Hey everyone
So I am having trouble with this project of mine. Basically, I need an LED to turn on when water is not present (dries out). So first I need this to happen with just a bowl of water (oh and I cannot add salt at any point). Then need it to also work with a bowl of wet sand, bowl of wet paper towels, soil, etc. So I took a 9v and ran a copper wire at each end of the bowl and then to a 9v normally open relay, however it only works when the wires are touching, it's not conducting through the water. Then tried it with a 3v relay, same problem... Hmmm.
Any help would be greatly appreciated!
So I am having trouble with this project of mine. Basically, I need an LED to turn on when water is not present (dries out). So first I need this to happen with just a bowl of water (oh and I cannot add salt at any point). Then need it to also work with a bowl of wet sand, bowl of wet paper towels, soil, etc. So I took a 9v and ran a copper wire at each end of the bowl and then to a 9v normally open relay, however it only works when the wires are touching, it's not conducting through the water. Then tried it with a 3v relay, same problem... Hmmm.
Any help would be greatly appreciated!