Touch sensing and heating multiplexing circuit and method and nursing instrument

Abstract

The invention discloses a touch sensing and heating multiplexing circuit and method and a nursing instrument. The touch sensing and heating multiplexing circuit comprises a switch module; the control module comprises a multiplexing control end, a transmitting electrode end and a receiving electrode end; the charging and discharging module is respectively connected with the transmitting electrode end and the receiving electrode end and is used for charging when the transmitting electrode end outputs the high level; the induction coil is respectively connected with the switch module and the charging and discharging module; when the on-off state of the switch module is a first state and the skin is close to the induction coil to form an induction capacitor, the charging and discharging module charges the induction capacitor, the receiving electrode end detects that the potential of the charging and discharging module is reduced, and the induction coil serves as a touch induction assembly; and when the on-off state of the switch module is a second state, the power supply supplies power to the induction coil, and the induction coil serves as a heating assembly. According to the invention, time division multiplexing of touch sensing and heating functions can be realized.

Description

Technical Field

[0001] The present invention relates to the technical field of nursing instruments, and in particular to a touch sensing and heating multiplexing circuit, method and nursing instrument. Background Art

[0002] With the progress and development of society, people pay more and more attention to the quality of life and image management. In order to keep themselves beautiful at all times, various intelligent beauty devices have emerged. With the increasing popularity of various beauty devices, people's demand for products is no longer satisfied with the effects brought by the functions, but also pays more and more attention to the convenience and comfort of the products. At present, most beauty devices on the market need to directly or indirectly contact human skin when used, or be used with corresponding gel lotion, or act on beauty products to promote human absorption.

[0003] For beauty instruments that integrate multiple functions, many products will add skin touch sensing functions to the contact surface for energy saving, safety and intelligence considerations. For instruments that have a heat sensing function and uniform heat sensing, users do not need to worry about adapting to the colder temperature when applying gel to trigger the induction to turn on the heating function. For some instruments that do not have a heating function or have uneven heating, they usually need a temperature adaptation process when used in different environments. If the instrument requires a heating function, it is necessary to add a heating circuit or heating chip, which increases the cost and complexity. In addition, such as CN209187158U and CN219266788U, the existing beauty instruments that have realized touch sensing and heating, the temperature heating circuit and the skin touch sensing circuit (skin touch sensing identifier) ​​are set separately. Summary of the invention

[0004] The main purpose of the present invention is to provide a touch sensing and heating multiplexing circuit, method and nursing instrument, which overcome the shortcomings of the prior art and realize time-sharing multiplexing of touch sensing and heating functions through one circuit.

[0005] The present invention adopts the following technical solution:

[0006] In a first aspect, a touch sensing and heating multiplexing circuit includes:

[0007] Switch module;

[0008] A control module, comprising a multiplexing control port, a transmitting electrode port and a receiving electrode port; the multiplexing control port is connected to the switch module to control the on / off state of the switch module;

[0009] The charging and discharging module is connected to the transmitting electrode end and the receiving electrode end respectively, and is charged when the transmitting electrode end outputs a high level;

[0010] The induction coil is connected to the switch module and the charge-discharge module respectively; when the on-off state of the switch module is a first state and the skin is close to the induction coil to form an induction capacitor, the charge-discharge module charges the induction capacitor, and the receiving electrode end detects that the potential of the charge-discharge module is reduced, and the induction coil serves as a touch sensing component; when the on-off state of the switch module is a second state, the power supply supplies power to the induction coil, and the induction coil serves as a heating component.

[0011] Preferably, the first state is an off state, and the second state is an on state.

[0012] Preferably, the switch module includes a first switch tube, a second switch tube and a third switch tube; the second end of the first switch tube is connected to the power supply, the third end of the first switch tube is connected to one end of the induction coil, the first end of the first switch tube is connected to the third end of the third switch tube; the first end of the third switch tube is connected to the multiplexing control end; the first end of the second switch tube is connected to the multiplexing control end, the second end of the second switch is connected to the other end of the induction coil, and the third end of the second switch tube and the second end of the third switch tube are grounded.

[0013] Preferably, the multiplexing control port is connected to the switch module to control the on / off state of the switch module, specifically including:

[0014] When the multiplexing control port outputs a low level, the switch module is controlled to be in the first state; when the multiplexing control port outputs a high level, the switch module is controlled to be in the second state.

[0015] Preferably, when the multiplexing control port outputs a low level, the transmitting electrode end outputs a high level with a duty cycle greater than 0 and less than 100%; when the multiplexing control port outputs a high level, the transmitting electrode end outputs a low level.

[0016] Preferably, when the transmitting electrode end outputs a low level, the multiplexing control port outputs a continuous high level within a first period of time, and outputs a high level with a duty cycle greater than 0 and less than 100% within a second period of time.

[0017] Preferably, the power supply is a direct current power supply; the size of the direct current power supply is related to the wire diameter, length and conductive layer thickness of the induction coil.

[0018] Preferably, the charging and discharging module is a capacitor.

[0019] Preferably, the touch sensing and heating multiplexing circuit further includes a first resistor and a second resistor; the transmitting electrode end is connected to one end of the charging and discharging module through the first resistor and the second resistor connected in series, one end of the charging and discharging module is also connected to the receiving electrode end, and the other end of the charging and discharging module is grounded; one end of the induction coil is connected to the connection point of the first resistor and the second resistor.

[0020] In a second aspect, a touch sensing and heating multiplexing method is provided, based on the touch sensing and heating multiplexing circuit, comprising:

[0021] In the touch sensing step, the control module controls the multiplexing control end to output a first level signal, and at the same time controls the sending electrode end to output a second level signal to charge the charging and discharging module, and the switch module is in a first state; when the skin and the induction coil are close to form an induction capacitor, the charging and discharging module charges the induction capacitor; the receiving electrode end detects that the potential of the charging and discharging module decreases, and the induction coil serves as a touch sensing component; after a first preset time, a heating step is performed;

[0022] In the heating step, the control module controls the multiplexing control end to output a third level signal, and controls the sending electrode end to output a fourth level signal, and the switch module is in the second state; the induction coil is powered by a power supply, and current flows through the induction coil, and the induction coil serves as a heating component; after the second preset time, the touch sensing step is performed.

[0023] Preferably, the first preset time and the second preset time are adjustable.

[0024] Preferably, the first level signal is a low level; the second level signal is a high level; the third level signal is a high level; and the fourth level signal is a low level.

[0025] In a third aspect, a touch sensing and heating multiplexing method is provided, based on the touch sensing and heating multiplexing circuit, comprising:

[0026] After receiving the touch sensing start instruction, the control module controls the multiplexing control end to output a first level signal, and at the same time controls the sending electrode end to output a second level signal to charge the charging and discharging module, and the switch module is in the first state; when the skin and the induction coil are close to form an induction capacitor, the charging and discharging module charges the induction capacitor; the receiving electrode end detects that the potential of the charging and discharging module is reduced, and the induction coil serves as a touch sensing component.

[0027] In a fourth aspect, a touch sensing and heating multiplexing method is provided, based on the touch sensing and heating multiplexing circuit, comprising:

[0028] After receiving the heating start instruction, the control module controls the multiplexing control end to output a third level signal, and at the same time controls the sending electrode end to output a fourth level signal, and the switch module is in the second state; the induction coil is powered by a power supply, and current flows through the induction coil, and the induction coil serves as a heating component.

[0029] In a fifth aspect, a nursing instrument comprises a nursing instrument body and the touch sensing and heating multiplexing circuit.

[0030] Compared with the prior art, the present invention has the following beneficial effects:

[0031] (1) The present invention uses an induction coil to realize the touch sensing function and the heating wire function, and controls the touch sensing and heating time-sharing multiplexing through a control module, so that the touch sensing function and the heating function are shared in the same circuit; in addition, the touch sensing and heating time-sharing multiplexing time can be changed, the heating power can be adjusted, different heating temperatures can be achieved, and comfort can be increased;

[0032] (2) The induction coils of the present invention are evenly distributed. For nursing instruments that have thermal sensing functions but have uneven thermal sensing on the contact surface due to heat source limitations, the induction coils can act as heating wires to improve the problem of uneven thermal sensing (for example, the heating head is composed of two parts, the middle part is a circular heating metal device, and the outer part of the heating device is a ring-shaped circuit board. The ring-shaped circuit board itself does not have a heating function. The induction coils are arranged on the circuit board and controlled by the control module to heat the induction coils synchronously in time, which can change the uneven state that only the center of the electrode head has thermal sensing, and achieve a relatively uniform temperature of the entire heating head); for nursing instruments that do not have a thermal sensing function, the contact surface can have a thermal sensing effect, thereby enhancing the use effect and improving comfort;

[0033] (3) The present invention uses an induction coil to realize a touch sensing function, which can not only improve convenience but also save energy and enhance safety.

[0034] The above description is only an overview of the technical solution of the present invention. In order to more clearly understand the technical means of the present invention so that it can be implemented in accordance with the contents of the specification, and in order to make the above and other purposes, features and advantages of the present invention more obvious and easy to understand, the specific implementation methods of the present invention are listed below.

[0035] Based on the following detailed description of specific embodiments of the present invention in conjunction with the accompanying drawings, those skilled in the art will become more aware of the above and other objects, advantages and features of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Figure 1 Schematic diagram of a touch sensing and heating multiplexing circuit according to Embodiment 1 of the present invention;

[0037] Figure 2 It is a structural schematic diagram of the induction coil of the first embodiment of the present invention;

[0038] Figure 3 Schematic diagram of control signals of the multiplexing control terminal and the transmitting electrode terminal during the touch and heating time-division multiplexing of the first embodiment of the present invention; wherein (a) is a schematic diagram when the frequency is slow; (b) is a schematic diagram when the frequency is fast;

[0039] Figure 4This is a flow chart of a touch sensing and heating multiplexing method according to a first embodiment of the present invention;

[0040] Figure 5 This is a flow chart of a touch sensing method according to Embodiment 2 of the present invention;

[0041] Figure 6 A schematic diagram of a control signal multiplexing timing control terminal and a transmitting electrode terminal during touch sensing function according to the second embodiment of the present invention;

[0042] Figure 7 This is a flow chart of a heating method according to Embodiment 3 of the present invention;

[0043] Figure 8 Schematic diagram of multiplexing control signals of the timing control end and the transmitting electrode end during the heating function of the third embodiment of the present invention; wherein (a) is a schematic diagram of the induction coil being continuously powered on for heating; and (b) is a schematic diagram of the induction coil being continuously powered on for heating and then performing constant temperature control. DETAILED DESCRIPTION

[0044] The technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention; it is obvious that the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments, and all other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention without making creative work are within the scope of protection of the present invention.

[0045] In the description of the present invention, it should be noted that the terms "comprises", "includes" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also includes other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, an element defined by the sentence "comprises a ..." does not exclude the existence of other identical elements in the process, method, article or device including the element.

[0046] In the description of the present invention, it should be noted that the terms "upper", "lower", "inner", "outer", "top / bottom" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific position, be constructed and operated in a specific position, and therefore cannot be understood as limiting the present invention. In addition, the terms "first" and "second" are used for descriptive purposes only and cannot be understood as indicating or implying relative importance.

[0047] In the description of the present invention, it should be noted that, unless otherwise clearly stipulated and limited, the terms "installed", "provided with", "mounted / connected", "connected", etc. should be understood in a broad sense. For example, "connected" can be a fixed connection, a detachable connection, or an integral connection. It can be a mechanical connection or an electrical connection. It can be a direct connection or an indirect connection through an intermediate medium. It can be the internal connection of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0048] Embodiment 1

[0049] A touch sensing and heating multiplexing circuit, comprising:

[0050] Switch module;

[0051] A control module, comprising a multiplexing control port, a transmitting electrode port and a receiving electrode port; the multiplexing control port is connected to the switch module to control the on / off state of the switch module;

[0052] The charging and discharging module is connected to the transmitting electrode end and the receiving electrode end respectively, and is charged when the transmitting electrode end outputs a high level;

[0053] The induction coil is connected to the switch module and the charge-discharge module respectively; when the on-off state of the switch module is a first state and the skin and the induction coil form an induction capacitor, the charge-discharge module charges the induction capacitor, and the receiving electrode end detects that the potential of the charge-discharge module decreases, and the induction coil serves as a touch sensing component; when the on-off state of the switch module is a second state, the power supply supplies power to the induction coil, and the induction coil serves as a heating component.

[0054] In this embodiment, see Figure 1 As shown, the control module is MCU control U1. The first state is the disconnected state, and the second state is the on state. When the multiplexed control terminal I / O PWM2 outputs a low level, the control switch module is in the disconnected state; when the multiplexed control terminal I / O PWM2 outputs a high level, the control switch module is in the on state. When the multiplexed control terminal I / OPWM2 outputs a low level, the transmitting electrode terminal TOUCH PWM1 outputs a PWM signal; when the multiplexed control terminal I / OPWM2 outputs a high level, the transmitting electrode terminal TOUCH PWM1 outputs a low level.

[0055] Specifically, the switch module includes a first switch tube Q1, a second switch tube Q2 and a third switch tube Q3; the second end 2 of the first switch tube Q1 is connected to the power supply, the third end 3 of the first switch tube Q1 is connected to one end of the induction coil coi1, the first end 1 of the first switch tube Q1 is connected to the third end 3 of the third switch tube Q3; the first end 1 of the third switch tube Q3 is connected to the multiplexing control end I / O PWM2; the first end 1 of the second switch tube Q2 is connected to the multiplexing control end I / O PWM2, the second end 2 of the second switch is connected to the other end of the induction coil coi1, and the third end 3 of the second switch tube Q2 and the second end 2 of the third switch tube Q3 are grounded.

[0056] In this embodiment, the first switch tube Q1 and the second switch tube Q2 are MOS tubes, and the third switch tube Q3 is a triode. The first end 1 of the first switch tube Q1 is a gate, the second end 2 of the first switch tube Q1 is a source, and the third end 3 of the first switch tube Q1 is a drain. The first end 1 of the second switch tube Q2 is a gate, the second end 2 of the second switch tube Q2 is a drain, and the third end 3 of the first switch tube Q1 is a source. The first end 1 of the third switch tube Q3 is a base, the second end 2 of the second switch tube Q2 is an emitter, and the third end 3 of the first switch tube Q1 is a collector.

[0057] In this embodiment, the charging and discharging module is a capacitor C1. The touch sensing and heating multiplexing circuit also includes a first resistor R1 and a second resistor R2; the transmitting electrode end TOUCH PWM1 is connected to one end of the capacitor C1 through the first resistor R1 and the second resistor R2 connected in series, one end of the capacitor C1 is also connected to the receiving electrode end TOUCH, and the other end of the capacitor C1 is grounded; one end of the induction coil coi1 is connected to the connection point of the first resistor R1 and the second resistor R2, the other end of the induction coil coi1 is connected to the second switch tube Q2, and the second end of the second switch tube Q2 is connected to the ground.

[0058] The touch sensing and heating multiplexing circuit also includes a second diode D1 connected in parallel with the second resistor R2. The purpose is that whether the induction coil is used as a touch sensing function or a heating function, it is best to release the residual electrical energy of the induction coil before switching, otherwise it will affect the use after switching, and the setting of the diode can speed up the release of residual electrical energy.

[0059] In this embodiment, see Figure 2As shown, the induction coil coi1 uses a copper conductor on the PCB board. According to the area of ​​the contact surface PCB board, the wiring is avoided away from the placement of other devices. According to the available DC power supply VCC, the wire diameter and length of the copper wiring are calculated. Alternatively, according to the wire diameter and length of the copper wiring, the DC power supply VCC to be used is calculated. The wiring is arranged as evenly as possible to achieve a better heating effect.

[0060] Specifically, the resistivity formula for copper routing is as follows:

[0061] R=ρL / S

[0062] Among them, ρ represents resistivity; L represents the length of the copper trace; S represents the conductor area.

[0063] The current carrying capacity formula of the induction coil coi1 is as follows:

[0064] I=K*T*0.44*A*0.725

[0065] Among them, K represents the correction coefficient. When the copper thickness is 1OZ, K is 0.048, and when the copper thickness is 0.50Z, K is 0.024; T represents the maximum temperature rise in °C; A represents the copper area in mil.

[0066] In this embodiment, when the induction coil coi1 is used as a touch coil to realize the touch sensing function, the sending electrode end TOUCH PWM1 of the control module sends PWM to charge the capacitor C1. When the multiplexing control end I / O PWM2 outputs a low level, the second switch tube Q2 and the third switch tube Q3 are turned off, and the gate of the first switch tube Q1 does not meet the turn-on condition, and the first switch tube Q1 is turned off; the sending electrode end TOUCH PWM1 outputs a high level to charge the capacitor C1. When the skin touches the PCB board where the induction coil coi1 is located, the induction coil coi1 forms an induction capacitor with the human body. At this time, the induction coil coi1 starts to charge, the capacitor C1 discharges, and the potential of the capacitor C1 decreases. The receiving electrode end TOUCH recognizes that the potential of the capacitor C1 decreases, triggers the touch sensing function, and uses the induction coil coi1 as a touch sensing component.

[0067] When the induction coil coi1 is used as a heating wire to realize the heating function, the multiplexing control terminal I / O PWM2 outputs a high level, the second switch tube Q2 and the third switch tube Q3 are turned on, the gate of the first switch tube Q1 detects the voltage division of the fourth resistor R4 (low resistance resistor) and the third resistor R3 (high resistance resistor), the first switch is turned on, and the DC power supply VCC supplies power to the induction coil coi1, and then passes through the second switch tube Q2 to the negative electrode VCC- of the DC power supply (in this embodiment, VCC- is the ground terminal). At this time, the induction coil coi1 is equivalent to a low resistance resistor. The coil resistor will start to heat up but will not be damaged when passing through a certain range of power (voltage and current). At this time, the induction coil coi1 acts as a heating wire to provide temperature, meet the skin contact heat sensation, or improve the uneven heat sensation.

[0068] From the above, this embodiment can realize the time-sharing multiplexing of the touch sensing function and the heating function. Specifically, the control module controls the multiplexing control terminal I / O PWM2 to output high and low levels alternately. When the output is low, the induction coil coi1 is used as a touch sensing component, and when the output is high, the induction coil coi1 is used as a heating wire function, and so on. For example, within 1s, the multiplexing control terminal I / O PWM2 outputs a low level for the first 0.3s, the switch tube is not turned on, and the induction coil coi1 is used as a touch sensing component. After 0.7s, the output is high, the switch tube is turned on, and the induction coil coi1 is used as a heating wire. In this way, it is ensured that within a 1s period, the induction coil coi1 acts as a touch sensing component such as a touch sensor and is used as a heating wire for heating, thereby realizing the time-sharing multiplexing of the touch sensing and heating functions.

[0069] For further information, see Figure 3 As shown, according to actual needs, the multiplexing control end can alternately output high level and low level, and the copper routing can quickly switch between the touch function and the heating function, so as to realize time-sharing multiplexing, which is equivalent to having both touch function and heating function.

[0070] For details, see Figure 3 (a) shows the time-division multiplexing of the induction coil as a touch function and a heating function when the frequency is slow. When the multiplexing control end outputs a high level, the transmitting electrode end outputs a low level, the Q1, Q2 and Q3 switches are in the on state, and the induction coil is heated. When the multiplexing control end outputs a low level, the transmitting electrode end outputs a high-low alternating PWM signal, and the induction coil is used as a touch sensing function. For a period of time, the multiplexing control end (I / O_PWM2) outputs a high-low alternating PWM signal, and the transmitting electrode end outputs a high-low alternating PWM signal. When the multiplexing control end (I / O_PWM2) outputs a high level, the transmitting electrode end outputs a low level, and when the multiplexing control end (I / O_PWM2) outputs a low level, the transmitting electrode end outputs a high-low alternating PWM signal.

[0071] See also Figure 3 As shown in (b), when the multiplexing control end (I / O_PWM2) outputs a high-low alternating PWM signal with a faster frequency, the transmitting electrode end outputs a high-low alternating PWM signal complementary to the multiplexing control end; the multiplexing control end (I / O_PWM2) outputs a high-low alternating PWM signal, and the transmitting electrode end outputs a high-low alternating PWM signal, the multiplexing control end (I / O_PWM2) outputs a high level, the transmitting electrode end outputs a low level, the multiplexing control end (I / O_PWM2) outputs a low level, and the transmitting electrode end outputs a high level signal.

[0072] This embodiment can also achieve heating power adjustment and heating temperature control. Control the different conduction times of the switch tube to adjust the heating power of the induction coil and achieve different heating temperatures. For example, within 1 minute, in the first 50 seconds, every 1 second is low level for 0.3 seconds, high level for 0.7 seconds, 0.3 seconds when the switch tube is closed as touch sensing, 0.7 seconds when the switch tube is opened as a heating function, and this cycle lasts for 50 seconds. The induction coil is continuously heated for 50 seconds and reaches the expected temperature; starting from the 50th second, every 1 second is low level for 0.7 seconds, the switch tube is closed as touch sensing, and high level for 0.3 seconds when the switch tube is opened as a heating function, shortening the heating time of the induction coil and maintaining the heating temperature within the required temperature range. It can be set specifically according to the application, and this embodiment does not limit it.

[0073] Furthermore, the present embodiment also discloses a care instrument, such as a beauty instrument, which, in addition to including the existing structure of the care instrument, is also provided with the touch sensing and heating multiplexing circuit of the present embodiment to realize touch sensing and heating multiplexing.

[0074] Based on the above touch sensing and heating multiplexing circuit, see Figure 4 As shown, for a nursing instrument that triggers touch sensing and heating multiplexing through a switch / button, the control module executes the following control method after receiving the corresponding function instruction:

[0075] In touch sensing step S401, the control module controls the multiplexing control end to output a first level signal, and controls the sending electrode end to output a second level signal to charge the charging and discharging module, and the switch module is in a first state; when the skin and the induction coil are close to form an induction capacitor, the charging and discharging module charges the induction capacitor; the receiving electrode end detects that the potential of the charging and discharging module decreases, and the induction coil is used as a touch sensing component until a first preset time is reached, and then a heating step is performed;

[0076] In the heating step S402, the control module controls the multiplexing control end to output a third level signal, and controls the sending electrode end to output a fourth level signal, and the switch module is in the second state; the induction coil is powered by the power supply, and current flows through the induction coil, and the induction coil serves as a heating component until the second preset time is reached, and then the touch sensing step is repeated.

[0077] It should be noted that the condition for the termination of the above method can be a preset total duration. When the cumulative duration reaches the total duration, the control is terminated. The condition for the termination of the above method can also be receiving an end instruction, which can be set according to specific needs and is not limited in this embodiment.

[0078] In addition, the execution order of the above steps can be adjusted according to the actual application, that is, the heating step can be executed first, and then the touch sensing step can be executed, and then the cycle control can be performed. This embodiment does not limit this.

[0079] Embodiment 2

[0080] The touch sensing and heating multiplexing circuit of this embodiment is the same as that of the first embodiment. Figure 5 As shown, the difference is that for the nursing instrument in which touch sensing and heating are controlled by different switches / buttons, after receiving the touch sensing function instruction, the control module executes the touch sensing control separately to start the touch sensing function, thereby meeting the user's multi-functional needs.

[0081] See also Figure 5 As shown, the touch sensing control method includes:

[0082] S501, the control module receives a touch sensing start instruction;

[0083] S502, control the multiplexing control end to output a first level signal, and at the same time control the sending electrode end to output a second level signal to charge the charging and discharging module, and the switch module is in the first state; when the skin and the induction coil are close to form an induction capacitor, the charging and discharging module charges the induction capacitor; the receiving electrode end detects that the potential of the charging and discharging module is reduced, and the induction coil serves as a touch sensing component.

[0084] For details, see Figure 6 As shown, in the selected mode, the induction coil is used as a touch sensing function. The sending electrode end (TOUCH_PWM1) outputs a PWM signal with alternating high and low levels, that is, the output high level duty ratio is a high level greater than 0 and less than 100%; the multiplexing control end (I / O_PWM2) outputs a low level, and the switch tubes Q3, Q2, and Q1 are all in the off state.

[0085] The high level in the PWM1 signal quickly charges the capacitor C1 through the resistor R1 and the diode D1, and the potential of the capacitor C1 rises. When the PWM1 signal is low, C1 begins to discharge through the resistors R2 and R1, and the discharge speed is slow (the PWM signal frequency is fast, for example, 200khZ). When the skin is close to the top of the induction coil, the human body and the induction coil form an induction capacitor, the PWM1 high level charges the induction capacitor, the C1 capacitor charges the induction capacitor, the potential of the C1 capacitor decreases, the chip detects the decrease in the potential of the C1 capacitor, and the induction function is triggered.

[0086] Embodiment 3

[0087] The touch sensing and heating multiplexing circuit of this embodiment is the same as that of the first embodiment. Figure 5 As shown, the difference is that for the nursing instrument in which touch sensing and heating are controlled by different switches / buttons, after receiving the heating function instruction, the control module executes the heating control separately to start the heating function, thereby meeting the user's multi-functional needs.

[0088] See also Figure 7 As shown in , the heating control method includes:

[0089] S503, the control module receives a heating start instruction;

[0090] S504, control the multiplexing control end to output a third level signal, and control the sending electrode end to output a fourth level signal, and the switch module is in the second state; power is supplied to the induction coil through the power supply, and current flows through the induction coil, and the induction coil serves as a heating component.

[0091] For details, see Figure 8 As shown in (a), in the selected mode, when the induction coil is used as a heating function, the sending electrode end (TOUCH_PWM1) outputs a low-level signal; the multiplexing control end (I / O_PWM2) outputs a high-level signal to turn on the Q3, Q2, and Q1. The DC power supply VCC supplies power to the coil, and the induction coil is continuously powered on for heating until the highest temperature that the coil can generate is reached.

[0092] See also Figure 8As shown in (b), in the selected mode, the requirements are: when the induction coil is used as a heating function. The sending electrode end (TOUCH_PWM1) outputs a low-level signal; the multiplexing control end (I / O_PWM2) outputs a high-level signal to turn on the Q3, Q2, and Q1 tubes. The DC power supply VCC supplies power to the coil, and the coil is heated. When the coil heating temperature reaches the preset temperature, it continuously outputs a high level in the first time, and the multiplexing control end (I / O_PWM2) outputs a PWM signal of alternating high and low levels, that is, it outputs a high level with a duty cycle greater than 0 and less than 100% in the second time. The coil is in an alternating state of power on and power off to control the temperature of the coil. The duty cycle is defined as the ratio of the high level time (i.e., the power-on time) to the total time in a pulse cycle.

[0093] It should be noted that the condition for the termination of the above method may be a preset duration, and the control is terminated when the duration is reached; the condition for the termination of the above method may also be receiving an end instruction, which is specifically set according to needs and is not limited in this embodiment.

[0094] The above is only a preferred specific implementation of the present invention; however, the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes according to the technical solution and its improved conception within the technical scope disclosed by the present invention, which should be covered by the protection scope of the present invention.

Claims

1. A touch sensing and heating multiplexing circuit, characterized in that: include: Switch module; A control module, comprising a multiplexing control end, a transmitting electrode end and a receiving electrode end; The multiplexing control port is connected to the switch module to control the on / off state of the switch module; The charging and discharging module is connected to the transmitting electrode end and the receiving electrode end respectively, and is charged when the transmitting electrode end outputs a high level; The induction coil is connected to the switch module and the charge-discharge module respectively; when the on-off state of the switch module is a first state and the skin is close to the induction coil to form an induction capacitor, the charge-discharge module charges the induction capacitor, and the receiving electrode end detects that the potential of the charge-discharge module is reduced, and the induction coil serves as a touch sensing component; when the on-off state of the switch module is a second state, the power supply supplies power to the induction coil, and the induction coil serves as a heating component.

2. The touch sensing and heating multiplexing circuit according to claim 1, characterized in that: The first state is an off state, and the second state is an on state.

3. The touch sensing and heating multiplexing circuit according to claim 2, characterized in that: The switch module includes a first switch tube, a second switch tube and a third switch tube; the second end of the first switch tube is connected to the power supply, the third end of the first switch tube is connected to one end of the induction coil, the first end of the first switch tube is connected to the third end of the third switch tube; the first end of the third switch tube is connected to the multiplexing control end; the first end of the second switch tube is connected to the multiplexing control end, the second end of the second switch is connected to the other end of the induction coil, and the third end of the second switch tube and the second end of the third switch tube are grounded.

4. The touch sensing and heating multiplexing circuit according to claim 1, characterized in that: The multiplexing control port is connected to the switch module to control the on / off state of the switch module, specifically including: When the multiplexing control port outputs a low level, the switch module is controlled to be in the first state; when the multiplexing control port outputs a high level, the switch module is controlled to be in the second state.

5. The touch sensing and heating multiplexing circuit according to claim 1, characterized in that: When the multiplexing control port outputs a low level, the transmitting electrode end outputs a high level with a duty cycle greater than 0 and less than 100%; when the multiplexing control port outputs a high level, the transmitting electrode end outputs a low level.

6. The touch sensing and heating multiplexing circuit according to claim 1, characterized in that: When the transmitting electrode terminal outputs a low level, the multiplexing control port outputs a continuous high level within a first period of time, and outputs a high level with a duty cycle greater than 0 and less than 100% within a second period of time.

7. The touch sensing and heating multiplexing circuit according to claim 1, characterized in that: The power supply is a direct current power supply; the size of the direct current power supply is related to the wire diameter, length and conductive layer thickness of the induction coil.

8. The touch sensing and heating multiplexing circuit according to claim 1, characterized in that: The charging and discharging module is a capacitor.

9. The touch sensing and heating multiplexing circuit according to claim 1, characterized in that: It also includes a first resistor and a second resistor; the sending electrode end is connected to one end of the charging and discharging module through the first resistor and the second resistor connected in series, one end of the charging and discharging module is also connected to the receiving electrode end, and the other end of the charging and discharging module is grounded; one end of the induction coil is connected to the connection point of the first resistor and the second resistor.

10. A touch sensing and heating multiplexing method, characterized in that: The touch sensing and heating multiplexing circuit according to any one of claims 1 to 9 comprises: In the touch sensing step, the control module controls the multiplexing control end to output a first level signal, and at the same time controls the sending electrode end to output a second level signal to charge the charging and discharging module, and the switch module is in a first state; when the skin and the induction coil are close to form an induction capacitor, the charging and discharging module charges the induction capacitor; the receiving electrode end detects that the potential of the charging and discharging module decreases, and the induction coil serves as a touch sensing component; after a first preset time, a heating step is performed; In the heating step, the control module controls the multiplexing control end to output a third level signal, and controls the sending electrode end to output a fourth level signal, and the switch module is in the second state; the induction coil is powered by a power supply, and current flows through the induction coil, and the induction coil serves as a heating component; after the second preset time, the touch sensing step is performed.

11. The touch sensing and heating multiplexing method according to claim 10, characterized in that: The first preset time and the second preset time are adjustable.

12. The touch sensing and heating multiplexing method according to claim 10, characterized in that: The first level signal is a low level; the second level signal is a high level; the third level signal is a high level; and the fourth level signal is a low level.

13. A touch sensing and heating multiplexing method, characterized in that: The touch sensing and heating multiplexing circuit according to any one of claims 1 to 9 comprises: After receiving the touch sensing start instruction, the control module controls the multiplexing control end to output a first level signal, and at the same time controls the sending electrode end to output a second level signal to charge the charging and discharging module, and the switch module is in the first state; when the skin and the induction coil are close to form an induction capacitor, the charging and discharging module charges the induction capacitor; the receiving electrode end detects that the potential of the charging and discharging module is reduced, and the induction coil serves as a touch sensing component.

14. A touch sensing and heating multiplexing method, characterized in that: The touch sensing and heating multiplexing circuit according to any one of claims 1 to 9 comprises: After receiving the heating start instruction, the control module controls the multiplexing control end to output a third level signal, and at the same time controls the sending electrode end to output a fourth level signal, and the switch module is in the second state; the induction coil is powered by a power supply, and current flows through the induction coil, and the induction coil serves as a heating component.

15. A nursing instrument, characterized in that: The invention comprises a nursing instrument body and a touch sensing and heating multiplexing circuit as claimed in any one of claims 1 to 9.

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