Inventors Yuriy Pchelnikov (left) and David Nyce and one of their SEF sensors. The devices use a sensing element consisting of conducting elements periodic along the direction of propagation of the ...

Recently I came across some non-contact liquid level sensors and gathered them out of curiosity. They have been available in the market for the past few years, but this time I was lucky enough to get ...

This is a very simple liquid detector that use a relay to open an evacuation van. You can use it for water or any liquid that conduct electricity. Use any PNP transistor that can stand the relay ...