In the present days, almost all houses store water in the underground tanks to pump the water into the upstairs tanks. while the water is being filled in the overhead tank, no one knows when the tank will get filled. So, the water overflows from the tank leading to wastage of energy and wastage of water. To overcome this problem, there is a solution in the form of an electronic water-level-alarm circuit, which indicates and help control the level of water in the overhead tanks.. A Water level alarm circuit using microcontroller is a low-cost controller, which is capable of dealing water levels in different systems to conserve water as well as money. It is useful for overhead water tanks, swimming pools boilers, etc.. This can be used in houses, factories, industries, chemical plants, Electrical substations , and other liquid storage systems.
Electronic Water level Indicator Circuit
An electronic water level Circuit observes the level of the water in the overhead tank and immediately switches on the water pump whenever the level goes below to a certain level in the tank. The water level of the overhead tank is indicated using 5 light emitting diodes(LEDs), and the water pump is switched off whenever the water level of the overhead tank gets completely filled up. The Electronic Water level alarm Circuit does not permit the pump to start if the level of the water inside the underground sump goes low, and switches off the pump even during the pumping period.
The above mentioned electronic water level alarm circuit diagram comprises of 4 probes, and that are placed in an overhead tank and also interfaced with the port 2 of the microcontroller. These probes are placed in such a way that they sense ¼th, 1/2th, ¾th and even full levels as they are located with equal spacing one above the other with the bottom positive probe. A positive voltage supply is located at the bottom of the overhead tank, and a full-level probe is arranged in the overhead tank and the other end is connected to the base terminals of the Q4 transistor through an R16 resistor.
When the level of the water in the overhead tank increases to the maximum, then the current flows through the transistor base terminal and the collector voltage becomes low and that is interfaced with the microcontroller port p2. 4. The programming of the microcontroller is done and the data can be sent to the microcontroller and LED. The level of water indicates D1 and automatically the motor switches off.
Whenever the water level goes below the full-level probe, then the base of the Q2 transistor opens by switching it off. When the Q2 transistor the collector voltage is high at P2.4, which means the overhead tank is not full and the same procedure is applied to the remaining probes like ¼, 1/2, 3/4 as they are connected to the base terminal of the q1,q2,q3 transistors and interfaced with the ports p2. 5, p2. 6, and p2. 7 while programming is done within the microcontroller. The D3, D4 and D5 LEDs glow as an indication of the levels, and then the transistor get on and the motor will be on.
The ports P0.0, P0.1, P0.2, P0.3 and P0.4 are interfaced with the LEDs for indicating the levels of the water tank and these ports are connected to the resistors. The P0.5 port is used to regulate the pump and the Q6 transistor remains on as the relay also gets activated while the P0.7 port is connected to the LED D7 as an indication of low level water in the sump and the LED glows.
Electronic Water Level Indicator with Alarm Circuit
An electronic water-level alarm circuit is nothing but a circuit connected with an alarm to the above electronic water level circuit which is capable of alerting inmates of a home when the water level is high or low or exceeds higher limits, this type of electronic water level indicator circuit is used.
The above circuit is similar to the electronic water level circuit except the alarm connected with it. As we have discussed above, for an exact level of water in the overhead tank, the sensing probes enable appropriate pins of the microcontroller. When these pins are logic high, then the microcontroller sends control signals to the speaker as well as to the LED indicators depending on the microcontroller program.
This electronic-water-level alarm system gives the information about the level of the water tank as ‘water tank is full’ and ‘water tank is empty’ so that any user can easily identify the level of the water. As the above discussed level control is of contact type wherein the probes are in contact with liquid or water. Therefore, there is a chance of it becoming acidic easily. This can be overcome by using a contactless sensor level measuring system which is described below.
Contactless Liquid Level Controller
The contactless liquid level controller project uses an ultrasonic sensor, which is used to sense the liquid level in a tank. This type of level control system is very useful wherever the liquids are of chemical in nature and it is not possible and practical to use contact type level sensors.
In this contactless liquid level controller project, the mains power supply is rectified and converted AC to DC by using a bridge rectifier, filtered and regulated to a circuit operating range, which is given to the microcontroller and other major componentsof the circuit. The ultrasonic sensor is also powered by this regulated DC supply.
The Ultrasonic sensor is attached to a liquid tank to continuously monitor the level of the water tank and whenever this limit exceeds, the sensor gives input to the microcontroller. Based on the program, the microcontroller sends control signals to the transistor, which is responsible for switching the relay so that the pump or motor gets turned on or off.
The liquid level distance is measured in centimeters, When the liquid level falls down to a set point limit, the pump starts sensing the signal of the ultrasonic sensor that comes from the transmitter sensor and gets reflected from the liquid level, which is received by the ultrasonic receiver sensor, then the o/p is fed to the microcontroller.
The liquid level limit can be varied based on the user requirement by placing an ultrasonic sensor in correct place. This liquid level information can be displayed on an LCD display, so that a user can easily identify the level in the tank.
This is all about the water level alarm circuit with contact and contact less sensors.We believe that you have got a better idea with the given circuit.Furthermore, any queries regarding this project, you can approach us by commenting in the comment section below. Here is a question for you .Till how much distance does the ultrasonic sensor senses?