This is the Simple Water-level indicator Circuit Diagram. n this a 
warning device WD1 is in series with SCR1. When the liquid level causes a
 conductive path between the probes, the SCR conducts sounding WD1. The 
warning device may be a Sonalert (TM), a lamp or a buzzer.D1 acts as a 
transient suppressor. Press SI to reset the circuit.
Simple Water-level indicator Circuit Diagram
Sourced By: Streampowers
 
