A non-contact sensing circuit based on capacitive induction

Abstract

The utility model discloses a kind of non-contact induction circuit based on electric capacity induction, including main control module, output module and power supply module;Main control module includes main control chip U2 and sensor TK2, sensor TK2 is used to generate induction signal, and main control chip U2 handles induction signal to obtain control signal;Output module modulation and output control signal.Thereby, non-contact capacitance detection is realized based on touch sensor, even if using environment is severe, surface is contaminated with stain, accurate hand sweep induction can also be realized, and compared with infrared emission tube, it has longer service life, effectively reduces maintenance cost.

Description

Technical Field

[0001] This utility model relates to the field of circuit design technology, and in particular to a non-contact sensing circuit based on capacitive sensing. Background Technology

[0002] Existing hand-scanning sensors use an electronic control unit to generate a digital signal, which in turn controls a transmitter to emit an infrared light signal. A receiver then receives the infrared light signal reflected from a hand, and the electronic control unit processes this signal into a digital signal to detect the hand's movement. However, in practical use, hand-scanning sensors are often installed in environments such as toilets and bathrooms, where the transmitter and receiver are easily contaminated with dirt, hindering the output or reception of the infrared light signal and causing detection failure. Furthermore, the infrared emitter used to excite the infrared light signal in hand-scanning sensors has a short lifespan and requires multiple replacements during its service life, significantly increasing maintenance costs. Utility Model Content

[0003] This embodiment discloses a non-contact sensing circuit based on capacitive sensing, specifically including: Main control module, output module and power supply module; The main control module includes a main control chip U2 and a sensor TK2. The sensor TK2 is used to generate a sensing signal, and the main control chip U2 processes the sensing signal to obtain a control signal. The output module modulates and outputs the control signal.

[0004] As an optional implementation, the sensor TK2 is used to measure capacitance changes within its detection range and generate the sensing signal.

[0005] As an alternative implementation, the capacitance change is generated based on the placement of the hand within the detection range.

[0006] As an optional implementation, pin 10 of the main control chip U2 is connected to the sensor TK2 to receive the sensing signal; Pin 16 of the main control chip U2 is connected to button K1 to turn the sensor TK2 on / off. The indicator LED is connected to pin 18 of the main control chip U2.

[0007] As an optional implementation, the output module includes a field-effect transistor Q1 and an output terminal P1; The gate and drain of the field-effect transistor Q1 are connected to pin 20 of the main control chip U2 to obtain the control signal; The drain of the field-effect transistor Q1 is connected to pin 4 of the output terminal P1.

[0008] As an optional implementation, the output terminal P1 is connected to the controlled device to transmit the modulated control signal to the controlled device.

[0009] As an optional implementation, the field-effect transistor Q1 modulates the control signal into a PWM format.

[0010] As an optional implementation, the power supply module includes a diode D1 and a voltage regulator chip U1; The diode D1 is connected to the second pin of the voltage regulator chip U1 via resistor R12; The voltage regulator chip U1 has its first pin grounded and its second pin outputting a 3.3V operating current.

[0011] As an optional implementation, the first pin of the main control chip U2 is connected to the operating current, and the third pin is grounded.

[0012] As an optional implementation, pin 5 of the main control chip U2 is connected to pin 3 of the control port J1 to obtain a clock signal; The 6th pin of the main control chip U2 is connected to the 4th pin of the control port J1 to obtain a serial signal.

[0013] Compared with the prior art, this embodiment has the following beneficial effects: In this embodiment, non-contact capacitance detection is achieved based on a touch sensor. Even in harsh environments with dirty surfaces, accurate hand-scan sensing can be achieved. Furthermore, it has a longer service life compared to infrared emitters, effectively reducing maintenance costs. Attached Figure Description

[0014] To more clearly illustrate the technical solutions in this embodiment, the accompanying drawings used in the embodiment will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0015] Figure 1 This is a schematic diagram of the circuit principle of a non-contact sensing circuit based on capacitive sensing disclosed in this embodiment. Detailed Implementation

[0016] The technical solutions in this embodiment will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this utility model, and not all embodiments. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of this utility model.

[0017] Please see Figure 1 This embodiment discloses a non-contact sensing circuit based on capacitive sensing, comprising: Main control module, output module and power supply module; The main control module includes a main control chip U2 and a sensor TK2. The sensor TK2 is used to generate sensing signals, and the main control chip U2 processes the sensing signals to obtain control signals. The output module modulates and outputs control signals.

[0018] As an optional implementation, sensor TK2 is used to measure capacitance changes within its detection range and generate a sensing signal.

[0019] In this embodiment, a touch-enabled sensor TK2 is used for capacitance detection. Compared to infrared emitters, which have high false alarm and failure rates and are easily affected by dirt, capacitance sensing is more accurate and can reduce the probability of false identification.

[0020] In addition, the lifespan of capacitive sensors is significantly longer than that of infrared emitting diodes, and their maintenance costs are significantly reduced compared to infrared sensing circuits.

[0021] As an alternative implementation, the capacitance change is generated based on the hand placement detection range.

[0022] Here, the human body is equivalent to a capacitor. When the hand approaches or touches the sensor TK2, a change in capacitance occurs between the hand and the sensor TK2. Based on the change in capacitance, it can be determined that the hand has entered the detection range.

[0023] Understandably, compared to infrared sensing modes that require calculation of reflection time and distance, this solution can determine whether hand-scanning control behavior exists simply by measuring whether the capacitance changes, without the need for complex data calculations and logical judgments.

[0024] As an optional implementation, pin 10 of the main control chip U2 is connected to sensor TK2 to receive sensing signals; Pin 16 of the main control chip U2 is connected to button K1 to turn sensor TK2 on / off; Pin 18 of the main control chip U2 is connected to an indicator LED.

[0025] As an optional implementation, the output module includes a field-effect transistor Q1 and an output terminal P1; The gate and drain of the field-effect transistor Q1 are connected to pin 20 of the main control chip U2 to obtain control signals; The drain of the field-effect transistor Q1 is connected to pin 4 of the output terminal P1.

[0026] As an optional implementation, the output terminal P1 is connected to the controlled device to transmit the modulated control signal to the controlled device.

[0027] As an optional implementation, the field-effect transistor Q1 modulates the control signal into a PWM format.

[0028] Here, the sensor TK2 measures the induction signal in analog format. The main control chip U2 modulates it into a digital signal, and then the output module modulates it into PWM format to directly drive controlled devices such as LED beads and perform dimming control.

[0029] As an optional implementation, the power supply module includes a diode D1 and a voltage regulator chip U1; Diode D1 is connected to pin 2 of voltage regulator chip U1 via resistor R12; The first pin of the voltage regulator chip U1 is grounded, and the second pin outputs a 3.3V operating current.

[0030] As an optional implementation, the first pin of the main control chip U2 is connected to the operating current, and the third pin is grounded.

[0031] As an optional implementation, pin 5 of the main control chip U2 is connected to pin 3 of the control port J1 to obtain a clock signal; Pin 6 of the main control chip U2 is connected to pin 4 of the control port J1 to obtain serial signals.

[0032] Here, the main control chip U2 can also operate under control based on external signals, thus providing diversified control strategies in addition to the hand-scanning sensing mode.

[0033] Compared with the prior art, this embodiment has the following beneficial effects: In this embodiment, non-contact capacitance detection is achieved based on a touch sensor. Even in harsh environments with dirty surfaces, accurate hand-scan sensing can be achieved. Furthermore, it has a longer service life compared to infrared emitters, effectively reducing maintenance costs.

Claims

1. A non-contact sensing circuit based on capacitive sensing, characterized in that, include: Main control module, output module and power supply module; The main control module includes a main control chip U2 and a sensor TK2. The sensor TK2 is used to generate a sensing signal, and the main control chip U2 processes the sensing signal to obtain a control signal. The output module modulates and outputs the control signal.

2. The non-contact sensing circuit based on capacitive sensing according to claim 1, characterized in that, include: The capacitance change is generated based on the placement of the hand within the detection range.

3. The non-contact sensing circuit based on capacitive sensing according to claim 1, characterized in that, include: Pin 10 of the main control chip U2 is connected to the sensor TK2 to receive the sensing signal; Pin 16 of the main control chip U2 is connected to button K1 to turn the sensor TK2 on / off. The indicator LED is connected to pin 18 of the main control chip U2.

4. A non-contact sensing circuit based on capacitive sensing according to claim 3, characterized in that, include: The output module includes a field-effect transistor Q1 and an output terminal P1; The gate and drain of the field-effect transistor Q1 are connected to pin 20 of the main control chip U2 to obtain the control signal; The drain of the field-effect transistor Q1 is connected to pin 4 of the output terminal P1.

5. A non-contact sensing circuit based on capacitive sensing according to claim 4, characterized in that, include: The output terminal P1 is connected to the controlled device to transmit the modulated control signal to the controlled device.

6. A non-contact sensing circuit based on capacitive sensing according to claim 4, characterized in that, include: The field-effect transistor Q1 modulates the control signal into a PWM format.

7. A non-contact sensing circuit based on capacitive sensing according to claim 1, characterized in that, include: The power supply module includes a diode D1 and a voltage regulator chip U1; The diode D1 is connected to the second pin of the voltage regulator chip U1 via resistor R12; The voltage regulator chip U1 has its first pin grounded and its second pin outputting a 3.3V operating current.

8. A non-contact sensing circuit based on capacitive sensing according to claim 7, characterized in that, include: The operating current is connected to pin 1 of the main control chip U2, and pin 3 is grounded.

9. A non-contact sensing circuit based on capacitive sensing according to claim 8, characterized in that, include: The fifth pin of the main control chip U2 is connected to the third pin of the control port J1 to obtain the clock signal; The 6th pin of the main control chip U2 is connected to the 4th pin of the control port J1 to obtain a serial signal.

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