch state.
[0019] Figure 4 It is Figure 2 a schematic diagram when the double - pole double - throw switch in is in the second switch state.
[0020] Figure 5 It is a schematic structural diagram of an example of a human body impedance detection circuit.
[0021] Explanation of reference numerals in the figure: PWM signal generator 41, operational amplifier 42, high - pass filter circuit 43, resonant filter circuit 44, current - limiting circuit 45, measurement electrode 46. Detailed implementation manners
[0022] Please refer to Figure 2 , the switch circuit of the common contact of the wearable electronic device proposed in this application includes: four contacts are arranged on the outer surface of the wearable electronic device, namely VCC contact, D + contact, D - contact, and GND contact. Six terminals are arranged inside the wearable electronic device, namely VCC terminal, D + terminal, detection + terminal, D - terminal, detection - terminal, and GND terminal. The VCC terminal, D + terminal, D - terminal, and GND terminal inside the wearable electronic device are connected to the USB charging circuit or USB data transmission circuit inside the wearable electronic device. The detection + terminal and detection - terminal inside the wearable electronic device are connected to the detection circuit inside the wearable electronic device, such as a human body impedance detection circuit, an ECG (Electrocardiography) monitoring circuit, etc. The VCC contact on the outer surface of the wearable electronic device is directly connected to the VCC terminal inside the wearable electronic device, and the GND contact on the outer surface of the wearable electronic device is directly connected to the GND terminal inside the wearable electronic device. The D + contact and D - contact on the outer surface of the wearable electronic device are connected to the D + terminal, detection + terminal, D - terminal, and detection - terminal inside the wearable electronic device through a double - pole double - throw switch.
[0023] The double - pole double - throw switch includes at least two switch states.
[0024] When the VCC terminal and the GND terminal inside the wearable electronic device are powered, the double-pole double-throw switch is in the first switch state. Please refer to Figure 3 , the first switch state is to connect the D+ contact and the D- contact on the outer surface of the wearable electronic device to the D+ terminal and the D- terminal inside the wearable electronic device respectively. At this time, the detection + terminal and the detection - terminal inside the wearable electronic device are floating. The first switch state is used for the wearable device to perform USB charging or connect a USB cable to transfer data.
[0025] When the VCC terminal and the GND terminal inside the wearable electronic device cannot be powered, the double-pole double-throw switch is in the second switch state. Please refer to Figure 4 , the second switch state is to connect the D+ contact and the D- contact on the outer surface of the wearable electronic device to the detection + terminal and the detection - terminal inside the wearable electronic device respectively. At this time, the D+ terminal and the D- terminal inside the wearable electronic device are floating. The second switch state is used for the detection function of the wearable device, such as human impedance detection, electrocardiogram monitoring, etc.
[0026] The D+ terminal, the detection + terminal, the D- terminal, and the detection - terminal inside the wearable electronic device of the present application share the D+ contact and the D- contact on the outer surface. That is, the D+ contact and the D- contact on the outer surface of the wearable electronic device can be used for both the charging function and the detection function, thus simplifying the internal and external structural design of the wearable electronic device.
[0027] The double-pole double-throw switch is, for example, an analog switch, that is, it is implemented by using an analog device that processes analog signals. For example, it is a switch device that controls the connection or disconnection of the signal link by using the characteristics of a JFET (Junction Field-Effect Transistor) or a MOSFET (Metal-Oxide-Semiconductor Field-Effect Transistor).
[0028] A processor is provided inside the wearable electronic device, such as an Application Processor. The switch state of the double-pole double-throw switch is controlled by the processor. For example, the processor controls the double-pole double-throw switch to switch the switch state through the GPIO (General-purpose input / output) port. The following three cases are typical application scenarios of the wearable electronic device of the present application.
[0029] Scenario 1: When the four contacts on the outer surface of the wearable electronic device are connected to a magnetic USB charger and the magnetic USB charger is connected to a power source, the VCC terminal and GND terminal inside the wearable electronic device are connected to the magnetic USB charger through the VCC contact and GND contact on the outer surface and then to the power source to obtain power supply. The processor of the wearable electronic device determines whether the wearable device is in the charging mode or the USB mode by detecting the power supply status of the VCC terminal and GND terminal, and then controls the double-pole double-throw switch to switch to the first switch state through the GPIO port. At this time, the processor of the wearable electronic device continues to control the charging status through the GPIO port.
[0030] Scenario 2: When the four contacts on the outer surface of the wearable electronic device are connected to a USB cable and the USB cable is connected to other electronic devices (such as a computer, a mobile phone, etc.), the VCC terminal and GND terminal inside the wearable electronic device are connected to the USB cable through the VCC contact and GND contact on the outer surface and then to other electronic devices to obtain power supply. The processor of the wearable electronic device determines whether the wearable device is in the charging mode or the USB mode by detecting the power supply status of the VCC terminal and GND terminal, and then controls the double-pole double-throw switch to switch to the first switch state through the GPIO port. At this time, the processor of the wearable electronic device continues to control the USB cable to transmit data through the GPIO port.
[0031] Scenario 3: In other cases except Scenario 1 and Scenario 2, the VCC terminal and GND terminal inside the wearable electronic device cannot obtain power supply. The processor of the wearable electronic device determines that the wearable device is in the detection mode by detecting the state that the VCC terminal and GND terminal do not obtain power supply, and then controls the double-pole double-throw switch to switch to the second switch state through the GPIO port. At this time, the processor of the wearable electronic device continues to control the realization of the detection function and obtain the detection result through the GPIO port.
[0032] Please refer to Figure 5, this is an example of a human body impedance detection circuit. The human body impedance detection circuit mainly makes judgments based on the characteristics of the human skin in the impedance circuit, and identifies whether it is human skin by analyzing the impedance characteristics and capacitance value of the circuit. If it has a high resistance value and a relatively small capacitance value, it is considered to be human skin. The human body impedance detection circuit includes a PWM (Pulse-width modulation) signal generator 41, an operational amplifier 42, a high-pass filter circuit 43, a resonant filter circuit 44, a current limiting circuit 45, and a measurement electrode 46. Among them, the PWM signal generator 41 is used to generate a PWM signal as the signal source of the human body impedance detection circuit. The operational amplifier 42 is used to pre-amplify the PWM signal. This pre-amplification helps to increase the amplitude of the PWM signal, making it more suitable for the processing of subsequent circuits. The operational amplifier 42 adopts a fully differential structure, for example. The high-pass filter circuit 43 is used to extract the high-frequency components in the PWM signal. The resonant filter circuit 44 is used to filter and select the frequency of the high-frequency part of the PWM signal. The current limiting circuit 45 is used to limit the current within the range of the human body safety current, playing a protective role for the human body. The measurement electrode 46 is used to make contact measurements with the human skin, that is Figure 2 the D+ contact and the D- contact located on the outer surface of the wearable electronic device in
[0033] In this application, by sharing two contacts on the outer surface of the wearable electronic device, these two contacts can be used for both charging and detection functions. This can reduce the design difficulty of the wearable electronic device and the manufacturing cost because fewer materials and components are required.
[0034] The above are only the preferred embodiments of this application and are not used to limit this application. For those skilled in the art, various changes and modifications can be made to this application. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of this application shall be included within the protection scope of this application.
Claims
1. A switch circuit for a common contact of a wearable electronic device, characterized in that: A VCC contact, a D+ contact, a D- contact, and a GND contact are provided on the outer surface of the wearable electronic device; a VCC terminal, a D+ terminal, a detection+ terminal, a D- terminal, a detection- terminal, and a GND terminal are provided inside the wearable electronic device; wherein the VCC terminal, the D+ terminal, the D- terminal, and the GND terminal are connected to a USB charging circuit or a USB data transmission circuit inside the wearable electronic device; and the detection+ terminal and the detection- terminal are connected to a detection circuit inside the wearable electronic device; The VCC contact is directly connected to the VCC terminal, and the GND contact is directly connected to the GND terminal; the D+ contact and the D- contact are connected to the D+ terminal, the detection+ terminal, the D- terminal, and the detection- terminal through a double-pole double-throw switch; the double-pole double-throw switch has at least two switch states; When the VCC terminal and the GND terminal are powered, the double-pole double-throw switch is in a first switch state; the first switch state is to connect the D+ contact and the D- contact to the D+ terminal and the D- terminal respectively, and at this time, the detection+ terminal and the detection- terminal are suspended; When the VCC terminal and the GND terminal are not powered, the double-pole double-throw switch is in the second switch state; the second switch state is to connect the D+ contact and the D- contact to the detection+ terminal and the detection- terminal respectively, and the D+ terminal and the D- terminal are suspended.
2. The switch circuit of the common contact of the wearable electronic device according to claim 1, characterized in that: The detection circuit includes any one of a human body impedance detection circuit and an electrocardiogram monitoring circuit.
3. The switch circuit of the common contact of the wearable electronic device according to claim 1, characterized in that: The D+ terminal, detection+ terminal, D- terminal, and detection- terminal inside the wearable electronic device share the D+ contact and D- contact on the outer surface of the wearable electronic device.
4. The switch circuit of the common contact of the wearable electronic device according to claim 1, characterized in that: The double-pole double-throw switch is an analog switch, which is implemented by a junction field effect transistor JFET or a metal oxide semiconductor field effect transistor MOSFET.
5. The switch circuit of the common contact of the wearable electronic device according to claim 1, characterized in that: A processor is also provided inside the wearable electronic device, and the switching state of the double-pole double-throw switch is controlled by the processor.
6. The switch circuit of the common contact of the wearable electronic device according to claim 5, characterized in that: The processor is an application processor AP; the processor controls the double-pole double-throw switch to switch the switch state through a general-purpose input / output GPIO port.
7. The switch circuit of the common contact of the wearable electronic device according to claim 6, characterized in that: When the four contacts on the outer surface of the wearable electronic device are connected to the magnetic USB charger and the magnetic USB charger is connected to the power supply, the VCC terminal and the GND terminal inside the wearable electronic device are connected to the magnetic USB charger through the VCC contact and the GND contact on the outer surface and then connected to the power supply to obtain power; the processor of the wearable electronic device determines whether the wearable device is in the charging mode or the USB mode by detecting the power supply status of the VCC terminal and the GND terminal, and then controls the double-pole double-throw switch to switch to the first switch state through the GPIO port; the processor of the wearable electronic device continues to control the charging status through the GPIO port.
8. The switch circuit for a common contact of a wearable electronic device according to claim 6, characterized in that: When the four contacts on the outer surface of the wearable electronic device are connected to the USB cable and the USB cable is connected to other electronic devices, the VCC terminal and the GND terminal inside the wearable electronic device are connected to the USB cable through the VCC contact and the GND contact on the outer surface and then connected to other electronic devices to obtain power; the processor of the wearable electronic device determines whether the wearable device is in charging mode or USB mode by detecting the power supply status of the VCC terminal and the GND terminal, and then controls the double-pole double-throw switch to switch to the first switch state through the GPIO port; the processor of the wearable electronic device continues to control the USB cable to transmit data through the GPIO port.
9. The switch circuit for a common contact of a wearable electronic device according to claim 6, characterized in that: When the VCC terminal and the GND terminal inside the wearable electronic device cannot obtain power, the processor of the wearable electronic device determines that the wearable device is in the detection mode by detecting the state that the VCC terminal and the GND terminal are not powered, and then controls the double-pole double-throw switch to switch to the second switch state through the GPIO port; the processor of the wearable electronic device continues to control the implementation of the detection function and obtain the detection results through the GPIO port.
10. The switch circuit of the common contact of the wearable electronic device according to claim 2, characterized in that: The human body impedance detection circuit includes a pulse width modulation (PWM) signal generator, an operational amplifier, a high-pass filter circuit, a resonant filter circuit, a current limiting circuit, and a measuring electrode; wherein the PWM signal generator is used to generate a PWM signal as a signal source for the human body impedance detection circuit; the operational amplifier is used to pre-amplify the PWM signal; the high-pass filter circuit is used to extract the high-frequency component in the PWM signal; the resonant filter circuit is used to filter and select the frequency of the high-frequency part of the PWM signal; the current limiting circuit is used to limit the current to a safe current range for the human body; and the measuring electrodes are used to perform contact measurement with the human skin, that is, the D+ contact and D- contact on the outer surface of the wearable electronic device.