My First Circuit: Water Level Indicator Alarm Circuit

The water level indicator is simple electronic circuit that detects and indicates the water level in an overhead tank or any other water container. The circuit I made, was a transistor based water level indicator. I used 4 BC547 npn transistors to indicate the 4 particular water levels in this circuit. I also used 3 LEDs to indicate the initial 3 water levels and a buzzer to indicate the final level.

Here, the transistors are used as switches. Initially the transistors are in OFF state. No voltage is applied to the base and no current is flowing through the collector and emitter. When the water level reaches to the particular level points, the positive side of the battery gets connected to the base of connected transistor. Then it gets into ON state and current starts flowing from collector to emitter, so that the connected LED blows for each level.

Generally, a transistor gets in ON state fully when a voltage of 0.7V is applied to the base. So I have used some resistors to limit the maximum base current. I also used some resistors to drop the voltage across LEDs, otherwise LEDs may blow up.



Comments

Popular Posts