Electronic anode protection-oriented control circuit and device
By using a simple circuit structure consisting of a comparator module and a switching transistor to control the voltage of the electronic anode module, the problems of complexity and insufficient reliability of existing electronic anode protection circuits are solved, achieving the effect of simplifying control logic and improving safety.
Patent Information
- Application Number
- CN202511559884.9
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-10-29
- Publication Date
- 2026-03-10
AI Technical Summary
Existing electronic anode protection circuits are complex, costly, and lack reliability. They are prone to abnormal output voltage of the electronic anode module due to MCU malfunctions, posing safety hazards such as corrosion and hydrogen accumulation.
A simple circuit structure consisting of a comparator module and a switching transistor is used. By controlling the on/off state of the switching transistor and based on the virtual short characteristic of the comparator module, the voltage across the positive and negative terminals of the electronic anode module is controlled, thus preventing the electronic anode from operating, simplifying the control logic, and improving reliability.
A simplified electronic anode protection circuit was implemented, which avoids accelerated corrosion of the electronic anode and hydrogen leakage, improves the reliability and safety of the circuit, and reduces costs.
Smart Images
Figure CN121642860A_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The present application relates to the technical field of electronic anode protection, and more particularly to an electronic anode protection-oriented control circuit and device. BACKGROUND
[0002] The existing electric water heaters or air energy water heaters generally need to increase electronic anode protection devices to protect the electronic anode installed in the water tank of the water heater. The electronic anode is a metal rod placed in the water tank of the water heater to prevent the water tank from being corroded and reduce scale. If the electronic anode protector is not increased, the water in the water tank will slowly corrode the metal shell of the water tank or produce scale on the auxiliary heater over time.
[0003] A common electronic anode protection method is to connect the negative electrode of the electronic anode to the metal inner shell and the positive electrode of the electronic anode to the water. Since the electronic anode module has two positive and negative lines that need to be connected to the corresponding control panel, improper installation can easily cause the positive and negative electrodes to be connected in reverse, which will have the opposite effect and accelerate corrosion. In addition, the ion concentration in the water affects the conductivity of the water. The higher the conductivity of the water, the better the water conductivity. Since the electronic anode protection is accompanied by the generation of hydrogen ions, if the voltage is too high or the current is too large, the hydrogen ions will overflow and accumulate under inappropriate conditions, forming a flammable and explosive hydrogen gas mixture, which can pose a certain risk in a closed water tank and easily cause an explosion.
[0004] The existing water heater with electronic anode protection uses a single-chip microcomputer (MCU) and software logic to obtain the voltage and conductivity information of the two ends of the electronic anode of the water heater through a sensor. According to the obtained voltage and conductivity information of the two ends of the electronic anode, the average output voltage is adjusted using digital sampling and discrete period in the next cycle to avoid accelerated corrosion caused by improper operation and improve safety. However, this method relies on complex MCU control logic, the circuit is complex, the cost is high, and if the MCU is abnormal, the output voltage of the electronic anode module will also be abnormal. SUMMARY
[0005] To solve the problem of complex circuit detection and protection method for electronic anode water heaters and insufficient reliability, the present application proposes an electronic anode protection-oriented control circuit and device, which simplifies the electronic anode control protection circuit and improves reliability.
[0006] To achieve the above technical effects, the technical solutions of the present application are as follows: In a first aspect, the present application proposes an electronic anode protection-oriented control circuit, which comprises: a comparator module, a switch tube, a first voltage source, a second voltage source, a grounding resistor, and an electronic anode module; The positive electrode of the electronic anode module is inserted into the water tank at one end, and is grounded through a grounding resistor at the other end; the negative electrode of the electronic anode is connected to the drain electrode of the switch tube and the metal inner container of the water tank respectively; the metal inner container is connected to the positive input end of the comparator module; the gate electrode of the switch tube is connected to the output end of the comparator module; the source electrode of the switch tube is connected to the first voltage source; and the negative input end of the comparator module is connected to the positive electrode of the second voltage source. After the switch tube is turned on, the voltage at the negative electrode of the electronic anode module and the positive electrode of the comparator module is the voltage value of the first voltage source, which is greater than the voltage value of the second voltage source; the output end of the comparator module outputs a high level; the switch tube is turned off; and the voltage between the positive electrode of the electronic anode module and the negative electrode of the electronic anode module is less than the working voltage of the electronic anode module, so that the electronic anode does not work.
[0007] In the technical solution, the comparator module is used to control the on-off of the switch tube, and the voltage between the positive electrode and the negative electrode of the electronic anode module is controlled based on the on-off state of the switch tube; when the electronic anode module is connected to the circuit, the switch tube is turned on, the voltage of the first voltage source is applied to the positive input end of the comparator, the voltage value of the first voltage source is greater than the voltage value of the second voltage source, the output end of the comparator module outputs a high level, the switch tube is turned off, and the voltage at the positive electrode of the electronic anode module follows the voltage of the second voltage source based on the virtual short characteristic of the comparator module; at this time, the voltage between the positive electrode and the negative electrode of the electronic anode module is insufficient to drive the electronic anode module to work, so the electronic anode stops working. The technical solution does not need additional control parts such as chips, only uses a simple circuit structure, avoids accelerated corrosion of the electronic anode, and has simple control logic and high reliability.
[0008] Preferably, the comparator module comprises a comparator , the positive input end of the comparator serves as the positive input end of the comparator module and is connected to the metal inner container of the water tank, the negative input end of the comparator serves as the negative input end of the comparator module and is connected to the positive electrode of the second voltage source , the first voltage source is connected to one end of the resistor and one end of the bias input end of the comparator respectively, the other end of the resistor is connected to the output end of the comparator , and the other end of the bias input end of the comparator is grounded.
[0009] Preferably, the switch tube is a Pmos tube.
[0010] Preferably, after the switch tube is turned off, the voltage at the negative electrode of the electronic anode module is the voltage of the second voltage source , and the voltage at the positive electrode of the electronic anode module satisfies the expression:
[0011] wherein, is the resistance value of the grounding resistor, is the equivalent resistance of the water in the water tank; the voltage between the positive terminal of the electronic anode module and the negative terminal of the electronic anode module is less than the working voltage of the electronic anode module, and the electronic anode does not work.
[0012] Preferably, the circuit further comprises: one end of the positive electrode of the electronic anode module is placed in the water tank, the drain terminal of the switch tube is connected, the negative terminal of the electronic anode is respectively connected to the metal inner container of the water tank, the positive input terminal of the comparator module, and one end of the grounding resistor, the other end of the grounding resistor is grounded, the gate terminal of the switch tube is connected to the output terminal of the comparator module, the source terminal of the switch tube is respectively connected to the first voltage source and the bias input terminal of the comparator module, and the negative input terminal of the comparator module is connected to the second voltage source.
[0013] Preferably, the voltage of the negative terminal of the electronic anode module satisfies the expression:
[0014]
[0015] wherein, represents the voltage of the first voltage source, and the comparator outputs a low level, the switch tube is turned on, the voltage between the positive terminal of the electronic anode module and the negative terminal of the electronic anode module is greater than the working voltage of the electronic anode module, and the electronic anode normally works.
[0016] Preferably, when the electronic anode normally works, the conductivity of the water increases, the equivalent resistance of the water in the water tank between the positive terminal of the electronic anode module and the negative terminal of the electronic anode module decreases, the current flowing through the electronic anode module increases, the overflow speed of hydrogen gas increases, the voltage division of the grounding resistor increases, the voltage input to the comparator module increases, and gradually approaches the voltage of the second voltage source , the output voltage of the comparator module decreases, the switch tube enters the non-saturation region, the drain-source voltage of the switch tube increases, and the voltage division between the positive terminal and the negative terminal of the electronic anode decreases.
[0017] Preferably, the voltage output by the second voltage source is .
[0018] Preferably, the voltage output by the first voltage source is .
[0019] In a second aspect, the application further provides a control device for the electronic anode, which comprises the control circuit for the electronic anode protection.
[0020] Compared with the prior art, the application has the following beneficial effects: The application provides a control circuit and device for the electronic anode protection, which controls the on-off of a switch tube by a comparator module, controls the voltage between the positive and negative poles of an electronic anode module based on the on-off of the switch tube, and turns on the switch tube when the electronic anode module is connected to the circuit, so that the voltage of a first voltage source is applied to the positive input end of the comparator, the voltage value of the first voltage source is greater than that of a second voltage source, the output end of the comparator module outputs a high level, the switch tube is turned off, the positive pole voltage of the electronic anode module follows the voltage of the second voltage source based on the virtual short feature of the comparator module, the voltage between the positive and negative poles of the electronic anode module is insufficient to drive the electronic anode module to work, and therefore the electronic anode stops working. In addition, when the electronic anode normally works, the conductivity of water increases, the equivalent resistance of water decreases, the current flowing through the electronic anode module increases, the hydrogen overflow speed increases, the voltage division of the grounding resistance increases, the voltage input to the comparator module increases and gradually approaches the voltage of the second voltage source, the output voltage of the comparator module decreases, the switch tube enters the non-saturation region, the drain-source voltage of the switch tube increases, and the voltage division between the positive and negative poles of the electronic anode decreases. The scheme does not need additional control parts such as chips, only uses a simple circuit structure, avoids the accelerated corrosion of the electronic anode, has simple control logic, and has high reliability. BRIEF DESCRIPTION OF DRAWINGS
[0021] Figure 1 FIG. 1 shows a structure schematic diagram of the control circuit for the electronic anode protection according to the application; Figure 2 FIG. 2 shows a specific structure schematic diagram of the control circuit for the electronic anode protection according to the application; Figure 3 FIG. 3 shows another structure schematic diagram of the control circuit for the electronic anode protection according to the application. DETAILED DESCRIPTION
[0022] The drawings are only used for illustrative description and cannot be understood as a limitation of the patent; In order to better illustrate the embodiment, some parts of the drawings are omitted, enlarged or reduced, and do not represent the actual size; For those skilled in the art, it is understandable that some known content in the drawings can be omitted.
[0023] The technical scheme of the application will be further described below in combination with the drawings and embodiments.
[0024] The position relationship described in the drawings is only for illustrative purposes and should not be construed as limiting the patent; Embodiment 1 This embodiment proposes a control circuit for electronic anode protection. The structural schematic diagram of the circuit is shown in Figure 1 The circuit comprises: a comparator module, a switch tube, a first voltage source, a second voltage source, a grounding resistor, and an electronic anode module; One end of the positive electrode of the electronic anode module is placed in a water tank, and the other end is grounded through the grounding resistor. The negative electrode of the electronic anode is connected to the drain electrode of the switch tube and the metal inner liner of the water tank, respectively. The metal inner liner is connected to the positive input end of the comparator module. The gate electrode of the switch tube is connected to the output end of the comparator module. The source electrode of the switch tube is connected to the first voltage source. The negative input end of the comparator module is connected to the positive electrode of the second voltage source. After the switch tube is turned on, the voltage at the negative electrode of the electronic anode module and the positive electrode of the comparator module is the voltage value of the first voltage source, which is greater than the voltage value of the second voltage source. The output end of the comparator module outputs a high level, the switch tube is turned off, the voltage between the positive electrode of the electronic anode module and the negative electrode of the electronic anode module is less than the working voltage of the electronic anode module, and the electronic anode does not work.
[0025] In this embodiment, the comparator module is used to control the on-off of the switch tube. Based on the on-off state of the switch tube, the voltage between the positive and negative electrodes of the electronic anode module is controlled. When the electronic anode module is connected to the circuit, the switch tube is turned on, the voltage of the first voltage source is applied to the positive input end of the comparator, the voltage value of the first voltage source is greater than the voltage value of the second voltage source, the output end of the comparator module outputs a high level, the switch tube is turned off, and based on the virtual short characteristic of the comparator module, the positive electrode voltage of the electronic anode module follows the voltage of the second voltage source. At this time, the voltage between the positive and negative electrodes of the electronic anode module is insufficient to drive the electronic anode module to work, so the electronic anode stops working. This scheme does not require additional control parts such as chips, only uses a simple circuit structure, avoids accelerated corrosion of the electronic anode, and has simple control logic and high reliability.
[0026] Embodiment 2 In this embodiment, the comparator module comprises a comparator The positive input end of the comparator is connected to the metal inner liner of the water tank as the positive input end of the comparator module. The negative input end of the comparator is connected to the positive electrode of the second voltage source as the negative input end of the comparator module. The first voltage source is connected to one end of the resistor and the positive input end of the comparator One end of the bias input terminal, resistor The other end is connected to a comparator The output of the comparator The other end of the bias input is grounded.
[0027] Specifically, the comparator The model is LM293. The negative terminal of the electronic anode module is connected to the positive input terminal of the comparator module and the metal inner liner of the water tank, respectively, and the second voltage source. The positive terminal is connected to the negative input terminal of the comparator module, the second voltage source. positive terminal and comparator The bias output terminal is grounded, and the first voltage source Connect resistors respectively One end of the comparator One end of the bias input is the comparator. powered by.
[0028] Specifically, the schematic diagram of the control circuit for electronic anode protection is as follows: Figure 2 As shown, in Figure 2 In this system, the resistance across the electronic anode module is equivalent to the resistance of the water in the tank. One end of the positive electrode of the electronic anode module is placed in the water tank, and the other end is grounded through a grounding resistor. The negative electrode of the electronic anode is connected to the drain electrode of the switching transistor and the metal inner liner of the water tank. The metal inner liner is connected to the positive input terminal of the comparator module. The gate terminal of the switching transistor is connected to the output terminal of the comparator module. The source terminal of the switching transistor is connected to the first voltage source. The negative input terminal of the comparator module is connected to the second voltage source.
[0029] In this embodiment, the switching transistor is a PMOS transistor.
[0030] Specifically, when the gate terminal of the PMOS transistor receives a high-level signal, the PMOS transistor is turned off; when the gate terminal of the PMOS transistor receives a low-level signal, the PMOS transistor is turned on; when the PMOS transistor is turned off, the drain and source of the PMOS transistor are open-circuited.
[0031] In this embodiment, after the switching transistor is turned off, the negative terminal voltage of the electronic anode module becomes the second voltage source. The voltage of the positive terminal of the electronic anode module. Satisfying the expression:
[0032] in, The resistance value of the grounding resistor is given. The equivalent resistance of the water in the tank; The voltage between the positive terminal of the electronic anode module and the negative terminal of the electronic anode module is less than the working voltage of the electronic anode module, and the electronic anode does not work.
[0033] Specifically, based on the virtual short characteristic of the comparator, the voltage received by the negative terminal of the electronic anode module is the second voltage source voltage ; the resistance value of the grounding resistor , and the equivalent resistance of the water in the water tank , so the voltage between the positive terminal and the negative terminal of the electronic anode module is less than the second voltage source voltage , and also less than the working voltage of the electronic anode module.
[0034] In this embodiment, another structural diagram of the circuit is shown in Figure 3 , and the circuit further comprises: One end of the positive terminal of the electronic anode module is placed in the water tank, and the drain terminal of the switch tube is connected. The negative terminal of the electronic anode is respectively connected to the metal inner container of the water tank, the positive input terminal of the comparator module, and one end of the grounding resistor. The other end of the grounding resistor is grounded. The gate terminal of the switch tube is connected to the output terminal of the comparator module. The source terminal of the switch tube is respectively connected to the first voltage source and the bias input terminal of the comparator module. The negative input terminal of the comparator module is connected to the second voltage source.
[0035] In this embodiment, the voltage of the negative terminal of the electronic anode module satisfies the expression:
[0036]
[0037] wherein, represents the voltage of the first voltage source, the comparator outputs a low level, the switch tube is turned on, and the voltage between the positive terminal of the electronic anode module and the negative terminal of the electronic anode module is greater than the working voltage of the electronic anode module, and the electronic anode normally works.
[0038] Specifically, at this time, the positive input terminal of the comparator module is connected to the negative terminal of the electronic anode module, and the negative input terminal of the comparator module is connected to the second voltage source voltage. At this time, the voltage of the negative terminal of the electronic anode module is much smaller than the second voltage source voltage, so the negative input of the comparator module is much greater than the positive input. The comparator outputs a low level, the Pmos tube is turned on, and the positive terminal of the electronic anode module is connected to the first voltage source voltage. At this time, the voltage of the positive terminal of the electronic anode module , and the voltage difference between the positive terminal and the negative terminal of the electronic anode module is sufficient to drive the electronic anode to normally work.
[0039] In the embodiment, when the electronic anode is working normally, the conductivity of water is increased, the equivalent resistance of water in the water tank between the positive terminal and the negative terminal of the electronic anode module is decreased , the current flowing through the electronic anode module is increased, the overflow speed of hydrogen is increased, the voltage of the ground resistance is increased, the voltage input to the comparator module is increased, gradually approaching the voltage of the second voltage source , the output voltage of the comparator module is decreased, the switch tube enters the non-saturation region, the drain-source voltage of the switch tube is increased, the voltage of the positive terminal and the negative terminal of the electronic anode is decreased.
[0040] Specifically, when the electronic anode is working normally, a small external DC voltage source is used to force the current to flow out of the positive terminal of the electronic anode, through the water in the water tank, and to the metal liner to be protected, which is equivalent to electrolyzing water, thereby generating ions at the positive terminal of the electronic anode and ions at the negative terminal of the electronic anode, these newly generated ions are charge carriers, and the presence of ions increases the conductivity of water.
[0041] Specifically, when the voltage of the positive terminal and the negative terminal of the electronic anode is decreased, according to Ohm's law, the current flowing through the water in the water tank is decreased, the electrolysis speed of water is slowed down, and the overflow speed of hydrogen is slowed down.
[0042] In the embodiment, the voltage output by the second voltage source .
[0043] Specifically, the voltage output by the second voltage source needs to be greater than the voltage of the negative terminal of the electronic anode module and less than the working voltage of the electronic anode module.
[0044] In the embodiment, the voltage output by the first voltage source .
[0045] Embodiment 3 The embodiment proposes a control device for electronic anode protection, in the embodiment, the device includes the control circuit structure for electronic anode protection described in embodiment 1 or embodiment 2, and further includes a shell for installing the circuit structure.
[0046] Obviously, the above embodiments of the present application are only examples for clearly explaining the present application, and are not intended to limit the embodiments of the present application. Based on the above description, other different forms of changes or variations can be made by those skilled in the art. Here, it is not necessary and impossible to exhaust all the embodiments. Any modification, equivalent replacement and improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the claims of the present application.
Claims
1. A control circuit for electronic anode protection, characterized in that The circuit comprises a comparator module, a switch tube, a first voltage source, a second voltage source, a grounding resistor and an electronic anode module; One end of the positive electrode of the electronic anode module is placed in a water tank, and the other end is grounded through the grounding resistor; the negative electrode of the electronic anode is connected to the drain electrode of the switch tube and the metal liner of the water tank respectively; the metal liner is connected to the positive input end of the comparator module; the gate electrode of the switch tube is connected to the output end of the comparator module; the source electrode of the switch tube is connected to the first voltage source; and the negative input end of the comparator module is connected to the second voltage source. After the switch tube is turned on, the voltage of the negative electrode of the electronic anode module and the positive electrode of the comparator module is the voltage value of the first voltage source, which is greater than the voltage value of the second voltage source; the output end of the comparator module outputs a high level; the switch tube is turned off; the voltage between the positive electrode of the electronic anode module and the negative electrode of the electronic anode module is less than the working voltage of the electronic anode module; and the electronic anode does not work.
2. The control circuit for electronic anode protection orientation according to claim 1, characterized in that, The comparator module comprises a comparator , the positive input end of the comparator is connected with the metal inner container of the water tank as the positive input end of the comparator module, the negative input end of the comparator is connected with the positive pole of the second voltage source as the negative input end of the comparator module, the first voltage source is respectively connected with one end of the resistor and one end of the bias input end of the comparator , the other end of the resistor is connected with the output end of the comparator , and the other end of the bias input end of the comparator is grounded.
3. The control circuit for electronic anode protection orientation according to claim 1, characterized in that, The switch tube is a Pmos tube.
4. The control circuit for electronic anode protection orientation according to claim 1, characterized in that, After the switch tube is turned off, the negative terminal voltage of the electron anode module is a second voltage source , and the positive terminal voltage of the electron anode module satisfies an expression: wherein, is the resistance value of the grounding resistance, is the equivalent resistance of the water in the tank; The voltage between the positive electrode of the electronic anode module and the negative electrode of the electronic anode module is less than the working voltage of the electronic anode module; and the electronic anode does not work.
5. The control circuit for electronic anode protection orientation according to claim 1, characterized in that, The circuit further comprises: One end of the positive electrode of the electronic anode module is placed in a water tank and connected to the drain electrode of the switch tube; the negative electrode of the electronic anode is connected to the metal liner of the water tank, the positive input end of the comparator module and one end of the grounding resistor respectively; the other end of the grounding resistor is grounded; the gate electrode of the switch tube is connected to the output end of the comparator module; the source electrode of the switch tube is connected to the first voltage source and the bias input end of the comparator module respectively; and the negative input end of the comparator module is connected to the second voltage source.
6. The control circuit for electronic anode protection orientation according to claim 5, characterized in that, The negative terminal voltage of the electronic anode module satisfies the expression: wherein, represents the voltage of the first voltage source, the comparator outputs a low level, the switch tube is turned on, the voltage between the positive end of the electron anode module and the negative end of the electron anode module is greater than the working voltage of the electron anode module, and the electron anode normally works.
7. The control circuit for electronic anode protection orientation according to claim 6, characterized in that, When the electronic anode is working normally, the conductivity of the water increases, and the equivalent resistance of the water in the tank between the positive and negative terminals of the electronic anode module increases. The decrease in voltage leads to an increase in the current flowing through the electronic anode module, accelerating the hydrogen escape rate and reducing the grounding resistance. As the voltage drop increases, the voltage input to the comparator module also increases, gradually approaching the second voltage source. The voltage decreases, the comparator module's output voltage drops, the switching transistor enters the non-saturation region, and the drain-source voltage of the switching transistor... As the voltage increases, the partial pressure between the positive and negative terminals of the electron anode decreases.
8. The control circuit for electronic anode protection orientation according to claim 7, characterized in that, a voltage output by the second voltage source .
9. The control circuit for electronic anode protection orientation according to claim 8, characterized in that, a voltage output by the first voltage source .
10. An electronic anode oriented control device, characterized by The device comprises the control circuit for the protection of the electronic anode according to any one of claims 1-9.