Capacitive touch key circuit

Abstract

The utility model relates to a capacitive touch key circuit, and relates to the technical field of household appliances. The circuit comprises a power supply control circuit, at least one touch key unit, a touch control chip, a frequency conversion control chip and a frequency conversion motor, wherein the touch key unit is connected with a corresponding key pin on the touch control chip; a first end of the power supply control circuit is connected with a first power supply pin of the touch control chip; a second end of the power supply control circuit is connected with a second power supply pin of the frequency conversion control chip; a U pin, a V pin and a W pin of the variable frequency control chip are respectively connected with a U phase, a V phase and a W phase of the variable frequency motor; and an input pin and an output pin of the frequency conversion control chip are respectively connected with an output pin and an input pin of the touch control chip. According to the invention, the control of the variable frequency motor by the capacitive touch key unit can be realized, and electrical interference is avoided.

Description

Technical Field

[0001] The present application relates to the field of household appliance technology, and in particular to a capacitive touch button circuit. Background Art

[0002] At present, some variable frequency home appliances still use physical buttons for control. As people's requirements for the appearance and technology of home appliances become higher and higher, physical buttons can no longer meet the needs of consumers. How to achieve stable control through capacitive touch buttons has become a concern for variable frequency home appliance manufacturers.

[0003] Therefore, a capacitive touch button circuit is urgently needed. Utility Model Content

[0004] Based on this, it is necessary to provide a capacitive touch button circuit for the above technical problems, the circuit includes a power control circuit, at least one touch button unit, a touch control chip, a frequency conversion control chip and a frequency conversion motor; wherein,

[0005] The touch button unit is connected to the corresponding button pin on the touch control chip;

[0006] The first end of the power control circuit is connected to the first power pin of the touch control chip;

[0007] The second end of the power control circuit is connected to the second power pin of the frequency conversion control chip;

[0008] The U, V and W pins of the variable frequency control chip are connected to the U phase, V phase and W phase of the variable frequency motor respectively;

[0009] The input pin and the output pin of the frequency conversion control chip are connected to the output pin and the input pin of the touch control chip respectively.

[0010] As an optional implementation, the power control circuit includes a rectifier element, a DC bus capacitor, an AC power supply, a transformer and a switching power supply chip; wherein,

[0011] The first end of the rectifier element is connected to the AC live wire of the AC power supply, the second end is connected to the AC neutral wire of the AC power supply, and the third end and the fourth end are connected to the first end and the second end of the DC bus capacitor respectively;

[0012] The first end of the DC bus capacitor is respectively connected to the third power pin of the switching power chip, the second power pin of the frequency conversion control chip and the first end of the transformer;

[0013] The second end of the DC bus capacitor is grounded;

[0014] The second end of the transformer is connected to the transformer control pin of the switching power chip, and the third end is connected to the first power pin of the touch control chip.

[0015] As an optional implementation, the power control circuit further includes a rectifier diode, a voltage-stabilizing resistor, a filter capacitor and a voltage-dividing resistor; wherein,

[0016] The positive electrode of the rectifier diode is connected to the transformer control pin of the switching power supply chip, and the negative electrode is connected to the first end of the voltage-stabilizing resistor;

[0017] The second end of the voltage-stabilizing resistor is respectively connected to the first end of the filter capacitor and the first end of the voltage-dividing resistor;

[0018] The second end of the filter capacitor and the second end of the voltage-dividing resistor are connected to the first end of the transformer.

[0019] As an optional implementation, the circuit further includes a first optical coupler and a second optical coupler; wherein,

[0020] The input end of the first optical coupler is connected to the output pin of the frequency conversion control chip, and the output end is connected to the input pin of the touch control chip, so as to avoid electrical mutual influence and mutual interference between the output pin of the frequency conversion control chip and the input pin of the touch control chip;

[0021] The input end of the second optical coupler is connected to the output pin of the touch control chip, and the output end is connected to the input pin of the frequency conversion control chip, so as to avoid electrical interaction and interference between the output pin of the touch control chip and the input pin of the frequency conversion control chip.

[0022] As an optional implementation, the power control circuit further includes a third optical coupler and a protection resistor; wherein,

[0023] The first end of the protection resistor is connected to the second end of the transformer, and the second end is connected to the input end of the third optical coupler;

[0024] The output end of the third optocoupler is connected to the switch control pin of the switching power supply chip, and is used to feed back the secondary DC voltage output by the transformer to the switching power supply chip, so that the switching power supply chip controls the transformer to output a stable secondary DC voltage according to the fed-back secondary DC voltage.

[0025] As an optional implementation, the transformer includes a primary coil, a secondary coil and a feedback coil; wherein,

[0026] The primary coil is connected to the first end of the DC bus capacitor;

[0027] The secondary coil is connected to the first power pin of the touch control chip;

[0028] The feedback coil is connected to the transformer control pin of the switching power supply chip.

[0029] As an optional implementation, the rectifying element is a bridge rectifier.

[0030] The present application provides a capacitive touch button circuit, and the technical solution provided by the embodiment of the present application brings at least the following beneficial effects: a capacitive touch button circuit, the circuit includes a power control circuit, at least one touch button unit, a touch control chip, a frequency conversion control chip and a frequency conversion motor; wherein the touch button unit is connected to the corresponding button pin on the touch control chip; the first end of the power control circuit is connected to the first power pin of the touch control chip; the second end of the power control circuit is connected to the second power pin of the frequency conversion control chip; the U, V and W pins of the frequency conversion control chip are respectively connected to the U phase, V phase and W phase of the frequency conversion motor; the input pin and output pin of the frequency conversion control chip are respectively connected to the output pin and input pin of the touch control chip. The user's pressing state is detected by the touch button unit, and the frequency conversion control chip receives the control signal according to the capacitance change and touch response, so as to realize the control of the frequency conversion motor by the touch button unit.

[0031] It should be understood that the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] In order to more clearly illustrate the embodiments of the utility model or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the utility model. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0033] Figure 1 A schematic diagram of the structure of a capacitive touch button circuit provided in an embodiment of the present application;

[0034] Figure 2 A schematic diagram of the structure of a power control circuit provided in an embodiment of the present application;

[0035] Figure 3 A schematic diagram of the structure of another power control circuit provided in an embodiment of the present application;

[0036] Figure 4 A schematic diagram of another power control circuit provided in an embodiment of the present application

[0037] Figure 5 A schematic diagram of the structure of another capacitive touch button circuit provided in an embodiment of the present application;

[0038] Figure 6 A schematic diagram of the structure of another power control circuit provided in an embodiment of the present application;

[0039] Figure 7 A schematic diagram of the structure of an example of a capacitive touch button circuit provided in an embodiment of the present application. DETAILED DESCRIPTION

[0040] In order to make the purpose, technical solution and advantages of the present application more clearly understood, the present application is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and are not used to limit the present application.

[0041] The following will describe in detail a capacitive touch button circuit provided by an embodiment of the present application in combination with a specific implementation method. Figure 1 A schematic diagram of a capacitive touch button circuit provided in an embodiment of the present application is shown in FIG. Figure 1 As shown, the details are as follows:

[0042] A capacitive touch button circuit includes a power control circuit 110, at least one touch button unit 120, a touch control chip 130, a frequency conversion control chip 140 and a frequency conversion motor 150; wherein,

[0043] The touch button unit 120 is connected to the corresponding button pin on the touch control chip 130;

[0044] A first end of the power control circuit 110 is connected to a first power pin of the touch control chip 130;

[0045] The second end of the power control circuit 110 is connected to the second power pin of the frequency conversion control chip 140;

[0046] The U, V and W pins of the variable frequency control chip 140 are connected to the U phase, V phase and W phase of the variable frequency motor 150 respectively;

[0047] The input pin and the output pin of the frequency conversion control chip 140 are connected to the output pin and the input pin of the touch control chip 130 respectively.

[0048] In implementation, the power control circuit 110 provides DC weak current to the touch control chip 130 and provides DC power to the frequency conversion control chip 140 through the first power pin and the second power pin, respectively. The principle of the capacitive touch button is to detect the pressing state of the button. When the capacitive touch button is pressed by the human body, the capacitance increases. When the capacitance value reaches the touch threshold, the touch responds. Each touch button unit 120 is connected to the corresponding button pin on the touch control chip 130. For example, the touch button unit 1201 is connected to the case pin 1301, which can be used to send the corresponding instruction of the touch button unit to the frequency conversion control chip 140 by pressing, so as to control the speed or start and stop of the frequency conversion motor 150. The input pin and output pin of the frequency conversion control chip 140 are respectively connected to the output pin and input pin of the touch control chip 130. The touch control chip 130 sends a control instruction to the frequency conversion control chip 140 and receives a feedback signal sent from the frequency conversion control chip 140.

[0049] Optionally, the model of the touch control chip 130 is YE8M2102 or YE8M2302, and the model of the frequency conversion control chip 140 is stm32F1xx or TMS320F28xx.

[0050] As an optional implementation, Figure 2 As shown, the power control circuit 110 includes a rectifier element 1101, a DC bus capacitor 1102, an AC power supply 1103, a transformer 1104 and a switching power supply chip 1105; wherein,

[0051] The first end of the rectifier element 1101 is connected to the AC live wire of the AC power source 1103, the second end is connected to the AC neutral wire of the AC power source 1103, and the third end and the fourth end are connected to the first end and the second end of the DC bus capacitor 1102 respectively;

[0052] The first end of the DC bus capacitor 1102 is respectively connected to the third power pin of the switch power chip 1105, the second power pin of the frequency conversion control chip 140 and the first end of the transformer 1104;

[0053] The second end of the DC bus capacitor 1102 is grounded;

[0054] The second end of the transformer 1104 is connected to the transformer control pin of the switch power chip 1105 , and the third end is connected to the first power pin of the touch control chip 130 .

[0055] In implementation, the AC power supply 1103 inputs AC power to the rectifying element 1101, and the rectifying element 1101 rectifies the AC power into strong DC power. The strong DC power is stabilized on the DC bus capacitor 1102 and output to the transformer 1104, the switching power supply chip 1105 and the frequency conversion control chip 140 respectively. The switching power supply chip 1105 outputs high-frequency pulses through the transformer control pin, which are transmitted to the output winding through the transformer 1104. The output winding obtains high-frequency pulse DC, and obtains strong DC power after rectification. The transformer 1104 converts the strong DC power into weak DC power to power the touch control chip 130.

[0056] Optionally, the model of the switching power supply chip is 1103STR456A or STR5412.

[0057] Optionally, the rectifying element 1101 is a bridge rectifier.

[0058] Optional, such as Figure 3 As shown, the transformer 1104 includes a primary coil 11041, a secondary coil 11042 and a feedback coil 11043; wherein,

[0059] The primary coil 11041 is connected to the first end of the DC bus capacitor 1102;

[0060] The secondary coil 11042 is connected to the first power pin of the touch control chip 130;

[0061] The feedback coil 11043 is connected to the transformer control pin of the switching power supply chip 1105 .

[0062] As an optional implementation, Figure 4 As shown, the power control circuit 110 also includes a rectifier diode 1106, a voltage-stabilizing resistor 1107, a filter capacitor 1108 and a voltage-dividing resistor 1109; wherein,

[0063] The positive electrode of the rectifier diode 1106 is connected to the transformer control pin of the switch power chip 1105, and the negative electrode is connected to the first end of the voltage-stabilizing resistor 1107;

[0064] The second end of the voltage-stabilizing resistor 1107 is connected to the first end of the filter capacitor 1108 and the first end of the voltage-dividing resistor 1109 respectively;

[0065] A second end of the filter capacitor 1108 and a second end of the voltage-dividing resistor 1109 are connected to a first end of the transformer 1104 .

[0066] In implementation, the switching power supply chip 1105 outputs high-frequency pulses, which are stabilized by the rectifier diode 1106 and the voltage-stabilizing resistor 1107 , and then filtered by the RC oscillation circuit composed of the filter capacitor 1108 and the voltage-dividing resistor 1109 , and then output to the transformer 1104 .

[0067] As an optional implementation, Figure 5 As shown, the circuit further includes a first optical coupler 160 and a second optical coupler 170; wherein,

[0068] The input end of the first optical coupler 160 is connected to the output pin of the frequency conversion control chip 140, and the output end is connected to the input pin of the touch control chip 130, so as to avoid electrical mutual influence and mutual interference between the output pin of the frequency conversion control chip 140 and the input pin of the touch control chip 130;

[0069] The input end of the second optical coupler 170 is connected to the output pin of the touch control chip 130 , and the output end is connected to the input pin of the frequency conversion control chip 140 , so as to avoid electrical interaction and interference between the output pin of the touch control chip 130 and the input pin of the frequency conversion control chip 140 .

[0070] In implementation, when the touch control chip 130 outputs a signal through the output pin, the diode at the input end of the first optocoupler 160 turns on and emits light, and the light intensity controls the way the photoresistor at the output end turns on, and then the frequency conversion control chip 140 receives the control signal. Similarly, when the frequency conversion control chip 140 outputs a feedback signal through the output pin, the diode at the input end of the second optocoupler 170 turns on and emits light, and the light intensity controls the way the photoresistor at the output end turns on, and then the touch control chip 130 receives the control signal. As a good electrical isolation element, the optocoupler can avoid electrical interaction and mutual interference between the touch control chip 130 and the frequency conversion control chip 140.

[0071] As an optional implementation, Figure 6 As shown, the power control circuit 110 further includes a third optical coupler 1110 and a protection resistor 1111; wherein,

[0072] A first end of the protection resistor 1111 is connected to a second end of the transformer 1104 , and a second end thereof is connected to an input end of the third optical coupler 1110 ;

[0073] The output end of the third optical coupler 1110 is connected to the switch control pin of the switch power chip 1105 .

[0074] In implementation, the protection resistor 1111 can protect the light-emitting diode in the third optocoupler 1110 from being damaged by a large current, and the third optocoupler 1110 can avoid electrical interference between the switching power chip 1105 and the transformer 1104. The secondary DC voltage output by the transformer 1104 is fed back to the switching power chip 1105 through the protection resistor 1111 and the third optocoupler 1110, and the switching power chip 1105 controls the transformer 1104 to output a stable secondary DC voltage according to the fed-back secondary DC voltage.

[0075] Optional, Figure 7 This is a schematic diagram of an example of a capacitive touch button circuit provided in an embodiment of the present application. Figure 7 As shown, the AC live wire ACL and the AC neutral wire CAN of the AC power supply 1103 are respectively connected to the first end and the second end of the rectifier element 1101, which are used to convert AC into DC. The DC power passes through the DC bus capacitor 1102 and the voltage divider resistor R6, and is output to the power pin V of the switching power chip 1105. The switching power chip 1105 outputs high-frequency pulses to the rectifier diode 1106 and the voltage regulator resistor 1107 through the transformer control pin D for voltage stabilization, and then passes through the RC oscillation circuit composed of the filter capacitor 1108 and the voltage divider resistor 1109 for filtering, and is output to the transformer 1104 for controlling the switch of the transformer 1104. The DC power is input into the transformer 1104 through the DC bus capacitor 1102. The secondary DC voltage output by the transformer 1104 is fed back to the switching power chip 1105 through the protection resistor 1111 and the third optical coupler 1110. The switching power chip 1105 controls the transformer 1104 according to the fed-back secondary DC voltage, and outputs a stable secondary DC voltage to the first power pin 1 of the touch control chip 130, which is used to power the touch control chip 130. When the user touches the touch button unit 120, the touch control chip 130 responds to the touch, and sends instructions to the input pin RX of the frequency conversion control chip 140 through the output pin TX and the first optical coupler 160. The frequency conversion control chip 140 controls the U phase, V phase and W phase of the frequency conversion motor 160 according to the instructions. The frequency conversion control chip 140 feeds back the motor signal to the input pin RX of the touch control chip 130 through the output pin TX and the second optical coupler 170, so as to realize the speed or start-stop control of the frequency conversion motor 160.

[0076] The circuit diagram provided in the embodiment of the utility model can also add a Y capacitor between the primary and secondary of the transformer to increase the anti-interference ability of the capacitive touch button circuit. However, through experiments, it is found that although the addition of a Y capacitor between the primary and secondary of the transformer can improve the anti-interference ability, the large starting current generated at the moment of starting the variable frequency motor will cause the voltage of the DC bus capacitor to drop instantly, causing the zero potential of the output weak DC to be disturbed, and the zero potential to be raised or become a negative voltage. Therefore, the present application cancels the setting of the Y capacitor.

[0077] The embodiment of the present application provides a capacitive touch button circuit, the circuit includes a power control circuit, at least one touch button unit, a touch control chip, a frequency conversion control chip and a frequency conversion motor; wherein the touch button unit is connected to the corresponding button pin on the touch control chip; the first end of the power control circuit is connected to the first power pin of the touch control chip; the second end of the power control circuit is connected to the second power pin of the frequency conversion control chip; the U, V and W pins of the frequency conversion control chip are respectively connected to the U phase, V phase and W phase of the frequency conversion motor; the input pin and output pin of the frequency conversion control chip are respectively connected to the output pin and input pin of the touch control chip. The user's pressing state is detected by the touch button unit, and the frequency conversion control chip receives the control signal according to the capacitance change and touch response, so as to realize the control of the frequency conversion motor by the touch button unit.

[0078] It can be understood that the same / similar parts between the various embodiments of the above method in this specification can refer to each other, and each embodiment focuses on the differences from other embodiments. For related points, please refer to the description of other method embodiments.

[0079] It should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" 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 other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, the elements defined by the sentence "comprise a ..." do not exclude the existence of other identical elements in the process, method, article or device including the elements.

[0080] It should also be noted that the user information (including but not limited to user device information, user personal information, etc.) and data (including but not limited to data used for display, data for analysis, etc.) involved in this application are all information and data authorized by the user or fully authorized by all parties.

[0081] Each embodiment in this specification is described in a related manner, and the same or similar parts between the embodiments can be referred to each other, and each embodiment focuses on the differences from other embodiments. In particular, for the system embodiment, since it is basically similar to the method embodiment, the description is relatively simple, and the relevant parts can be referred to the partial description of the method embodiment.

[0082] The technical features of the above embodiments may be combined arbitrarily. To make the description concise, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0083] The above-mentioned embodiments only express several implementation methods of the present application, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the utility model patent. It should be pointed out that, for a person of ordinary skill in the art, several variations and improvements can be made without departing from the concept of the present application, and these all belong to the protection scope of the present application. Therefore, the protection scope of the patent of the present application shall be subject to the attached claims.

Claims

1. A capacitive touch button circuit, characterized in that: The circuit comprises a power supply control circuit (110), at least one touch key unit (120), a touch control chip (130), a frequency conversion control chip (140) and a frequency conversion motor (150); wherein: The touch key unit (120) is connected to a corresponding key pin on the touch control chip (130); A first end of the power control circuit (110) is connected to a first power pin of the touch control chip (130); The second end of the power control circuit (110) is connected to the second power pin of the frequency conversion control chip (140); The U, V and W pins of the variable frequency control chip (140) are respectively connected to the U phase, V phase and W phase of the variable frequency motor (150); The input pin and the output pin of the frequency conversion control chip (140) are respectively connected to the output pin and the input pin of the touch control chip (130).

2. The circuit according to claim 1, characterized in that The power control circuit (110) comprises a rectifier element (1101), a DC bus capacitor (1102), an AC power supply (1103), a transformer (1104) and a switching power supply chip (1105); wherein: The first end of the rectifying element (1101) is connected to the AC live wire of the AC power source (1103), the second end is connected to the AC neutral wire of the AC power source (1103), and the third end and the fourth end are connected to the first end and the second end of the DC bus capacitor (1102), respectively; The first end of the DC bus capacitor (1102) is respectively connected to the third power pin of the switch power chip (1105), the second power pin of the frequency conversion control chip (140), and the first end of the transformer (1104); The second end of the DC bus capacitor (1102) is grounded; The second end of the transformer (1104) is connected to the transformer control pin of the switch power chip (1105), and the third end is connected to the first power pin of the touch control chip (130).

3. The circuit according to claim 2, characterized in that The power supply control circuit (110) further comprises a rectifier diode (1106), a voltage-stabilizing resistor (1107), a filter capacitor (1108) and a voltage-dividing resistor (1109); wherein: The positive electrode of the rectifier diode (1106) is connected to the transformer control pin of the switch power chip (1105), and the negative electrode is connected to the first end of the voltage-stabilizing resistor (1107); The second end of the voltage-stabilizing resistor (1107) is respectively connected to the first end of the filter capacitor (1108) and the first end of the voltage-dividing resistor (1109); The second end of the filter capacitor (1108) and the second end of the voltage-dividing resistor (1109) are connected to the first end of the transformer (1104).

4. The circuit according to claim 1, characterized in that The circuit further comprises a first optical coupler (160) and a second optical coupler (170); wherein, The input end of the first optical coupler (160) is connected to the output pin of the frequency conversion control chip (140), and the output end is connected to the input pin of the touch control chip (130), so as to avoid electrical mutual influence and mutual interference between the output pin of the frequency conversion control chip (140) and the input pin of the touch control chip; The input end of the second optical coupler (170) is connected to the output pin of the touch control chip (130), and the output end is connected to the input pin of the frequency conversion control chip (140), so as to avoid electrical mutual influence and mutual interference between the output pin of the touch control chip (130) and the input pin of the frequency conversion control chip (140).

5. The circuit according to claim 3, characterized in that The transformer (1104) comprises a primary coil (11041), a secondary coil (11042) and a feedback coil (11043); wherein, The primary coil (11041) is connected to a first end of the DC bus capacitor (1102); The secondary coil (11042) is connected to a first power pin of the touch control chip (130); The feedback coil (11043) is connected to the transformer control pin of the switching power supply chip (1105).

6. The circuit according to claim 2, characterized in that The power supply control circuit (110) further includes a third optical coupler (1110) and a protective resistor (1111); wherein, The first end of the protection resistor (1111) is connected to the second end of the transformer (1104), and the second end is connected to the input end of the third optical coupler (1110); The output end of the third optical coupler (1110) is connected to the switch control pin of the switching power supply chip (1105), and is used to feed back the secondary DC voltage output by the transformer (1104) to the switching power supply chip (1105), so that the switching power supply chip (1105) controls the transformer (1104) to output a stable secondary DC voltage according to the fed-back secondary DC voltage.

7. The circuit according to claim 3, characterized in that The rectifying element (1101) is a bridge rectifier.

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