CN112260386B - Water heater and power supply switching device thereof - Google Patents

Abstract

The invention discloses a water heater and a power switching device thereof. The device comprises: a switching circuit for switching the power supply of the gas water heater, wherein the power supply of the gas water heater includes an external AC power supply and a backup power supply; power failure detection circuit, the power-down detection circuit is connected with the external AC power supply, and the power-down detection circuit outputs a detection signal by detecting whether the external AC power supply is powered off; the control circuit, the control circuit is connected with the power-down detection circuit and the switching circuit, and the control circuit is based on the detection signal. The switching circuit is controlled to supply power to the gas water heater through the external AC power supply when the external AC power supply is not powered off, and to supply power to the gas water heater through the standby power supply when the external AC power supply is powered off. Therefore, the power switching device of the water heater in the embodiment of the present invention can automatically switch to the backup power supply when the external AC power fails, so as to ensure the normal operation of the water heater and further ensure that the user can take a bath normally.

Description

Water heater and its power switching device

technical field

The invention relates to the technical field of household electrical appliances, in particular to a water heater and a power switching device thereof.

Background technique

In related technologies, gas water heaters are generally powered by mains electricity, that is, AC220V power supply. However, the problem in related technologies is that when users take a bath, after the mains power is turned off, the gas water heater stops working immediately, causing users to be unable to take a bath normally. At the same time, Exhaust gas from the combustion chamber cannot be discharged normally, which poses a safety hazard.

Contents of the invention

The present invention aims to solve one of the technical problems in the related art at least to a certain extent.

Therefore, the first object of the present invention is to provide a power switching device for a water heater, so that when the external AC power supply fails, the user can take a bath normally and improve the user experience.

A second object of the present invention is to propose a water heater.

To achieve the above purpose, the embodiment of the first aspect of the present invention proposes a power switching device for a water heater, including: a switching circuit, the switching circuit is used to switch the power supply of the gas water heater, wherein the gas water heater The power supply includes an external AC power supply and a backup power supply; a power failure detection circuit, the power failure detection circuit is connected with the external AC power supply, and the power failure detection circuit outputs a detection signal by detecting whether the external AC power supply is powered off ; A control circuit, the control circuit is connected to the power-down detection circuit and the switching circuit, and the control circuit controls the switching circuit according to the detection signal, so that when the external AC power supply is not powered off The gas water heater is powered by the external AC power supply, and the gas water heater is powered by the backup power supply when the external AC power supply fails.

According to the power switching device of the water heater proposed in the embodiment of the present invention, the power supply of the gas water heater is switched through the switching circuit, wherein the power supply of the gas water heater includes an external AC power supply and a backup power supply, and the power-off detection circuit is connected to the external AC power supply. The power-off detection circuit outputs a detection signal by detecting whether the external AC power is power-off. The control circuit is connected with the power-failure detection circuit and the switching circuit. The external AC power supply supplies power to the gas water heater, and when the external AC power fails, the backup power supply supplies power to the gas water heater. Therefore, the power switching device of the water heater in the embodiment of the present invention can automatically switch to the backup power supply when the external AC power supply is powered off, so as to ensure the normal operation of the gas water heater and the normal discharge of exhaust gas, thereby ensuring that the user can take a bath normally and improving the user's use experience.

According to an embodiment of the present invention, the power-down detection circuit includes: a first resistor, one end of which is connected to the first end of the external AC power supply; a first diode, the first two The anode of the pole tube is connected to the other end of the first resistor; the second diode, the cathode of the second diode is connected to the cathode of the first diode, and the cathode of the second diode The anode is connected to the second end of the external AC power supply; the optocoupler, the first end of the optocoupler is connected to the cathode of the second diode and the cathode of the first diode, and the optocoupler The second end of the optocoupler is connected to the second end of the external AC power supply, the third end of the optocoupler is connected to the control circuit, and the fourth end of the optocoupler is grounded.

According to an embodiment of the present invention, the control circuit includes: an input unit, the input unit is connected to the power-down detection circuit; a reference unit providing a reference voltage; a comparison unit, the first input terminal of the comparison unit is connected to the The input unit is connected, the second input terminal of the comparison unit is connected with the reference unit; the switch unit, the control terminal of the switch unit is connected with the output terminal of the comparison unit, and the first terminal of the switch unit It is connected with the first DC power supply, and the second terminal of the switch unit is connected with the switching circuit.

According to an embodiment of the present invention, the input unit includes: a first capacitor, one end of the first capacitor is connected to the first input end of the comparison unit, and the other end of the first capacitor is grounded; a charging circuit, The first end of the charging circuit is connected to the first DC power supply, the second end of the charging circuit is connected to one end of the first capacitor; the discharging circuit, the first end of the discharging circuit is connected to the One end of the first capacitor is connected, and the second end of the discharge circuit is grounded; the charging control subunit is connected between the first end of the charging circuit and the first DC power supply.

According to an embodiment of the present invention, the charging loop includes: a third diode, the anode of which is connected to the charging control subunit; a third resistor, one end of which is connected to The cathode of the third diode is connected, and the other end of the third resistor is connected with one end of the first capacitor.

According to an embodiment of the present invention, the discharge circuit shares the third resistor with the charge circuit, and the discharge circuit further includes a fourth resistor, one end of the fourth resistor is connected to one end of the third resistor , the other end of the fourth resistor is grounded.

According to an embodiment of the present invention, the charging control subunit includes: a fifth resistor, one end of which is connected to the first DC power supply; a sixth resistor, which is connected to the first The other end of the fifth resistor is connected, and the other end of the sixth resistor is connected to the power-down detection circuit; the first switch tube, the control end of the first switch tube is connected to the other end of the fifth resistor, so The first end of the first switch tube is connected to the first DC power supply, and the second end of the first switch tube is connected to the first end of the charging circuit.

According to an embodiment of the present invention, the reference unit includes: a second capacitor, one end of the second capacitor is connected to the second input end of the comparison unit, and the other end of the second capacitor is grounded; a seventh resistor , one end of the seventh resistor is connected to the first DC power supply, the other end of the seventh resistor is connected to one end of the second capacitor; an eighth resistor, one end of the eighth resistor is connected to the The other end of the seventh resistor is connected, and the other end of the eighth resistor is grounded.

According to an embodiment of the present invention, the switch unit includes: a ninth resistor, one end of the ninth resistor is connected to the output end of the comparison unit; a tenth resistor, one end of the tenth resistor is connected to the first The other end of the nine resistors is connected, and the other end of the tenth resistor is connected to the first DC power supply; the second switch tube, the control end of the second switch tube is connected to one end of the tenth resistor, so The first end of the second switch tube is connected to the first DC power supply, and the second end of the second switch tube is connected to the switching circuit.

According to an embodiment of the present invention, the first DC power supply is provided by the backup power supply, and the power switching device further includes a backup power detection circuit, and the backup power detection circuit is connected to the first end of the switch unit and Between the first DC power supplies, wherein the standby power supply detection circuit includes: a third switch tube, the first end of the third switch tube is connected to the first DC power supply, and the third switch tube The second end of the tube is connected to the first end of the switch unit; the eleventh resistor, one end of the eleventh resistor is connected to the first DC power supply, and the other end of the eleventh resistor is connected to the The control end of the third switching tube is connected; the twelfth resistor, one end of the twelfth resistor is connected to the other end of the eleventh resistor; the voltage regulator tube, the cathode of the voltage regulator tube is connected to the first The other ends of the twelve resistors are connected, and the anode of the regulator tube is grounded.

According to an embodiment of the present invention, the switching circuit includes: a single-pole double-throw relay, the common end of the single-pole double-throw switch in the single-pole double-throw relay is connected to the power input end of the water heater, and the single-pole double-throw relay The first end of the SPDT switch in the SPDT relay is connected to the backup power supply, the second end of the SPDT switch in the SPDT relay is connected to the power conversion module of the water heater, and the power conversion module is connected to the The external AC power supply is connected, one end of the coil in the SPDT relay is connected to the control circuit, and the other end of the coil in the SPDT relay is grounded; the fourth diode, the fourth two The cathode of the pole diode is connected to one end of the coil in the SPDT relay, and the anode of the fourth diode is connected to the other end of the coil in the SPDT relay.

According to an embodiment of the present invention, the power switching device of the water heater further includes a prompt circuit connected to the switching circuit, the prompt circuit includes: a light emitting diode, the anode of the light emitting diode is connected to the single pole double throw One end of the coil in the relay is connected; the second resistor, one end of the second resistor is connected with the cathode of the light emitting diode, and the other end of the second resistor is grounded.

To achieve the above purpose, the embodiment of the second aspect of the present invention provides a water heater, including the power switching device for the water heater described in the embodiment of the first aspect of the present invention.

According to the water heater proposed by the embodiment of the present invention, the power switching device provided can automatically switch to the backup power supply when the external AC power fails, so as to ensure the normal operation of the gas water heater and the normal discharge of exhaust gas, thereby ensuring that the user can bathe normally.

Description of drawings

1 is a schematic block diagram of a power switching device for a water heater according to an embodiment of the present invention;

2 is a schematic block diagram of a power switching device for a water heater according to an embodiment of the present invention;

Fig. 3 is a schematic circuit diagram of a power switching device for a water heater according to an embodiment of the present invention.

Detailed ways

Embodiments of the present invention are described in detail below, examples of which are shown in the drawings, wherein the same or similar reference numerals designate the same or similar elements or elements having the same or similar functions throughout. The embodiments described below by referring to the figures are exemplary and are intended to explain the present invention and should not be construed as limiting the present invention.

The water heater and its power switching device according to the embodiments of the present invention will be described below with reference to the accompanying drawings.

FIG. 1 is a schematic block diagram of a power switching device for a water heater according to an embodiment of the present invention. As shown in FIG. 1 , the power switching device for a water heater according to an embodiment of the present invention includes a switching circuit 10 , a power-down detection circuit 20 and a control circuit 30 .

Wherein, the switching circuit 10 is used to switch the power supply of the gas water heater, wherein the power supply of the gas water heater includes an external AC power supply VSS and a backup power supply VSS1; By detecting whether the external AC power supply VSS is powered off to output a detection signal; the control circuit 30 is connected to the power failure detection circuit 20 and the switching circuit 10, and the control circuit 30 controls the switching circuit 10 according to the detection signal, so that the external AC power supply VSS does not drop The gas water heater is powered by the external AC power supply VSS during power on, and the gas water heater is powered by the backup power supply VSS1 when the external AC power supply VSS is powered off.

It should be noted that the external AC power supply VSS may be AC220V mains power, the backup power supply VSS1 may be a battery, and the backup power supply VSS1 may provide DC power required for normal operation of the gas water heater.

It can be understood that when the power failure detection circuit 20 detects that the external AC power supply VSS is not powered off, the control circuit 30 controls the switching circuit 10 to continue to supply power to the gas water heater through the external AC power supply VSS. When the external AC power supply VSS is powered off, the control circuit 30 controls the switching circuit 10 to supply power to the gas water heater through the standby power supply VSS1.

Therefore, the power switching device of the water heater in the embodiment of the present invention can automatically switch to the backup power supply VSS1 to supply power when the external AC power supply VSS is powered off, so as to ensure the normal operation of the gas water heater and the normal discharge of exhaust gas, thereby ensuring that the user can bathe normally and improve User experience.

Specifically, according to an embodiment of the present invention, as shown in FIG. 3 , the power-off detection circuit 20 includes: a first resistor R1, a first diode D1, a second diode D2, and an optocoupler IC2. The first resistor R1 One end of the external AC power supply VSS is connected to the first end VSS-L; the anode of the first diode D1 is connected to the other end of the first resistor R1; the cathode of the second diode D2 is connected to the first end of the first diode D1 The cathode is connected, the anode of the second diode D2 is connected to the second terminal VSS-N of the external AC power supply VSS; the first terminal of the optocoupler IC2 is connected to the cathode of the second diode D2 and the cathode of the first diode D1 The second end of the optocoupler IC2 is connected to the second end VSS-N of the external AC power supply VSS, the third end of the optocoupler IC2 is connected to the control circuit 30 , and the fourth end of the optocoupler IC2 is grounded.

It should be noted that the optocoupler IC2 may include a light emitting diode and a phototransistor, and the electrical isolation between the power-down detection circuit 20 and the control circuit 30 can be realized through the optocoupler IC2.

It can be understood that the external AC power supply VSS can be AC220V commercial power, and the AC220V commercial power can be a sine wave voltage with a frequency of 50Hz. When the first terminal VSS-L of the external AC power supply VSS outputs a positive half-cycle voltage, the optocoupler IC2 The light-emitting diode emits light, so that the phototransistor in the optocoupler IC2 is turned on.

Further, according to an embodiment of the present invention, as shown in FIG. 2 , the control circuit 30 includes: an input unit 31, a reference unit 32, a comparison unit 33 and a switch unit 34, the input unit 31 is connected to the power-down detection circuit 20; The unit 32 is used to provide the reference voltage; the first input terminal of the comparison unit 33 is connected with the input unit 31, and the second input terminal of the comparison unit 33 is connected with the reference unit 32; the control terminal of the switch unit 34 is connected with the output terminal of the comparison unit 33 , the first end of the switch unit 34 is connected to the first DC power supply DVSS, and the second end of the switch unit 34 is connected to the switching circuit 10 .

Wherein, the first DC power supply DVSS is provided by the standby power supply VSS1, the first DC power supply DVSS can be, for example, 12V DC power, and the comparing unit 33 can be a comparator.

Specifically, according to an embodiment of the present invention, as shown in FIG. 3 , the input unit 31 includes: a first capacitor C1, a charging circuit 310, a discharging circuit 311, and a charging control subunit 312. One end of the first capacitor C1 is connected to the comparison unit 33 connected to the first input end, the other end of the first capacitor C1 is grounded; the first end of the charging circuit 310 is connected to the first DC power supply DVSS, and the second end of the charging circuit 310 is connected to one end of the first capacitor C1; discharge The first end of the loop 311 is connected to one end of the first capacitor C1, and the second end of the discharge loop 311 is grounded; the charging control subunit 312 is connected between the first end of the charging loop 310 and the first DC power supply DVSS.

More specifically, according to an embodiment of the present invention, as shown in FIG. 3 , the charging circuit 310 includes: a third diode D3 and a third resistor R3, and the anode of the third diode D3 is connected to the charging control subunit 312 ; One end of the third resistor R3 is connected to the cathode of the third diode D3, and the other end of the third resistor R3 is connected to one end of the first capacitor C1.

Further, according to an embodiment of the present invention, as shown in FIG. 3 , the discharge circuit 311 and the charge circuit 310 share the third resistor R3, the discharge circuit 311 also includes a fourth resistor R4, one end of the fourth resistor R4 is connected to the third resistor One end of R3 is connected, and the other end of the fourth resistor R4 is grounded.

Further, according to an embodiment of the present invention, as shown in FIG. 3 , the charging control subunit 312 includes: a fifth resistor R5, a sixth resistor R6, and a first switching tube Q1, one end of the fifth resistor R5 is connected to the first straight The sixth resistor R6 is connected to the other end of the fifth resistor R5, and the other end of the sixth resistor R6 is connected to the power-down detection circuit 20; the control end of the first switch tube Q1 is connected to the other end of the fifth resistor R5 The first end of the first switching tube Q1 is connected to the first DC power supply DVSS, and the second end of the first switching tube Q1 is connected to the first end of the charging circuit 310 .

Specifically, according to an embodiment of the present invention, as shown in FIG. 3 , the reference unit 32 includes: a second capacitor C2, a seventh resistor R7 and an eighth resistor R8, one terminal of the second capacitor C2 is connected to the second terminal of the comparison unit 33 The input end is connected, and the other end of the second capacitor C2 is grounded; one end of the seventh resistor R7 is connected with the first DC power supply DVSS, and the other end of the seventh resistor R7 is connected with one end of the second capacitor C2; one end of the eighth resistor R8 It is connected with the other end of the seventh resistor R7, and the other end of the eighth resistor R8 is grounded.

Further, according to an embodiment of the present invention, as shown in FIG. 3 , the switch unit 34 includes: a ninth resistor R9, a tenth resistor R10 and a second switch tube Q2, one end of the ninth resistor R9 is connected to the output of the comparison unit 33 One end of the tenth resistor R10 is connected to the other end of the ninth resistor R9, and the other end of the tenth resistor R10 is connected to the first DC power supply DVSS; the control end of the second switching tube Q2 is connected to one end of the tenth resistor R10 The first end of the second switching tube Q2 is connected to the first DC power supply DVSS, and the second end of the second switching tube Q2 is connected to the switching circuit 10 .

It can be understood that when the external AC power supply VSS is normally powered, that is, it is not powered off, and the output of the first terminal VSS-L of the external AC power supply VSS is a positive half-cycle voltage, the light-emitting diode in the optocoupler IC2 emits light, and the phototransistor in the optocoupler IC2 is turned on, so that the first switch tube Q1 is turned on, and the first DC power supply DVSS charges the first capacitor C1 through the first switch tube Q1, the third diode D3 and the third resistor R3, and the voltage of the first capacitor C1 When charging to the reference voltage, the output terminal of the comparison unit 33 outputs a high level, so that the second switching tube Q2 is turned off.

When the external AC power supply VSS is normally powered, that is, it is not powered off, and the output of the first terminal VSS-L of the external AC power supply VSS is a negative half-cycle voltage, the optocoupler IC2 does not work, so that the first switching tube Q1 is turned off, and the first capacitor C1 Start to discharge through the third resistor R3 and the fourth resistor R4. It should be noted that at this time, the discharge of the first capacitor C1 is less, the voltage of the first capacitor C1 is still higher than the reference voltage, and the output terminal of the comparison unit 33 still outputs a high voltage. level, so that the second switching tube Q2 is turned off.

After the external AC power supply VSS is powered off, the optocoupler IC2 does not work, so that the first switch tube Q1 is turned off, and the first capacitor C1 starts to discharge to be lower than the reference voltage through the third resistor R3 and the fourth resistor R4, and the comparison unit 33 The output end outputs a low level, and the second switch tube Q2 is turned on.

Further, according to an embodiment of the present invention, as shown in FIGS. 2-3 , the power switching device further includes a backup power detection circuit 40, and the backup power detection circuit 40 is connected to the first end of the switch unit 34 and the first DC power supply DVSS Among them, the standby power detection circuit 40 includes: a third switch tube Q3, an eleventh resistor R11, a twelfth resistor R12, and a regulator tube ZD1, and the first end of the third switch tube Q3 is connected to the first DC power supply DVSS The second end of the third switch tube Q3 is connected to the first end of the switch unit 34; one end of the eleventh resistor R11 is connected to the first DC power supply DVSS, and the other end of the eleventh resistor R11 is connected to the third switch tube The control terminal of Q3 is connected; one end of the twelfth resistor R12 is connected to the other end of the eleventh resistor R11; the cathode of the regulator ZD1 is connected to the other end of the twelfth resistor R12, and the anode of the regulator ZD1 is grounded. Wherein, the regulated voltage value of the regulator tube ZD1 may be 10.5V.

It can be understood that after the external AC power supply VSS is powered off, the optocoupler IC2 does not work, the first switch tube Q1 is turned off, and the first capacitor C1 starts to discharge to be lower than the reference voltage through the third resistor R3 and the fourth resistor R4, and the comparison unit The output terminal of 33 outputs a low level, and the second switching tube Q2 is turned on. At this time, when the voltage of the first DC power supply DVSS is greater than 10.5V, the voltage regulator tube ZD1 is turned on, and the third switching tube Q3 is turned on. The double-throw relay RL1 can normally pull in, however, when the voltage of the first DC power supply DVSS is less than 10.5V, the regulator tube ZD1 is turned off, the third switching tube Q3 is turned off, and the SPDT relay RL1 cannot be normally pulled in.

Therefore, after the external AC power supply VSS is powered off and the voltage of the backup power supply VSS1 is low, the power supply of the gas water heater can be automatically cut off to prevent the backup power supply VSS1 from feeding power.

Further, according to an embodiment of the present invention, as shown in FIG. 3 , the switching circuit 10 includes: a single-pole double-throw relay RL1 and a fourth diode D4, the common end of the SPDT switch in the single-pole double-throw relay RL1 and The power input terminal VIN of the water heater is connected, the first end of the SPDT switch in the SPDT relay RL1 is connected to the backup power supply VSS1, the second end of the SPDT switch in the SPDT relay RL1 is connected to the power conversion module of the water heater 50 is connected, and the power conversion module 50 is connected with the external AC power supply VSS, one end of the coil in the SPDT relay RL1 is connected with the control circuit 30, and the other end of the coil in the SPDT relay RL1 is grounded; the fourth diode D4 The cathode of the fourth diode D4 is connected to one end of the coil in the SPDT relay RL1, and the anode of the fourth diode D4 is connected to the other end of the coil in the SPDT relay RL1.

It should be noted that the power conversion module 50 can be an AC/DC switching power supply, which is used to convert the AC power provided by the external AC power supply VSS into the DC power required for the normal operation of the gas water heater.

It can be understood that when the external AC power supply VSS is normally powered, that is, it is not powered off, and the output of the first terminal VSS-L of the external AC power supply VSS is a positive half-cycle voltage, the light-emitting diode in the optocoupler IC2 emits light, and the phototransistor in the optocoupler IC2 is turned on, the first switch tube Q1 is turned on, so that the first DC power supply DVSS charges the first capacitor C1 through the first switch tube Q1, the third diode D3 and the third resistor R3, and the voltage of the first capacitor C1 When charging to the reference voltage, the output terminal of the comparison unit 33 outputs a high level, so that the second switching tube Q2 is turned off, the SPDT relay RL1 is not pulled in, and the common terminal of the SPDT switch in the SPDT relay RL1 is connected to the The second end of the SPDT switch in the SPDT relay RL1 is connected, and the AC power provided by the external AC power supply VSS is converted into DC power by the power conversion module 50 to supply power to the gas water heater, so that it does not need to consume the power of the standby power supply VSS1.

When the external AC power supply VSS is normally powered, that is, it is not powered off, and the output of the first terminal VSS-L of the external AC power supply VSS is a negative half-cycle voltage, the optocoupler IC2 does not work, so that the first switching tube Q1 is turned off, and the first capacitor C1 Start to discharge through the third resistor R3 and the fourth resistor R4. It should be noted that at this time, the discharge of the first capacitor C1 is less, the voltage of the first capacitor C1 is still higher than the reference voltage, and the output terminal of the comparison unit 33 still outputs a high voltage. level, so that the second switching tube Q2 is turned off, the SPDT relay RL1 is not closed, the common end of the SPDT switch in the SPDT relay RL1 is connected to the second end of the SPDT switch in the SPDT relay RL1 connection, the AC power provided by the external AC power supply VSS is converted into DC power by the power conversion module 50 to supply power to the gas water heater, so that it does not need to consume the power of the standby power supply VSS1.

After the external AC power supply VSS is powered off, the optocoupler IC2 does not work, the first switch tube Q1 is turned off, the first capacitor C1 starts to discharge to be lower than the reference voltage through the third resistor R3 and the fourth resistor R4, and the output of the comparison unit 33 terminal outputs low level, the second switch tube Q2 is turned on, at this time, when the voltage of the first DC power supply DVSS is greater than 10.5V, the voltage regulator tube ZD1 is turned on, the third switch tube Q3 is turned on, and the single-pole double-throw relay RL1 pulls in, the common end of the SPDT switch in the SPDT relay RL1 is connected to the first end of the SPDT switch in the SPDT relay RL1, and the backup power supply VSS1 starts to supply power to the gas water heater. Therefore, after the external AC power supply VSS is powered off and the standby power supply VSS1 has sufficient power, it can automatically switch to the standby power supply VSS1 to supply power.

Further, according to an embodiment of the present invention, as shown in Figure 2-3, the power switching device of the water heater also includes a prompt circuit 60, the prompt circuit 60 is connected to the switching circuit 10, and the prompt circuit 60 includes: a light emitting diode LED1 and a second The anode of the resistor R2 is connected to one end of the coil of the SPDT relay RL1; one end of the second resistor R2 is connected to the cathode of the LED1, and the other end of the second resistor R2 is grounded.

It can be understood that after the external AC power supply VSS is powered off, the optocoupler IC2 does not work, the first switch tube Q1 is turned off, and the first capacitor C1 starts to discharge to be lower than the reference voltage through the third resistor R3 and the fourth resistor R4, and the comparison unit The output terminal of 33 outputs a low level, and the second switching tube Q2 is turned on. At this time, when the voltage of the first DC power supply DVSS is greater than 10.5V, the voltage regulator tube ZD1 is turned on, and the third switching tube Q3 is turned on. The double-throw relay RL1 pulls in, and the light-emitting diode LED1 lights up to prompt the backup power supply VSS1 to supply power to the gas water heater when it is working.

To sum up, according to the power supply switching device for water heater proposed in the embodiment of the present invention, the power supply of the gas water heater is switched through the switching circuit. The power supply is connected, and the power failure detection circuit outputs a detection signal by detecting whether the external AC power supply is powered off. The control circuit is connected with the power failure detection circuit and the switching circuit. The gas water heater is powered by an external AC power supply when the power is on, and the gas water heater is powered by a backup power supply when the external AC power supply fails. Therefore, the power switching device of the water heater in the embodiment of the present invention can automatically switch to the backup power supply when the external AC power supply is powered off, so as to ensure the normal operation of the gas water heater and the normal discharge of exhaust gas, thereby ensuring that the user can take a bath normally and improving the user's use experience.

Based on the power switching device for a water heater in the above embodiments, an embodiment of the present invention further provides a water heater, including the aforementioned power switching device for a water heater.

According to the water heater proposed by the embodiment of the present invention, the power switching device provided can automatically switch to the backup power supply when the external AC power fails, so as to ensure the normal operation of the gas water heater and the normal discharge of exhaust gas, thereby ensuring that the user can bathe normally.

In describing the present invention, it should be understood that the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", " Back", "Left", "Right", "Vertical", "Horizontal", "Top", "Bottom", "Inner", "Outer", "Clockwise", "Counterclockwise", "Axial", The orientation or positional relationship indicated by "radial", "circumferential", etc. is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying the referred device or element Must be in a particular orientation, be constructed in a particular orientation, and operate in a particular orientation, and therefore should not be construed as limiting the invention.

In addition, the terms "first" and "second" are used for descriptive purposes only, and cannot be interpreted as indicating or implying relative importance or implicitly specifying the quantity of indicated technical features. Thus, the features defined as "first" and "second" may explicitly or implicitly include at least one of these features. In the description of the present invention, "plurality" means at least two, such as two, three, etc., unless otherwise specifically defined.

In the present invention, unless otherwise clearly specified and limited, terms such as "installation", "connection", "connection" and "fixation" should be understood in a broad sense, for example, it can be a fixed connection or a detachable connection , or integrated; it may be mechanically connected or electrically connected; it may be directly connected or indirectly connected through an intermediary, and it may be the internal communication of two components or the interaction relationship between two components, unless otherwise specified limit. Those of ordinary skill in the art can understand the specific meanings of the above terms in the present invention according to specific situations.

In the present invention, unless otherwise clearly specified and limited, the first feature may be in direct contact with the first feature or the first and second feature may be in direct contact with the second feature through an intermediary. touch. Moreover, "above", "above" and "above" the first feature on the second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is higher in level than the second feature. "Below", "beneath" and "beneath" the first feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is less horizontally than the second feature.

In the description of this specification, descriptions referring to the terms "one embodiment", "some embodiments", "example", "specific examples", or "some examples" mean that specific features described in connection with the embodiment or example , structure, material or characteristic is included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms are not necessarily directed to the same embodiment or example. Furthermore, the described specific features, structures, materials or characteristics may be combined in any suitable manner in any one or more embodiments or examples. In addition, those skilled in the art can combine and combine different embodiments or examples and features of different embodiments or examples described in this specification without conflicting with each other.

Although the embodiments of the present invention have been shown and described above, it can be understood that the above embodiments are exemplary and should not be construed as limiting the present invention, those skilled in the art can make the above-mentioned The embodiments are subject to changes, modifications, substitutions and variations.

Claims (11)

1. A power switching device for a water heater, comprising:

the switching circuit is used for switching a power supply of the water heater, wherein the power supply of the water heater comprises an external alternating current power supply and a standby power supply;

the power failure detection circuit is connected with the external alternating current power supply and outputs a detection signal by detecting whether the external alternating current power supply is powered down or not;

the control circuit is connected with the power failure detection circuit and the switching circuit and controls the switching circuit according to the detection signal so as to supply power to the water heater through the external alternating current power supply when the external alternating current power supply is not powered down and supply power to the water heater through the standby power supply when the external alternating current power supply is powered down;

the control circuit includes:

the input unit is connected with the power failure detection circuit;

a reference unit providing a reference voltage;

the first input end of the comparison unit is connected with the input unit, and the second input end of the comparison unit is connected with the reference unit;

the control end of the switch unit is connected with the output end of the comparison unit, the first end of the switch unit is connected with a first direct current power supply, and the second end of the switch unit is connected with the switching circuit;

the input unit includes:

one end of the first capacitor is connected with the first input end of the comparison unit, and the other end of the first capacitor is grounded;

a first end of the charging loop is connected with the first direct current power supply, and a second end of the charging loop is connected with one end of the first capacitor;

a first end of the discharge loop is connected with one end of the first capacitor, and a second end of the discharge loop is grounded;

a charge control subunit connected between the first end of the charging loop and the first direct current power supply.

2. The power switching device of a water heater of claim 1, wherein the power down detection circuit comprises:

one end of the first resistor is connected with the first end of the external alternating current power supply;

the anode of the first diode is connected with the other end of the first resistor;

a second diode, wherein a cathode of the second diode is connected with a cathode of the first diode, and an anode of the second diode is connected with a second end of the external alternating current power supply;

the first end of the optical coupler is connected with the cathode of the second diode and the cathode of the first diode, the second end of the optical coupler is connected with the second end of the external alternating current power supply, the third end of the optical coupler is connected with the control circuit, and the fourth end of the optical coupler is grounded.

3. The power switching device of a water heater of claim 1, wherein the charging circuit comprises:

the anode of the third diode is connected with the charging control subunit;

and one end of the third resistor is connected with the cathode of the third diode, and the other end of the third resistor is connected with one end of the first capacitor.

4. The power switching device of a water heater according to claim 3, wherein the discharging circuit and the charging circuit share the third resistor, the discharging circuit further comprises a fourth resistor, one end of the fourth resistor is connected to one end of the third resistor, and the other end of the fourth resistor is grounded.

5. The power switching device of a water heater of claim 3, wherein the charge control subunit comprises:

one end of the fifth resistor is connected with the first direct current power supply;

the sixth resistor is connected with the other end of the fifth resistor, and the other end of the sixth resistor is connected with the power failure detection circuit;

the control end of the first switch tube is connected with the other end of the fifth resistor, the first end of the first switch tube is connected with the first direct-current power supply, and the second end of the first switch tube is connected with the first end of the charging loop.

6. The power switching apparatus of a water heater according to claim 1, wherein the reference unit comprises:

one end of the second capacitor is connected with the second input end of the comparison unit, and the other end of the second capacitor is grounded;

one end of the seventh resistor is connected with the first direct-current power supply, and the other end of the seventh resistor is connected with one end of the second capacitor;

and one end of the eighth resistor is connected with the other end of the seventh resistor, and the other end of the eighth resistor is grounded.

7. The power switching apparatus of a water heater according to claim 1, wherein the switching unit comprises:

one end of the ninth resistor is connected with the output end of the comparison unit;

one end of the tenth resistor is connected with the other end of the ninth resistor, and the other end of the tenth resistor is connected with the first direct-current power supply;

and the control end of the second switch tube is connected with one end of the tenth resistor, the first end of the second switch tube is connected with the first direct-current power supply, and the second end of the second switch tube is connected with the switching circuit.

8. The power switching apparatus of a water heater according to claim 1, wherein the first direct current power is provided by the backup power, the power switching apparatus further comprising a backup power detecting circuit connected between the first terminal of the switching unit and the first direct current power, wherein the backup power detecting circuit comprises:

a first end of the third switching tube is connected with the first direct current power supply, and a second end of the third switching tube is connected with the first end of the switching unit;

one end of the eleventh resistor is connected with the first direct-current power supply, and the other end of the eleventh resistor is connected with the control end of the third switching tube;

a twelfth resistor, one end of which is connected with the other end of the eleventh resistor;

and the cathode of the voltage-stabilizing tube is connected with the other end of the twelfth resistor, and the anode of the voltage-stabilizing tube is grounded.

9. The power switching device of a water heater according to claim 1, wherein the switching circuit comprises:

the public end of a single-pole double-throw switch in the single-pole double-throw relay is connected with the power input end of the water heater, the first end of the single-pole double-throw switch in the single-pole double-throw relay is connected with the standby power supply, the second end of the single-pole double-throw switch in the single-pole double-throw relay is connected with the power conversion module of the water heater, the power conversion module is connected with the external alternating current power supply, one end of a coil in the single-pole double-throw relay is connected with the control circuit, and the other end of the coil in the single-pole double-throw relay is grounded;

and the cathode of the fourth diode is connected with one end of the coil in the single-pole double-throw relay, and the anode of the fourth diode is connected with the other end of the coil in the single-pole double-throw relay.

10. The power switching device of a water heater of claim 9, further comprising a prompt circuit connected to the switching circuit, the prompt circuit comprising:

the anode of the light-emitting diode is connected with one end of a coil in the single-pole double-throw relay;

and one end of the second resistor is connected with the cathode of the light-emitting diode, and the other end of the second resistor is grounded.

11. A water heater characterized by comprising a power switching device of the water heater according to any one of claims 1-10.

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