Rain Alarm Using AND Gate

Introduction

Rain Alarm Project is a simple but very useful project that detects Rain (Rain Water) and automatically triggers an alarm or buzzer. Water is a basic need in every one’s life. Saving water and proper usage of water is very important. Here is an easy project which will give the alarm when there is rain, so that we can make some actions for rain water harvesting and also save the rain water for using it later.

With the help of saving this rain water through rain water harvesting, we can increase the levels of underground water by using underwater recharge technique. Rain water detector will detect the rain and make an alert; rain water detector is used in the irrigation field, home automation, communication, automobiles etc. Here is the simple and reliable circuit of rain water detector which can be constructed at low cost.

Components

• 7408 IC AND Gate
• Buzzer
• Battery 5V
• Rain Sensor
• Connecting Wires

      Working

        As we know that AND gives output 1 when both inputs are 1 if any of the input of AND is 0 then its output becomes 0. Using this property of AND gate we can construct Rain Alarm Project. First input of AND gate should be given 1 permanently. And the other input is attached to the rain sensor if sensor detects some sort of rain it gives electricity. In this way both inputs of AND gate should be 1 and output buzzer will start buzzing.

        Truth table of AND gate is given in Table 1.

            Table 1: Truth Table of AND Gate

Input 1	Input 2	Output
0	0	0
0	1	0
1	0	0
1	1	1

Circuit Diagram is given in Figure 1.

Figure. 1 : Circuit Diagram

        Data Sheet of AND gate is given in Figure 2.

Figure. 2 : Data Sheet of AND Gate

        Conclusion

Rain senor should be kept in the open place at 30 to 40 degrees from the ground. As a result, rain water will not be present on the sensor for long time. This circuit will automatically switch of the alarm after sometime until the rain stops.