RAIN DETECTOR USING ASTABLE MULTIVIBRATOR

Here we going to make a rain detector using astable multivibrator and simlpe conitinuouity tester.
These circuits are we already learned in my previous post. We all know water is a precious thing in earth. Also  it is less in earth so we want to protect and reduce the use of water.
Use of this circuit we can save the rain water whenever the raining occur.


Working

It have two parts astable using ne555 and simple continuity tester.The input to the astable is given by, through a continuity circuit. It have two wires A&B it is placed just near each other. But both have no 
connection. The continuity circuit closed by when raining occur the water particles falls on the two wires A&B.Thus the circuit get closed and the 10V is inputed to the astable multivibrator.Astable can produce squarewaves when input is given to it. In this circuit we use a melody sound generator ic UM66. It is used to produce sound when raining occur. It have 3 pins used as input,output ground.The output from the astable is given to the input of the ic UM66. First the output is given to the bc548 transistor to amplify it. After it given to the input to UM66. The output from the UM66 is again given to the bc548 to for amplification. and then given to the speaker.And the speaker produce the sound. If the raining is continuous the sound  also continuously  produced.
Place the circuit except the A&B wires and speaker. Place the speaker in the place is where it is to be hear.
And place the wires A&B in open and close to each other for rain fall occur.

Components for wiring this circuit

NE555
UM66
Q1=Q2   = BC548
Ra      = 6.8K
Rb      = 6.8K
R       = 360Ω
Rc     = 220Ω
D       = LED
C       = 0.1µF
C1      = 0.01µF
S       = speaker 8Ω