this water level sensor can alarm you when water reaches at the top of your tank
Step 1: Materials Needed
the materials needed are
Transistor bc 548
2 resistors 220 ohms
9v battery cap
Step 2: Transistor Assembly
Take your transitor and connect 2 wires to the middel wire and the right hand side wire.
Then take one 220 ohms resitor and connect it to anyone of the wires coming out
Step 3: Led Assembly and the Transistor Circit
At first connect a resistor to the longer leg of the led
Then connect a wire to the led 's resistors leg
after it comes the bit confusing part Conneting the transistor circit to the led circit to do it connect one wire to the one leg of the transistor circit's resistor
now you'll be left with 3 wires 2 from the transistor circit and 1 from the led circit
one leg of the led will be left
Step 4: Connecting Wires and Battery
Now take the battery cap and then connect the black wire to the left leg of the led and red wire to the transistor circit's resistor's wire
now you'll be left with 2 wires you may connect then to electrodes.
Step 5: See It Working!!
when the electrodes will br dipped in water the led will glow