Electric water pumping device and water inlet protection circuit

Abstract

The utility model discloses a water inlet protection circuit and an electric water pumping device. The water inlet protection circuit comprises a humidity detection device which is arranged in the electric water pumping device; the humidity detection device is used for detecting the content of water molecules in the electric water pumping device and outputting a corresponding humidity signal; the first end of the control circuit is connected with the output end of a power supply assembly of the electric water pumping device, the second end is connected with a water pump in the electric water pumping device, and the third end is connected with the output end of the humidity detection device; and the control circuit is used for switching off a power supply loop between the power supply assembly and the water suction pump when the humidity signal is received and the voltage value of the humidity signal is greater than or equal to a first preset voltage value. When the humidity signal voltage value output by the humidity detection device is larger than or equal to the first preset voltage value, the control circuit judges that water enters the electric water pumping device, the power supply loop between the power supply assembly and the water suction pump is disconnected, and therefore the circuit is protected.

Description

Technical Field

[0001] The utility model relates to the technical field of electric water pumps, in particular to an electric water pump and a water inlet protection circuit thereof. Background Art

[0002] With the development of lithium battery applications, many purely manual products have been gradually transformed into lithium-powered products. For example, the manual push-type water pump used in bottled water is gradually being replaced by smart electric water pumps. Smart electric water pumps can automatically discharge water with just a light press of a button, and can also stop automatically without having to keep pressing to discharge water. Compared with traditional manual water pumps, they are smart, convenient and fast.

[0003] However, the smart electric water pump is often in contact with water and is prone to water ingress. Electronic products are prone to short circuits and other faults after water ingress. Therefore, the smart electric water pump may fail to automatically pump water, the switch button may fail, and it may not be turned off. This will cause water on the ground, and people may slip when passing by, or the expensive wooden floor may be soaked. Utility Model Content

[0004] The main purpose of the utility model is to provide a water ingress protection circuit, which is intended to prevent short circuit and other faults from occurring in electronic products after water ingress.

[0005] In order to achieve the above-mentioned purpose, the utility model provides a water inlet protection circuit, which is applied to an electric water pump; the protection circuit comprises:

[0006] A humidity detection device, the humidity detection device is arranged inside the electric water pump; the humidity detection device is used to detect the water molecule content inside the electric water pump and output a corresponding humidity signal;

[0007] A control circuit, a first end of which is connected to the output end of the power supply component of the electric water pump, a second end of which is connected to the water pump in the electric water pump, and a third end of which is connected to the output end of the humidity detection device; the control circuit is used to receive the humidity signal and cut off the power supply circuit between the power supply component and the water pump when the voltage value of the humidity signal is greater than or equal to a first predetermined voltage value.

[0008] Optionally, the water inlet protection circuit further includes:

[0009] An interface connected to a fourth terminal of the control circuit; the interface is used to receive a start-up voltage signal and output the start-up voltage signal to the control circuit;

[0010] The control circuit is used to detect the voltage value of the humidity signal after receiving the start voltage signal, and to conduct the power supply circuit between the power supply component and the water pump when the voltage value of the humidity signal is less than a first predetermined voltage value.

[0011] Optionally, the control circuit further includes:

[0012] A detection circuit, the input end of which is connected to the output end of the humidity detection device; the detection circuit is used to receive the humidity signal and output a safety signal when the voltage value of the humidity signal is less than a first predetermined voltage value;

[0013] A switch circuit, a first end of which is connected to the power supply component, and a second end of which is connected to the water pump; the switch circuit is used to turn on / off the electrical circuit between the power supply component and the water pump when receiving a control instruction;

[0014] A main control circuit, a first end of which is connected to the interface, a second end of which is connected to the detection circuit, and an output end of which is connected to the switch circuit; the main control circuit is used to output a conduction control instruction to the switch circuit after receiving the starting voltage signal and detecting the safety signal, so as to control the switch circuit to conduct the electrical circuit between the power supply component and the water pump.

[0015] Optionally, the switch circuit includes:

[0016] A charge and discharge management circuit, wherein the first end is connected to the interface, the second end is connected to the power supply component, and the third end is connected to the water pump; the charge and discharge management circuit is used to detect the input voltage value of the interface and the output voltage value of the power supply component, and is used to manage the charging process of the power supply component according to the input voltage value of the interface and the output voltage value of the power supply component;

[0017] A drive circuit, wherein the input end is connected to the main control circuit, and the output end is connected to the gate of the first MOS tube in the charge and discharge management circuit which is arranged in the circuit between the power supply component and the water pump; the drive circuit is used to control the conduction of the first MOS tube after receiving the conduction control instruction.

[0018] Optionally, the interface includes a USB interface.

[0019] Optionally, the charge and discharge management circuit includes:

[0020] A voltage detection circuit, the input end of which is connected to the output end of the power supply component; the voltage detection circuit is used to detect the output voltage of the power supply component and then output it;

[0021] A second MOS tube, a drain connected to the interface, and a source connected to the power supply component;

[0022] A control module, a first end of which is connected to the output end of the voltage detection circuit, and a second end of which is connected to the gate of the second MOS tube; the control module is used to manage the charging process of the power supply component according to the input voltage value of the interface and the output voltage of the power supply component, and to control the second MOS tube to shut down when the output voltage of the power supply component is greater than a second predetermined voltage value.

[0023] Optionally, the charge and discharge management circuit further includes:

[0024] An indication circuit, the first end of which is connected to the voltage detection circuit; the indication circuit is used to emit a light signal, a sound signal or a vibration signal when the output voltage value of the power supply component is less than a third predetermined voltage value, so as to remind the user that the power supply component needs to be charged.

[0025] Optionally, the indication circuit comprises:

[0026] A light emitting diode, a second triode, a sixth resistor and a second comparison amplifier;

[0027] The anode of the light-emitting diode is connected to the first voltage, and the cathode is connected to the first end of the sixth resistor; the second end of the sixth resistor is connected to the collector of the second transistor; the collector of the second transistor is connected to the output end of the second comparison amplifier, and the emitter is grounded; the first input end of the second comparison amplifier is connected to the output end of the voltage detection circuit, and the second input end is connected to the third voltage.

[0028] The utility model also provides an electric water pump, which comprises the water inlet protection circuit.

[0029] The utility model discloses a water inlet protection circuit, which is applied to an electric water pump, and the water inlet protection circuit includes: a humidity detection device, which is arranged inside the electric water pump; the humidity detection device is used to detect the water molecule content inside the electric water pump and output a corresponding humidity signal; a control circuit, the first end of which is connected to the output end of the power supply component of the electric water pump, the second end is connected to the water pump in the electric water pump, and the third end is connected to the output end of the humidity detection device; the control circuit is used to receive the humidity signal and cut off the power supply circuit between the power supply component and the water pump when the voltage value of the humidity signal is greater than or equal to a first predetermined voltage value. The utility model determines that the electric water pump has water inflow through the control circuit when the voltage value of the humidity signal output by the humidity detection device is greater than or equal to the first predetermined voltage value, and cuts off the power supply circuit between the power supply component and the water pump, thereby protecting the circuit. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] In order to more clearly illustrate the embodiments of the utility model or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the utility model. For ordinary technicians in this field, other drawings can be obtained based on the structures shown in these drawings without paying creative work.

[0031] Figure 1 This is a structural schematic diagram of an embodiment of a water inlet protection circuit of the utility model;

[0032] Figure 2 This is a structural schematic diagram of another embodiment of the water inlet protection circuit of the utility model;

[0033] Figure 3 This is a structural schematic diagram of another embodiment of the water inlet protection circuit of the utility model;

[0034] Figure 4 It is a structural schematic diagram of another embodiment of the water inlet protection circuit of the utility model.

[0035] Description of Figure Numbers:

[0036] Label name Label name 10 Humidity detection device 2210 Charge and discharge management circuit 20 Control Circuit 2220 Drive circuit 30 interface 22110 Voltage detection circuit 210 Detection circuit 22120 Control Module 220 Switching Circuit 22130 Indicator circuit 230 Main control circuit Q1 The first MOS tube Q2 The second MOS tube

[0037] The realization of the purpose, functional features and advantages of the utility model will be further explained in conjunction with embodiments and with reference to the accompanying drawings. DETAILED DESCRIPTION

[0038] The following will be combined with the drawings in the embodiments of the utility model to clearly and completely describe the technical solutions in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments of the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0039] It should be noted that all directional indications in the embodiments of the present invention (such as up, down, left, right, front, back...) are only used to explain the relative position relationship, movement status, etc. between the components under a certain specific posture (as shown in the accompanying drawings). If the specific posture changes, the directional indication will also change accordingly.

[0040] In the present invention, unless otherwise clearly specified and limited, the terms "connection", "fixation", etc. should be understood in a broad sense. For example, "fixation" can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0041] In addition, in the present utility model, descriptions such as "first", "second", etc. are only used for descriptive purposes and cannot be understood as indicating or implying their relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In addition, the technical solutions between the various embodiments can be combined with each other, but they must be based on the ability of ordinary technicians in the field to implement them. When the combination of technical solutions is contradictory or cannot be implemented, it should be deemed that such a combination of technical solutions does not exist and is not within the scope of protection required by the present utility model.

[0042] Reference Figure 1 The utility model provides a water inlet protection circuit, which is applied to an electric water pump; the protection circuit comprises:

[0043] A humidity detection device 10, wherein the humidity detection device 10 is disposed inside the electric water pump; the humidity detection device 10 is used to detect the water molecule content inside the electric water pump and output a corresponding humidity signal;

[0044] The control circuit 20 has a first end connected to the output end of the power supply component of the electric water pump, a second end connected to the water pump in the electric water pump, and a third end connected to the output end of the humidity detection device 10; the control circuit 20 is used to receive the humidity signal and cut off the power supply circuit between the power supply component and the water pump when the voltage value of the humidity signal is greater than or equal to a first predetermined voltage value.

[0045] It is easy to understand that the water inlet protection circuit is applied to an electric water pump. During the water pumping process, the circuit board of the electric water pump may be flooded, resulting in a short circuit and causing losses. The water inlet protection circuit proposed in this scheme includes a humidity detection device 10 and a control circuit 20; wherein the humidity detection device 10 detects the water molecule content inside the electric water pump and outputs a humidity signal to the control circuit 20; the voltage value of the humidity signal is related to the water molecule content detected by the humidity detection device 10. When the electric water pump is not flooded, the voltage value of the humidity signal output by the humidity detection device 10 is less than the first predetermined voltage value; when the electric water pump is flooded, the voltage value of the humidity signal output by the humidity detection device 10 is greater than or equal to the first predetermined voltage value. It should be understood that whether the electric water pump is flooded can be determined by detecting the water molecule content inside the electric water pump; by setting a first predetermined voltage value, it can be determined whether the electric water pump is flooded by comparing the voltage value of the humidity signal with the first predetermined voltage value. The first predetermined voltage value can be determined by the R&D personnel according to the experimental results. After receiving the humidity signal, the control circuit 20 compares the humidity signal with a first predetermined voltage value; when the voltage value of the humidity signal is greater than or equal to the first predetermined voltage value, it indicates that water has entered the electric water pump; at this time, the control circuit 20 shuts off the power supply circuit between the power supply component and the water pump, cuts off the energy supply, and protects the circuit. The power supply component is used to provide energy, and the power supply component may include a sodium battery, a lithium battery, or a lithium iron phosphate battery, etc.; the water pump includes a motor, which is used to provide power for the electric water pump to pump water.

[0046] The humidity detection device 10 may include a humidity sensor, which may specifically include a humidity sensitive resistor, an electrolyte ion type humidity sensitive element or a humidity sensitive capacitor, etc. The control circuit 20 may include a control device such as an MCU, an FPGA, and a SOC.

[0047] The utility model discloses a water inlet protection circuit, which is applied to an electric water pump. The water inlet protection circuit includes: a humidity detection device 10, which is arranged inside the electric water pump; the humidity detection device 10 is used to detect the water molecule content inside the electric water pump and output a corresponding humidity signal; a control circuit 20, the first end of which is connected to the output end of the power supply component of the electric water pump, the second end is connected to the water pump in the electric water pump, and the third end is connected to the output end of the humidity detection device 10; the control circuit 20 is used to receive the humidity signal and cut off the power supply circuit between the power supply component and the water pump when the voltage value of the humidity signal is greater than or equal to a first predetermined voltage value. The utility model determines that the electric water pump has water inflow through the control circuit 20 when the voltage value of the humidity signal output by the humidity detection device 10 is greater than or equal to the first predetermined voltage value, and cuts off the power supply circuit between the power supply component and the water pump, thereby protecting the circuit.

[0048] Considering that the electric water pump stops working after the water inlet protection circuit detects that the humidity exceeds the standard, the chip in the water inlet protection circuit is dormant; however, after the electric water pump is manually treated for water ingress, the dormant chip needs to be reawakened and the water inlet protection circuit needs to be activated.

[0049] Reference Figure 1 In one embodiment of the present utility model, the water inlet protection circuit further includes:

[0050] An interface 30, the interface 30 being connected to a fourth terminal of the control circuit 20; the interface 30 being used to receive a start-up voltage signal and output the start-up voltage signal to the control circuit 20;

[0051] The control circuit 20 is used to detect the voltage value of the humidity signal after receiving the start voltage signal, and to conduct the power supply circuit between the power supply component and the water pump when the voltage value of the humidity signal is less than a first predetermined voltage value.

[0052] In this embodiment, the interface 30 is connected to the fourth end of the control circuit 20, and the fourth end of the control circuit 20 can be connected to the chip pin in the control circuit 20, and in particular, the fourth end of the control circuit 20 is connected to the interrupt pin of the chip; when the user manually handles the water inflow condition of the electric water pump, the electric water pump needs to be restarted. The user can connect to the interface 30 by using an interface 30 module that matches the interface 30, and output a start-up voltage signal to the interface 30. The interface 30 outputs the start-up voltage signal to the control circuit 20. In particular, the interface 30 can be a standard USB interface 30, a micro-USB interface 30, or a Type-C interface 30, etc. The interface 30 has a power supply terminal; the voltage signal output by the power supply terminal can be the start-up voltage signal; when the control circuit 20 receives the start-up voltage signal, it means that the user has manually handled the problem of water inflow of the electric water pump and tried to restart. After receiving the starting voltage signal, the control circuit 20 first detects the voltage value of the humidity signal, and compares the voltage value of the humidity signal with the first predetermined voltage value; when the voltage value of the humidity signal is less than the first predetermined voltage value, the control circuit 20 turns on the power supply circuit between the power supply component and the water pump; that is, after the water molecule content inside the electric water pump is lower than the water molecule content corresponding to the first predetermined voltage value, the control circuit 20 turns on the power supply circuit between the power supply component and the water pump to power the water pump, and the electric water pump resumes the pumping function.

[0053] After receiving the starting voltage signal, the control circuit 20 detects the voltage value of the humidity signal. If the voltage value of the humidity signal is greater than or equal to the first predetermined voltage value, it means that the water molecule content inside the electric water pump is greater than or equal to the water molecule content corresponding to the first predetermined voltage value, and there is a risk of circuit short circuit. At this time, in order to protect the circuit, the control circuit 20 still disconnects the power supply circuit between the power supply component and the water pump.

[0054] Reference Figure 2 In one embodiment of the utility model, the control circuit 20 further includes: a detection circuit 210, the input end of which is connected to the output end of the humidity detection device 10; the detection circuit 210 is used to receive the humidity signal and output a safety signal when the voltage value of the humidity signal is less than a first predetermined voltage value;

[0055] A switch circuit 220, a first end of which is connected to the power supply component, and a second end of which is connected to the water pump; the switch circuit 220 is used to turn on / off the electrical circuit between the power supply component and the water pump when receiving a control instruction;

[0056] The main control circuit 230 has a first end connected to the interface 30, a second end connected to the detection circuit 210, and an output end connected to the switch circuit 220; the main control circuit 230 is used to output a conduction control instruction to the switch circuit 220 after receiving the starting voltage signal and detecting the safety signal, so as to control the switch circuit 220 to conduct the electrical circuit between the power supply component and the water pump.

[0057] In this embodiment, when the voltage value of the humidity signal is less than the first predetermined voltage value, the detection circuit 210 outputs a safety signal to the main control circuit 230, indicating that the water molecule content inside the electric water pump is less than the water molecule content corresponding to the first predetermined voltage value and is within a safe range. In one embodiment of the utility model, the humidity detection device 10 is an analog device, which outputs an analog quantity; the detection circuit 210 includes a detection comparison circuit, which may include a first comparison amplifier, the first input terminal of the first comparison amplifier is connected to a first predetermined voltage, and the second input terminal is connected to the humidity signal; when the voltage value of the humidity signal is less than the first predetermined voltage value, the first comparison amplifier outputs a high level or a low level according to the specific access signal of the input terminal.

[0058] The switch circuit 220 is connected to the power supply component, the water pump and the main control circuit 230 respectively, and can cut off or conduct the electrical circuit between the power supply component and the water pump. The switch circuit 220 may include a MOS tube, a triode, an IGBT tube or a relay, etc.

[0059] The first end of the main control circuit 230 is connected to the interface 30, and the second end is connected to the detection circuit 210; the main control circuit 230 can receive a start-up voltage signal through the interface 30, and can also receive a safety signal from the detection circuit 210. When the main control circuit 230 receives the start-up voltage signal and the safety signal, it outputs a conduction control instruction to the switch circuit 220 to control the switch circuit 220 to conduct the electrical circuit between the power supply component and the water pump. When the main control circuit 230 does not receive the start-up voltage signal and the safety signal at the same time, it controls the switch circuit 220 to shut off the electrical circuit between the power supply component and the water pump to prevent the electric water pump from restarting when the water inflow situation is not handled. The main control circuit 230 includes a controller, which can be a control chip, such as MCU, FPGA or SOC, etc.

[0060] Reference Figure 3 In one embodiment of the present utility model, the switch circuit 220 includes:

[0061] A charge and discharge management circuit 2210, a first end connected to the interface 30, a second end connected to the power supply component, and a third end connected to the water pump; the charge and discharge management circuit 2210 is used to detect the input voltage value of the interface 30 and the output voltage value of the power supply component, and to manage the charging process of the power supply component according to the input voltage value of the interface 30 and the output voltage value of the power supply component;

[0062] The driving circuit 2220 has an input end connected to the main control circuit 230, and an output end connected to the gate of the first MOS tube Q1 in the charge and discharge management circuit 2210, which is arranged in the circuit between the power supply component and the water pump; the driving circuit 2220 is used to control the first MOS tube Q1 to be turned on after receiving the conduction control instruction.

[0063] In this embodiment, the first end of the charge and discharge management circuit 2210 is connected to the interface 30, the second end is connected to the power supply component, and the third end is connected to the water pump; the charge and discharge management circuit 2210 can turn on or off the electrical circuit between the interface 30 and the power supply component, and can also turn on or off the electrical circuit between the water pump and the power supply component. The charge and discharge management circuit 2210 may include a charge and discharge management chip, such as: DW01 chip, DW06 chip, 4054 chip or MP2722 chip, etc. In addition, the charge and discharge management circuit 2210 also includes a first MOS tube Q1, which is arranged in the electrical circuit between the power supply component and the water pump.

[0064] It should be understood that the input end of the driving circuit 2220 can be connected to the chip pin of the main control circuit 230. Because the driving ability of the chip pin is limited, adding the driving circuit 2220 to the electrical circuit between the chip pin and the gate of the first MOS tube Q1 can improve the driving ability of the chip pin. The output end of the driving circuit 2220 is connected to the gate of the first MOS tube Q1, and is used to control the first MOS tube Q1 to conduct after receiving the conduction control instruction, and connect the electrical circuit between the power supply component and the water pump. In an embodiment of the utility model, the driving circuit 2220 includes: a first transistor, a first resistor and a second resistor. The first end of the first resistor is connected to the first DC voltage, and the second end is connected to the collector of the first transistor; the base of the first transistor is connected to the main control circuit 230, and the emitter is connected to the first end of the second resistor and the gate of the first MOS tube Q1; the second end of the second resistor is grounded.

[0065] The charge and discharge management circuit 2210 also detects the input voltage value of the interface 30 and the output voltage value of the power supply component, and manages the charging process of the power supply component according to the input voltage value of the interface 30 and the output voltage of the power supply component.

[0066] When the input voltage value of the interface 30 is less than or equal to the output voltage value of the power supply component, the charge and discharge management circuit 2210 disconnects the electrical circuit between the interface 30 and the power supply component to prevent the power supply component from discharging to the interface 30. When the input voltage value of the interface 30 is greater than the output voltage value of the power supply component, the charge and discharge management circuit 2210 conducts the electrical circuit between the interface 30 and the power supply component, and changes the charge and discharge mode of the power supply component according to the voltage of the power supply component. In one embodiment of the utility model, when it is detected that the output voltage of the power supply component is 4.2V, the overcharge protection is triggered and charging is no longer performed. When the output voltage of the power supply component is 2.5-2.8V, the trickle charging mode is started, and the charging current is 1 / 10 of the set charging. When the output voltage of the power supply component is 2.8V-4.0V, the constant current charging mode is started, and the charging current is the set charging current. When the output voltage of the power supply component is 4.0-4.2V, the constant voltage charging mode is entered, and the charging current slowly decreases until it is charged to 4.2V, and then the charging is cut off and the battery is fully charged. When the power supply component discharges to 2.6V, it enters over-discharge protection. The charge and discharge management module disconnects the water pump from the power supply component, and the power supply component stops discharging.

[0067] In an embodiment of the present utility model, the humidity detection device 10 may include:

[0068] Humidity sensitive resistor and third resistor;

[0069] The first end of the humidity-sensitive resistor is connected to the power supply component, and the second end is connected to the input end of the rectifier circuit and the first end of the third resistor; the second end of the third resistor is grounded.

[0070] In this embodiment, the humidity-sensitive resistor has a low resistance value when the air water molecule content is high, and has a high resistance value when the air water molecule content is low. The resistance voltage divider circuit formed by the humidity-sensitive resistor and the third resistor divides the AC voltage and outputs it to the control circuit. The humidity-sensitive resistor can be a lithium chloride humidity-sensitive resistor or an organic polymer film humidity-sensitive resistor, etc.

[0071] The combination of the humidity-sensitive resistor and the third resistor ensures that the humidity detection device 10 outputs a high voltage when the water molecule content is high, and outputs a low voltage when the water molecule content is low.

[0072] In an embodiment of the present invention, the interface 30 includes a USB interface 30 .

[0073] Reference Figure 4 In one embodiment of the present utility model, the charge and discharge management circuit 2210 includes:

[0074] The voltage detection circuit 22110 has an input end connected to the output end of the power supply component; the voltage detection circuit 22110 is used to detect the output voltage of the power supply component and then output it;

[0075] A second MOS transistor Q2, a drain connected to the interface 30, and a source connected to the power supply component;

[0076] The control module 22120 has a first end connected to the output end of the voltage detection circuit 22110, and a second end connected to the gate of the second MOS tube Q2; the control module 22120 is used to manage the charging process of the power supply component according to the input voltage value of the interface 30 and the output voltage of the power supply component, and is used to control the second MOS tube Q2 to be turned off when the output voltage of the power supply component is greater than a second predetermined voltage value.

[0077] In this embodiment, the voltage detection circuit 22110 may include a resistor voltage divider circuit to detect the output voltage of the power supply component. For example, the resistor voltage divider circuit includes a fourth resistor and a fifth resistor, wherein the first end of the fourth resistor is connected to the output voltage of the power supply component, and the second end is connected to the first end of the fifth resistor and the first end of the control module 22120; the second end of the fifth resistor is grounded. The control module 22120 is used to manage the charging process of the power supply component according to the input voltage value of the interface 30 and the output voltage of the power supply component; the control module 22120 may include a control chip such as MCU or SOC. The second MOS tube Q2 is arranged between the interface 30 and the electrical circuit of the power supply component. When the output voltage of the power supply component is greater than the second predetermined voltage value, the control module 22120 controls the second MOS tube Q2 to turn off, so as to stop the charging of the power supply component or prevent the power supply component from discharging to the interface 30; the second MOS tube Q2 may be an NMOS tube. The second predetermined voltage value may be determined by the R&D personnel. The second predetermined voltage value may represent that the power supply component is fully charged. The control module 22120 controls the second MOS tube Q2 to be turned off when the output voltage of the power supply component is greater than the second predetermined voltage value, thereby preventing the power supply component from being overcharged.

[0078] Reference Figure 4 In one embodiment of the present utility model, the charge and discharge management circuit 2210 further includes:

[0079] The indication circuit 22130 has a first end connected to the voltage detection circuit 22110; the indication circuit 22130 is used to emit a light signal, a sound signal or a vibration signal when the output voltage value of the power supply component is less than a third predetermined voltage value, so as to remind the user that the power supply component needs to be charged.

[0080] In this embodiment, in order to prompt the user to charge when the power supply component of the electric water pump is low on power; the indication circuit 22130 receives the output voltage of the power supply component from the voltage detection circuit 22110, and compares the output voltage of the power supply component with a third predetermined voltage value, and the third predetermined voltage value can represent that the power supply component is low on power and needs to be charged; in one embodiment, the third predetermined voltage value can be the voltage value when the power supply component is over-discharged, for example: 2.6V; the third predetermined voltage value can be determined by R&D personnel based on experiments.

[0081] When the indicator circuit 22130 determines that the output voltage value of the power supply component is less than the third predetermined voltage value, the indicator circuit 22130 sends a light signal, a sound signal or a vibration signal to remind the user that the power supply component needs to be charged. Specifically, the indicator circuit 22130 may include a light emitting diode, a speaker or a vibration motor, etc.

[0082] In one embodiment of the present invention, the indication circuit 22130 includes:

[0083] A light emitting diode, a second triode, a sixth resistor and a second comparison amplifier.

[0084] The anode of the light-emitting diode is connected to the first voltage, and the cathode is connected to the first end of the sixth resistor; the second end of the sixth resistor is connected to the collector of the second transistor; the collector of the second transistor is connected to the output end of the second comparison amplifier, and the emitter is grounded; the first input end of the second comparison amplifier is connected to the output end of the voltage detection circuit 22110, and the second input end is connected to the third voltage.

[0085] In this embodiment, the second transistor is an NPN transistor, the voltage detection circuit 22110 is connected to the negative input terminal of the second comparison amplifier, the positive input terminal of the second comparison amplifier is connected to a third voltage, and the voltage value of the third voltage is the same as the third predetermined voltage value. When the output voltage value of the power supply component is less than the third predetermined voltage value, the second transistor is turned on, there is a voltage difference between the anode and the cathode of the light-emitting diode, and the light-emitting diode is turned on and emits light.

[0086] The utility model also proposes an electric water pump, which includes the water inlet protection circuit. The specific embodiment of the water inlet protection circuit can refer to the above embodiment. Since the electric water pump includes all the embodiments of the water inlet protection circuit, it at least has the beneficial effects brought by the embodiments of the water inlet protection circuit.

[0087] The above description is only an optional embodiment of the present invention, and does not limit the patent scope of the present invention. All equivalent structural changes made by using the contents of the present invention specification and drawings under the inventive concept of the present invention, or directly / indirectly applied in other related technical fields are included in the patent protection scope of the present invention.

Claims

1. A water inlet protection circuit, characterized in that: The water inlet protection circuit is applied to an electric water pump; the protection circuit comprises: A humidity detection device, the humidity detection device is arranged inside the electric water pump; the humidity detection device is used to detect the water molecule content inside the electric water pump and output a corresponding humidity signal; A control circuit, a first end of which is connected to the output end of the power supply component of the electric water pump, a second end of which is connected to the water pump in the electric water pump, and a third end of which is connected to the output end of the humidity detection device; the control circuit is used to receive the humidity signal and cut off the power supply circuit between the power supply component and the water pump when the voltage value of the humidity signal is greater than or equal to a first predetermined voltage value.

2. The water inlet protection circuit according to claim 1, characterized in that: The water inlet protection circuit also includes: An interface connected to a fourth terminal of the control circuit; the interface is used to receive a start-up voltage signal and output the start-up voltage signal to the control circuit; The control circuit is used to detect the voltage value of the humidity signal after receiving the start voltage signal, and to conduct the power supply circuit between the power supply component and the water pump when the voltage value of the humidity signal is less than a first predetermined voltage value.

3. The water inlet protection circuit according to claim 2, characterized in that: The control circuit further comprises: A detection circuit, the input end of which is connected to the output end of the humidity detection device; the detection circuit is used to receive the humidity signal and output a safety signal when the voltage value of the humidity signal is less than a first predetermined voltage value; A switch circuit, a first end of which is connected to the power supply component, and a second end of which is connected to the water pump; the switch circuit is used to turn on / off the electrical circuit between the power supply component and the water pump when receiving a control instruction; A main control circuit, a first end of which is connected to the interface, a second end of which is connected to the detection circuit, and an output end of which is connected to the switch circuit; the main control circuit is used to output a conduction control instruction to the switch circuit after receiving the starting voltage signal and detecting the safety signal, so as to control the switch circuit to conduct the electrical circuit between the power supply component and the water pump.

4. The water inlet protection circuit according to claim 3, characterized in that: The switch circuit comprises: A charge and discharge management circuit, wherein the first end is connected to the interface, the second end is connected to the power supply component, and the third end is connected to the water pump; the charge and discharge management circuit is used to detect the input voltage value of the interface and the output voltage value of the power supply component, and is used to manage the charging process of the power supply component according to the input voltage value of the interface and the output voltage value of the power supply component; A drive circuit, wherein the input end is connected to the main control circuit, and the output end is connected to the gate of the first MOS tube in the charge and discharge management circuit which is arranged in the circuit between the power supply component and the water pump; the drive circuit is used to control the conduction of the first MOS tube after receiving the conduction control instruction.

5. The water inlet protection circuit according to any one of claims 2 to 4, characterized in that: The interface includes a USB interface.

6. The water inlet protection circuit according to claim 4, characterized in that: The charge and discharge management circuit comprises: A voltage detection circuit, the input end of which is connected to the output end of the power supply component; the voltage detection circuit is used to detect the output voltage of the power supply component and then output it; A second MOS tube, a drain electrode connected to the interface, and a source electrode connected to the power supply component; A control module, a first end of which is connected to the output end of the voltage detection circuit, and a second end of which is connected to the gate of the second MOS tube; the control module is used to manage the charging process of the power supply component according to the input voltage value of the interface and the output voltage of the power supply component, and to control the second MOS tube to shut down when the output voltage of the power supply component is greater than a second predetermined voltage value.

7. The water ingress protection circuit according to claim 6, characterized in that: The charge and discharge management circuit also includes: An indication circuit, the first end of which is connected to the voltage detection circuit; the indication circuit is used to emit a light signal, a sound signal or a vibration signal when the output voltage value of the power supply component is less than a third predetermined voltage value, so as to remind the user that the power supply component needs to be charged.

8. The water inlet protection circuit according to claim 7, characterized in that: The indicating circuit comprises: a light emitting diode, a second triode, a sixth resistor and a second comparison amplifier; The anode of the light-emitting diode is connected to the first voltage, and the cathode is connected to the first end of the sixth resistor; the second end of the sixth resistor is connected to the collector of the second transistor; the collector of the second transistor is connected to the output end of the second comparison amplifier, and the emitter is grounded; the first input end of the second comparison amplifier is connected to the output end of the voltage detection circuit, and the second input end is connected to the third voltage.

9. An electric water pump, characterized in that: The electric water pump comprises a water inlet protection circuit as described in any one of claims 1 to 8.

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