Simple liquid detector using logic gate

A very simple liquid detector can be built using electronic diagram below. The liquid detector is a detector with liquid alternating voltage and can be built using some very simple electronic components. Voltage alternative for this circuit is made using a gate with Schmit trigger function, which works as an alternative power oscillator.
If between both electrodes is electrically conductive fluid as a result of recovery action diodes D1 and D2, capacitor C4 is charged. When the capacitor voltage reaches the switching of logic gate N2 and connects aclanseaza relay device is connected to it. When the electrodes make no longer contact, the relay switches off the device connected to it.