KR20220048197A - Capacitive button circuit - Google Patents

Abstract

The present invention relates to a touch button circuit comprising a square wave signal generating circuit, a sinusoidal boosting circuit, and an electrostatic response sampling circuit. An output part of the square wave signal generating circuit and a signal input part of the sinusoidal boosting circuit are connected. A signal output part of the sinusoidal boosting circuit and a signal input part of the electrostatic response sampling circuit are connected. It is possible to identify an electrostatic response button, which is connected to the signal output part of the electrostatic response sampling circuit and the signal input part of a square wave signal generator. And it is possible to manufacture a button circuit with high stability and easy realization at a low cost.

Description

Capacitive button circuit {CAPACITIVE BUTTON CIRCUIT}

The present invention relates to a capacitive button circuit, in particular to a capacitive touch button circuit.

In general, the most important touch button technology at present can be divided into two types: an electric resistive touch button and a capacitively sensitive button. The electrical resistance type touch button needs to attach a thin touch resistance film to the surface of the equipment. It is known that the durability of the touch resistance film is relatively weak. In contrast, capacitive touch technology eliminates the need for drilling on non-metallic surfaces and is waterproof, anti-pollution, and easy to clean. In addition, there is no hole, so there is no wear of the mechanical switch, and the long life is an advantage. In addition, in the future, more and more electronic products, home appliances, etc. are focusing on product development by introducing capacitive touch-sensitive buttons to all products. Accordingly, many electronic component suppliers who supply components to electronic products and home appliance manufacturers are also expanding their application research on capacitive touch sensitive buttons, and are also releasing specialized chips that work with many capacitive touch sensitive buttons. However, the cost of these chips is relatively high, making them difficult to apply to a series of low-cost circuits. In addition, the current series of touch-sensitive button circuits have a disadvantage in that their radio wave AC defense capability is relatively low and malfunctions are easy to occur.

The present invention discloses a capacitive touch button circuit (Touch switch). The capacitive touch button circuit includes a square wave signal generating circuit, a sinusoidal step-up circuit, and an electrostatic response sampling circuit. The above-described square wave signal generating circuit output unit and the signal input unit of the sine boosting circuit are connected, and the signal output unit of the sine boosting circuit and the signal input unit of the electrostatic reaction sampling circuit are connected. And the signal output part of the electrostatic reaction sampling circuit and the signal input part of the square wave signal generator are connected. The present invention generates a spherical signal through a microcontroller and receives the electrostatic voltage signal of the electrostatic sensitive circuit to the A/D terminal of the microcontroller. The signal passes through the microcontroller to cause large and small changes in the electrostatic signal at both ends of the electrostatic signal. This makes it possible to identify the capacitive touch-sensitive button, and it is possible to manufacture a button with high stability and easy realization at low cost.

Korean Patent Registration No. 1591293 describes a capacitive touch input device in which an input terminal of a touch input detection circuit and an output terminal of a compensation circuit are connected to a sensing electrode. In addition, Korean Patent Laid-Open No. 10-2011-76059 describes a technique for measuring a strong touch sensor while increasing the sensitivity of the touch sensor. However, this invention did not provide a low-cost and stable touch circuit.

The capacitive touch button circuit of the present invention includes a square wave signal generating circuit, a sinusoidal step-up circuit, and an electrostatic sensitive sampling circuit. The output of the above-described square wave signal generating circuit and the signal input of the sine boosting circuit are connected, and the signal output of the sine boosting circuit and the signal input of the electrostatic reaction sampling circuit are connected. And it is realized in connection with the signal output part of the electrostatic reaction sampling circuit and the signal input part of the square wave signal generator.

In order to overcome the shortcomings of the current technology and the problems that exist therefrom, the present invention provides a kind of simplified circuit structure, low cost, and stable and reliable capacitive touch circuit.

In order to solve the above problems, it includes a square wave signal generating circuit, a sinusoidal boosting circuit, and an electrostatic reaction sampling circuit, connected to the square wave signal generating circuit output unit and the signal input unit of the sinusoidal boosting circuit, and having an electrostatic reaction with the signal output unit of the sinusoidal boosting circuit The signal input unit of the sampling circuit is connected, and the signal output unit of the electrostatic reaction sampling circuit is connected to the signal input unit of the square wave signal generating circuit.

In addition, the sinusoidal step-up circuit comprises a transistor Q1, a first register R1, a second register R2, a third register R3, a first capacitor C1, a second capacitor C2, and a third capacitor. (C3), a first diode (D1), and an inductor (L1), wherein one terminal of the first register is used as a signal input part of the sine step-up circuit, the other terminal is connected to the base of the transistor, and the first capacitor and the first register are connected in parallel, the third resistor, the second register and the inductor are connected in series in order, the other terminal of the inductor is connected to the collector of the transistor, the other terminal of the third register and the power supply and one terminal of the second capacitor is connected between the second and third resistors, the other terminal is grounded, and the anode of the first diode and one terminal of the third capacitor and the emitter terminal of the transistor are connected. and the collector of the transistor is used as a signal input part of the sine boost circuit, and the positive terminal of the first diode and the other terminal of the third capacitor are connected to the collector of the transistor.

In addition, the electrostatic sensitive sampling circuit includes an electrostatic sensitive button (K), a second diode (D2), a third diode (D3), a fourth register (R4), a fifth register (R5), and a fourth capacitor (C4). wherein the second diode and the third diode are connected to one terminal of the anode, the fourth register, and the fifth register, and the sensitive electrode of the electrostatic sensitive button, and the anode terminal of the second diode and the other terminal of the fourth register are connected to each other They are connected together to become a signal input part of the electrostatic responsive sampling circuit, and are connected to the collector of the transistor, and the positive terminal of the third diode, the other terminal of the fifth register, and one terminal of the fourth capacitor are connected together to form an electrostatic responsive sampling circuit It becomes a signal output part of , which is characterized in that it is connected to the signal input part of the square wave generator circuit.

The square wave signal generating circuit is configured by a microcontroller, and has a PWM terminal of the output square wave signal as a signal input terminal, is connected to the signal input part of the sine step-up circuit, and uses the A/D terminal of the microcontroller as a signal input part, It is characterized in that it is connected to the signal output unit of the electrostatic sensitive sampling circuit.

The square wave signal is characterized in that the output impulse coefficient is a square wave signal of 50%.

The fourth and fifth registers of the touch button circuit have the same electrical parameters, and the second diode and the third diode have the same electrical parameters.

According to the present invention, the signal output part of the electrostatic response sampling circuit and the signal input part of the square wave signal generator are connected to generate a rectangular signal through the microcontroller and receive the static voltage signal of the electrostatic response circuit to the A/D terminal of the microcontroller. As a result, it is possible to identify the capacitive touch sensitive button, and there is an effect that can be easily realized at a low cost.

1 is a circuit diagram of an embodiment of the present invention.

Hereinafter, the present invention will be described in detail with reference to the drawings.

The above-described sinusoidal boosting circuit includes a transistor, a first resistor, a second resistor, a third resistor, a first capacitor, a second capacitor, a third capacitor, a first diode, and an inductor. One side of the above-described first register is used as a signal input unit of the sinusoidal step-up circuit, the other side is connected to the base of the transistor, and the above-described first capacitor and the first register are connected in parallel. In addition, the third resistor, the second resistor, and the inductor are connected in order, and the collector of the transistor is connected to the other end of the inductor. Connect the power supply to the other end of the third register, and connect one terminal of the second capacitor between the second register and the third register. The other side is grounded. The anode of the first diode and one terminal of the third capacitor are connected to the emitter terminal of the transistor. The collector of the transistor is used as a signal input part of the sine step-up circuit, and the anode of the first diode and the other end of the third sensor are connected to the collector of the transistor.

The electrostatic sensitive sampling circuit described above includes an electrostatic sensitive button (K), a second diode (D2), a third diode (D3), a fourth register (R4), a fifth register (R5), and a fourth capacitor (C4) do. The anodes of the above-described second and third diodes are connected to one terminal of the fourth and fifth registers, and the sensitive electrode of the electrostatic sensitive button. The anode of the second diode and the other terminal of the fourth register are connected together to become a signal input part of the electrostatic sensitive sampling circuit, and is connected to the collector of the transistor. The anode of the third diode is connected together with the other terminal of the fifth resistor and one terminal of the fourth capacitor.

The above-described square wave signal generating circuit is configured by a microcontroller, and uses the PWM terminal of the output square wave signal as a signal input terminal, and is connected to the signal input part of the sine step-up circuit. Use the A/D terminal of the microcontroller as a signal input part and connect it to the signal output part of the capacitive sampling circuit.

In practical applications, there is always more than one button on an electronic device. Therefore, the capacitive touch button circuit can be expanded very conveniently if necessary. You just need to add a corresponding capacitive button circuit according to the actual button demand. Furthermore, the fourth and fifth registers of the above-described capacitive touch button circuit have the same electrical parameters. The above-described second and third diodes have the same electrical parameters.

The present invention generates a square signal through a microcontroller and receives the electrostatic voltage signal of the electrostatic sensitive circuit to the A/D terminal of the microcontroller. Large and small changes occur in the electrostatic signal at both ends of the electrostatic passing through the microcontroller. This makes it possible to identify the electrostatic-sensitive button, and it is possible to realize a circuit with high stability and easy realization at low cost.

Hereinafter, the present invention will be described in more detail through specific examples with reference to the drawings for the convenience of understanding the present invention.

As shown in Fig. 1, the capacitive touch button circuit includes a square wave signal generating circuit, a sinusoidal step-up circuit, and an electrostatic sensitive sampling circuit. The above-described square wave signal generating circuit output unit and the signal input unit of the sine boosting circuit are connected, and the signal output unit of the sine boosting circuit and the signal input unit of the electrostatic reaction sampling circuit are connected. And it is connected to the signal output part of the electrostatic response sampling circuit and the signal input part of the square wave signal generator.

The sinusoidal boosting circuit includes a transistor Q1, a first resistor R1, a second resistor R2, a third resistor R3, a first capacitor C1, a second capacitor C2, a third capacitor C3, a first diode D1, and an inductor L1.

One terminal of the first register is used as a signal input unit of the sine step-up circuit, the other terminal is connected to the base of the transistor Q1, and the above-described first capacitor C1 and the first register R1 are connected in parallel. In addition, the third resistor R3, the second resistor R2, and the inductor L1 are connected in series in this order, and the other terminal of the inductor L1 is connected to the collector of the transistor. The other terminal of the third register R3 and the power source VCC are connected, and one terminal of the second capacitor C2 is connected between the second resistor R2 and the third register R3. Here, the other terminal is grounded. The positive terminal of the first diode, one terminal of the third capacitor C3, and the emitter terminal of the transistor are connected to each other. The collector of the transistor serves as a signal input part of the sine booster circuit, and the positive terminal of the first diode D1 and the other terminal of the third capacitor C3 are connected to the collector of the transistor Q1.

The above-described electrostatic sensitive sampling circuit includes an electrostatic sensitive button K, a second diode D2, a third diode D3, a fourth register R4, a fifth register R5, and a fourth capacitor C4. The second diode D2 and the anode of D3 of the third diode described above, one terminal of the fourth, resistor R4, and fifth register R5 are connected to the sensitive electrode of the electrostatic sensitive button K. The anode of the second diode D2 and the other end of the fourth register R4 are connected together to become a signal input part of the electrostatic responsive sampling circuit and is connected to the collector of the transistor Q1. The other terminal of the anode fifth register R5 of the third diode D3 and one terminal of the fourth capacitor C4 are connected together to become a signal output part of the electrostatic sensitive sampling circuit and connected to the signal input part of the square wave generator circuit.

The above-described square wave signal generating circuit is configured by a microcontroller, and has a PWM terminal of the output square wave signal as a signal input terminal and is connected to a signal input part of the sine step-up circuit. Use the A/D terminal of the microcontroller as a signal input part and connect it to the signal output part of the capacitive sampling circuit.

The following is a description of an embodiment of the present invention.

First, the output frequency of the PWM terminal of the microcontroller is set to 500 kHz, and the impulse coefficient is made to be a square wave signal of 50%. After the sine step-up circuit is processed, the signal moves to the capacitive sampling circuit, and finally, the fourth sensor C4 of the capacitive sampling circuit and the voltage signal input from both sides are advanced to the A/D port of the microcontroller for processing. When the square wave signal reaches a high level, the circuit expands to the fourth register R4, and due to the fourth register R4, the fifth register R5 has the same electrical parameters, the second diode D2, the third diode D3 also has the same parameters, so that the charging time constant and the electric discharge time constant are the same. Meanwhile, the microcontroller may convert the voltage values of both sides of the fourth capacitor into numerical values through the A/D port, thereby calculating and comparing the magnitude of change in the voltage values of both sides of the fourth capacitor. When a finger touches the electrostatic sensitive button, the electromagnetic field existing in the electrostatic sensitive button changes, and the electric charge of the fourth capacitor also changes, and accordingly, the voltage on both sides of the fourth capacitor C4 changes. In other words, when the amount of voltage change on both sides of the fourth capacitor C4 reaches a certain level of demand, the microcontroller system can recognize whether the electrostatic response button is pressed due to this. Therefore, the amplitude value of the output square wave signal is small due to the limitation of the output start-up capability of the microcontroller, and in order to stabilize the amplitude value of the output square wave signal, the microcontroller receives the output square wave signal boosting process and then powers off again Generates a signal to the inductive sampling circuit. And it avoids the possibility that a button reading error can be formed even if there is no finger touch button.

The above-described embodiments are the best implementation manners of the present invention, and do not limit the present invention, and any obvious replacements without departing from the premise of the present invention are within the protection scope of the present invention.

The present invention can be used in a low-cost and stable capacitive touch button circuit.

Claims (6)

a square wave signal generating circuit, a sinusoidal step-up circuit, and an electrostatic reaction sampling circuit, wherein the square wave signal generating circuit output unit and the signal input unit of the sinusoidal step-up circuit are connected, the signal output unit of the sinusoidal step-up circuit and the signal input unit of the electrostatic reaction sampling circuit A capacitive touch button circuit, characterized in that it is connected to the signal output unit of the electrostatic response sampling circuit and the signal input unit of the square wave signal generating circuit. The method of claim 1,
The sinusoidal step-up circuit comprises a transistor Q1, a first register R1, a second register R2, a third register R3, a first capacitor C1, a second capacitor C2, and a third capacitor C3. ), including a first diode (D1) and an inductor (L1),
One terminal of the first register is used as a signal input part of the sine step-up circuit, the other terminal is connected to the base of the transistor, the first capacitor and the first register are connected in parallel, and the third resistor, the second register and the inductor are connected in parallel. are connected in series in order,
The other terminal of the inductor is connected to the collector of the transistor, the other terminal of the third register and the power are connected, one terminal of the second capacitor is connected between the second register and the third resistor, and the other terminal is grounding, and connecting the anode of the first diode and one terminal of the third capacitor to the emitter terminal of the transistor,
A capacitive touch button circuit, characterized in that the collector of the transistor is used as a signal input part of the sine step-up circuit, and the positive terminal of the first diode and the other terminal of the third capacitor are connected to the collector of the transistor. The method of claim 1,
The electrostatic sensitive sampling circuit includes an electrostatic sensitive button (K), a second diode (D2), a third diode (D3), a fourth register (R4), a fifth register (R5) and a fourth capacitor (C4), ,
One terminal of the anode of the second diode and the third diode, one terminal of the fourth and fifth registers, and the sensitive electrode of the electrostatic sensitive button are connected, and the positive terminal of the second diode and the other terminal of the fourth register are connected together It becomes the signal input part of the electrostatic sensitive sampling circuit,
It is connected to the collector of the transistor, and the positive terminal of the third diode, the other terminal of the fifth resistor, and one terminal of the fourth capacitor are connected together to become a signal output part of the electrostatic sensitive sampling circuit, which is a signal input part of the square wave generator circuit Capacitive touch button circuit, characterized in that connected to. The method of claim 1,
The square wave signal generating circuit is configured by a microcontroller, and has a PWM terminal of the output square wave signal as a signal input terminal, is connected to the signal input part of the sine step-up circuit, and uses the A/D terminal of the microcontroller as a signal input part, Capacitive touch button circuit, characterized in that it is connected to the signal output of the capacitive sampling circuit. 5. The method of claim 1 or 4,
The square wave signal is a capacitive touch button circuit, characterized in that the output impact coefficient is a square wave signal of 50%. The method of claim 1,
The fourth and fifth registers of the touch button circuit have the same electrical parameters, and the second diode and the third diode have the same electrical parameters.

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