A water immersion detection apparatus

Abstract

The application belongs to the technical field of detection circuit, and relates to a water immersion detection device for outputting corresponding detection signals according to water immersion detection results, comprising a detection circuit, a first switch circuit, a second switch circuit and a signal output circuit. The detection circuit is electrically connected with the first switch circuit, is used for detecting whether water immersion occurs, and controls the first switch circuit to be turned on or turned off according to a detection result. The second switch circuit is electrically connected with the first switch circuit, is used for controlling the second switch circuit to be turned on or turned off according to a turn-on or turn-off result of the first switch circuit. The signal output circuit is electrically connected with the second switch circuit, and is used for outputting corresponding detection signals according to the turn-on or turn-off of the second switch circuit. The water immersion detection device provided in the application utilizes the resistance characteristic of water, equivalently connects the detected water into a circuit as a resistance, so that water immersion detection is realized, and the water immersion detection device can be embedded into a system without interface docking.

Description

Technical Field

[0001] This application relates to the field of detection circuit technology, specifically to a water immersion detection device. Background Technology

[0002] The application of sensors has become increasingly mature. However, water immersion sensors on the market are usually external RS485 devices. Firstly, they are large in size and inconvenient to install in some confined spaces. Secondly, the connection cycle is long and requires a large amount of manpower and resources.

[0003] Those skilled in the art have been seeking solutions to the above problems. Summary of the Invention

[0004] The technical problem to be solved by this application is to provide a water immersion detection device that can be embedded into the system without interface docking, in order to address the deficiencies of the prior art.

[0005] To achieve the above objectives, this application employs the following technical solution:

[0006] This application provides a water immersion detection device for outputting a corresponding detection signal based on the water immersion detection result. The device comprises: a detection circuit, a first switching circuit, a second switching circuit, and a signal output circuit. The detection circuit is electrically connected to the first switching circuit and is used to detect whether the environment is a water immersion environment, and control the first switching circuit to open or close based on the detection result. The second switching circuit is electrically connected to the first switching circuit and is used to control the second switching circuit to open or close based on the opening / closing result of the first switching circuit. The signal output circuit is electrically connected to the second switching circuit and is used to output a corresponding detection signal based on the opening / closing of the second switching circuit.

[0007] Optionally, the detection circuit includes a first probe, a first power supply, and a second probe; the first probe is coupled to the first power supply, and the second probe is connected to a common low voltage terminal; the first probe and the second probe are used to determine whether the device is in a water immersion state, and the first probe and the second probe are conductive when the device is in a water immersion state.

[0008] Optionally, the first switching circuit includes a first switch, the control terminal of the first switch is coupled to the first power supply, the first path terminal of the first switch is connected to a common low voltage terminal, and the second path terminal of the first switch is coupled to the control terminal of the second switch. The first power supply is also used to output a working voltage to the control terminal of the first switch to enable the first switch to conduct when the first probe and the second probe are not in a water immersion state.

[0009] Optionally, the second switching circuit includes a second switch and a third switch; the control terminal of the second switch is also coupled to the first power supply, the first path terminal of the second switch is connected to a common low voltage terminal, and the second path terminal of the second switch is connected to the second path terminal of the third switch; the first power supply is also used to output a working voltage to the control terminal of the second switch to enable the second switch to conduct when the first switch is off; the first path terminal of the third switch is coupled to the first power supply, the third path terminal of the third switch is connected to a ground terminal, and the fourth path terminal of the third switch is connected to the signal output terminal; the first power supply is also used to output a working voltage to the third switch to enable the third switch to conduct when the second switch is on.

[0010] Optionally, the signal output circuit includes a second power supply, and the signal output terminal is coupled to the second power supply. The second power supply is used to output a low voltage signal to the signal output terminal when the third switch is turned on, or to output a high voltage signal to the signal output terminal when the third switch is turned off; wherein, the low voltage signal is used to indicate that the detected environment is flooded, and the high voltage signal is used to indicate that the detected environment is not flooded.

[0011] Optionally, the detection circuit further includes: a first protection circuit; the first protection circuit includes a first diode and a first capacitor, the first terminal of the first diode is connected to the first power supply, the second terminal of the first diode is coupled to the first probe, the first capacitor is connected in parallel with the first diode, and the first protection circuit is used to absorb the peak voltage output by the first power supply.

[0012] Optionally, the detection circuit further includes: a second protection circuit; the second protection circuit includes a second diode and a first resistor, the first terminal of the second diode is connected to the second probe, the second terminal of the second diode is connected to a common low voltage terminal, and the first resistor is connected in parallel with the second diode; the second protection circuit is used to absorb the peak voltage output of the first power supply to protect the front-end circuit when the second probe is connected to a loop including the first probe and the first power supply.

[0013] Optionally, the detection circuit further includes a second resistor, a third resistor, and a fourth resistor, wherein a first end of the second resistor is connected to the first power supply, a second end of the second resistor is connected to the first probe through the third resistor, and the fourth resistor is located between the second probe and a common low voltage terminal.

[0014] Optionally, the first switching circuit further includes a fifth resistor, the first end of which is connected to the second end of the second resistor, and the second end of which is connected to the control terminal of the first switch.

[0015] Optionally, the second switching circuit further includes: a sixth resistor, a seventh resistor, an eighth resistor, a ninth resistor, and a tenth resistor. The first end of the sixth resistor is connected to the first power supply, the second end of the sixth resistor is connected to the control terminal of the second switch through the seventh resistor, the first end of the eighth resistor is connected to the first power supply, the second end of the eighth resistor is connected to the first pass terminal of the third switch through the ninth resistor, and the tenth resistor is located between the second power supply and the signal output terminal.

[0016] The water immersion detection device provided in this application utilizes the resistive properties of water, treating the detected water as an equivalent resistor connected to the circuit, thereby achieving water immersion detection. No interface connection is required, and it can be well embedded into the system in smart devices.

[0017] To make the above and other objects, features and advantages of this application more apparent and understandable, preferred embodiments are described below in detail with reference to the accompanying drawings. Attached Figure Description

[0018] The present application will now be described in detail with reference to the accompanying drawings and specific embodiments;

[0019] Figure 1 This is a schematic diagram of the circuit structure of a water immersion detection device provided in an embodiment of this application. Detailed Implementation

[0020] It should be understood that the specific embodiments described herein are merely illustrative of this application and are not intended to limit this application.

[0021] Figure 1 This is a schematic diagram of the circuit structure of a water immersion detection device provided in one embodiment of this application. Please refer to... Figure 1 The specific implementation adopts the following technical solution:

[0022] A water immersion detection device 10, used to output a corresponding detection signal based on the water immersion detection result, includes: a detection circuit 11, a first switching circuit 12, a second switching circuit 13, and a signal output circuit 14. The detection circuit 11 is electrically connected to the first switching circuit 12, the second switching circuit 13 is electrically connected to the first switching circuit 12, and the signal output circuit 14 is electrically connected to the second switching circuit 13. The detection circuit 11 is used to detect whether the surrounding environment is a water immersion environment and controls the first switching circuit 12 to open or close based on the detection result. The second switching circuit 13 is used to control the second switching circuit 13 to open or close based on the opening / closing result of the first switching circuit 12. The signal output circuit 14 is used to output a corresponding detection signal based on the opening / closing of the second switching circuit 13.

[0023] In one embodiment, the detection circuit 11 includes a first probe water+, a first power supply VDD, and a second probe water-; the first probe water+ is coupled to the first power supply VDD, and the second probe water- is connected to a common low voltage terminal. The first probe water+ and the second probe water- are used to determine whether the device is in a water immersion state, and the first probe water+ and the second probe water- are conductive when they are in a water immersion state.

[0024] In this embodiment, the method for detecting whether the environment is a water-immersed environment can be by detecting parameters such as resistance and voltage of the environment. For example, a sensing device can be connected between the first probe (water+) and the second probe (water-) to sense the change in resistance between them. If the change in resistance reaches a preset threshold, it is determined that the first probe (water+) and the second probe (water-) are in a water-immersed state, i.e., the environment is a water-immersed environment; if the change in resistance does not reach the preset threshold, it is determined that the first probe (water+) and the second probe (water-) are not in a water-immersed state, i.e., the environment is a non-water-immersed environment. In other embodiments, the change in voltage between the first probe (water+) and the second probe (water-) can also be detected. If the change in voltage reaches a preset threshold, it is determined that the first probe (water+) and the second probe (water-) are in a water-immersed state, i.e., the environment is a water-immersed environment; if the change in voltage does not reach the preset threshold, it is determined that the first probe (water+) and the second probe (water-) are not in a water-immersed state, i.e., the environment is a non-water-immersed environment.

[0025] In this embodiment, the second probe, water-, is connected to the common low-voltage terminal.

[0026] In one embodiment, the first switching circuit 12 includes a first switch Q1, the control terminal of the first switch Q1 is coupled to a first power supply VDD, the first path terminal of the first switch Q1 is connected to a common low voltage terminal, and the second path terminal of the first switch Q1 is coupled to the control terminal of the second switch Q2; the first power supply VDD is also used to output a working voltage to the control terminal of the first switch Q1 to turn on the first switch Q1 when the first probe water+ and the second probe water- are not in a water immersion state.

[0027] In one embodiment, the second switching circuit 13 includes a second switch Q2 and a third switch Q3. The control terminal of the second switch Q2 is also coupled to the first power supply VDD. The first path terminal of the second switch Q2 is connected to the common low voltage terminal, and the second path terminal of the second switch Q2 is connected to the second path terminal of the third switch Q3. The first power supply VDD is also used to output a working voltage to the control terminal of the second switch Q2 when the first switch Q1 is turned off, so that the second switch Q2 is turned on.

[0028] In one embodiment, the first path terminal of the third switch Q3 is coupled to the first power supply VDD, the third path terminal of the third switch Q3 is connected to the ground terminal, and the fourth path terminal of the third switch Q3 is connected to the signal output terminal water-det. The first power supply VDD is also used to output the working voltage to the third switch Q3 when the second switch Q2 is turned on so that the third switch Q3 is turned on.

[0029] In this embodiment, the first switch Q1 and the second switch Q2 are both NMOS transistors, and the third switch Q3 is an optocoupler. In other embodiments, the first switch Q1, the second switch Q2, and the third switch Q3 can also be transistors.

[0030] In one embodiment, the signal output circuit 14 includes a second power supply V3, and the signal output terminal water-det is coupled to the second power supply V3. The second power supply V3 is used to output a low voltage signal to the signal output terminal water-det when the third switch Q3 is turned on, or to output a high voltage signal to the signal output terminal water-det when the third switch Q3 is turned off.

[0031] In this embodiment, the first power supply VDD is 5V and the second power supply V3 is 3.3V.

[0032] In one embodiment, the detection circuit 11 further includes: a first protection circuit; the first protection circuit includes a first diode D1 and a first capacitor C1, the first path terminal of the first diode D1 is connected to the first power supply VDD, the second path terminal of the first diode D1 is coupled to the first probe water+, and the first capacitor C1 is connected in parallel to the first diode D1. The first protection circuit is used to absorb the peak voltage output by the first power supply VDD.

[0033] In one embodiment, the detection circuit 11 further includes a second protection circuit; the second protection circuit includes a second diode D2 and a first resistor R1, the first path terminal of the second diode D2 is connected to the second probe water-, the second path terminal of the second diode D2 is connected to a common low voltage terminal, and the first resistor R1 is connected in parallel with the second diode D2; the second protection circuit is used to absorb the spike voltage output of the first power supply VDD to protect the front-end circuit when the second probe water- is connected to a loop including the first probe water+ and the first power supply VDD.

[0034] In this embodiment, both the first diode D1 and the second diode D2 are bidirectional transient suppression diodes.

[0035] In one embodiment, the detection circuit 11 further includes: a second resistor R2, a third resistor R3, and a fourth resistor R4. The first end of the second resistor R2 is connected to the first power supply VDD, the second end of the second resistor R2 is connected to the first probe water+ through the third resistor R3, and the fourth resistor R4 is located between the second probe water- and the common low voltage terminal.

[0036] In one embodiment, the first switch circuit 12 further includes a fifth resistor R5, the first end of which is connected to the second end of the second resistor R2, and the second end of the fifth resistor R5 is connected to the control terminal of the first switch Q1.

[0037] In one embodiment, the second switch circuit 13 further includes: a sixth resistor R6, a seventh resistor R7, an eighth resistor R8, a ninth resistor R9, and a tenth resistor R10. The first end of the sixth resistor R6 is connected to the first power supply VDD, and the second end of the sixth resistor R6 is connected to the control terminal of the second switch Q2 through the seventh resistor R7. The first end of the eighth resistor R8 is connected to the first power supply VDD, and the second end of the eighth resistor R8 is connected to the first pass terminal of the third switch Q3 through the ninth resistor R9. The tenth resistor R10 is located between the second power supply V3 and the signal output terminal water-det.

[0038] The working principle of this application is as follows: This application utilizes the principle of liquid conductivity for water immersion detection. During normal operation, the first probe (water+) and the second probe (water-) are insulated from air. When the first probe (water+) and the second probe (water-) are in a water-immersion state, i.e., when the environment is determined to be water-immersed, the water between the first probe (water+) and the second probe (water-) approximates a resistance. Therefore, the second probe (water-) can obtain the operating voltage output from the first power supply VDD. The voltage at the control terminal of the first switch Q1 is pulled down to a low level, and the first switch Q1 is turned off. When the first switch Q1 is off, the first power supply VDD outputs an operating voltage to the second switch Q2, causing the second switch Q2 to conduct. This, in turn, causes the first power supply VDD to output an operating voltage to the third switch Q3, causing the third switch Q3 to conduct. At this time, the first power supply VDD, the second switch Q2, and the third switch Q3 form a closed loop. When the third switch Q3 is on, the second power supply V3 outputs an operating voltage to the ground terminal. At this time, the voltage at voltage point TP is pulled down to a low level, and the signal output terminal water-det outputs a low voltage signal. This low voltage signal indicates that the detected environment is water-immersed.

[0039] Alternatively, if the first probe (water+) and the second probe (water-) are not submerged in water (i.e., the environment is non-submerged), the electrical connection between the second probe (water-) and the first probe (water+) and the first power supply VDD is broken. The first power supply VDD outputs its operating voltage to the first switch Q1, raising the voltage at the control terminal of the first switch Q1 to a high voltage state, thus turning on the first switch Q1. When the first switch Q1 is on, there is no voltage difference between the first and second path terminals of the first switch Q1, and the voltage at the control terminal of the second switch Q2 is pulled down to a low level, thus turning off the second switch Q2. When the second switch Q2 is off, the first power supply VDD cannot form a closed loop with the second switch Q2 and the third switch Q3, resulting in a significant voltage difference between the first and second path terminals of the third switch Q3, thus turning off the third switch Q3. When the third switch Q3 is activated, the second power supply V3 outputs its operating voltage to the signal output terminal water-det. At this time, the voltage at voltage point TP is raised to a high level, and the signal output terminal water-det outputs a high voltage signal. This high voltage signal is used to indicate that there is no water immersion in the detected environment.

[0040] Obviously, the foregoing has shown and described the basic principles, main features, and advantages of this application. Those skilled in the art should understand that this application is not limited to the above embodiments. The embodiments and descriptions in the specification are merely illustrative of the principles of this application. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of this application should be included within the scope of protection of this application.

Claims

1. A water immersion detection device for outputting a corresponding detection signal according to a water immersion detection result, characterized by, The utility model relates to a detection circuit, a first switch circuit, a second switch circuit and a signal output circuit. The detection circuit is electrically connected with the first switch circuit, and is used for detecting whether water immersion occurs and controlling the first switch circuit to be turned on or turned off according to the detection result. The second switch circuit is electrically connected with the first switch circuit, and is used for controlling the second switch circuit to be turned on or turned off according to the turning-on or turning-off result of the first switch circuit. The signal output circuit is electrically connected with the second switch circuit, and is used for outputting a corresponding detection signal according to the turning-on or turning-off of the second switch circuit. The detection circuit includes a first probe, a first power supply and a second probe. The first probe is coupled to the first power supply, and the second probe is connected to a common low-voltage terminal. The first probe and the second probe are used to determine whether a water immersion state occurs, and the first probe and the second probe are conductive when they are in the water immersion state. The first switch circuit includes a first switch, and the second switch circuit includes a second switch and a third switch. The control end of the first switch is coupled to the first power supply, the first path end of the first switch is connected to the common low-voltage terminal, and the second path end of the first switch is coupled to the control end of the second switch. The first power supply is also used to output a working voltage to the control end of the first switch to make the first switch conductive when the first probe and the second probe are not in the water immersion state. The control end of the second switch is also coupled to the first power supply, the first path end of the second switch is connected to the common low-voltage terminal, and the second path end of the second switch is connected to the second path end of the third switch. The first power supply is also used to output a working voltage to the control end of the second switch to make the second switch conductive when the first switch is turned off. The first path end of the third switch is coupled to the first power supply, the third path end of the third switch is connected to a ground terminal, the fourth path end of the third switch is connected to the signal output terminal, and the first power supply is also used to output a working voltage to the third switch to make the third switch conductive when the second switch is turned on. The signal output circuit includes a second power supply, the signal output terminal is coupled to the second power supply, and the second power supply is used to output a low-voltage signal to the signal output terminal when the third switch is turned on, or output a high-voltage signal to the signal output terminal when the third switch is turned off. The low-voltage signal is used to indicate that the detected environment has water immersion, and the high-voltage signal is used to indicate that the detected environment does not have water immersion. The detection circuit further includes a first protection circuit. The first protection circuit includes a first diode and a first capacitor. The first path end of the first diode is connected to the first power supply, the second path end of the first diode is coupled to the first probe, and the first capacitor is connected in parallel to the first diode. The first protection circuit is used to absorb the peak voltage output by the first power supply.

2. The water immersion detection apparatus of claim 1, wherein ​ 3. The water immersion detection apparatus of claim 2, wherein The detection circuit further comprises a second protection circuit; the second protection circuit comprises a second diode and a first resistor, a first passage end of the second diode is connected with the second probe, a second passage end of the second diode is connected with a common low voltage end, and the first resistor is connected in parallel with the second diode; the second protection circuit is used for absorbing a spike voltage output by the first power supply to protect the front-end circuit when the second probe is connected into a loop comprising the first probe and the first power supply.

4. The water immersion detection apparatus of claim 2 or claim 3, wherein, The detection circuit further comprises a second resistor, a third resistor and a fourth resistor, a first end of the second resistor is connected with the first power supply, a second end of the second resistor is connected with the first probe through the third resistor, and the fourth resistor is located between the second probe and the common low voltage end.

5. The water immersion detection apparatus of claim 1, wherein, The first switch circuit further comprises a fifth resistor, a first end of the fifth resistor is connected with the second end of the second resistor, and a second end of the fifth resistor is connected with a control end of the first switch.

6. The water immersion detection apparatus of claim 1, wherein The second switch circuit further comprises a sixth resistor, a seventh resistor, an eighth resistor, a ninth resistor and a tenth resistor, a first end of the sixth resistor is connected with the first power supply, a second end of the sixth resistor is connected with a control end of the second switch through the seventh resistor, a first end of the eighth resistor is connected with the first power supply, a second end of the eighth resistor is connected with a first passage end of the third switch through the ninth resistor, and the tenth resistor is located between the second power supply and the signal output end.

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