Charging control circuit board for water purifier

Abstract

The utility model discloses a charging control circuit board for a water purifier, which is rectangular and is provided with a first edge and a second edge which are far away from each other as well as a third edge and a fourth edge which are far away from each other, a single chip microcomputer, and at least one water outlet control circuit, a flow detection circuit and a card swiping module interface which are electrically connected with the single chip microcomputer are arranged on the back surface of the billing control circuit board; the water outlet control circuit is used for being electrically connected with a water outlet valve of the water purifier; the flow detection circuit is used for metering the water yield of the water purifier; the card swiping module interface is arranged adjacent to the first edge and is used for being externally connected with a card swiping module of the water purifier; a display screen is arranged in the center of the front face of the billing control circuit board and electrically connected with the single-chip microcomputer. The billing control circuit board can be applied to the water purifier, so that the water purifier can purchase water in a card swiping mode, the billing control circuit board can accurately meter the water yield of the water purifier, and the water yield and the cost are displayed through the display screen.

Description

Technical Field

[0001] This application relates to the field of water purifiers, and more specifically to a billing control circuit board for water purifiers. Background Technology

[0002] A water purifier, also known as a water filter or water purifier, is a water treatment device that performs deep filtration and purification of water.

[0003] Water purifiers are primarily billed using three methods: by flow rate, by time, and by package. Flow rate billing is the most common method used in daily life, charging based on the actual amount of purified water used, usually measured in liters or cubic meters. For example, some centralized water purification systems in residential communities may use this method, where residents pay according to their water consumption. This billing method is relatively fair and encourages water conservation. However, there is still room for improvement and optimization in the billing control circuit boards within existing water purifiers. Utility Model Content

[0004] To address the aforementioned technical problems, this application provides a billing control circuit board for a water purifier. The billing control circuit board is rectangular, having a first edge and a second edge that are mutually separated, as well as a third edge and a fourth edge that are mutually separated. The back of the billing control circuit board is provided with a microcontroller and at least one water outlet control circuit, a flow detection circuit, and a card reader interface electrically connected to the microcontroller. The water outlet control circuit is used to electrically connect to the water outlet valve of the water purifier. The flow detection circuit is used to measure the water output of the water purifier. The flow detection circuit includes a flow meter interface, a first flow detection resistor, and a second flow detection resistor. The flow meter interface is a three-pin interface, located near the first edge, for connecting an external flow meter; the first pin of the flow meter interface is electrically connected to a first DC power supply, the second pin of the flow meter interface is connected to the first DC power supply after being connected in series with the first flow detection resistor and the second flow detection resistor, and the electrical connection point of the first flow detection resistor and the second flow detection resistor is connected to the billing terminal of the microcontroller; the third pin of the flow meter interface is grounded; the card reader module interface is located near the first edge, for connecting an external card reader module; a display screen is located at the center of the front of the billing control circuit board, and the display screen is electrically connected to the microcontroller.

[0005] In some embodiments of this application, the water outlet control circuit includes a valve interface, a water outlet control field-effect transistor, a first water outlet control resistor, and a second water outlet control resistor. The valve interface is disposed adjacent to the second edge and is a two-pin interface for connecting to the water outlet valve of the water purifier. The first pin of the valve interface is also electrically connected to a second DC power supply, and the second pin of the valve interface is electrically connected to the drain of the water outlet control field-effect transistor. The gate of the water outlet control field-effect transistor is electrically connected to the first water outlet control resistor and then connected to the water outlet control terminal of the microcontroller. The gate of the water outlet control field-effect transistor is also electrically connected to the second water outlet control resistor and then grounded. The source of the water outlet control field-effect transistor is grounded.

[0006] In some embodiments of this application, the card reader module interface is a four-pin interface, wherein the first pin of the card reader module interface is electrically connected to the first DC power supply, the second pin is grounded, and the third and fourth pins are connected to the microcontroller serial port for communication.

[0007] In some embodiments of this application, a plurality of touch buttons are provided on the front side of the billing control circuit board near the third edge, and a touch chip SC04B is provided on the back side of the billing control circuit board. Each touch button is electrically connected to an input terminal of the touch chip SC04B, and the corresponding output terminal of the touch chip SC04B is electrically connected to the microcontroller.

[0008] In some embodiments of this application, a first status indicator diode and a second status indicator diode are further disposed on the front side of the billing control circuit board near the fourth edge; a heating detection interface is disposed on the back side of the billing control circuit board near the fourth edge, the heating detection interface being used to connect an external heating device of a water purifier; the heating detection interface is a three-pin interface, the first pin of the heating detection interface is electrically connected to a first display resistor and then connected to the positive terminal of the first status indicator diode, the negative terminal of the first status indicator diode is electrically connected to the second pin of the heating detection interface; a first protection diode is further disposed between the positive and negative terminals of the first status indicator diode; the third pin of the heating detection interface is electrically connected to a second display resistor and then connected to the positive terminal of the second status indicator diode, the negative terminal of the second status indicator diode is electrically connected to the second pin of the heating detection interface; a second protection diode is further disposed between the positive and negative terminals of the second status indicator diode.

[0009] In some embodiments of this application, an Internet of Things (IoT) module is also provided on the back of the billing control circuit board, and the IoT module is electrically connected to the microcontroller.

[0010] In some embodiments of this application, a third state indicator diode is also provided on the front side of the billing control circuit board near the fourth edge. The third state indicator diode is arranged side by side with the first state indicator diode and the second state indicator diode. The positive terminal of the third state indicator diode is electrically connected to a first DC power supply, and the negative terminal of the third state indicator diode is electrically connected to a resistor and then electrically connected to the microcontroller.

[0011] In some embodiments of this application, the back of the billing control circuit board also has a power interface, which is adjacent to the second edge and arranged side by side with the valve interface. The power interface is used to introduce a second DC power supply. The back of the billing control circuit board also has a first power conversion chip XL1509, the input terminal of which is electrically connected to the second DC power supply, and the output terminal outputs the first DC power supply.

[0012] In some embodiments of this application, a second power conversion chip HT7333 is also provided on the back of the billing control circuit board. The input terminal of the second power conversion chip HT7333 is electrically connected to a first DC power supply, and the output terminal outputs a third DC power supply.

[0013] In some embodiments of this application, the display screen is powered by the third DC power supply.

[0014] The beneficial effects of this application are as follows: This utility model discloses a billing control circuit board for a water purifier. The billing control circuit board is rectangular, with a first edge and a second edge that are far apart from each other, as well as a third edge and a fourth edge that are far apart from each other. A microcontroller and at least one water outlet control circuit, a flow detection circuit, and a card reader interface electrically connected to the microcontroller are disposed on the back of the billing control circuit board. The water outlet control circuit is used to electrically connect to the water outlet valve of the water purifier. The flow detection circuit is used to measure the water output of the water purifier. The card reader interface is disposed near the first edge for connecting an external card reader module of the water purifier. A display screen is disposed at the center of the front of the billing control circuit board, and the display screen is electrically connected to the microcontroller. The billing control circuit board can be used in water purifiers, enabling water purchase via card swiping, and the billing control circuit board can accurately measure the water output of the water purifier, displaying the water volume and cost on the display screen. Attached Figure Description

[0015] To more clearly illustrate the technical solutions in the embodiments of the application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort, wherein:

[0016] Figure 1 This is a front view of the billing control circuit board for a water purifier according to this utility model;

[0017] Figure 2 This is a schematic diagram of the back of the billing control circuit board for a water purifier according to this utility model;

[0018] Figure 3 This is a schematic diagram of the microcontroller in the billing control circuit board of the present invention for a water purifier;

[0019] Figure 4 This is a schematic diagram of the water outlet control circuit in the billing control circuit board of a water purifier, which is a product of this utility model.

[0020] Figure 5 This is a schematic diagram of the flow detection circuit in the billing control circuit board of a water purifier according to this utility model;

[0021] Figure 6 This is a schematic diagram of the card swiping module interface in the billing control circuit board of a water purifier according to this utility model;

[0022] Figure 7 This is a schematic diagram of the touch chip SC04B in the billing control circuit board of a water purifier according to this utility model;

[0023] Figure 8 This is a schematic diagram of the circuit connection of the first state indicator diode and the second state indicator diode in the billing control circuit board of the present invention for a water purifier.

[0024] Figure 9 This is a schematic diagram of the circuit connection of the third state indicator diode in the billing control circuit board of a water purifier according to this utility model;

[0025] Figure 10 This is a schematic diagram of the circuit connection between the microcontroller and the display screen in the billing control circuit board of a water purifier according to this utility model;

[0026] Figure 11 This is a schematic diagram of the first power conversion chip XL1509 in the billing control circuit board of a water purifier according to this utility model;

[0027] Figure 12 This is a schematic diagram of the second power conversion chip HT7333 in the billing control circuit board of a water purifier according to this utility model. Detailed Implementation

[0028] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other alternative implementation methods obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0029] like Figures 1 to 2 As shown, in one embodiment of a billing control circuit board for a water purifier, the billing control circuit board is rectangular in shape and has a first edge S1 and a second edge S2 that are far apart from each other, as well as a third edge S3 and a fourth edge S4 that are far apart from each other. The billing control circuit board also has a fixing hole D along the circumferential direction, through which it can be fixed inside the water purifier. After the billing control circuit board is electrically connected to the various electronic components inside the water purifier, it can realize various controls and displays of the water purifier, including but not limited to controlling the water purifier to flow out purified water and billing the amount of water discharged.

[0030] like Figure 1 As shown, a display screen 10 is located at the center of the front of the billing control circuit board. This display screen 10 can show various parameters of the water purifier, such as water output and cost information. Figure 2 In the billing control circuit board, a microcontroller (U3) is located on the back, which is electrically connected to the display screen 10. The back of the billing control circuit board also has at least one water outlet control circuit, a flow detection circuit, and a card reader module interface, all electrically connected to the microcontroller. The water outlet control circuit is used to electrically connect to the water outlet valve of the water purifier and control the opening or closing of the water outlet valve. The flow detection circuit is used to measure the water output of the water purifier. The card reader module interface is used to connect an external card reader module for the water purifier, allowing users to swipe their cards to dispense water.

[0031] Please see Figure 3 and Figure 4 , Figure 3 This is a schematic diagram of a microcontroller. Figure 4 This is a schematic diagram of the water outlet control circuit. Figure 4 The water outlet control circuit includes valve interface J5, water outlet control MOSFET Q7, first water outlet control resistor R32, and second water outlet control resistor R37. Please refer to [link / reference needed]. Figure 2Valve interface J5 is located adjacent to the second edge S2. Valve interface J5 is a two-pin interface used to connect to the water outlet valve of the water purifier. Specifically, the first pin of valve interface J5 (the positive terminal of the water outlet valve) is also electrically connected to the second DC power supply +24, which supplies power to the positive terminal of the water outlet valve. The second pin of valve interface J5 (the negative terminal of the water outlet valve) is electrically connected to the drain of the water outlet control MOSFET Q7. The drain of the water outlet control MOSFET Q7 is electrically connected to the negative terminal of the protection diode D10. The positive terminal of the protection diode D10 is electrically connected to the second DC power supply +24. The gate of the water outlet control MOSFET Q7 is electrically connected to the first water outlet control resistor R32 and then connected to... Figure 3 The water outlet control terminal P1.7 of the microcontroller is connected to the gate of the water outlet control field-effect transistor Q7, which is also electrically connected to the third water outlet control resistor R36 and then grounded. The gate of the water outlet control field-effect transistor Q7 is also electrically connected to the second water outlet control resistor R37 and then grounded. The source of the water outlet control field-effect transistor Q7 is grounded.

[0032] In this embodiment, when the microcontroller's water outlet control terminal P1.7 drives the water outlet control MOSFET Q7 to conduct, the second pin (negative terminal of the water outlet valve) of valve interface J5 is grounded, the water outlet valve opens, and purified water flows out of the water purifier. Preferably, in this embodiment, the water purifier has two water outlet valves, namely a hot water outlet valve and a room temperature water outlet valve; two water outlet control circuits are correspondingly arranged on the back of the billing control circuit board, which are connected to the hot water outlet valve and the room temperature water outlet valve respectively through valve interface J5 and valve interface J6.

[0033] For further details, please refer to Figure 3 and Figure 5 , Figure 5 This is a schematic diagram of a flow detection circuit. Figure 5 In the circuit, the flow detection circuit includes a flow meter interface J7, a first flow detection resistor R29, and a second flow detection resistor R26. The flow meter interface J7 is a three-pin interface. Figure 2 The flow meter interface J7 is located near the first edge S1 of the billing control circuit board and is used to connect an internal flow meter of the water purifier. The flow meter measures the water output of the water purifier. The first pin of the flow meter interface J7 (the power supply terminal of the flow meter) is electrically connected to the first DC power supply +5V. The second pin of the flow meter interface J7 (the sampling terminal of the flow meter) is connected in series with the first flow detection resistor R29 and the second flow detection resistor R26 and then connected to the first DC power supply +5V. The electrical connection between the first flow detection resistor R29 and the second flow detection resistor +5V is connected to... Figure 3The billing terminal P3.3 of the microcontroller and the third pin (grounding terminal of the flow meter) of the flow meter interface J7 are grounded. In this embodiment, when purified water flows out of the hot water outlet valve and / or the normal temperature water outlet valve of the water purifier, the flow meter inside the water purifier measures the water output, and the second pin (sampling terminal of the flow meter) of the flow meter interface J7 transmits the sampling signal to the microcontroller, so that the water purifier can calculate the water fee.

[0034] like Figure 2 and Figure 6 As shown, to facilitate the connection of the water purifier's card-swiping module to the billing control circuit board, a card-swiping module interface J8 is provided on the first edge S1 adjacent to the billing control circuit board, enabling the water purifier to have the function of purchasing water by card. Figure 6 In the interface, J8 of the card reader module is a four-pin interface. The first pin of J8 (the power supply terminal of the card reader module) is electrically connected to the first DC power supply +5V, which supplies power to the card reader module. The second pin of J8 (the ground terminal of the card reader module) is grounded. The third and fourth pins (the serial communication terminals of the card reader module) are connected to... Figure 3 The microcontroller's pins (P0.0 and P0.1) are connected for serial communication.

[0035] Furthermore, such as Figure 1 and Figure 7 As shown, to facilitate manual control of the water purifier, multiple touch buttons (K1~K3) are located near the third edge of the front of the billing control circuit board. Touch button K1 represents hot water dispensing, touch button K2 represents the end button, and touch button K3 represents room temperature water dispensing. A touch chip SC04B is located on the back of the billing control circuit board. Each touch button is electrically connected to one input terminal (CIN0~CIN3) of the touch chip SC04B, and the corresponding output terminals (OUT0~OUT2) of the touch chip SC04B are also connected to… Figure 3 The microcontroller (pins P1.2, P5.2, P0.7) is electrically connected. When the user presses the touch button (K1~K3), the touch chip SC04B transmits the corresponding switch signal to the microcontroller, causing the microcontroller to control the corresponding components of the water purifier to perform actions (such as opening or closing the hot water outlet valve and the normal temperature water outlet valve).

[0036] Furthermore, such as Figure 1 and Figure 8 As shown, in order to facilitate the display of the status of the heating device inside the water purifier, a first status indicator diode VL2 and a second status indicator diode VL3 are also provided on the front side of the billing control circuit board near the fourth edge S4. The first status indicator diode VL2 illuminates to indicate that the heating device is in the heating state; the second status indicator diode VL3 illuminates to indicate that the heating device is in the heat preservation state.

[0037] Specifically, such as Figure 8 As shown, a heating detection interface J2 is provided on the back of the billing control circuit board near the fourth edge. The heating detection interface J2 is used to connect the heating device inside the water purifier. The heating detection interface J2 is a three-pin interface. The first pin (first power supply terminal) of the heating detection interface J2 is electrically connected to the first display resistor R13 and then connected to the positive terminal of the first status indicator diode VL2. The negative terminal of the first status indicator diode VL2 is electrically connected to the second pin (ground terminal) of the heating detection interface. A first protection diode D5 is also provided between the positive and negative terminals of the first status indicator diode VL2. When the heating device inside the water purifier is in the heating state, the first pin (first power supply terminal) of the heating detection interface J2 supplies power to the first status indicator diode VL2, causing the first status indicator diode VL2 to light up.

[0038] The third pin of the heating detection interface J2 is electrically connected to the second display resistor R13 and then connected to the positive terminal (second power supply terminal) of the second status indicator diode VL3. The negative terminal of the second status indicator diode VL3 is electrically connected to the second pin (ground terminal) of the heating detection interface. A second protection diode D6 is also provided between the positive and negative terminals of the second status indicator diode VL3. When the heating device inside the water purifier is in the heat preservation state, the third pin (second power supply terminal) of the heating detection interface J2 supplies power to the second status indicator diode VL3, causing the second status indicator diode VL3 to light up.

[0039] In some embodiments, the billing control circuit board is also electrically connected to the heating device inside the water purifier to control the heating device to turn on or off.

[0040] Furthermore, in this embodiment, an Internet of Things (IoT) module is also provided on the back of the billing control circuit board. The IoT module is electrically connected to the microcontroller to enable communication between the water purifier and the remote control terminal. The IoT module can be an existing IoT chip, such as an IoT module comprising an EC600N chip and a SIM card.

[0041] Furthermore, such as Figure 1 and Figure 9 As shown, to facilitate displaying whether the water purifier is connected to the Internet of Things (IoT), a third status indicator diode VL1 is also provided on the front of the billing control circuit board near the fourth edge S4. The third status indicator diode VL1 illuminates to indicate that the water purifier is connected to the IoT; Figure 1 In the circuit, the third state indicator diode VL1 is arranged side by side with the first state indicator diode VL2 and the second state indicator diode VL3; the positive terminal of the third state indicator diode VL1 is electrically connected to the first DC power supply +5V, and the negative terminal of the third state indicator diode VL1 is electrically connected to the resistor R1 and then... Figure 3The microcontroller's network display control terminal P4.0 is electrically connected. When the water purifier is connected to the network, the microcontroller's network display control terminal P4.0 controls the third status indicator diode VL1 to illuminate.

[0042] Furthermore, such as Figure 10 As shown, the microcontroller is electrically connected to the display screen via display interface J4. Figure 10 In the display interface J4, the first pin is grounded, the second pin serves as the power supply pin for the display screen, and the second pin is electrically connected to the third DC power supply +3.3V; the third to seventh pins of the display interface J4 are respectively electrically connected to diodes (D7, D8, D12, D13, D7) and then corresponding to... Figure 3 The pins (P4.1, P1.4, P6.1, P6.2, P6.3) of the microcontroller are electrically connected to enable data transmission between the microcontroller and the microcontroller. The third to seventh pins of the display interface J4 are each electrically connected to a pull-up resistor (R19, R21, R22, R27, R40) and then connected to a third DC power supply of +3.3V. The eighth pin of the display interface J4 serves as the backlight control pin. It is electrically connected to the first backlight control resistor R23 and then to the collector of the backlight control transistor Q4. The emitter of the backlight control transistor Q4 is grounded, and the base of the backlight control transistor Q4 is electrically connected to the second backlight control resistor R28 and then connected to... Figure 3 Pin P0.5 of the microcontroller connects to the base of the backlight control transistor Q4, which is then grounded via the third backlight control resistor R35. The microcontroller controls the backlight of the display screen by turning the backlight control transistor Q on or off.

[0043] Furthermore, such as Figure 2 and Figure 11 As shown, the back of the billing control circuit board also has a power interface J1. Power interface J1 is adjacent to the second edge S2 and arranged side-by-side with valve interfaces (J5 and J6). Power interface J1 is used to introduce a second DC power supply of +24V; Figure 11 As shown, a first power conversion chip XL1509 is also located on the back of the billing control circuit board. The input terminal IN of the first power conversion chip XL1509 is connected to the protection resistor RT1 and the protection diode D3, and then connected to the second DC power supply +24V. The output terminal OUT is connected to the inductor L1 and outputs the first DC power supply +5V. It can be seen that the first power conversion chip XL1509 can convert the second DC power supply +24V to the first DC power supply +5V, thereby supplying power to various parts of the billing control circuit board.

[0044] Furthermore, such as Figure 12As shown, a second power conversion chip HT7333 is also provided on the back of the billing control circuit board. The input terminal Vin of the second power conversion chip HT7333 is electrically connected to the first DC power supply +5V, and the output terminal Vout outputs the third DC power supply +3.3V. It can be seen that the second power conversion chip HT7333 can convert the first DC power supply +5V to the third DC power supply +3.3V, thereby supplying power to various parts of the billing control circuit board.

[0045] Finally, it should be noted that if any directional indication (such as up, down, left, right, front, back, etc.) is involved in the embodiments of this application, the directional indication is only used to explain the relative positional relationship and movement of each component in a certain specific posture (as shown in the figure). If the specific posture changes, the directional indication will also change accordingly.

[0046] Furthermore, if the embodiments of this application involve descriptions such as "first" or "second," these descriptions are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, features defined with "first" or "second" may explicitly or implicitly include at least one of those features. Additionally, the technical solutions of various embodiments can be combined with each other, but this must be based on the ability of those skilled in the art to implement them. If the combination of technical solutions is contradictory or impossible to implement, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection claimed in this application.

[0047] The above are merely embodiments of this application and do not limit the scope of this patent application. Any equivalent structural or procedural changes made using the content of this application's specification and drawings, or direct or indirect applications in other related technical fields, are similarly included within the scope of patent protection of this application.

Claims

1. A billing control circuit board for a water purifier, characterized in that: The billing control circuit board is rectangular in shape and has a first edge and a second edge that are far apart from each other, as well as a third edge and a fourth edge that are far apart from each other. The back of the billing control circuit board is provided with a microcontroller and at least one water outlet control circuit, a flow detection circuit, and a card reader module interface electrically connected to the microcontroller. The water outlet control circuit is used to electrically connect to the water outlet valve of the water purifier; the flow detection circuit is used to measure the water output of the water purifier; the flow detection circuit includes a flow meter interface, a first flow detection resistor, and a second flow detection resistor. The flow meter interface is a three-pin interface, located near the first edge, for connecting an external flow meter; the first pin of the flow meter interface is electrically connected to a first DC power supply; the second pin of the flow meter interface is connected to the first DC power supply after connecting the first flow detection resistor and the second flow detection resistor in series; the electrical connection point of the first flow detection resistor and the second flow detection resistor is connected to the billing terminal of the microcontroller; the third pin of the flow meter interface is grounded; the card reader module interface is located near the first edge for connecting an external card reader module. A display screen is located at the center of the front of the billing control circuit board, and the display screen is electrically connected to the microcontroller.

2. The billing control circuit board for a water purifier according to claim 1, characterized in that: The water outlet control circuit includes a valve interface, a water outlet control field-effect transistor, a first water outlet control resistor, and a second water outlet control resistor. The valve interface is located adjacent to the second edge and is a two-pin interface used to connect to the water outlet valve of the water purifier. The first pin of the valve interface is also electrically connected to a second DC power supply, and the second pin of the valve interface is electrically connected to the drain of the water outlet control field-effect transistor. The gate of the water outlet control field-effect transistor is electrically connected to the first water outlet control resistor and then connected to the water outlet control terminal of the microcontroller. The gate of the water outlet control field-effect transistor is also electrically connected to the second water outlet control resistor and then grounded. The source of the water outlet control field-effect transistor is grounded.

3. The billing control circuit board for a water purifier according to claim 1, characterized in that: The card reader module interface is a four-pin interface. The first pin of the card reader module interface is electrically connected to the first DC power supply, the second pin is grounded, and the third and fourth pins are connected to the microcontroller serial port for communication.

4. The billing control circuit board for a water purifier according to claim 1, characterized in that: The front of the billing control circuit board is provided with a plurality of touch buttons near the third edge, and the back of the billing control circuit board is provided with a touch chip SC04B. Each touch button is electrically connected to an input terminal of the touch chip SC04B, and the corresponding output terminal of the touch chip SC04B is electrically connected to the microcontroller.

5. The billing control circuit board for a water purifier according to claim 1, characterized in that: The billing control circuit board also has a first state indicator diode and a second state indicator diode disposed on the front side near the fourth edge; A heating detection interface is provided on the back of the billing control circuit board near the fourth edge. The heating detection interface is used to connect the heating device of the water purifier. The heating detection interface is a three-pin interface. The first pin of the heating detection interface is electrically connected to the first display resistor and then connected to the positive terminal of the first status indicator diode. The negative terminal of the first status indicator diode is electrically connected to the second pin of the heating detection interface. A first protection diode is also provided between the positive and negative terminals of the first status indicator diode. The third pin of the heating detection interface is electrically connected to the second display resistor and then connected to the positive terminal of the second status indicator diode. The negative terminal of the second status indicator diode is electrically connected to the second pin of the heating detection interface. A second protection diode is also provided between the positive and negative terminals of the second status indicator diode.

6. The billing control circuit board for a water purifier according to claim 5, characterized in that: The back of the billing control circuit board is also equipped with an Internet of Things (IoT) module, which is electrically connected to the microcontroller.

7. The billing control circuit board for a water purifier according to claim 6, characterized in that: A third state indicator diode is also provided on the front side of the billing control circuit board near the fourth edge. The third state indicator diode is arranged side by side with the first state indicator diode and the second state indicator diode. The positive terminal of the third state indicator diode is electrically connected to the first DC power supply, and the negative terminal of the third state indicator diode is electrically connected to a resistor and then electrically connected to the microcontroller.

8. The billing control circuit board for a water purifier according to claim 2, characterized in that: The back of the billing control circuit board also has a power interface, which is adjacent to the second edge and arranged side by side with the valve interface. The power interface is used to introduce a second DC power supply. The back of the billing control circuit board also has a first power conversion chip XL1509. The input terminal of the first power conversion chip XL1509 is electrically connected to the second DC power supply, and the output terminal outputs the first DC power supply.

9. The billing control circuit board for a water purifier according to claim 8, characterized in that: The billing control circuit board also has a second power conversion chip HT7333 on its back. The input terminal of the second power conversion chip HT7333 is electrically connected to the first DC power supply, and the output terminal outputs the third DC power supply.

10. The billing control circuit board for a water purifier according to claim 9, characterized in that: The display screen is powered by the third DC power supply.

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