Disclosure of Invention
The present invention is directed to solving, at least to some extent, one of the technical problems in the art described above. Therefore, an object of the present invention is to provide a protection device for an electric water heater, which can effectively prevent error protection and ensure normal use of the electric water heater.
The second purpose of the invention is to provide an electric water heater.
In order to achieve the above object, a first aspect of the present invention provides a protection device for an electric water heater, wherein the electric water heater includes a power cord and a body, the body includes a thermal circuit breaker, a controller, a heater and a liner, the power cord includes a three-pole pin, the three-pole pin is connected with an external power socket in an insertion manner, and the protection device includes: the three-pole linkage switch is connected with the three-pole pin so as to connect and disconnect a zero line, a live line and a ground line which are connected with a power supply; a live and ground voltage detection circuit for detecting a live and ground voltage signal between the live line and the ground line; the zero ground voltage detection circuit is used for detecting a zero ground voltage signal between the zero line and the ground line; the main control chip is respectively connected with the live voltage and ground voltage detection circuit and the zero ground voltage detection circuit, and is used for judging whether the voltage between the live wire and the ground wire is abnormal or not according to the live voltage and ground voltage signal and judging whether the voltage exists between the zero line and the ground wire or not according to the zero ground voltage signal; the first detection unit is arranged corresponding to the ground wire and is used for detecting a current signal of the ground wire; the leakage control chip is respectively connected with the main control chip and the first detection unit and used for judging whether the ground wire has current or not according to a current signal of the ground wire, wherein the leakage control chip is used for generating a ground wire live protection instruction when the voltage between the live wire and the ground wire is abnormal and the current exists in the ground wire, or when the voltage between the live wire and the ground wire is normal, the voltage exists between the zero wire and the ground wire and the current exists in the ground wire; the tripping circuit is connected with the leakage control chip and used for receiving the earth wire live protection instruction and generating a tripping instruction according to the earth wire live protection instruction; and the tripping mechanism is respectively connected with the three-pole linkage switch and the tripping circuit and is used for receiving and executing the tripping instruction so as to control the zero line, the live line and the ground wire to be in a breaking state by controlling the three-pole linkage switch.
According to the protection device of the electric water heater, the live voltage and ground voltage signal between the live wire and the ground wire is detected through the live voltage and ground voltage detection circuit, the zero ground voltage signal between the zero line and the ground wire is detected through the zero ground voltage detection circuit, the current signal of the ground wire is detected through the first detection unit, then through the logic judgment of the main control chip and the leakage control chip, whether the ground wire is electrified or not is judged by combining the live voltage and ground voltage signal, the zero ground voltage signal and the current signal of the ground wire, and the ground wire is controlled to be in the breaking state to realize the ground wire electrified protection, so that the safety and the reliability of the ground wire protection are improved by cutting off the three-pole power supply, the error protection can be effectively prevented, and the normal use of the electric water heater is ensured.
In addition, the protection device for an electric water heater according to the above embodiment of the present invention may further have the following additional technical features:
further, the protection device of the electric water heater further comprises: the zero-fire power failure detection circuit is used for detecting a power failure signal between the zero line and the live line; the zero-fire voltage detection circuit is used for detecting a zero-fire voltage signal between the zero line and the live line; the over-temperature detection circuit is used for detecting a temperature signal of the three-pole pin, wherein the control chip is respectively connected with the zero-fire power-down detection circuit, the zero-fire voltage detection circuit and the over-temperature detection circuit, and is used for judging whether power down occurs between the zero line and the live wire according to the power-down signal, generating a power-down protection instruction when power down occurs between the zero line and the live wire, judging whether voltage between the zero line and the live wire is overvoltage or undervoltage according to the zero-fire voltage signal, generating an overvoltage protection instruction or an undervoltage protection instruction when the voltage between the zero line and the live wire is overvoltage or undervoltage, judging whether the three-pole pin is over-temperature according to the temperature signal, generating an over-temperature protection instruction when the three-pole pin is over-temperature, and receiving the power-down protection instruction, The overvoltage protection instruction, the undervoltage protection instruction or the overtemperature protection instruction, and the tripping instruction is generated according to the power-down protection instruction, the overvoltage protection instruction, the undervoltage protection instruction or the overtemperature protection instruction.
Further, the protection device of the electric water heater further comprises: the second detection unit corresponds to the zero line and the live wire, the second detection unit is connected with the leakage control chip, the second detection unit is used for detecting the leakage signal of the zero line or the live wire, the leakage control chip generates a leakage protection instruction when the zero line or the live wire leaks electricity according to the leakage signal, and the tripping circuit is used for receiving the leakage protection instruction and generating the tripping instruction according to the leakage protection instruction.
Further, the protection device of the electric water heater further comprises a power circuit, and the power circuit comprises: the rectifying unit is arranged corresponding to the zero line and the live line and is used for converting alternating current input by the zero line and the live line into first direct current; the voltage reduction unit is used for reducing the voltage of the first direct current to obtain a second direct current; and the voltage stabilizing unit is used for stabilizing the voltage of the second direct current.
The zero-fire voltage detection circuit and the zero-fire power failure detection circuit are arranged corresponding to the rectification unit.
Further, the trip circuit includes: one end of the trip coil is connected with the direct-current positive end of the power circuit; the anode end of the first controlled silicon is connected with the other end of the trip coil, the cathode end of the first controlled silicon is connected with the direct-current cathode end of the power circuit, and the control end of the first controlled silicon is respectively connected with the main control chip and the leakage control chip; the cathode end of the second silicon controlled rectifier is connected with one end of the trip coil, and the control end of the second silicon controlled rectifier is respectively connected with the main control chip and the leakage control chip; the anode end of the rectifier diode is connected with one end of the trip coil, and the cathode end of the rectifier diode is connected with the anode end of the second controlled silicon; and one end of the charge-discharge capacitor is connected with the direct-current negative end of the power circuit, and the other end of the charge-discharge capacitor is connected with the anode end of the second controlled silicon.
Wherein, the control chip obtains a power-on reset signal through the power circuit, and generates a power-on reset instruction according to the power-on reset signal, and the protection device further comprises: the power-on action circuit is connected with the control chip and is used for receiving the power-on reset instruction and generating a power-on action instruction according to the power-on reset instruction; and the power-on action mechanism is connected with the power-on action circuit and is used for receiving and executing the power-on action command so as to control the zero line, the live line and the ground wire to be in a connected state by controlling the three-pole linkage switch.
Further, the protection device of the electric water heater further comprises: the reset circuit is connected with the main control chip, the main control chip is used for generating a manual reset instruction according to manual reset operation on the reset circuit, and the power-on action circuit is used for receiving the manual reset instruction and generating the power-on action instruction according to the manual reset instruction.
Further, the protection device of the electric water heater further comprises: and the zero-fire leakage test circuit corresponds to the zero line and the live line and is connected with the second detection unit, and the leakage control chip generates the leakage protection instruction according to the manual test operation of the zero-fire leakage test circuit.
Further, the protection device of the electric water heater further comprises an indication and alarm circuit, wherein the indication and alarm circuit comprises: the power supply indicating unit is connected with the main control chip and is used for sending power-on prompting information when the main control chip judges that power failure does not occur between the zero line and the live wire; and the alarm unit is connected with the main control chip and is used for sending alarm prompt information when the earth leakage control chip generates the earth wire live protection instruction.
In order to achieve the above object, in a second aspect of the present invention, an electric water heater is provided, which includes the protection device of the electric water heater according to the first aspect of the present invention.
The electric water heater according to the embodiment of the invention can effectively prevent error protection and ensure normal use.
Detailed Description
Reference will now be made in detail to embodiments of the present invention, examples of which are illustrated in the accompanying drawings, wherein like or similar reference numerals refer to the same or similar elements or elements having the same or similar function throughout. The embodiments described below with reference to the drawings are illustrative and intended to be illustrative of the invention and are not to be construed as limiting the invention.
The electric water heater and the protection device thereof according to the embodiment of the invention are described below with reference to the accompanying drawings.
As shown in fig. 1, the electric water heater according to the embodiment of the present invention may further include a power cord 200 and a body 300 in addition to the protection device 100 (not shown in fig. 1), as shown in fig. 1 and 2, the body 300 may include a thermal cut-off 310, a controller 320, a heater 330 and an inner container 340, the power cord 200 may include a three-pole pin 210, and the three-pole pin 210 may be connected to an external power socket in a plug-in manner.
The inner container 340 is a positive displacement device for storing water, and includes a container body, a water outlet pipe and a water inlet pipe, and the heater 330 is used for heating the water stored in the inner container. The controller 320 can perform temperature sensing control, and the controller 320 can control the heater 330 to be automatically connected with or disconnected from the external power supply according to the first temperature threshold, so as to control the water temperature of the inner container within a set range. In one embodiment of the present invention, the first temperature threshold of the controller 320 may be a temperature value below 85 ℃. The thermal circuit breaker 310 is a mechanical device for temperature sensing control by using a liquid working medium or a bimetallic element, the thermal circuit breaker 310 can perform power-off protection on the heater 330 according to a second temperature threshold, specifically can prevent the temperature of the inner container from being too high by simultaneously cutting off the live wire L and the zero line N pole of the working loop of the heater 330, and the second temperature threshold cannot be changed by a user and cannot be automatically reset after power-off protection. In one embodiment of the present invention, the second temperature threshold of the thermal cutout 310 may be a temperature value lower than 110 ℃.
In one embodiment of the present invention, as shown in fig. 3, the controller 320 may include a power supply unit 321, a relay unit 322, a relay control circuit 323, a microprocessor 324, a temperature sensor 325, a temperature detection circuit 326, and a display operation circuit 327.
The power supply unit 321 may include a transformer 01 and a rectifying and filtering circuit 02, wherein the transformer 01 may be a transformer with electrical isolation, an input end of the transformer is connected to two poles of a zero line N and a live line L of a power supply, and the power supply is stepped down by the transformer 01 and then output to the rectifying and filtering voltage stabilizing circuit 02. The rectifying, filtering and voltage stabilizing circuit 02 converts the ac power stepped down by the transformer 01 into a stable dc power, and supplies power to the relay unit 322, the relay control circuit 323, the microprocessor 324, the temperature sensor 325, the temperature detection circuit 326, and the display operation circuit 327.
The temperature sensor 325 may be a component including a thermistor, as shown in fig. 1 and 2, a temperature sensing body of the temperature sensor 325 may be installed inside the inner container 340 for measuring the temperature of the water stored in the inner container 340 to obtain a water storage temperature signal, and the temperature detection circuit 326 may process the temperature signal input by the temperature sensor 325 and output the processed temperature signal to the microprocessor 324. The microprocessor 324 can operate and determine the temperature signal inputted from the temperature detection circuit 326, and output a control command for turning on or off to the relay control circuit 323. The relay control circuit 323 may receive a control command output from the microprocessor 324 and output an on or off control command to the relay unit 322, and the relay unit 322 may control the power supply of the heater operation circuit to be in an on or off state according to the control command transmitted from the relay control circuit 323. The display operation circuit 327 may include a display unit and an operation unit, the display operation circuit 327 may be configured to send a manual operation instruction to the microprocessor 324 and can display a signal output by the microprocessor 324, and in an embodiment of the present invention, the display operation circuit 327 may include a touch screen.
Fig. 4 is a schematic structural diagram of a protection device of an electric water heater according to an embodiment of the invention.
As shown in fig. 4, the protection device 100 of the electric water heater according to the embodiment of the present invention includes a three-pole gang switch 110, a voltage detection circuit 120 for fire and ground, a voltage detection circuit 130 for zero and ground, a main control chip 140, a first detection unit 150 (not shown, including 151 and 152), a leakage control chip 160, a trip circuit 170, and a trip mechanism 180.
The three-pole linked switch 110 is connected with the three-pole pin 210 to connect and disconnect a zero line N, a live line L and a ground line E which are connected with a power supply; the voltage detection circuit 120 is configured to detect a voltage signal between the live line L and the ground line E; the zero ground voltage detection circuit 130 is configured to detect a zero ground voltage signal between the zero line N and the ground line E; the main control chip 140 is connected to the live voltage and ground voltage detection circuit 120 and the zero ground voltage detection circuit 130, respectively, and the main control chip 140 is configured to determine whether the voltage between the live line L and the ground line E is abnormal according to the live voltage and ground voltage signal, and determine whether a voltage exists between the zero line N and the ground line E according to the zero ground voltage signal; the first detecting unit 150 is disposed corresponding to the ground line E, and the first detecting unit 150 is configured to detect a current signal of the ground line E; the leakage control chip 160 is connected to the main control chip 140 and the first detection unit 150, respectively, and the leakage control chip 160 is configured to determine whether a current exists in the ground line E according to a current signal of the ground line E, where the leakage control chip 160 is configured to generate a ground line E live protection instruction when a voltage between the live line L and the ground line E is abnormal and the ground line E has a current, or when a voltage between the live line L and the ground line E is normal, a voltage between the null line N and the ground line E exists and the ground line E has a current; the tripping circuit 170 is connected with the leakage control chip 160, and the tripping circuit 170 is used for receiving the earth wire E live protection instruction and generating a tripping instruction according to the earth wire E live protection instruction; the tripping mechanism 180 is respectively connected with the three-pole linkage switch 110 and the tripping circuit 170, and the tripping mechanism 180 is used for receiving and executing a tripping instruction so as to control the zero line N, the live line L and the ground line E to be in a breaking state by controlling the three-pole linkage switch 110.
The main control chip 140 of the embodiment of the present invention may be a single chip, and the leakage control chip 160 may be an IC chip capable of implementing its functions. As shown in fig. 4, the first detecting unit 150 may include a first electromagnetic coil 151 disposed on the ground line E and a ground line E current detecting circuit 152.
The main control chip 140 may determine that the voltage between the live line L and the ground line E is abnormal when the voltage value between the live line L and the ground line E detected by the live and ground voltage detection circuit 120 is less than or equal to a first preset voltage, and determine that the voltage between the live line L and the ground line E is normal when the voltage value between the live line L and the ground line E detected by the live and ground voltage detection circuit 120 is greater than or equal to a second preset voltage. The main control chip 140 may determine that there is no voltage between the zero line N and the ground line E when the voltage value between the zero line N and the ground line E detected by the zero ground voltage detection circuit 130 is less than or equal to a third preset voltage, and determine that there is a voltage between the zero line N and the ground line E when the voltage value between the zero line N and the ground line E detected by the zero ground voltage detection circuit 130 is greater than or equal to a fourth preset voltage. The leakage control chip 160 may determine that the ground line E has a current when the current value of the ground line E detected by the first detecting unit 150 is greater than or equal to a first preset current.
In an embodiment of the present invention, when the voltage value Ule between the live wire L and the ground wire E detected by the live voltage detection circuit 120 is less than or equal to the first preset voltage value Ule1, the voltage signal may be input to the single chip microcomputer, the single chip microcomputer may perform an operation judgment and output a fire ground abnormality signal to the leakage control chip 160, at this time, the leakage control chip 160 may set the zero ground voltage signal input by the zero ground voltage detection circuit 130 through the single chip microcomputer to an invalid state, that is, the zero ground voltage signal does not participate in the logic judgment, as long as the leakage control chip 160 judges that the current value Ie of the ground wire E detected by the first electromagnetic induction coil 151 and the ground wire E current detection circuit 152 is greater than or equal to the first preset current value Ie1, the leakage control chip 160 outputs a ground wire E live protection command to the trip circuit 170, and then the trip circuit 170 immediately drives the trip mechanism 180 to perform an action to switch the linked three-pole switch 110 from a switched-on state, and finally, three poles of a zero line N, a live line L and a ground line E of the electric water heater are quickly switched to a breaking state, so that the ground line E of the electric water heater is protected in an electrified way. The first preset voltage value Ule1 can be set within 110V, the first preset current value Ie1 can be set within 30mA, and the preferred values are 15mA and 30 mA.
In an embodiment of the present invention, when the voltage value Ule between the live wire L and the ground wire E detected by the live wire voltage detection circuit 120 is equal to or greater than the second preset voltage Ule2, the voltage signal may be input to the single-chip microcomputer, the single-chip microcomputer may perform an operation judgment and output a fire ground normal signal to the leakage control chip 160, and at this time, a zero ground voltage signal may be further judged, if the voltage value Une between the zero line N and the ground wire E detected by the zero ground voltage detection circuit 130 is equal to or less than the third preset voltage Une1, the voltage signal may be input to the single-chip microcomputer, the single-chip microcomputer may perform an operation judgment and output a zero ground electricity absence judgment signal to the leakage control chip 160, and in this state, the leakage control chip 160 sets the ground wire E current signal input by the first electromagnetic induction coil 151 and the ground wire E current detection circuit 152 to an inactive state, that is, the ground wire E, the leakage control chip 160 does not output the live protection instruction of the ground wire E, and the trip circuit 170 does not output the trip instruction, so that the false protection action caused by the interference of the environment to the ground wire E can be prevented. The setting range of the second preset voltage Ule2 may be above 110V.
In an embodiment of the present invention, when the voltage value Ule between the live line L and the ground line E detected by the live voltage and ground voltage detection circuit 120 is equal to or greater than the second preset voltage Ule2, the voltage signal may be input to the single chip microcomputer, the single chip microcomputer may perform an operation judgment and output a normal signal of the live line to the leakage control chip 160, and at this time, a zero ground voltage signal may be further judged, if the voltage value Une between the zero line N and the ground line E detected by the zero ground voltage detection circuit 130 is equal to or greater than the fourth preset voltage Une2, the voltage signal may be input to the single chip microcomputer, the single chip microcomputer performs an operation judgment and outputs a zero ground determining signal to the leakage control chip 160, and then judges the ground line E current signal input by the first electromagnetic induction coil 151 and ground line E current detection circuit 152, if the current value Ie of the ground line E detected by the first electromagnetic induction coil 151 and ground line E current detection circuit 152 is equal to or greater than the first preset current value Ie1, the earth leakage control chip 160 outputs an earth wire E live protection instruction to the trip circuit 170, and then the trip circuit 170 immediately drives the trip mechanism 180 to perform an action, so as to switch the three-pole linkage switch 110 from the on state to the off state, and finally quickly switch the three poles of the zero line N, the live line L and the earth wire E of the electric water heater to the off state, thereby realizing the earth wire E live protection function of the electric water heater.
According to the protection device of the electric water heater, the live voltage and ground voltage signal between the live wire and the ground wire is detected through the live voltage and ground voltage detection circuit, the zero ground voltage signal between the zero line and the ground wire is detected through the zero ground voltage detection circuit, the current signal of the ground wire is detected through the first detection unit, then through the logic judgment of the main control chip and the leakage control chip, whether the ground wire is electrified or not is judged by combining the live voltage and ground voltage signal, the zero ground voltage signal and the current signal of the ground wire, and the ground wire is controlled to be in the breaking state to realize the ground wire electrified protection, so that the safety and the reliability of the ground wire protection are improved by cutting off the three-pole power supply, the error protection can be effectively prevented, and the normal use of the electric water heater is ensured.
The electric water heater provided by the embodiment of the invention not only has the ground wire E live protection function capable of preventing error protection, but also has the zero-fire power-off protection function, the overvoltage protection function, the undervoltage protection function, the overtemperature protection function, the zero-fire leakage protection function, the power-on switching-on function and the like.
As shown in fig. 4, the protection device 100 of the electric water heater according to the embodiment of the present invention may further include a zero fire power failure detection circuit 190, a zero fire voltage detection circuit 1100, an over temperature detection circuit 1110, a second detection unit 1120 (not shown, including 1121 and 1122), a power circuit 1130, a power-on action circuit 1140, and a power-on action mechanism 1150.
In one embodiment of the present invention, the zero power loss detection circuit 190 is used for detecting a power loss signal between the zero line N and the live line L; the zero-fire voltage detection circuit 1100 is used for detecting a zero-fire voltage signal between the zero line N and the live line L; the over-temperature detection circuit 1110 is used to detect a temperature signal of the three-pole pin. Wherein the control chip is respectively connected with the zero-fire power failure detection circuit 190, the zero-fire voltage detection circuit 1100 and the overtemperature detection circuit 1110, the control chip is used for judging whether power failure occurs between the zero line N and the live line L according to the power failure signal and generating a power failure protection instruction when the power failure occurs between the zero line N and the live line L, judging whether the voltage between the zero line N and the live line L is overvoltage or undervoltage according to the zero line voltage signal, generating an overvoltage protection instruction or an undervoltage protection instruction when the voltage between the zero line N and the live line L is overvoltage or undervoltage, and judging whether the three-pole pin is over-temperature according to the temperature signal, and generating an over-temperature protection instruction when the three-pole pin is over-temperature, wherein the trip circuit 170 is used for receiving a power-down protection instruction, an over-voltage protection instruction, an under-voltage protection instruction or an over-temperature protection instruction, and generating a tripping instruction according to the power failure protection instruction, the overvoltage protection instruction, the undervoltage protection instruction or the overtemperature protection instruction.
The main control chip 140 may determine that a power failure occurs between the zero line N and the live line L when a non-waveform time of an ac waveform of the zero line N and the live line L detected by the zero line power failure detection circuit 190 is greater than or equal to a first preset time, and determine that a voltage between the zero line N and the live line L is excessive when a voltage between the zero line N and the live line L detected by the zero line voltage detection circuit 1100 is greater than or equal to a fifth preset voltage, and determine that a voltage between the zero line N and the live line L is insufficient when a voltage between the zero line N and the live line L detected by the zero line voltage detection circuit 1100 is less than or equal to a sixth preset voltage, and determine that the three-pole pin is over-warm when a temperature of the three-pole pin detected by the over-warm detection circuit 1110 is greater than or equal to the first preset temperature value.
In a specific embodiment of the present invention, the zero-fire power-down detection circuit 190 can process the zero-fire alternating voltage, then input the processed zero-fire alternating voltage to the single chip for operation and judge whether a normal alternating current waveform exists, if the continuous waveform-free time, i.e. the power-down time Tln, is greater than or equal to the first preset time Tln1, the single chip outputs a power-down protection instruction to the trip circuit 170, the trip circuit 170 can generate a trip instruction, then the trip circuit 170 immediately drives the trip mechanism 180 to execute an action to switch the three-pole linkage switch 110 from the on state to the off state, and finally the three poles of the zero line N, the live line L and the ground line E of the electric water heater are quickly switched to the off state, thereby implementing the zero-. The value range of the set value first preset time Tln1 can be within 5s, and the time required by the three-pole linked switch 110 to complete the breaking action after the zero-fire power failure detection circuit 190 detects that the power failure time Tln is greater than or equal to the first preset time Tln1 can be less than or equal to 0.5 s.
Through the zero-fire power-off protection function, the protection can be carried out when the power supply of the electric water heater is normal, and the zero line N, the live line L and the ground line E of the power supply can be automatically cut off after the zero-fire power-off of the power supply of the electric water heater occurs, so that the electric water heater is ensured to be always in a safe isolation state, and the safety of the electric water heater is further improved.
In a specific embodiment of the present invention, the zero voltage signal output by the zero voltage detection circuit 1100 is input to the single chip for operation and judgment, if the voltage Uln between the zero line N and the live line L is less than or equal to the sixth preset voltage Umin, the single chip outputs an under-voltage protection instruction to the trip circuit 170, or the voltage Uln between the zero line N and the live line L is greater than or equal to the fifth preset voltage Umax, the single chip outputs an over-voltage protection instruction to the trip circuit 170, and then the trip circuit 170 immediately drives the trip mechanism 180 to perform an action so as to switch the three-pole linkage switch 110 from the on state to the off state, and finally the three poles of the zero line N, the live line L and the ground line E of the electric water heater are quickly switched to the off state, thereby implementing the under-voltage protection function or the over-voltage. The setting range of the sixth preset voltage Umin may be 180V for 100-.
In a specific embodiment of the present invention, the over-temperature detection circuit 1110 may detect temperature signals of the pins of the poles of the zero line N, the live line L, and the ground line E and output the temperature signals to the single chip, after the operation processing, if the temperature T is greater than or equal to a first preset temperature T1, the single chip outputs an over-temperature protection instruction to the trip circuit 170, the trip circuit 170 may generate a trip instruction, and then the trip circuit 170 immediately drives the trip mechanism 180 to perform an action to switch the three-pole linkage switch 110 from the on state to the off state, so as to finally quickly switch the three poles of the zero line N, the live line L, and the ground line E of the electric water heater to the off state, thereby implementing the over-. The range of the first preset temperature T1 may be within 180 ℃, and the time required for the over-temperature detection circuit 1110 to complete the breaking operation of the three-pole linked switch 110 after detecting that the temperature T is greater than or equal to the first preset temperature T1 may be less than or equal to 3 min.
In an embodiment of the present invention, the second detecting unit 1120 may be disposed corresponding to the neutral line N and the live line L, and the second detecting unit 1120 is connected to the leakage control chip 160, and the second detecting unit 1120 is configured to detect a leakage signal of the neutral line N or the live line L. The leakage control chip 160 generates a leakage protection instruction when it is determined that the zero line N or the live line L has a leakage according to the leakage signal, and the trip circuit 170 is configured to receive the leakage protection instruction and generate a trip instruction according to the leakage protection instruction. The second detection unit 1120 may include a second electromagnetic coil 1121 and a zero-fire leakage detection circuit 1122.
The leakage control chip 160 may determine that the leakage occurs in the zero line N or the live line L when the leakage current value of the zero line N or the live line L detected by the second detection unit 1120 is greater than or equal to a second preset current.
In an embodiment of the present invention, the zero-fire leakage signal output by the second electromagnetic induction coil 1121 and the zero-fire leakage detection circuit 1122 is input to the leakage control chip 160 for performing operation and judgment, if the leakage current value Iln of the zero line N or the live line L is greater than or equal to the second preset current Iln1, the leakage control chip 160 outputs a leakage protection instruction to the trip circuit 170, and then the trip circuit 170 immediately drives the trip mechanism 180 to perform a trip action to further enable the three-pole linked switch 110 to operate, so as to finally enable the three poles of the zero line N, the live line L and the ground line E of the electric water heater to be rapidly switched from the on state to the off state, thereby implementing the zero-fire leakage protection function of the electric water heater. The set range of the second preset current Iln1 may be within 30mA, and the preferred values are 5mA, 6mA, 10mA and 15mA, and the time required from the detection of the leakage current value Iln of the zero line N or the live line L by the second electromagnetic induction coil 1121 to the completion of the turn-off operation of the three-pole linked switch 110 after the second preset current Iln1 is greater than or equal to 0.1s may be less than or equal to.
As shown in fig. 4, the power circuit 1130 may include a rectifying unit 1131, a voltage dropping unit 1132, and a voltage stabilizing unit 1133. The rectifying unit 1131 is disposed corresponding to the zero line N and the live line L, and the rectifying unit 1131 may adopt a half-wave or full-wave rectifying circuit structure for converting the alternating current input by the zero line N and the live line L into the first direct current. The voltage reducing unit 1132 is connected to the rectifying unit 1131, and the voltage reducing unit 1132 may have a resistance-capacitance voltage reducing circuit structure, and is configured to reduce the voltage of the first direct current to obtain a second direct current. The voltage stabilizing unit 1133 is connected to the voltage reducing unit 1132, and the voltage stabilizing unit 1133 may adopt a 7805 three-terminal voltage stabilizing integrated circuit plus a filter capacitor circuit structure for stabilizing the voltage of the second direct current.
The zero-fire voltage detection circuit 1100 and the zero-fire power failure detection circuit 190 may be arranged corresponding to the rectifying unit 1131.
In an embodiment of the present invention, the control chip may obtain the power-on reset signal through the power circuit 1130, and generate the power-on reset instruction according to the power-on reset signal. The power-on action circuit 1140 is connected to the control chip, and the power-on action circuit 1140 is used for receiving a power-on reset instruction and generating a power-on action instruction according to the power-on reset instruction; the power-on action mechanism 1150 is connected to the power-on action circuit 1140, and the power-on action mechanism 1150 is configured to receive and execute a power-on action command, so as to control the neutral line N, the live line L, and the ground line E to be in a connected state by controlling the three-pole linked switch 110.
In an embodiment of the present invention, when the single chip automatically identifies that the power circuit 1130 supplying power to the single chip is powered on, the single chip may output a power-on reset signal to the power-on action circuit 1140, the power-on reset signal sends a power-on action command to the upper electric action mechanism 1150 through the power-on action circuit 1140, and then the power-on action circuit 1140 immediately drives the power-on action mechanism 1150 to perform an action to turn on the three-pole linkage switch 110, so as to finally enable the three poles of the zero line N, the live line L and the ground line E of the electric water heater to be rapidly switched to a turn-on state, thereby. The time required from the power-on of the power circuit 1130 to the completion of the turn-on of the three-pole gang switch 110 may be less than or equal to 0.5 s.
In addition, as shown in fig. 4, the protection device 100 of the electric water heater according to the embodiment of the present invention may further include a reset circuit 1160, a zero leakage test circuit 1170, an indication and alarm circuit 1180, and a function expansion interface 1190.
The reset circuit 1160 is connected to the main control chip 140, the main control chip 140 is configured to generate a manual reset instruction according to a manual reset operation on the reset circuit 1160, and the power-on action circuit 1140 is configured to receive the manual reset instruction, generate a power-on action instruction according to the manual reset instruction, and output the power-on action instruction to the power-on action mechanism 1150, so that the power-on action mechanism 1150 controls the zero line N, the live line L, and the ground line E to be in a connected state by controlling the three-pole linkage switch 110.
The zero-fire leakage test circuit 1170 corresponds to the zero line N and the live line L and is connected with the second detection unit 1120, and the zero-fire leakage test circuit 1170 can comprise a test key and is used for manual test operation by triggering the test key. The leakage control chip 160 also generates leakage protection instructions based on manual testing operations on the zero fire leakage test circuit 1170. Through the manual leakage test, it can be verified whether the protection device 100 of the embodiment of the present invention can operate effectively.
The indication and alarm circuit 1180 may include a power indication unit and an alarm unit. The power supply indicating unit is connected with the main control chip 140 and is used for sending power-on prompting information when the main control chip 140 judges that power failure does not occur between the zero line N and the live line L; the alarm unit is connected to the main control chip 140, and the alarm unit is configured to send out alarm prompt information when the earth leakage control chip 160 generates an earth wire E live protection instruction, so as to indicate that the electric water heater is in a dangerous state.
The function expansion interface 1190 is used to access other subsequently developed function modules to implement function expansion of the power line.
In one embodiment of the present invention, as shown in fig. 5, the trip circuit 170 may include a trip coil L1, a first silicon controlled SCR1, a second silicon controlled SCR2, a rectifier diode D1, and a charge and discharge capacitor C1. One end of the trip coil L1 is connected to the positive dc terminal of the power circuit 1130; the anode end of the first silicon controlled rectifier SCR1 is connected with the other end of the trip coil L1, the cathode end of the first silicon controlled rectifier SCR1 is connected with the direct-current negative end of the power circuit 1130, and the control end of the first silicon controlled rectifier SCR1 is connected with the main control chip 140 and the leakage control chip 160 respectively; the cathode end of the second silicon controlled rectifier SCR2 is connected with one end of the trip coil L1, and the control end of the second silicon controlled rectifier SCR2 is respectively connected with the main control chip 140 and the electric leakage control chip 160; the anode end of the rectifier diode D1 is connected with one end of the trip coil L1, and the cathode end of the rectifier diode D1 is connected with the anode end of the second SCR 2; one end of the charge-discharge capacitor C1 is connected to the dc negative terminal of the power circuit 1130, and the other end of the charge-discharge capacitor C1 is connected to the anode terminal of the second SCR 2.
When the zero line N and the live line L of the power supply of the electric water heater are powered on, the power circuit 1130 may provide a working power supply for the trip circuit 170, and meanwhile, the power circuit 1130 may charge the charging and discharging capacitor C1. When the zero line N and the live line L of the power supply of the electric water heater are powered on, the control end of the first silicon controlled SCR1 is turned on by receiving a ground line E live protection instruction, a power-down protection instruction, an overvoltage protection instruction, an undervoltage protection instruction, an overtemperature protection instruction, a leakage protection instruction and the like sent by the main control chip 140 or the leakage control chip 160, the power circuit 1130 provides power for the trip coil L1, so that the trip coil L1 attracts the iron core of the trip coil to transmit a tripping action to the trip mechanism 180 after being powered on, that is, the trip circuit 170 sends the tripping instruction in the form of attracting the iron core, and the trip mechanism 180 disconnects the switches corresponding to the zero line N, the live line L and the ground line E in the three-pole linked switch 110 by receiving the tripping action, thereby realizing the disconnection of the zero line N, the live line L and. When the zero line N and the live line L of the power supply of the electric water heater lose power, the second silicon controlled rectifier SCR2 receives the instruction to conduct, the charging and discharging capacitor C1 can provide power for the trip coil L1, and the rectifier diode D1 can play a circuit isolation role at this time.
It should be noted that, in an embodiment of the present invention, as shown in fig. 4, the three-pole linked switch 110, the voltage detection circuit 120 for fire and ground, the detection circuit 130 for zero and ground voltage, the main control chip 140, the first detection unit 150, the leakage control chip 160, the trip circuit 170, the trip mechanism 180, the detection circuit 190 for zero and power failure, the detection circuit 1100 for zero and ground voltage, the over-temperature detection circuit 1110, the second detection unit 1120, the power supply circuit 1130, the power-on action circuit 1140, the power-on action mechanism 1150, the reset circuit 1160, the test circuit 1170 for zero and power leakage, the indication and alarm circuit 1180, and the function expansion interface 1190 may be disposed corresponding to the power supply line 200. The power cord 200 may further include a power cord 220 and a connector 230, wherein the power cord 220 may be used to connect the protection device 100 to the connector 230 and the connector 230 may be used to connect the power cord 220 to the thermal circuit breaker 310.
The invention further provides an electric water heater corresponding to the embodiment.
The electric water heater according to the embodiment of the present invention includes the protection device for an electric water heater according to the above embodiment of the present invention, and the specific implementation manner thereof can refer to the above embodiment, and is not described herein again to avoid redundancy.
The electric water heater according to the embodiment of the invention can effectively prevent error protection and ensure normal use.
In the description of the present invention, it is to be understood that the terms "central," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," "circumferential," and the like are used in the orientations and positional relationships indicated in the drawings for convenience in describing the invention and to simplify the description, and are not intended to indicate or imply that the referenced device or element must have a particular orientation, be constructed and operated in a particular orientation, and are not to be considered limiting of the invention.
Furthermore, the terms "first", "second" and "first" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of the present invention, "a plurality" means two or more unless specifically defined otherwise.
In the present invention, unless otherwise expressly stated or limited, the terms "mounted," "connected," "secured," and the like are to be construed broadly and can, for example, be fixedly connected, detachably connected, or integrally formed; can be mechanically or electrically connected; either directly or indirectly through intervening media, either internally or in any other relationship. The specific meanings of the above terms in the present invention can be understood by those skilled in the art according to specific situations.
In the present invention, unless otherwise expressly stated or limited, the first feature "on" or "under" the second feature may be directly contacting the first and second features or indirectly contacting the first and second features through an intermediate. Also, a first feature "on," "over," and "above" a second feature may be directly or diagonally above the second feature, or may simply indicate that the first feature is at a higher level than the second feature. A first feature being "under," "below," and "beneath" a second feature may be directly under or obliquely under the first feature, or may simply mean that the first feature is at a lesser elevation than the second feature.
In the description herein, references to the description of the term "one embodiment," "some embodiments," "an example," "a specific example," or "some examples," etc., mean that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the invention. In this specification, the schematic representations of the terms used above are not necessarily intended to refer to the same embodiment or example. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples. Furthermore, various embodiments or examples and features of different embodiments or examples described in this specification can be combined and combined by one skilled in the art without contradiction.
Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention, and that variations, modifications, substitutions and alterations can be made to the above embodiments by those of ordinary skill in the art within the scope of the present invention.