Simple Water Level Controller Circuits Assignment Sample

The circuit diagram consists of two main components: a water sensor and a relay circuit.

Here's how the circuit works:

1. Water Sensor: The water sensor is made up of two metal probes (A and B) that are placed at different levels in the water tank. When the water level rises and touches both the probes, a small current flows between them.

2. Transistor Circuit: The transistor circuit is responsible for amplifying the small current from the water sensor and driving the relay.

• Transistors Q1 and Q2 (BC547) are used as a voltage comparator. When the water level is below the probes (no contact), the base of Q1 is at a higher voltage than the base of Q2, keeping Q1 ON and Q2 OFF.

• When the water level rises and makes contact between the probes, the base voltage of Q2 becomes higher than that of Q1, turning Q2 ON and Q1 OFF.

• When Q2 turns ON, it activates the relay.

3. Relay Circuit: The relay is used to control the water supply. When the relay is energized, it cuts off the power supply to the water pump, preventing further water from entering the tank.

• The relay coil (RL1) is connected to the collector of Q2 and the positive supply.

• When Q2 is ON, it energizes the relay coil, and the relay contacts (RL1-1 and RL1-2) switch to disconnect the power supply to the water pump.

4. Power Supply: The circuit requires a 12V DC power supply, which is connected to the collector of Q1 and the positive terminal of the relay coil.

Please note that while this circuit provides a basic water level control function, it may not have advanced features such as adjustable sensitivity, overflow protection, or indication of water levels. Additionally, it is important to ensure proper electrical safety precautions when working with water and electricity.