Liquid level monitoring circuit, liquid level monitoring system and liquid level monitoring device
By using a combination of AC signal and conductive probes in the liquid level monitoring circuit, the problem of poor liquid conductivity during DC signal monitoring is solved, and more accurate and reliable liquid level monitoring is achieved and costs are reduced.
Patent Information
- Application Number
- CN202421037943.7
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-05-13
- Publication Date
- 2024-12-20
- Estimated Expiration
- 2034-05-13
AI Technical Summary
When the existing liquid level monitoring circuit uses DC signal to monitor, the presence or status of the liquid may not be monitored normally when the conductivity of the liquid is poor, resulting in poor reliability of the monitoring results.
The liquid level monitoring circuit including a first isolation unit, a second isolation unit, a monitoring unit, a first conductive probe and a second conductive probe is used to monitor the liquid level by using the AC signal generated by the AC signal generation unit. When the liquid immerses the probe, the liquid level is monitored. , the probes are connected to form a loop, and the monitoring unit outputs a monitoring signal.
Because AC current can penetrate the electrodeposited layer in the liquid, more accurate monitoring of liquid levels is achieved, the reliability of liquid level monitoring is improved, and the cost is reduced.
Smart Images
Figure CN222211866U_ABST
Abstract
Description
Technical Field
[0001] The present application belongs to the technical field of liquid level monitoring, and in particular, relates to a liquid level monitoring circuit, a liquid level monitoring system and a liquid level monitoring device. Background Art
[0002] Liquid level monitoring is a technology that uses electronic circuits to detect the horizontal height or level of liquid. Liquid level monitoring plays a vital role in places such as power boxes or machine rooms. The presence or absence of liquid may affect the operation and safety of the equipment, so it needs to be monitored and controlled in a timely manner. However, existing liquid level monitoring circuits usually use DC signals for monitoring. When the conductivity of the liquid is poor, the DC circuit may not be able to properly monitor the presence or status of the liquid, thereby affecting the reliability of the monitoring results. Therefore, the use of DC signal monitoring in existing liquid level monitoring circuits may result in poor reliability of monitoring results. Utility Model Content
[0003] The embodiments of the present application provide a liquid level monitoring circuit, a liquid level monitoring system and a liquid level monitoring device, which can solve the problem that the existing liquid level monitoring circuit uses DC signal monitoring, which may lead to poor reliability of monitoring results.
[0004] In a first aspect, an embodiment of the present application provides a liquid level monitoring circuit, including a first isolation unit, a second isolation unit, a monitoring unit, a first conductive probe, and a second conductive probe, wherein the first conductive probe is used to be electrically connected to a first end of an AC signal generating unit through the first isolation unit, the second conductive probe is electrically connected to the monitoring unit through the second isolation unit, the monitoring unit is used to be electrically connected to a second end of the AC signal generating unit, and the monitoring unit is also used to be electrically connected to a control unit;
[0005] The AC signal generating unit is used to output an AC signal; the first isolation unit is used to isolate the first conductive probe from the AC signal generating unit, and the second isolation unit is used to isolate the second conductive probe from the monitoring unit; when the liquid immerses the first conductive probe and the second conductive probe, the first conductive probe and the second conductive probe are connected, so that the first isolation unit and the second isolation unit are connected, and the monitoring unit is used to output a monitoring signal to the control unit.
[0006] In a possible implementation manner of the first aspect, the first isolation unit includes a first resistor, a first end of the first resistor is used to be electrically connected to a first end of the AC signal generating unit, and a second end of the first resistor is electrically connected to the first conductive probe.
[0007] In a possible implementation manner of the first aspect, the second isolation unit includes a second resistor, a first end of the second resistor is electrically connected to the monitoring unit, and a second end of the second resistor is electrically connected to the second conductive probe.
[0008] In a possible implementation of the first aspect, the monitoring unit includes an optocoupler, a first input end of the optocoupler is used to be electrically connected to the second end of the AC signal generating unit, a first output end of the optocoupler is electrically connected to the second isolation unit, a second input end of the optocoupler is used to be electrically connected to a power supply and the control unit respectively, and a second output end of the optocoupler is grounded.
[0009] In a possible implementation manner of the first aspect, the liquid level monitoring circuit further includes a filtering unit, and the filtering unit is electrically connected to the control unit and the monitoring unit respectively;
[0010] The filtering unit is used to filter out high-frequency signals in the monitoring signal.
[0011] In a possible implementation manner of the first aspect, the filtering unit includes a first capacitor, a first end of the first capacitor is electrically connected to the control unit and the monitoring unit respectively, and a second end of the first capacitor is grounded.
[0012] In a possible implementation of the first aspect, the liquid level monitoring circuit further includes an alarm unit, and the alarm unit is electrically connected to the control unit and the monitoring unit respectively;
[0013] The alarm unit is used to output alarm information when the first conductive probe and the second conductive probe are immersed in liquid.
[0014] In a possible implementation of the first aspect, the liquid level monitoring circuit also includes a scale, a first fixed seat and a second fixed seat, the first fixed seat and the second fixed seat are both connected to the scale and are slidably connected to the scale, the first conductive probe is connected to the first fixed seat, and the second conductive probe is connected to the second fixed seat.
[0015] In a second aspect, an embodiment of the present application provides a liquid level monitoring system, comprising a control unit, an AC signal generating unit, and at least one liquid level monitoring circuit according to any one of the first aspects, wherein the control unit is electrically connected to the monitoring units in all the liquid level monitoring circuits, respectively, and the AC signal generating unit is electrically connected to the monitoring units in all the liquid level monitoring circuits and the first isolation unit, respectively;
[0016] The control unit is used to receive the monitoring signals output by all the monitoring units and output a control signal according to the monitoring signals; the AC signal generating unit is used to output an AC signal.
[0017] In a third aspect, an embodiment of the present application provides a liquid level monitoring device, comprising the liquid level monitoring system described in any one of the second aspects.
[0018] Compared with the prior art, the embodiments of the present invention have the following beneficial effects:
[0019] The liquid level monitoring circuit provided in the embodiment of the present application includes a first isolation unit, a second isolation unit, a monitoring unit, a first conductive probe and a second conductive probe. When the liquid immerses the first conductive probe and the second conductive probe, the first conductive probe and the second conductive probe are connected, so that the first isolation unit and the second isolation unit are connected, so that the AC signal generating unit, the monitoring unit, the second isolation unit, the second conductive probe, the liquid level, the first conductive probe and the first isolation unit form a loop. At this time, the monitoring unit can output a monitoring signal to the control unit to achieve real-time monitoring of the liquid level in the device to be tested. It can be seen that the liquid level monitoring circuit provided in the embodiment of the present application uses the AC signal generated by the AC signal generating unit to monitor the liquid level. Since the AC current can penetrate the electric polarization layer in the liquid, the liquid level can be monitored more accurately, which solves the problem that the existing liquid level monitoring circuit uses DC signal monitoring, which may lead to poor reliability of the monitoring result, and improves the reliability of liquid level monitoring. BRIEF DESCRIPTION OF THE DRAWINGS
[0020] In order to more clearly illustrate the technical solutions in the embodiments of the present application, 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 present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.
[0021] Figure 1 is a principle block diagram of a liquid level monitoring circuit provided in an embodiment of the present application;
[0022] Figure 2 is a circuit connection diagram of a liquid level monitoring circuit provided in an embodiment of the present application;
[0023] Figure 3 is a principle block diagram of a liquid level monitoring circuit provided in another embodiment of the present application;
[0024] Figure 4 It is a principle block diagram of a liquid level monitoring system provided in one embodiment of the present application.
[0025] In the figure: 10, liquid level monitoring circuit; 101, first isolation unit; 102, second isolation unit; 103, monitoring unit; 104, filtering unit; 105, alarm unit; 20, AC signal generating unit; 30, control unit. DETAILED DESCRIPTION
[0026] In the following description, specific details such as specific system structures, technologies, etc. are provided for the purpose of illustration rather than limitation, so as to provide a thorough understanding of the embodiments of the present application. However, it should be clear to those skilled in the art that the present application may also be implemented in other embodiments without these specific details. In other cases, detailed descriptions of well-known systems, devices, circuits, and methods are omitted to prevent unnecessary details from obstructing the description of the present application.
[0027] It should be understood that when used in the present specification and the appended claims, the term "comprising" indicates the presence of described features, wholes, steps, operations, elements and / or components, but does not exclude the presence or addition of one or more other features, wholes, steps, operations, elements, components and / or combinations thereof.
[0028] It should also be understood that the term “and / or” used in the specification and appended claims refers to any and all possible combinations of one or more of the associated listed items, and includes these combinations.
[0029] As used in the specification and appended claims of this application, the term "if" can be interpreted as "when" or "uponce" or "in response to determining" or "in response to detecting", depending on the context. Similarly, the phrase "if it is determined" or "if [described condition or event] is detected" can be interpreted as meaning "uponce it is determined" or "in response to determining" or "uponce [described condition or event] is detected" or "in response to detecting [described condition or event]", depending on the context.
[0030] In addition, in the description of the present application specification and the appended claims, the terms "first", "second", "third", etc. are only used to distinguish the descriptions and cannot be understood as indicating or implying relative importance.
[0031] References to "one embodiment" or "some embodiments" etc. described in the specification of this application mean that one or more embodiments of the present application include specific features, structures or characteristics described in conjunction with the embodiment. Therefore, the statements "in one embodiment", "in some embodiments", "in some other embodiments", "in some other embodiments", etc. that appear in different places in this specification do not necessarily refer to the same embodiment, but mean "one or more but not all embodiments", unless otherwise specifically emphasized in other ways. The terms "including", "comprising", "having" and their variations all mean "including but not limited to", unless otherwise specifically emphasized in other ways.
[0032] Existing liquid level monitoring circuits usually use DC signals for monitoring. When the conductivity of the liquid is poor, the DC circuit may not be able to properly monitor the presence or state of the liquid, thereby affecting the reliability of the monitoring results. Therefore, the use of DC signals for monitoring in existing liquid level monitoring circuits may result in poor reliability of the monitoring results.
[0033] Based on the above problems, the liquid level monitoring circuit provided in the embodiment of the present application includes a first isolation unit, a second isolation unit, a monitoring unit, a first conductive probe and a second conductive probe. When the liquid immerses the first conductive probe and the second conductive probe, the first conductive probe and the second conductive probe are connected, so that the first isolation unit and the second isolation unit are connected, so that the AC signal generating unit, the monitoring unit, the second isolation unit, the second conductive probe, the liquid level, the first conductive probe and the first isolation unit form a loop. At this time, the monitoring unit can output a monitoring signal to the control unit to achieve real-time monitoring of the liquid level in the device to be tested. It can be seen that the liquid level monitoring circuit provided in the embodiment of the present application uses the AC signal generated by the AC signal generating unit to monitor the liquid level. Since the AC current can penetrate the electric polarization layer in the liquid, the liquid level can be monitored more accurately, which solves the problem that the existing liquid level monitoring circuit uses the DC signal for monitoring, which may lead to poor reliability of the monitoring result, and improves the reliability of the liquid level monitoring.
[0034] In order to illustrate the technical solution described in this application, a specific embodiment is provided below for illustration.
[0035] Figure 1 FIG. 1 shows a principle block diagram of a liquid level monitoring circuit 10 provided in an embodiment of the present application. Figure 1 As shown, the liquid level monitoring circuit 10 includes a first isolation unit 101, a second isolation unit 102, a monitoring unit 103, a first conductive probe A and a second conductive probe B. The first conductive probe A is used to be electrically connected to the first end of the AC signal generating unit 20 through the first isolation unit 101, the second conductive probe B is electrically connected to the monitoring unit 103 through the second isolation unit 102, the monitoring unit 103 is used to be electrically connected to the second end of the AC signal generating unit 20, and the monitoring unit 103 is also used to be electrically connected to the control unit 30.
[0036] Specifically, the first conductive probe A and the second conductive probe B are both arranged in the device to be tested. When the liquid in the device to be tested immerses the first conductive probe A and the second conductive probe B, the first conductive probe A and the second conductive probe B are connected, so that the first isolation unit 101 and the second isolation unit 102 are connected, so that the AC signal generating unit 20, the monitoring unit 103, the second isolation unit 102, the second conductive probe B, the liquid level, the first conductive probe A and the first isolation unit 101 form a loop. At this time, the monitoring unit 103 can output a monitoring signal to the control unit 30 to realize real-time monitoring of the liquid level in the device to be tested. It can be seen that the liquid level monitoring circuit 10 provided in the embodiment of the present application uses the AC signal generated by the AC signal generating unit 20 to monitor the liquid level. Since the AC current can penetrate the electric polarization layer in the liquid level, the liquid level can be monitored more accurately, which solves the problem that the existing liquid level monitoring circuit 10 uses the DC signal monitoring which may lead to poor reliability of the monitoring result, and improves the reliability of the liquid level monitoring.
[0037] It should be noted that the existing liquid level monitoring method generally uses a water level sensor to monitor the liquid level. The water level sensor is expensive, resulting in a high cost of the existing liquid level monitoring. The liquid level monitoring circuit 10 provided in the embodiment of the present application has a simple structure and does not require an expensive water level sensor, thereby reducing the cost of liquid level monitoring.
[0038] It should be noted that the first conductive probe A and the second conductive probe B can be located at the same horizontal position, and there is a preset distance between the first conductive probe A and the second conductive probe B. Specifically, the first conductive probe A and the second conductive probe B are located at the same horizontal position, which can ensure that the first conductive probe A and the second conductive probe B monitor the liquid level at the same reference point, which helps to eliminate the error caused by the uneven or uneven surface of the liquid and improve the accuracy of liquid level monitoring. The preset distance can be set according to the actual monitoring situation, and it is not easy to be too large or too small. If the distance between the first conductive probe A and the second conductive probe B is too large, the resistance of the liquid may increase, which will also affect the accuracy of monitoring. If the distance between the first conductive probe A and the second conductive probe B is too small, a short circuit may occur, affecting the normal operation of the liquid level monitoring circuit 10. Therefore, in order to ensure the accuracy of monitoring, selecting a suitable preset distance as the distance between the first conductive probe A and the second conductive probe B can not only ensure that the resistance of the liquid is small, but also prevent short circuits, thereby improving the reliability of liquid level monitoring.
[0039] Exemplarily, the designer may select a preset distance between the first conductive probe A and the second conductive probe B. For example, the preset distance between the first conductive probe A and the second conductive probe B may be selected to be 6 mm.
[0040] It should be noted that the first conductive probe A and the second conductive probe B can be replaced by two liquid level sensing probes, and the device for sensing the liquid level is not limited here.
[0041] It should be noted that the AC signal generating unit 20 may include but is not limited to 50 Hz AC power or AC signals of other frequencies generated by a transformer, and a suitable AC signal may be set according to specific liquid level monitoring scenarios and monitoring requirements to meet the needs of liquid level monitoring.
[0042] It should be noted that the liquid level monitoring circuit 10 provided in the embodiment of the present application can monitor different liquid levels with conductive properties, not only water, but also hydrochloric acid, sulfuric acid, liquid metals (such as mercury, sodium, etc.), etc.
[0043] In one embodiment of the present application, Figure 2 As shown, the first isolation unit 101 includes a first resistor R1, a first end of the first resistor R1 is used to be electrically connected to a first end of the AC signal generating unit 20, and a second end of the first resistor R1 is electrically connected to the first conductive probe A.
[0044] Specifically, the first resistor R1 is connected in series at the first conductive probe A to isolate the first conductive probe A from the AC signal generating unit 20 to protect the first conductive probe A from the external environment (such as electromagnetic interference or electrostatic discharge, etc.). At the same time, the first resistor R1 is also used to limit the current to prevent the current in the circuit from being too large and causing damage to the components in the liquid level monitoring circuit 10. When the first conductive probe A and the second conductive probe B are connected, the AC signal generating unit 20, the monitoring unit 103, the second isolation unit 102, the second conductive probe B, the liquid, the first conductive probe A and the first resistor R1 form a loop. At this time, when the AC signal generating unit 20 generates an AC signal, the AC signal will flow through the first resistor R1. In this process, the first resistor R1 can limit the current to prevent excessive current from damaging the components in the liquid level monitoring circuit 10.
[0045] In one embodiment of the present application, Figure 2 As shown, the second isolation unit 102 includes a second resistor R2, a first end of the second resistor R2 is electrically connected to the monitoring unit 103, and a second end of the second resistor R2 is electrically connected to the second conductive probe B.
[0046] Specifically, the second resistor R2 is connected in series at the second conductive probe B to isolate the second conductive probe B and the monitoring unit 103 to protect the second conductive probe B from the external environment (such as electromagnetic interference or electrostatic discharge, etc.). At the same time, the second resistor R2 is also used for current limiting to prevent the current in the circuit from being too large and causing damage to the components in the liquid level monitoring circuit 10. When the first conductive probe A and the second conductive probe B are connected, the AC signal generating unit 20, the monitoring unit 103, the second resistor R2, the second conductive probe B, the liquid, the first conductive probe A and the first resistor R1 form a loop. At this time, when the AC signal generating unit 20 generates an AC signal, the AC signal will flow through the second resistor R2. In this process, the second resistor R2 can limit the size of the current to prevent excessive current from damaging the components in the liquid level monitoring circuit 10.
[0047] It should be noted that the designer can adjust the resistance value of the first resistor R1 and the resistance value of the second resistor R2 according to actual conditions, so as to improve the sensitivity and response speed of the liquid level monitoring circuit 10 .
[0048] In one embodiment of the present application, Figure 2 As shown, the monitoring unit 103 includes an optocoupler U1, a first input end of the optocoupler U1 is used to be electrically connected to the AC signal generating unit 20, a first output end of the optocoupler U1 is electrically connected to the second isolation unit 102, a second input end of the optocoupler U1 is used to be electrically connected to the power supply and the control unit 30 respectively, and a second output end of the optocoupler U1 is grounded.
[0049] Specifically, the anode of the light-emitting diode in the optocoupler U1 serves as the first input terminal of the optocoupler U1, the cathode of the light-emitting diode serves as the first output terminal of the optocoupler U1, the collector probe of the phototransistor in the optocoupler U1 serves as the second input terminal of the optocoupler U1, and the emitter of the phototransistor serves as the second output terminal of the optocoupler U1. When the liquid in the device to be tested immerses the first conductive probe A and the second conductive probe B, the first conductive probe A and the second conductive probe B are connected, and the AC signal generating unit 20, the anode of the light-emitting diode, the cathode of the light-emitting diode, the second resistor R2, the second conductive probe B, the liquid level, the first conductive probe A and the first resistor R1 form a loop. At this time, the light-emitting diode emits light, and its light intensity corresponds to the change of the input signal of the phototransistor. Therefore, when the light-emitting diode emits light, the phototransistor will be in a conducting state, that is, the collector probe and the emitter of the phototransistor are connected. When the phototransistor is in a conducting state, the monitoring signal input to the control unit 30 is a square wave signal. When the liquid in the device to be tested does not submerge the first conductive probe A and the second conductive probe B or there is no liquid in the device to be tested, there is no conduction between the first conductive probe A and the second conductive probe B, and a closed loop cannot be formed. The light-emitting diode in the optocoupler U1 will not emit light, the phototransistor is in a disconnected state, and the monitoring signal input to the control unit 30 is a continuous high-level signal.
[0050] It should be noted that the monitoring unit 103 uses the optical coupler U1 to achieve signal isolation between the liquid level monitoring circuit 10 and the control unit 30, so that changes in the liquid level monitoring environment will not affect the control unit 30, ensuring a more stable operation of the control unit 30.
[0051] In one embodiment of the present application, Figure 3 As shown, the liquid level monitoring circuit 10 further includes an alarm unit 105, which is electrically connected to the control unit 30 and the monitoring unit 103. The alarm unit 105 is used to output alarm information when the first conductive probe A and the second conductive probe B are immersed in liquid.
[0052] Specifically, when the liquid in the device under test immerses the first conductive probe A and the second conductive probe B, the phototransistor in the optocoupler U1 is in the on state, and current flows through the alarm unit 105, so that the alarm unit 105 is powered, thereby outputting alarm information to notify the user in time.
[0053] It should be noted that the alarm information is generally sent to the user in the form of sound, light signal or electrical signal.
[0054] In one embodiment of the present application, Figure 2As shown, the alarm unit 105 includes a third resistor R3, a first end of the third resistor R3 is electrically connected to the power supply VCC, and a second end of the third resistor R3 is electrically connected to the monitoring unit 103 and the control unit 30 respectively.
[0055] Specifically, the third resistor R3 can be replaced by a buzzer or a light-emitting body (light-emitting diode). When the liquid immerses the first conductive probe A and the second conductive probe B, the phototransistor is in the on state, and the buzzer or the light-emitting body is energized to emit a sound or a light signal to notify the user in time.
[0056] In one embodiment of the present application, Figure 3 As shown, the liquid level monitoring circuit 10 further includes a filtering unit 104, which is electrically connected to the control unit 30 and the monitoring unit 103 respectively, and is used to filter out high-frequency signals in the monitoring signal.
[0057] Specifically, the monitoring signal may be subject to various interferences, including high-frequency signals such as electromagnetic interference and noise interference. High-frequency signals may affect the accuracy and stability of the monitoring signal, and therefore need to be filtered by the filtering unit 104. By selecting a suitable frequency range, the high-frequency signal is filtered out, and only the basic components in the monitoring signal are retained. The influence of the high-frequency signal on the monitoring signal output to the control unit 30 can be effectively reduced, and the anti-interference ability of the liquid level monitoring circuit 10 can be effectively improved, thereby ensuring the accuracy and reliability of the monitoring result.
[0058] In one embodiment of the present application, Figure 2 As shown, the filtering unit 104 includes a first capacitor C1, a first end of the first capacitor C1 is electrically connected to the control unit 30 and the monitoring unit 103 respectively, and a second end of the first capacitor C1 is grounded.
[0059] Specifically, the first capacitor C1 has the ability to allow high-frequency signals to pass through and isolate low-frequency signals, thereby filtering out high-frequency signals in the monitoring signal, making the monitoring signal output to the control unit 30 more stable and reliable, and improving the reliability of the liquid level monitoring circuit 10.
[0060] In one embodiment of the present application, the liquid level monitoring circuit also includes a scale, a first fixed seat and a second fixed seat, the first fixed seat and the second fixed seat are both connected to the scale and are slidably connected to the scale, the first conductive probe A is connected to the first fixed seat, and the second conductive probe B is connected to the second fixed seat.
[0061] Specifically, the scale can be installed on the inner wall of the device to be tested, perpendicular to the bottom of the device to be tested. The first conductive probe A can be fixed on the first fixing seat, and the second conductive probe B can be fixed on the second fixing seat. Since both the first fixing seat and the second fixing seat can be moved on the scale, the distance between the first conductive probe A and the second conductive probe B can be changed accordingly. After the positions of the first fixing seat and the second fixing seat on the scale are determined, the distance between the first conductive probe A and the second conductive probe B can be determined, so that the liquid level can be accurately monitored. This design can improve the monitoring flexibility of the liquid level monitoring circuit 10, and is suitable for devices to be tested of different sizes or shapes.
[0062] like Figure 4 As shown, the present application also discloses a liquid level monitoring system, including a control unit 30, an AC signal generating unit 20 and at least one of the above-mentioned liquid level monitoring circuits 10, the control unit 30 is electrically connected to the monitoring units 103 in all the liquid level monitoring circuits 10, and the AC signal generating unit 20 is electrically connected to the monitoring units 103 in all the liquid level monitoring circuits 10 and the first isolation unit 101.
[0063] Specifically, when the liquid level monitoring system includes only one liquid level monitoring circuit 10, the AC signal generating unit 20 is used to output an AC signal to the liquid level monitoring circuit 10, and the control unit 30 is used to receive the monitoring signal output by the monitoring unit 103, and output a control signal according to the monitoring signal. In this way, real-time monitoring of the liquid level is achieved. When the liquid level monitoring system includes multiple liquid level monitoring circuits 10, the AC signal generating unit 20 is used to output an AC signal to all liquid level monitoring circuits 10, and the control unit 30 is used to receive the monitoring signals output by all monitoring units 103, and determine the depth of the liquid according to all monitoring signals. In this way, monitoring of the liquid depth is achieved.
[0064] It should be noted that if Figure 2 As shown, the AC signal generating unit 20 includes an AC signal source P1 , wherein pin 1 of the AC signal source P1 serves as a first end of the AC signal source P1 , and pin 2 of the AC signal source P1 serves as a second end of the AC signal source P1 .
[0065] Exemplarily, if the liquid level monitoring system includes three liquid level monitoring circuits 10, the first liquid level monitoring circuit 10 is set at the first position of the device to be tested, the second liquid level monitoring circuit 10 is set at the second position of the device to be tested, and the third liquid level monitoring circuit 10 is set at the third position of the device to be tested. Among them, the first position is at the bottom of the device to be tested, the second position is 10 cm directly above the first position, and the third position is 10 cm directly above the second position. If the first monitoring signal received by the control unit 30 is a square wave signal, the second monitoring signal received is a square wave signal, and the third monitoring signal received is a continuous high-level signal. This shows that the liquid depth in the device to be tested is 20 cm higher than the bottom and 30 cm lower than the bottom, thereby realizing the monitoring of the liquid depth. Designers can select the distance and position of each liquid level monitoring circuit 10 according to actual conditions to improve the accuracy of liquid depth monitoring, which is not limited here.
[0066] In one embodiment of the present application, the liquid level monitoring system further includes a communication unit, which is electrically connected to the control unit 30 and the monitoring platform respectively, and is used to output a communication signal according to the control signal.
[0067] Specifically, the communication unit is used to connect the control unit 30 and the monitoring platform, and is used to communicate with the monitoring platform so as to transmit the status information of the liquid level monitoring system (such as liquid status, liquid depth, alarm information, etc.) to the monitoring platform, so that the monitoring platform can know the operation status of the liquid level monitoring system in a timely manner.
[0068] It should be noted that the connection method between the communication unit and the monitoring platform can be wired or wireless, such as Ethernet, Wi-Fi or Bluetooth, etc. The communication signal can be a digital signal or an analog signal.
[0069] The present application also discloses a liquid level monitoring device, including the above-mentioned liquid level monitoring system. The liquid level monitoring device adopts the above-mentioned liquid level monitoring system to monitor the liquid level more accurately and improve the reliability of liquid level monitoring.
[0070] Since the processing and functions implemented by the liquid level monitoring system and the liquid level monitoring device in this embodiment basically correspond to the embodiments, principles and examples of the aforementioned liquid level monitoring circuit, for the details not fully described in this embodiment, please refer to the relevant descriptions in the aforementioned embodiments, and no further details will be given here.
[0071] The embodiments described above are only used to illustrate the technical solutions of the present application, rather than to limit them. Although the present application has been described in detail with reference to the aforementioned embodiments, a person skilled in the art should understand that the technical solutions described in the aforementioned embodiments may still be modified, or some of the technical features may be replaced by equivalents. Such modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present application, and should all be included in the protection scope of the present application.
Claims
1. A liquid level monitoring circuit, characterized in that: It includes a first isolation unit, a second isolation unit, a monitoring unit, a first conductive probe and a second conductive probe, wherein the first conductive probe is used to be electrically connected to a first end of an AC signal generating unit through the first isolation unit, the second conductive probe is electrically connected to the monitoring unit through the second isolation unit, the monitoring unit is used to be electrically connected to a second end of the AC signal generating unit, and the monitoring unit is also used to be electrically connected to a control unit; The AC signal generating unit is used to output an AC signal; the first isolation unit is used to isolate the first conductive probe from the AC signal generating unit, and the second isolation unit is used to isolate the second conductive probe from the monitoring unit; when the liquid immerses the first conductive probe and the second conductive probe, the first conductive probe and the second conductive probe are conductive, and the monitoring unit is used to output a monitoring signal to the control unit.
2. The liquid level monitoring circuit according to claim 1, characterized in that: The first isolation unit includes a first resistor, a first end of the first resistor is used to be electrically connected to a first end of the AC signal generating unit, and a second end of the first resistor is electrically connected to the first conductive probe.
3. The liquid level monitoring circuit according to claim 1, characterized in that: The second isolation unit includes a second resistor, a first end of the second resistor is electrically connected to the monitoring unit, and a second end of the second resistor is electrically connected to the second conductive probe.
4. The liquid level monitoring circuit according to claim 1, characterized in that: The monitoring unit includes an optocoupler, a first input end of the optocoupler is used to be electrically connected to the second end of the AC signal generating unit, a first output end of the optocoupler is electrically connected to the second isolation unit, a second input end of the optocoupler is used to be electrically connected to a power supply and the control unit respectively, and a second output end of the optocoupler is grounded.
5. The liquid level monitoring circuit according to any one of claims 1 to 4, characterized in that: The liquid level monitoring circuit further comprises a filter unit, and the filter unit is electrically connected to the control unit and the monitoring unit respectively; The filtering unit is used to filter out high-frequency signals in the monitoring signal.
6. The liquid level monitoring circuit according to claim 5, characterized in that: The filtering unit includes a first capacitor, a first end of the first capacitor is electrically connected to the control unit and the monitoring unit respectively, and a second end of the first capacitor is grounded.
7. The liquid level monitoring circuit according to any one of claims 1 to 4, characterized in that: The liquid level monitoring circuit further comprises an alarm unit, and the alarm unit is electrically connected to the control unit and the monitoring unit respectively; The alarm unit is used to output alarm information when the first conductive probe and the second conductive probe are immersed in liquid.
8. The liquid level monitoring circuit according to any one of claims 1 to 4, characterized in that: The liquid level monitoring circuit also includes a scale, a first fixed seat and a second fixed seat, the first fixed seat and the second fixed seat are both connected to the scale and are slidably connected to the scale, the first conductive probe is connected to the first fixed seat, and the second conductive probe is connected to the second fixed seat.
9. A liquid level monitoring system, characterized in that: It comprises a control unit, an AC signal generating unit and at least one liquid level monitoring circuit according to any one of claims 1 to 8, wherein the control unit is electrically connected to the monitoring units in all the liquid level monitoring circuits respectively, and the AC signal generating unit is electrically connected to the monitoring units in all the liquid level monitoring circuits and the first isolation unit respectively; The control unit is used to receive the monitoring signals output by all the monitoring units and output a control signal according to the monitoring signals; the AC signal generating unit is used to output an AC signal.
10. A liquid level monitoring device, characterized in that: Includes the liquid level monitoring system as described in claim 9.