This project outlines how to build a simple and effective Water Tank Level Indicator that uses LEDs to show the current water level and a Buzzer to alert you when the tank is full, preventing messy and wasteful overflow. This circuit uses the conductive property of water to complete a circuit, illuminating LEDs at various heights.
Components Required
- . Transistors-BC548 -(3) ►https://amzn.to/33POs9S
- Resistors-2.2KΩ-(3), 100Ω-(3)►https://amzn.to/2Rs3zDM ►https://amzn.to/3uXjVCU
- LEDs(different colored)-(3)►https://amzn.to/3oqiCu2
- Battery-9v►https://amzn.to/3frFsNJ
- Battery clip
- Stainless steel pieces-(4)
- Connecting wires
- Zero PCB►https://amzn.to/3wdNC38
Circuit
How It Works
The system works based on the principle that water is electrically conductive, capable of completing a low-current circuit:
- The Common (Reference) Wire: A main common ground wire is placed at the very bottom of the water tank. This wire acts as the common negative reference for all the level circuits.
- Level Wires (Sensors): Separate sensor wires are suspended into the tank at the desired low, medium, and high-level points.
- Circuit Completion:
- The positive side of the battery is connected through the control circuit to the base of a transistor for each level.
- When the water rises high enough to touch the Low Level Wire and the Common Wire at the bottom, a tiny current flows through the water, completing the circuit to the base of the transistor.
- This small base current causes the transistor to switch ON, allowing a larger current to flow from the battery’s positive terminal, through the transistor’s collector-emitter path, and light up the Low Level LED.
- Sequential Indication: As the water continues to rise, it sequentially touches the Medium and Full Level wires, activating their corresponding transistors and illuminating the LEDs one by one.
Level Indications
The system provides a clear visual signal:
- Red LED Glows: Water is at a Low Level (First level sensor is touched).
- Red + Yellow LEDs Glow: Water is at a Medium Level (Second level sensor is touched).
- All LEDs Glow + Buzzer Sounds: Water is at the Full Level (Highest sensor is touched), and the Buzzer immediately sounds to alert you to turn off the pump or motor.
Construction Notes
- Sensor Installation: The stripped end of the wires must be carefully adjusted to correspond to the exact water levels you want to monitor in the tank.
- Circuit Assembly: All components (LEDs, resistors, transistors, and buzzer) are mounted inside the enclosure box, with the LEDs visible on the front panel and the sensor wires running out to the tank. This DIY project offers a practical and energy-efficient way to manage water usage and prevent overflows at home.
Watch the full video tutorial here: How to make a Water tank level indicator with buzzer| Stop water tank overflow at Home | DIY