One summer after I had moved into my new house I found that the sprinkler system didn't work correctly. I noticed that when the water was not on the sprinkler heads still leaked water. I figured that the values were probably dirty and were not closing properly. So I set out one morning to bleed the values and clean them up as necessary. The only problem is I had no idea where the valves were located. I knew they were under the ground somewhere in my yard. I looked and looked but could not find them. I used a metal detector, probed the ground, everything. Then I had an idea about building the following circuit.
The valves make a clicking noise when their solenoids open and close the water valve. I figured that if I turn the valves on and off (after turning off the water supply) and listen then I might be able to hear the valves operating. The problem is that I didn't have anybody that would stand around flipping the switch on/off while I walked around the yard listening. So I built this circuit and connected it to the sprinkler system. Within two minutes I found the valves and had the leaks all fixed.
Parts List: wire, (AA,AAA,C,D or 9V) batteries, toggle switch, relay, leds, NTE955 timer chip, 1k resistors, 5k resitors, 4k resistor, 100uF capacitor, battery clip or battery pack holder, circuit board.
Step 1: Tools Used for This Project
The tools used for this project are as follows: