A heating abnormality detection circuit for a water storage type water heater

Abstract

The utility model discloses a kind of heating abnormality detection circuit of water storage type water heater, and the heating abnormality detection is provided with power supply by the power supply circuit of the controller of electric water heater, it is characterized by: the heating abnormality detection circuit includes drive relay circuit, opto-coupler control circuit, the drive relay circuit can drive relay on-off, and relay sends on-off signal, and the opto-coupler control circuit opto-coupler U2 receives relay on-off signal to carry out on-off, when opto-coupler U2 cannot receive relay signal or receive error signal, abnormal phenomenon can be detected to appear.The utility model realizes the purpose of heating abnormality detection by using the function of the opto-coupler U2, effectively avoids heating element failure, overheating, short circuit and other problems, timely protects user from electric shock, fire and other potential risks caused by electric water heater heating abnormality. By increasing a low-cost, simple structure circuit board, heating abnormality detection function can be realized.

Description

Technical Field

[0001] This utility model relates to the field of electronic application technology, specifically to a heating abnormality detection circuit for a storage-type electric water heater. Background Technology

[0002] Storage-type electric water heaters are widely used due to their advantages such as high safety, clean energy, multi-point water supply, and low cost. They ensure users have access to hot water at any time by storing hot water for long-term or temporary use and are equipped with devices to control or limit water temperature. However, storage-type electric water heaters may encounter abnormalities during the heating process, such as heating element malfunction, overheating, or short circuits. These abnormalities not only affect the normal operation of the water heater but may also cause serious safety accidents such as fires. Therefore, this application aims to add a circuit board to the heating module of a storage-type electric water heater to detect whether the water heater is heating abnormally and to promptly disconnect the relay in case of abnormal heating to protect the circuit and personal safety. Utility Model Content

[0003] The purpose of this utility model is to address the current situation where existing storage-type electric water heaters lack the function of detecting abnormal heating, and to provide a water heater heating abnormality detection circuit to detect whether the water heater is heating abnormally, and to disconnect the relay in time when an abnormal heating occurs to protect the circuit and personal safety, thereby overcoming the shortcomings of the prior art.

[0004] To solve the above-mentioned technical problems, the technical solution of this utility model is as follows:

[0005] A heating anomaly detection circuit for a storage-type electric water heater, wherein the heating anomaly detection is powered by the power supply circuit of the water heater's controller, characterized in that: the heating anomaly detection circuit includes a drive relay circuit and an optocoupler control circuit, wherein the drive relay circuit comprises an output port MCU_OUT, capacitors C5 and C8, resistors R11 and R20, transistors Q1 and Q5, and electrolytic capacitor EC3. The circuit consists of resistors R28 and R29, diode D8, relay REL2, and a coil. The output port MCU_OUT is filtered by resistor R20 and capacitors C8 and C5, and then connected to the base of transistor Q1. The emitter of transistor Q1 is connected to the positive terminal of the 5V power supply. The collector is connected to electrolytic capacitor EC3, resistors R28 and R29 through resistor R11. Resistor R29 is connected to the base of transistor Q5. Electrolytic capacitor EC3, resistor R28, and the emitter of transistor Q5 are grounded. The collector of transistor Q5 is connected to diode D8 and the coil. The other end of diode D8 and the coil is connected to the positive terminal of the 12V power supply. Relay REL2 is connected to a 220V input. This circuit drives the relay to open and close, and the relay sends an on / off signal.

[0006] The optocoupler control circuit consists of resistors R40, R45, and R49, a reverse diode D4, an optocoupler U2, resistors R18 and R31, a capacitor C11, and a microcontroller MUC. Relay REL2 is connected to the reverse diode D4 and the first pin of optocoupler U2 via three series resistors R49, R45, and R40. The second pin of optocoupler U2 and the other end of the reverse diode D4 are connected to 220VAC. N, the fourth pin of optocoupler U2 is connected to resistors R18 and R31. The other end of resistor R31 is connected to the positive terminal of the 5V power supply. The other end of resistor R18 is connected to capacitor C11 and the microcontroller MCU. Capacitor C11 and the third pin of optocoupler U2 are grounded. The 220V output of relay REL2 flows through the voltage divider of three series resistors R40, R45 and R49 to optocoupler U2 and reverse diode D4. Optocoupler U2 receives the relay on / off signal to control the on / off state. When optocoupler U2 does not receive the relay signal or receives an incorrect signal, an abnormal phenomenon can be detected.

[0007] The optocoupler U2 is an EL817C, the transistor Q1 is a PNP type, and the transistor Q5 is an NPN type.

[0008] The above technical solution has the following beneficial effects:

[0009] By employing the function of the aforementioned optocoupler U2, the purpose of heating anomaly detection is achieved, effectively avoiding problems such as heating element failure, overheating, and short circuits. This enables the detection and protection against heating anomalies, promptly protecting users from potential risks such as electric shock and fire caused by abnormal heating of the water heater, and improving the user experience.

[0010] This invention is applied to storage-type electric water heaters. By adding a low-cost, simple circuit board, the function of detecting abnormal heating can be realized. Attached Figure Description

[0011] Figure 1 This is the circuit diagram for detecting heating abnormalities according to this utility model. Detailed Implementation

[0012] To further illustrate the technical means and effects adopted by this utility model to achieve its intended purpose, the specific implementation methods of this utility model are described in detail below with reference to the accompanying drawings and preferred embodiments:

[0013] This utility model discloses a heating anomaly detection circuit for a storage-type electric water heater. The heating anomaly detection circuit is powered by the power supply circuit of the water heater's controller. The heating anomaly detection circuit includes a drive relay circuit and an optocoupler control circuit. The drive relay circuit consists of an output port MCU_OUT, capacitors C5 and C8, resistors R11 and R20, transistors Q1 and Q5, and an electrolytic capacitor EC3. The circuit consists of resistors R28 and R29, diode D8, relay REL2, and a coil. The output port MCU_OUT is filtered by resistor R20 and capacitors C8 and C5, and then connected to the base of transistor Q1. The emitter of transistor Q1 is connected to the positive terminal of the 5V power supply. The collector is connected to electrolytic capacitor EC3, resistors R28 and R29 through resistor R11. Resistor R29 is connected to the base of transistor Q5. Electrolytic capacitor EC3, resistor R28, and the emitter of transistor Q5 are grounded. The collector of transistor Q5 is connected to diode D8 and the coil. The other end of diode D8 and the coil is connected to the positive terminal of the 12V power supply. Relay REL2 is connected to a 220V input. This circuit drives the relay to open and close, and the relay sends an on / off signal.

[0014] The optocoupler control circuit consists of resistors R40, R45, and R49, a reverse diode D4, an optocoupler U2, resistors R18 and R31, a capacitor C11, and a microcontroller MUC. Relay REL2 is connected to the reverse diode D4 and the first pin of optocoupler U2 via three series resistors R49, R45, and R40. The second pin of optocoupler U2 and the other end of the reverse diode D4 are connected to 220VAC. N, the fourth pin of optocoupler U2 is connected to resistors R18 and R31. The other end of resistor R31 is connected to the positive terminal of the 5V power supply. The other end of resistor R18 is connected to capacitor C11 and the microcontroller MCU. Capacitor C11 and the third pin of optocoupler U2 are grounded. The 220V output of relay REL2 flows through the voltage divider of three series resistors R40, R45 and R49 to optocoupler U2 and reverse diode D4. Optocoupler U2 receives the relay on / off signal to control the on / off state. When optocoupler U2 does not receive the relay signal or receives an incorrect signal, an abnormal phenomenon can be detected.

[0015] The optocoupler U2 is an EL817C, the transistor Q1 is a PNP type, and the transistor Q5 is an NPN type.

[0016] As a manifestation of the functionality of this utility model, the specific working process of this heating anomaly detection circuit is described in detail below:

[0017] When the electric water heater is working normally, the controller's power circuit supplies power to the heating anomaly detection circuit, driving the relay circuit and optocoupler control circuit to work together to achieve real-time monitoring of the heating status.

[0018] The signal output from the MCU_OUT output port is processed and then controlled by the switching on and off of transistors Q1 and Q5 to turn relay REL2 on and off. Relay REL2 is connected to a 220V input, and its on / off state directly reflects the operating status of the heating circuit. It transmits the on / off signal to optocoupler U2, which then switches on and off according to the signal status. Under normal circumstances, optocoupler U2 accurately receives and transmits signals, allowing the microcontroller MCU to obtain a stable signal and determine that the heating status is normal. When optocoupler U2 fails to receive a signal or receives an incorrect signal, the microcontroller MCU detects the abnormality, thus enabling the detection of heating anomalies.

[0019] All components involved in this utility model can be general standard parts or components known to those skilled in the art. Their structure, principle and control method are known to those skilled in the art through technical manuals or conventional experimental methods.

[0020] The above description is merely a preferred embodiment of the present utility model and does not constitute any limitation on the technical scope of the present utility model. Therefore, other circuits obtained by using the same or similar technical features as the above embodiments of the present utility model are all within the protection scope of the present utility model.

Claims

1. A heating anomaly detection circuit for a storage-type water heater, powered by the power supply circuit of the water heater's controller, characterized in that: The heating anomaly detection circuit includes a drive relay circuit and an optocoupler control circuit. The drive relay circuit consists of an output port MCU_OUT, capacitors C5 and C8, resistors R11 and R20, transistors Q1 and Q5, electrolytic capacitor EC3, resistors R28 and R29, diode D8, relay REL2, and a coil. The output port MCU_OUT is filtered by resistor R20 and capacitors C8 and C5 and then connected to the base of transistor Q1. The emitter of transistor Q1 is connected to the positive terminal of a 5V power supply. The collector is connected to electrolytic capacitor EC3, resistors R28 and R29 through resistor R11. Resistor R29 is connected to the base of transistor Q5. Electrolytic capacitor EC3, resistor R28, and the emitter of transistor Q5 are grounded. The collector of transistor Q5 is connected to diode D8 and the coil. The other end of diode D8 and the coil is connected to the positive terminal of a 12V power supply. Relay REL2 is connected to a 220V input. This circuit drives the relay to switch on and off, and the relay sends an on / off signal. The optocoupler control circuit consists of resistors R40, R45, and R49, a reverse diode D4, an optocoupler U2, resistors R18 and R31, a capacitor C11, and a microcontroller MCU. Relay REL2 is connected to the reverse diode D4 and the first pin of optocoupler U2 via three series resistors R49, R45, and R40. The second pin of optocoupler U2 and the other end of the reverse diode D4 are connected to a 220V AC input. The fourth pin of optocoupler U2 is connected to resistors R18 and R31. The other end of resistor R31 is connected to the positive terminal of a 5V power supply. The other end of resistor R18 is connected to capacitor C11 and the microcontroller MCU. Capacitor C11 and the third pin of optocoupler U2 are grounded. The 220V output from relay REL2 is divided by three series resistors R40, R45, and R49 and flows to optocoupler U2 and the reverse diode D4. Optocoupler U2 receives relay on / off signals to control the relay's operation. An abnormality can be detected when optocoupler U2 does not receive a relay signal or receives an incorrect signal.

2. The heating abnormality detection circuit for a storage-type water heater according to claim 1, characterized in that: The optocoupler U2 is model EL817C.

3. The heating abnormality detection circuit for a storage-type water heater according to claim 1, characterized in that: The transistor Q1 is a PNP type, and the transistor Q5 is an NPN type.

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