Water outlet power-off protection circuit of electric water heater

Abstract

The utility model relates to the technical field of protection circuits, in particular to a water outlet power-off protection circuit of an electric water heater, which comprises a capacitor bank, an electromagnetic water flow switch RV, a coil winding and a follow current group, the capacitor bank comprises a capacitor C7, a capacitor C8 and a capacitor C9, the coil winding comprises a coil L1, a coil L2 and a coil L3, and the coil L1, the coil L2 and the coil L3 are connected with the electromagnetic water flow switch RV. The follow current group comprises a rectifier bridge VD2 and a relay K1, the electromagnetic water flow switch RV and the capacitor C9 are connected in the water outlet power-off protection circuit in parallel, and the coil L3 and the capacitor C8 are connected in the water outlet power-off protection circuit in parallel and connected with the relay K1 in series; and when the temperature in the electric water heater CZ is higher than a preset value, the time-base integrated circuit IC sends a signal to the relay J from the pin 9, so that the relay J acts, the indicator light LED2 is lightened, the contact J1-1 and the contact J2-2 of the relay J are disconnected, the water outlet power-off protection circuit is in an open-circuit state, and the electric water heater CZ stops heating.

Description

Technical Field

[0001] This utility model relates to the field of protection circuit technology, and in particular to a power-off protection circuit for water outlet of an electric water heater. Background Technology

[0002] An electric water heater is a water heater that uses electricity as its energy source to heat water. It converts electrical energy into heat energy through a heating element. The heating element is generally made of resistance wire, and the most common types are immersion heating elements and pipe heating elements. Immersion heating elements are directly immersed in the water, and heat is transferred to the water through the water flow. Pipe heating elements heat the water through pipes.

[0003] Existing electric water heaters typically have a water flow sensor installed in the outlet pipe. When the hot water tap is turned on, the water flow sensor detects the flow and converts it into an electrical signal. This signal is then transmitted to the control circuit to determine if water is flowing. The control circuit receives the signal from the water flow sensor and, upon receiving a signal indicating water flow, initiates further monitoring of the water heater's operating status. Simultaneously, the control circuit immediately issues a power-off command, cutting off the water heater's power supply and implementing a power-off protection mechanism. However, this method has a drawback: relying solely on the water flow sensor and control circuit cannot amplify the signal from the sensor. This results in low sensitivity in the entire power-off control system, posing a safety hazard. Utility Model Content

[0004] The main purpose of this utility model is to provide a power outage protection circuit for electric water heaters to solve the problem of low sensitivity of fuses working alone in related technologies.

[0005] To achieve the above objectives, according to one aspect of this utility model, a power-off protection circuit for an electric water heater is provided, comprising: a power-off protection circuit for an electric water heater CZ, wherein when the electric water heater CZ dispenses water, the power-off protection circuit is disconnected, and the electric water heater CZ is de-energized. The power-off protection circuit for an electric water heater CZ includes a capacitor bank, an electromagnetic flow switch RV, a coil winding, and a freewheeling circuit. The capacitor bank includes capacitors C7, C8, and C9. The coil winding includes coils L1, L2, and L3. The freewheeling circuit includes a rectifier bridge VD2 and a relay K1. The electromagnetic flow switch RV and capacitor C9 are connected in parallel in the power-off protection circuit for an electric water heater CZ. The coil L3 and capacitor C8 are connected in parallel in the power-off protection circuit for an electric water heater CZ and are connected in series with the relay K1. One end of capacitor C7 is connected to the relay K1, and the other end is connected to the rectifier bridge VD2. The other end of the rectifier bridge VD2 is connected to capacitor C9. The coil L1 is wound around the protected live wire, and the coil L2 is wound around the protected neutral wire.

[0006] Furthermore, the rectifier bridge VD2 consists of four diodes, which convert the input 220V AC power into DC power to provide DC power for the water outage protection circuit. The relay K1 includes contact K1-1 and contact K1-2. Contact K1-1 is connected between capacitor C9 and coil L1, and K1-2 is connected to the DC input pin of rectifier bridge VD2.

[0007] Furthermore, the power outage protection circuit also includes a timer integrated circuit (IC), a rectifier circuit, a voltage regulator circuit, a relay circuit, an indicator circuit, and a detection circuit.

[0008] Furthermore, the rectifier circuit includes a transformer B, a rectifier bridge VD1, a capacitor C6, a switch K, and an electric water heater CZ; the SS voltage regulator circuit includes a capacitor C5, a transistor BG2, a resistor R11, and a Zener diode DW; the relay circuit includes a diode D4, a relay J, a resistor R10, and an indicator LED2; and the indicator circuit includes indicator LED1, indicator LED3, a capacitor C3, a capacitor C4, a resistor R6, a resistor R7, a resistor R8, a resistor R9, and a diode D3.

[0009] Furthermore, the detection circuit includes a detection resistor group, a detection capacitor group, a detection potentiometer group, a detection diode group, and a transistor BG1. The detection resistor group includes resistors R1, R2, R3, R4, and R5. The detection potentiometer group includes potentiometers W1 and W2. The detection diode group includes diodes D1 and D2. The detection capacitor group includes capacitors C1 and C2.

[0010] Furthermore, the input pin of transformer B is connected to the AC power supply via switch K, and the output pin is connected to the electric water heater CZ. The enable pin of transformer B is connected to the DC input pin of rectifier bridge VD2 via contact K1-2. The feedback pin of transformer B is connected to the AC input pin of rectifier bridge VD1. The DC output pin of rectifier bridge VD1 is connected to capacitor C9. Capacitor C6 is connected in parallel with rectifier bridge VD1 between the collectors of transformer B and transistor BG2. Resistor R11 is connected between the collector and base of transistor BG2. Zener diode DW is connected in series between capacitor C6 and resistor R11.

[0011] Furthermore, diode D3 and resistor R6 are both connected to pin 5 of the timer IC. Resistor R9, capacitor C4, and capacitor C5 are connected in series between the emitters of diode D3 and transistor BG2. Resistor R8 and indicator LED3 are connected in series between pin 5 of the timer IC and the emitter of transistor BG2. Indicator LED1 is connected in series with resistor R6. Capacitor C3 is connected to pin 3 of the timer IC. Resistor R10 is connected in series with indicator LED2 and is connected in parallel with diode D4 and relay J between pins 4 and 9 of the timer IC. Relay J includes contacts J1-1 and J2-2, both of which are connected to the terminals of electric water heater CZ.

[0012] Furthermore, resistor R4 is connected to pin 2 of the timer IC, resistor R3 is connected to pin 11 of the timer IC, diodes D1 and D2 and resistor R5 are all connected to pin 6 of the timer IC, capacitor C2 is connected in series between diode D2 and resistor R5, one end of resistor R2 is connected to the emitter of transistor BG1 and the other end is connected to resistor R5, one end of capacitor C1 is connected to the collector of transistor BG1 and the other end is connected to resistor R5, potentiometer W1 is connected to the collector of transistor BG1, potentiometer W2 is connected to diode D2, and diode D1 and resistor R1 are both connected to the base of transistor BG1.

[0013] Compared with the prior art, this utility model has the following beneficial effects: When the temperature inside the electric water heater CZ is higher than the predetermined value, the timer integrated circuit IC sends a signal from pin 9 to the relay J, causing the relay J to operate, and the indicator light LED2 lights up, indicating that the water temperature inside the electric water heater CZ has reached the set value. At the same time, the contacts J1-1 and J2-2 of the relay J open, the water outlet power-off protection circuit is in an open circuit state, and the electric water heater CZ stops heating; when the temperature inside the electric water heater CZ is lower than the predetermined value, the relay J does not operate, the water outlet power-off protection circuit closes, the electric water heater CZ starts heating, and the indicator light LED1 lights up, indicating that the electric water heater CZ is heating; when the electromagnetic water flow... When switch RV detects water flowing from the water heater, it sends an electrical signal to the coil winding. The current in the live wire of coil L1 and the neutral wire of coil L2 becomes unbalanced, generating magnetic flux. Coil L3 induces a voltage signal, which sends a signal to relay K1. Contacts K1-1 and K1–2 of relay K1 open, and the water outlet power-off protection circuit is in an open circuit state. The water heater CZ stops heating, allowing the user to use hot water without electricity, ensuring separation of people from electricity and guaranteeing personal safety. When a short circuit occurs in the water outlet power-off protection circuit, the current flowing through the electromagnetic flow switch RV increases, causing the electromagnetic flow switch RV to open, cutting off the water outlet power-off protection circuit, and the water heater CZ stops heating. Attached Figure Description

[0014] Figure 1 This is the circuit diagram of the water outlet power failure protection circuit of this utility model;

[0015] Figure 2 This is a partial enlarged view of the power-off protection circuit for the water outlet of this utility model. Detailed Implementation

[0016] To further illustrate the technical means and effects adopted by this utility model in order to achieve the intended utility model purpose, the following detailed description of the specific implementation methods, structure, features and effects of this utility model is provided in conjunction with the accompanying drawings and preferred embodiments.

[0017] Please see Figure 1 and Figure 2 This embodiment provides a power outage protection circuit for an electric water heater, including: a power outage protection circuit that disconnects when the electric water heater CZ dispenses water, thus cutting off power to the electric water heater CZ and preventing accidental electric shock during use. The power outage protection circuit includes a capacitor bank, an electromagnetic flow switch RV, a coil winding, and a freewheeling circuit. The capacitor bank includes capacitors C7, C8, and C9. The coil winding includes coils L1, L2, and L3. The freewheeling circuit includes a rectifier bridge VD2 and a relay K1. The electromagnetic flow switch RV and capacitor C9 are connected in parallel in the power outage protection circuit. Coil L3 and capacitor C8 are connected in parallel in the power outage protection circuit and connected in series with relay K1. One end of capacitor C7 is connected to relay K1, and the other end is connected to rectifier bridge VD2. The other end of rectifier bridge VD2 is connected to capacitor C9. Coil L1 is wound around the protected live wire, and coil L2 is wound around the protected neutral wire.

[0018] The rectifier bridge VD2 consists of four diodes that convert the input 220V AC power into DC power, providing DC power to the water outlet power failure protection circuit. The relay K1 includes contact K1-1 and contact K1-2. Contact K1-1 is connected between capacitor C9 and coil L1, and K1-2 is connected to the DC input pin of rectifier bridge VD2.

[0019] The power outage protection circuit also includes a timer integrated circuit (IC), a rectifier circuit, a voltage regulator circuit, a relay circuit, an indicator circuit, and a detection circuit.

[0020] The rectifier circuit includes transformer B, rectifier bridge VD1, capacitor C6, switch K, and electric water heater CZ; the SS voltage regulator circuit includes capacitor C5, transistor BG2, resistor R11, and Zener diode DW; the relay circuit includes diode D4, relay J, resistor R10, and indicator LED2; the indicator circuit includes indicator LED1, indicator LED3, capacitor C3, capacitor C4, resistor R6, resistor R7, resistor R8, resistor R9, and diode D3.

[0021] The detection circuit includes a detection resistor group, a detection capacitor group, a detection potentiometer group, a detection diode group, and a transistor BG1. The detection resistor group includes resistors R1, R2, R3, R4, and R5. The detection potentiometer group includes potentiometers W1 and W2. The detection diode group includes diodes D1 and D2. The detection capacitor group includes capacitors C1 and C2.

[0022] The input pin of transformer B is connected to the AC power supply through switch K, and the output pin is connected to the electric water heater CZ. The enable pin of transformer B is connected to the DC input pin of rectifier bridge VD2 through contact K1-2. The feedback pin of transformer B is connected to the AC input pin of rectifier bridge VD1. The DC output pin of rectifier bridge VD1 is connected to capacitor C9. Capacitor C6 is connected in parallel with rectifier bridge VD1 between the collectors of transformer B and transistor BG2. Resistor R11 is connected between the collector and base of transistor BG2. Zener diode DW is connected in series between capacitor C6 and resistor R11.

[0023] Transformer B steps down the 220V AC mains power to provide a suitable AC voltage for the water outlet power outage protection circuit.

[0024] Diode D3 and resistor R6 are both connected to pin 5 of the timer IC. Resistor R9, capacitor C4 and capacitor C5 are connected in series between the emitter of diode D3 and transistor BG2. Resistor R8 and indicator LED3 are connected in series between pin 5 of the timer IC and the emitter of transistor BG2. Indicator LED1 is connected in series with resistor R6. Capacitor C3 is connected to pin 3 of the timer IC. Resistor R10 is connected in series with indicator LED2 and is connected in parallel with diode D4 and relay J between pins 4 and 9 of the timer IC. Relay J includes contacts J1-1 and J2-2, both of which are connected to the terminals of electric water heater CZ.

[0025] Resistor R4 is connected to pin 2 of the timer IC, resistor R3 is connected to pin 11 of the timer IC, diodes D1 and D2 and resistor R5 are all connected to pin 6 of the timer IC, capacitor C2 is connected in series between diode D2 and resistor R5, one end of resistor R2 is connected to the emitter of transistor BG1 and the other end is connected to resistor R5, one end of capacitor C1 is connected to the collector of transistor BG1 and the other end is connected to resistor R5, potentiometer W1 is connected to the collector of transistor BG1, potentiometer W2 is connected to diode D2, and diode D1 and resistor R1 are both connected to the base of transistor BG1.

[0026] The rectifier bridge VD1 converts the AC output from transformer B into DC. Capacitors C5 (100μF) and C6 (470μF) filter the rectified DC to smooth the voltage waveform and reduce ripple. Zener diode DW acts as a voltage regulator to ensure a stable DC output voltage for the water supply power-off protection circuit. Transistor BG1, as a signal amplification element, together with potentiometers W1 and W2, capacitors C1 and C2, and resistors R1-R3, forms a signal detection and preliminary processing circuit that amplifies the detected temperature signal. When the water temperature in the electric water heater is lower than the set value and no water flows out, the electric water heater CZ starts heating the water inside. When the water temperature reaches the set value, the electric water heater CZ stops heating. Potentiometers W1 and W2 are used to adjust the sensitivity and threshold of the circuit, setting the trigger conditions for the electric water heater CZ to heat the water inside.

[0027] Pins 2 and 6 of the timer IC are connected to transistor BG1 (3DG6), potentiometers W1 (10k), W2 (10k), capacitors C1 and C2, etc., to detect the temperature signal inside the water heater CZ and convert it into an electrical signal suitable for processing by the timer IC. When the temperature inside the water heater CZ is higher than the preset value, the timer IC sends a signal from pin 9 to relay J, causing relay J to activate. Indicator LED2 lights up, indicating that the water temperature inside the water heater CZ has reached the set value. At the same time, contacts J1-1 and J2-2 of relay J open, the water outlet power-off protection circuit is in an open circuit state, and the water heater CZ stops heating. When the temperature inside the water heater CZ is lower than the preset value, the relay... When the water heater J does not operate, the water outlet power-off protection circuit is closed, and the water heater CZ starts heating. The indicator light LED1 illuminates, indicating that the water heater CZ is heating. When the electromagnetic flow switch RV detects water flowing out of the water heater, it sends an electrical signal to the coil winding. The current in the live wire in coil L1 and the neutral wire in coil L2 becomes unbalanced, generating magnetic flux. Coil L3 induces a voltage signal, which sends a signal to relay K1. The contacts K1-1 and K1-2 of relay K1 open, and the water outlet power-off protection circuit is in an open circuit state, so the water heater CZ stops heating. When a short circuit occurs in the water outlet power-off protection circuit, the current flowing through the electromagnetic flow switch RV increases, causing the electromagnetic flow switch RV to open and disconnect the water outlet power-off protection circuit, so the water heater CZ stops heating.

[0028] The above description is merely a preferred embodiment of the present utility model and is not intended to limit the present utility model in any way. Although the present utility model has been disclosed above with reference to a preferred embodiment, it is not intended to limit the present utility model. Any person skilled in the art can make some modifications or alterations to the above-disclosed technical content to create equivalent embodiments without departing from the scope of the present utility model. Any simple modifications, equivalent changes and alterations made to the above embodiments based on the technical essence of the present utility model without departing from the scope of the present utility model shall still fall within the scope of the present utility model.

Claims

1. A power-off protection circuit for the water outlet of an electric water heater, characterized in that, include: The water outlet power failure protection circuit disconnects when water is discharged from the electric water heater CZ, thus de-energizing the water heater CZ. This circuit includes a capacitor bank, an electromagnetic flow switch RV, a coil winding, and a freewheeling circuit. The capacitor bank includes capacitors C7, C8, and C9. The coil winding includes coils L1, L2, and L3. The freewheeling circuit includes a rectifier bridge VD2 and a relay K1. The electromagnetic flow switch RV and capacitor C9 are connected in parallel within the circuit. Coil L3 and capacitor C8 are connected in parallel within the circuit and connected in series with relay K1. One end of capacitor C7 is connected to relay K1, and the other end is connected to rectifier bridge VD2. The other end of rectifier bridge VD2 is connected to capacitor C9. Coil L1 is wound around the protected live wire, and coil L2 is wound around the protected neutral wire.

2. The electric water heater outlet power-off protection circuit according to claim 1, characterized in that, The rectifier bridge VD2 consists of four diodes, which convert the input 220V AC power into DC power to provide DC power for the water outlet power failure protection circuit. The relay K1 includes contact K1-1 and contact K1-2. Contact K1-1 is connected between capacitor C9 and coil L1, and K1-2 is connected to the DC input pin of rectifier bridge VD2.

3. The electric water heater outlet power-off protection circuit according to claim 2, characterized in that, The power outage protection circuit also includes a timer integrated circuit (IC), a rectifier circuit, a voltage regulator circuit, a relay circuit, an indicator circuit, and a detection circuit.

4. The electric water heater outlet power-off protection circuit according to claim 3, characterized in that, The rectifier circuit includes transformer B, rectifier bridge VD1, capacitor C6, switch K and electric water heater CZ; the SS voltage regulator circuit includes capacitor C5, transistor BG2, resistor R11 and Zener diode DW; the relay circuit includes diode D4, relay J, resistor R10 and indicator LED2; the indicator circuit includes indicator LED1, indicator LED3, capacitor C3, capacitor C4, resistor R6, resistor R7, resistor R8, resistor R9 and diode D3.

5. The electric water heater outlet power-off protection circuit according to claim 3, characterized in that, The detection circuit includes a detection resistor group, a detection capacitor group, a detection potentiometer group, a detection diode group, and a transistor BG1. The detection resistor group includes resistors R1, R2, R3, R4, and R5. The detection potentiometer group includes potentiometers W1 and W2. The detection diode group includes diodes D1 and D2. The detection capacitor group includes capacitors C1 and C2.

6. The electric water heater outlet power-off protection circuit according to claim 4, characterized in that, The input pin of transformer B is connected to the AC power supply via switch K, and the output pin is connected to the electric water heater CZ. The enable pin of transformer B is connected to the DC input pin of rectifier bridge VD2 via contact K1-2. The feedback pin of transformer B is connected to the AC input pin of rectifier bridge VD1. The DC output pin of rectifier bridge VD1 is connected to capacitor C9. Capacitor C6 is connected in parallel with rectifier bridge VD1 between the collectors of transformer B and transistor BG2. Resistor R11 is connected between the collector and base of transistor BG2. Zener diode DW is connected in series between capacitor C6 and resistor R11.

7. The electric water heater outlet power-off protection circuit according to claim 4, characterized in that, The diode D3 and resistor R6 are both connected to pin 5 of the timer IC. Resistor R9, capacitor C4 and capacitor C5 are connected in series between the emitter of diode D3 and transistor BG2. Resistor R8 and indicator LED3 are connected in series between pin 5 of the timer IC and the emitter of transistor BG2. Indicator LED1 is connected in series with resistor R6. Capacitor C3 is connected to pin 3 of the timer IC. Resistor R10 is connected in series with indicator LED2 and is connected in parallel with diode D4 and relay J between pins 4 and 9 of the timer IC. Relay J includes contacts J1-1 and J2-2, both of which are connected to the terminals of electric water heater CZ.

8. The electric water heater outlet power-off protection circuit according to claim 5, characterized in that, Resistor R4 is connected to pin 2 of the timer IC, resistor R3 is connected to pin 11 of the timer IC, diodes D1 and D2 and resistor R5 are all connected to pin 6 of the timer IC, capacitor C2 is connected in series between diode D2 and resistor R5, one end of resistor R2 is connected to the emitter of transistor BG1 and the other end is connected to resistor R5, one end of capacitor C1 is connected to the collector of transistor BG1 and the other end is connected to resistor R5, potentiometer W1 is connected to the collector of transistor BG1, potentiometer W2 is connected to diode D2, and diode D1 and resistor R1 are both connected to the base of transistor BG1.

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