Water Level Indicator1
A simple water level indicator using a transistor
The water level indicator works using LED, 220 ohm resistor, BC547 transistor, and a 9V battery.
The transistor acts as a switch. The positive terminal of the battery is connected to the water whose level is to be found out. The base terminal of the transistors is arranged in the ascending order depending upon the length from the top. As the water fills. The positive will be in contact with the base terminal and the small voltage will result to change the flow of electrons from emitter to collector and thus the LED lights. Similarly, as the water rises, the other LED lights and we can understand, the water has reached the top. This simple water level indicator helps us to determine the level of the water.