Liquid level detection circuit
By using a simple liquid level detection circuit, electrodes and transistors are used to detect changes in liquid level. Combined with light and voice alarms, this solves the problems of traditional liquid level detection, such as the inability to remotely monitor and high cost, and achieves low-cost liquid level detection and alarm functions.
Patent Information
- Application Number
- CN202520145740.8
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-01-22
- Publication Date
- 2026-01-27
- Estimated Expiration
- 2035-01-22
AI Technical Summary
Existing liquid level detection methods cannot achieve remote monitoring and are costly. Traditional liquid level sensors are not suitable for confined spaces.
A simple liquid level detection circuit is used to detect changes in liquid level using the first and second electrodes. An NPN transistor and a light-emitting diode provide light prompts, and an inverter and a buzzer provide voice alarms.
It achieves low-cost liquid level detection, and can provide light prompts and issue voice alarms at the same time, making it suitable for small spaces such as water tanks, water towers or pools.
Smart Images
Figure CN223841260U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of electronic technology, and in particular to a liquid level detection circuit. Background Technology
[0002] For water-using facilities and other liquid containers that use water tanks, water towers or pools as water sources, it is necessary to ensure sufficient water volume, which is usually determined by the liquid level to determine whether there is a water shortage.
[0003] Traditional methods of manual observation are only suitable for on-site monitoring, not for remote monitoring, and are unsuitable for situations with confined spaces. Existing liquid level detection typically uses liquid level sensors, which are relatively expensive. Utility Model Content
[0004] To overcome the above-mentioned defects, this utility model aims to provide a liquid level detection circuit with simple structure, high reliability, and low cost; it can effectively detect the liquid level and provide light prompts while also issuing a voice alarm.
[0005] To achieve the above objectives, the technical solution adopted by this utility model is as follows:
[0006] A liquid level detection circuit includes: a first electrode and a second electrode, both of which are placed at a predetermined liquid level position and do not contact each other;
[0007] The first electrode is connected to the base of the first NPN transistor and one end of the first resistor. The collector of the first NPN transistor is connected to one end of the second resistor, the anode of the first light-emitting diode, and one end of the fourth resistor. The other end of the fourth resistor is connected to the base of the second NPN transistor. The cathode of the first light-emitting diode is connected to one end of the third resistor. The collector of the second NPN transistor is connected to one end of the fifth resistor and the anode of the second light-emitting diode. The cathode of the second light-emitting diode is connected to one end of the sixth resistor. The other ends of the first resistor, the second resistor, and the fifth resistor are all connected to a power supply. The second electrode, the emitter of the first NPN transistor, the other end of the third resistor, the emitter of the second NPN transistor, and the other end of the sixth resistor are all grounded.
[0008] Preferably, both the first electrode and the second electrode are metal rods.
[0009] Preferably, the first light-emitting diode is a red light-emitting diode, and the second light-emitting diode is a green light-emitting diode.
[0010] Furthermore, the collector of the first NPN transistor is also connected to the cathode of the diode, the anode of the diode is connected to the input terminal of the first inverter, one end of the seventh resistor and one end of the capacitor, the output terminal of the first inverter is connected to the other end of the seventh resistor and the input terminal of the second inverter, the output terminal of the second inverter is connected to the other end of the capacitor and one end of the buzzer, and the other end of the buzzer is grounded.
[0011] Preferably, the first inverter and the second inverter are located in the same NOT gate integrated circuit.
[0012] Preferably, the power supply is provided by the first inverter and the second inverter.
[0013] This invention can be used for water shortage detection in water tanks, water towers, or pools. Specifically: A first electrode and a second electrode are installed in the water tank, water tower, or pool. When the water level is normal, the first and second electrodes are immersed in the liquid. Due to the conductivity of water, the base of the first NPN transistor is at a low potential, so the first NPN transistor is not conducting. The collector of the first NPN transistor is at a high potential, and the first LED emits light, indicating sufficient water. Simultaneously, the base of the second NPN transistor is at a high potential, so the second NPN transistor is conducting. The collector of the second NPN transistor is at a low potential, and the second LED does not emit light. Because the collector of the second NPN transistor is at a low potential, the isolation diode conducts, causing the audio oscillator composed of the first and second inverters to stop oscillating, and the buzzer to remain silent.
[0014] When the water level drops below the first and second electrodes, there is no electrical conductivity between them. The base of the first NPN transistor is at a high potential, making it conduct. The collector of the first NPN transistor is at a low potential, causing the first LED to turn off. Simultaneously, the base of the second NPN transistor is at a low potential, making it non-conducting. The collector of the second NPN transistor is at a high potential, causing the second LED to light up, indicating a water shortage. Because the collector of the second NPN transistor is at a high potential, the isolation diode is not conducting. The audio oscillator, composed of the first and second inverters, starts oscillating, and the buzzer sounds, providing an audible alarm.
[0015] Of course, this invention is also applicable to level detection of other conductive liquids.
[0016] This invention can effectively detect liquid levels, providing both visual and audio alerts. It features a simple structure, high reliability, and low cost. Attached Figure Description
[0017] Figure 1 This is the circuit schematic diagram of this utility model. Detailed Implementation
[0018] To make the objectives, technical solutions, and advantages of this utility model clearer, the following detailed description is provided in conjunction with the accompanying drawings.
[0019] Example 1
[0020] This embodiment discloses a liquid level detection circuit, specifically as follows: Figure 1 As shown, this embodiment includes a first electrode A and a second electrode B, both of which are metal rods. The first electrode A and the second electrode B are both placed at a predetermined liquid level position, such as in a water tower, water tank, or pool, and the first electrode A and the second electrode B do not contact each other.
[0021] The first electrode A is connected to the base of the first NPN transistor Q1 and one end of the first resistor R1. The collector of the first NPN transistor Q1 is connected to one end of the second resistor R2, the anode of the first light-emitting diode LED1, and one end of the fourth resistor R4. The other end of the fourth resistor R4 is connected to the base of the second NPN transistor Q2. The cathode of the first light-emitting diode LED1 is connected to one end of the third resistor R3. The collector of the second NPN transistor Q2 is connected to one end of the fifth resistor R5 and the anode of the second light-emitting diode LED2. The cathode of the second light-emitting diode LED2 is connected to one end of the sixth resistor R6. The other ends of the first resistor R1, the second resistor R2, and the fifth resistor R5 are all connected to the power supply VCC. The second electrode B, the emitter of the first NPN transistor Q1, the other end of the third resistor R3, the emitter of the second NPN transistor Q2, and the other end of the sixth resistor R6 are all grounded to GND. The first light-emitting diode LED1 is red, and the second light-emitting diode LED2 is green, conforming to conventional display methods.
[0022] This embodiment can detect whether there is a water shortage by liquid level detection and provide corresponding light indication.
[0023] Example 2
[0024] This embodiment discloses a liquid level detection circuit. Based on Embodiment 1, this embodiment adds a voice alarm function, specifically as follows: Figure 1 As shown, the collector of the first NPN transistor Q1 is also connected to the cathode of the diode D1. The anode of the diode D1 is connected to the input terminal of the first inverter U1, one end of the seventh resistor R7, and one end of the capacitor C1. The output terminal of the first inverter U1 is connected to the other end of the seventh resistor R7 and the input terminal of the second inverter U2. The output terminal of the second inverter U2 is connected to the other end of the capacitor C1 and one end of the buzzer B1. The other end of the buzzer B1 is grounded to GND.
[0025] The first inverter U1 and the second inverter U2 can be two gates from the same NOT gate integrated circuit, such as CD4096. The power supply of CD4096 is the same VCC as that of the first NPN transistor Q1 and the second NPN transistor Q2.
[0026] This embodiment provides both light indication and alarm functions.
[0027] The other parts of this embodiment are the same as those in Embodiment 1, so they will not be described again.
[0028] Of course, there may be other embodiments of this utility model. Without departing from the spirit and essence of this utility model, those skilled in the art can make various corresponding changes and modifications based on this utility model, but these corresponding changes and modifications should all fall within the protection scope of the appended claims of this utility model.
Claims
1. A liquid level detection circuit, characterized in that, include: The first electrode and the second electrode are both placed at a predetermined liquid level position, and the first electrode and the second electrode do not contact each other. The first electrode is connected to the base of the first NPN transistor and one end of the first resistor. The collector of the first NPN transistor is connected to one end of the second resistor, the anode of the first light-emitting diode, and one end of the fourth resistor. The other end of the fourth resistor is connected to the base of the second NPN transistor. The cathode of the first light-emitting diode is connected to one end of the third resistor. The collector of the second NPN transistor is connected to one end of the fifth resistor and the anode of the second light-emitting diode. The cathode of the second light-emitting diode is connected to one end of the sixth resistor. The other ends of the first resistor, the second resistor, and the fifth resistor are all connected to a power supply. The second electrode, the emitter of the first NPN transistor, the other end of the third resistor, the emitter of the second NPN transistor, and the other end of the sixth resistor are all grounded.
2. The liquid level detection circuit according to claim 1, characterized in that, Both the first electrode and the second electrode are metal rods.
3. The liquid level detection circuit according to claim 1, characterized in that, The first LED is a red LED, and the second LED is a green LED.
4. The liquid level detection circuit according to claim 1, 2 or 3, characterized in that, The collector of the first NPN transistor is also connected to the cathode of the diode. The anode of the diode is connected to the input terminal of the first inverter, one end of the seventh resistor, and one end of the capacitor. The output terminal of the first inverter is connected to the other end of the seventh resistor and the input terminal of the second inverter. The output terminal of the second inverter is connected to the other end of the capacitor and one end of the buzzer. The other end of the buzzer is grounded.
5. The liquid level detection circuit according to claim 4, characterized in that, The first inverter and the second inverter are located in the same NOT gate integrated circuit.
6. The liquid level detection circuit according to claim 3, characterized in that, The power supply provides power to the first inverter and the second inverter.