Water Sensor or Alarm Using 2N2222 Transistors

Introduction: Water Sensor or Alarm Using 2N2222 Transistors

About: just a hobbyist

Who doesnt hate it when it rains while some stuff are outside?(and you dont realise it is raining). At least I do! That is why I came up with this kind of project. Lets started!

Step 1: Tools and Components Needed:




A breadboard

Some wire

A wire stripper and/or cutter to cut/strip wire

A power source

BIG headpones to avoid hearing the buzzer when experimenting(Optional)

Step 2: Placing Buzzer and Transistors

All locations are shown in the picture. Buzzer + is on the + bus

Step 3: Making the Connections

Connect all the components as shown on the picture. Optionally you can add a LED in parallel with the buzzer for visual alarm too.

Step 4: Connecting the Sense Wires and Sticking Them to a Surface

Sense wires should be connected as shown in the picture. You should be extra careful about this step.They should be sticked to a non-conductive surface as close as possible so a single drop of water can short them but they doesnt touch each other.

Step 5: HAVE FUN!

This circuit can work with a wide range of supply voltages. In my case i am using my variable power supply set to 5V. Buzzer and LED(if you added it) will be activated when somebody touches both of the sense wires or water does. For this version you will need to wipe away the water on sense wires to turn Buzzer and LED off. Thank you for reading `till the end and HAVE FUN!

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    2 years ago on Step 5

    This seems simple but a type of innovation anyway. I liked it. I wonder how much rain will activate it?


    Tip 2 years ago

    Although the project seems simple enough, I would appreciate a circuit diagram too, to see what's happening circuit wise.


    Reply 2 years ago

    Thank you for the tip, i noticed that a circuit diagram is missing too after publishing. I am now adding circuit diagrams to my instructable(s).


    2 years ago on Introduction

    Thnx. The post is very useful for the beginners.