Hi
i am ajinkya
this is my first Instructable -SIMPLE WATER DETECTOR
For this project u will need the following parts:
1.IC 555 timer-1
2.Small size generel purpose PCB(Single Sided)-2
3.Buzzer-1
4.Red LED(5mm)-1
5.electrolytic capacitor-2.2uF -1
6.Resistor's-R1=1k Ohm
                        R2=100kOhm
7.A 9v Battery-1
8. Wires(optional)
9.breadboard(optional)
10.Soldering Iron

Also the sensor board is my homemade sensor board made out of generel purpose pcb.
to make this u will need:
1.A small PCB(Single sided).
2.Laser printer(only laser printer is better) & OHP sheet.
3.FeCl3(Ferrus Cloride) PCB Etching Solution.
4.Cloths iron.

Gathered Parts Together?
Ready?
ok.......

Now Look carefully following circuit Diagram & try out the circuit on bread board first.
if it is working properly go to making its PCB version. the PCB for the project is shown here.
The pcbs r homemade here.
If u r new to pcb making then dont worry......... U can make pcb's at home
to learn this pls visit to the link-http://iamsuhasm.wordpress.com/2008/12/10/making-pcbs-the-right-way/
on the SUHAS'S BLOG.
After that fix all the parts on the pcb(not the sensor board) as per the following images & ckt diagram.
Fixed??? Ok Now attach the probes to sensor board & give power supply.
Now drip some water on the sensor board & see what happens!!!!!

U can use these ckt as a automatic wiper starter for u r car by replacing only the buzzer to motor & few ckt changes for continuous motor rotation.

See video on below attachment(the video format is MP4 so use video player which supports the MP4 format)
(Note:TO MAKE THE SENSOR BOARD THE COPPER PCB IS NOT BETTER DUE TO OXIDATION. U CAN USE ALLUMINIUM FOILS/STAINLESS STEEL PLATES)


 PLEASE RATE IF U LIKE N COMMENT!!!!!!!!!!!!!!