How to make a Water tank Overflow Alarm

Hello friends, Welcome to the another simple electronics tutorial. In this tutorial, you will know how to make a simple water tank overflow alarm and the explanation of working of this project. It is used to give a Indication whether a tank gets full or not using buzzer. It gives a buzz sound when the tank gets full. The Circuit which controls the buzzer according to variation in water level is very simple to make and also to understand. The circuit consists of only a few component which you can easily find from your local electronics store. The total cost for this project is only about Rs.80/- only. So friends, let's begin to make this project.

Step 1- Things Needed.

[ Circuit Parts ]

> BC547 NPN Transistor - 1 piece. ( you can use any NPN Transistor )

> 100 ohm resistor - 2 pieces.

> 1000uf/25v electrolytic capacitor - 1 piece.

> Led - 1 piece. ( The color of led depends on you. you can use any color. )

> 9V Buzzer - 1 piece.

> 9v Battery - 1 piece.

> 9v Battery Cap - 1 piece.

> Small Switch - 1 piece.

> Project Circuit Board/ Perforated Board - 1 piece.

> Some Wires.

[Miscellaneous Parts]

 > Double Sided Tape.

> Plastic Box. ( Used for Casing the project ).

Step 2 - Tools Needed.

> Soldering Iron.

> Soldering Wire.

> Soldering Flux.

> Wire Cutter.

Step 3 - Studying the Circuit Diagram.

Circuit Diagram

So friends, above is the Circuit Diagram of this project. I request you to please understand the circuit diagram. This will help you to overcome the problems that you will face while making this project if you are a beginner to electronics. If you have any problem/question regarding the working of the circuit. then scroll down and read the explanation of working of the circuit. This will certainly give the answer to your question/ solution to problem. 

Circuit Diagram

Working of the Circuit:)

The working of the Circuit is very Simple. If you had read my previous article, Water level Indicator then you can easily understand the working of the Circuit.

Now let's know the explanation of working of the circuit. The circuit consists of only a few components. The main component of the circuit is the BC547 NPN Transistor, Which acts as a switch for controlling the buzzer. (Click here to read the working of BC547 NPN Transistor ). It works as when the Sensor Wires touches the Water, the connection between the base of NPN Transistor and (+) of battery completes (due to some conductivity in water). Now, according to theory, if the transistor base pin gets vcc, then the transistor gets switched on and the collector pin and emitter pin connects together within the transistor. The coolector pin of the transistor is connected to negative of buzzer and the emitter is connected to negative of battery. So, when the sensor is in water the negative of buzzer is getting negative voltage from battery. The positive of Buzzer is already connected to positive of battery. So, buzzer makes a buzz sound because the buzzer is getting desired power to turn on. 

So, when the tank gets full the buzzer gets on and when the sensor is out of water the base is not getting any (+) voltage and the transistor gets switched off which turn off the buzzer.

The 1000uf/25v capacitor is used to provide some time to the buzz sound from buzzer. The more capacitance means the more time for which the buzzer buzzes.

So friends, this is all about the working of the circuit's explanation....

Simple Water Tank Overflow Alarm

For better Explanation, Please Watch the Video and please send your feedback/suggestions for any enhancement in the video.

I hope you like this Electronics Tutorial. If you have any Problem, then ask me in Comment Box.