Water level indicator with transistor
Overflowing of water from the tank is considered as one of the common problems everyone faces in their daily life, most of the time water is wasted without, timely communication to turn off the water pump.
In this post, we are come up with an electronic solution for the water wasting problem at motor pumping, in this article we introduce two water level indicators, water level indicator using transistor BC547 and water level indicator using BC547 and relay.
We include the simplest circuit of water level indicator, the circuit pros and cons are been included in this post, and we try to ensure a clear idea about water level indicator device.
The main purpose of this project
Most of the projects available on the internet, particularly related to our real-time applications circuits are mostly not tested or perfectly designed, in this post, we try to make a water level indicator with 5 level indication using BC547 transistor and also a relay-based water level indicator.
Water level indicator using transistor BC547 circuit
BC547 transistor is the important component used here for the indication process, this particular is capable of indicating 5 levels of water, starting from 20% of water to 100% of water.
Due to this application transistor works as a switch in this water level indicator using transistor BC547 circuit, and LEDs are used to indicate the levels with different colors.
Circuit explanation of water level indicator
In this circuit, we have 5 BC547 transistors, and then the input of the transistor that is base terminals of all 5 transistors, will be submerged in the water at different levels.
And the emitter terminals of transistors are joined together and last at the transistor output terminal collector we have LEDs combined with a resistor for running the LEDs.
Last we have our power supply, for this circuit, we have a 9v DC supply.
Working of water level indicator
When the power supply is given to the circuit, the circuit starts working, in the water tank total of 6 copper needles will be submerged, such as 5 level needles with a common needle.
When there is no water in the tank, we have no indication, after filling 20% of water, the circuit becomes completed by water touches the needle and transistor becomes ON and LED1 is ON.
Then water is again filled up to 40%, the transistor becomes ON, and the LED starts glowing, so the same working operation is repeated up to 100% water filled in the tank.
This water level indicator using transistor BC547 project gives you a basic idea about water level indicator, this is a basic project manages to understand about the water indicator system.
Using this circuit we can make hobby circuits or mini-projects of water level indicator, so for an advanced real-time application, we introduce a relay-based water level indicator circuit.
Water level indicator using relay
When we consider the water level indicator circuit using the relay, this particular circuit is the extended or improved version from the first water level indicator using the BC547 transistor.
The specialty of the relay circuit is, they are capable of work in AC, and also they can control the water pump with a pulse generated within the circuit.
Circuit explanation of water level indicator using relay
The needle deposition in the water at different levels is almost the same as the first transistor-based circuit, here we have four needles, needle A at the top level, B needle at the middle position, and C needle at the bottom, and also we have a common needle D placed at the top for the circuit completion in water.
Water level indicator BC546 transistor setup
The water levels may be sensed by the circuit using BC546 transistors Q1, Q2, and Q3, they are allotted to sense the position of water at the tank, R1, R2, and R3 resistors are used as base resistors, which is used to limit base current and allow proper 0.7v to the transistor for the operation.
When we look into the indication part of the circuit, R4, R5, and R6 resistors used with the LEDs to limit the transistor collector current and make way to drive the D1, D2, and D3 LEDs.
Purpose of Relay in this circuit
The main purpose of the relay in this circuit is when the water level goes down relay gets energized and switches ON the water pump and also when the water level becomes full relay gets energized and switches OFF the water pump.
Both these operations may be done due to relay works in latch mode of operation, relay starts at a position after they switch, due to this reason why water pump remains ON, even when the water level goes above.
Latch switching of relays
For setting relay works in latching mode, we only need one set of N/O contacts.
At the time when relay gets activated, N/O contacts close which is to form short across collector and the emitter of Q6 transistor, this particular operation makes the state of Q6 transistor irrelevant to the operation of the relay and which make the relay remains at ON state as long as the transistor Q5 is ON, but the only way to switch OFF the relay by switching OFF the transistor Q5, and this will happened automatically when the water level becomes full.
And also the opposite working operation happens when the water level is at the bottom level and the relay gets energized to start the pump.
For designing proper PCB layout for both the water level indicator circuits, such as water level indicator using transistor BC547 and water level indicator using the relay.
The water level indicator circuit using transistor BC547 is termed a mini project, even they need a proper PCB designed boards for accurate working, but in the case of water level indicator using relay PCB layout is a must thing because they dealing with AC and motor controlling systems.
Application of water level indicator projects
When we consider the applications of water level indicator, which is not limited only underwater level indication, but also they had application at oil tank overflow applications, pool water level controlling applications, irrigation automation system controlling applications, and tsunami warning stations.