Automatic water tank level controller motor driver circuit- Engineering project without Microcontroller

Automatic water level controller circuit is a simple engineering project. It can automatically switch ON and OFF the domestic water pump set depending on the tank water level. You can implement this motor driver circuit at your home or college using less costly components. The approximated cost of the project is about $5 only. The main advantage of this water level controller circuit is that it automatically controls the water pump without any user interaction.
The heart of this pump controller circuit is a NE 555 IC; Here we have manipulated the flip flop inside the 555 timer IC. Our project consists of two water level sensors, one fixed at the top and other at the bottom. Working of this circuit is almost similar to a bi stable mutlivibrator. Simulation of this circuit is also given below. Definitely this will help you to do your academic project.

Circuit Diagram

Automatic+Water+Tank+Controller+Engineering+Project Automatic water tank level controller motor driver circuit  Engineering project without Microcontroller

Components Required

  1. Power supply (6v)
  2. NE 555 timer IC
  3. Resistors (100Ωx2, 10kΩ)
  4. Relay (6V, 30A)
  5. BC 548 transistor x2
  6. 1N4007 Diode

Working of Automatic water tank level controller

  • We know the property of 555 timer IC, i.e. its output goes HIGH when voltage at the second pin(trigger pin) is less than 1/3 Vcc.
  • Also we can reset back the IC by applying a LOW voltage at the 4th pin (Reset pin).
  • In this project 3 wires are dipped in water tank. Let us define two water levels- Bottom (Low) level and Top (Up) level. One of the wire or probe is from Vcc.
  • The probe from bottom level is connected to the trigger (2nd) pin of 555 IC. So the voltage at 2nd pin is Vcc when it is covered by water.
  • When water level goes down, the 2nd pin gets disconnected(untouched) from water i.e. voltage at the trigger pin becomes less than Vcc. Then the output of 555 becomes high.
  • The output of 555 is fed to a BC548 transistor, it energizes the relay coil and the water pump set is turned ON.
  • While the water level rises, the top level probe is covered by water and the transistor becomes ON. Its collector voltage goes to Vce(sat) =0.2.
  • The low voltage at the 4th pin resets the IC. So the output of 555 becomes 0V. Hence the motor will turn OFF automatically.
  • For simple demonstration of this project you can use a DC motor directly at the output of 555 instead of relay.
  • For practical implementation, you must use a relay. Rating of relay is chosen according to the load (Motor). 32 Ampere relay is best suited for domestic applications.

Also read: How to connect relay:Relays working with animation

Simulation of the Project

Motor+ok+ gif Automatic water tank level controller motor driver circuit  Engineering project without Microcontroller

The mouse click on the bottom level and top level switches show the level of water, From the animation you can see that when the water is at the bottom level the motor starts working and when water reaches at top level motor stops functioning.
Also read:

Now, here is your water level controller project. Was this project helpful to you? Don’t forget to use the comment box below to share your views and clarify any doubt regarding the project.

PCB layout

Automatic+Water+Tank+Controller+Engineering+Project+PCB Automatic water tank level controller motor driver circuit  Engineering project without MicrocontrollerAutomatic+Water+Tank+Controller+Engineering+Project+PCB+layout Automatic water tank level controller motor driver circuit  Engineering project without Microcontroller
Click on the images for enlarged view

Components Pin out

555pinout1 Automatic water tank level controller motor driver circuit  Engineering project without Microcontroller
BC547 Automatic water tank level controller motor driver circuit  Engineering project without Microcontroller

211 thoughts on “Automatic water tank level controller motor driver circuit- Engineering project without Microcontroller

    • I'm also having same problem. Nothing happened after switched on. The 100 Ohm resistor heated up. Changed another transistor but same problem. Not working.

    • Hi Daryl,
      Please see to that if your relay is working fine, you can do that by connecting to 6V Vcc(if 6V relay is used). Also check if diode is connected properly.

    • Hi Admin,
      I have the same problem of heat generation at 100 ohm resistor attached to pin no 3.
      I have used 12v supply and relay, I have checked the circuit is working fine, only problem is heat generation at 100ohm when water level is low and the relay is charged to on position. please reply.

  1. Sir,

    I want to use it for 5 storey building.Pl let me know
    1) VCC = 6 volt and relay = 6volt is suitable ?
    2) From ground floor to terrece using 2 pair telephone cable for sensers is good to drive the circuit? Its approximately 30 metres cable length.

  2. I had purchased one kit from your online store, i have existing panel board in digital as well as old style analog. Can you let me know how to connect relay ? I have on and off button in both the panel.
    Thanking you

  3. hi,
    dear i built this project at proteus nd as well multisim to simulat it but its not woeking properly….
    moter turn off when water goes to upper level nd start as water level goes down uper level … but ther is nothing about the low level switch either it will be on or off moter does not start when water level goes down to low level…..i can send yu the simulating file of this

  4. This almost has the the functionality I’m looking for. We have a low yielding well and have to use a water storage system. It is bad to run a well dry so the pump would have to have to turn on once level drops below the high level sensor and turn on for short durations and then off allowing the well to replenish. Cycling in this fashion till the storage tank returns to the high level mark. Then of course a dry-run circuit would be optimal to ensure no damage is done to the pump if anything goes wrong. Anyway this could be done?

    • Hi Nick,
      To implement “Dry Run” is very simple, I will publish an article regarding simple dry run circuit in near future.


  5. Hi Jaseem
    i try your circuit and working good, but i have one little problem
    i need then relay have about 30 sec delay

  6. So I only have 2 probes
    the first is powered with 12Vdc
    the second and ‘connected to the base of the transistor in series with a potentiometer
    I need that the first pulse on the base of the transistor, the relay energizes and remains energized for 1 minute (adjustable time), regardless if the base signal comes up or stops.
    after the selected time, the timer turns off by itself, and is ready to receive the new signal of the base.
    I need this’ cause when the charge pump water, the water level is not ‘stable and the relay’ directly connected to the collector of the transistor off and attacks constantly for about 1 minute, until the level of ‘water will not be stabilized. in this way the life of the pump to be very small.
    I hope I explained clearly

    • Hi Sing,
      Thank you for asking doubts to CircuitsGallery. This diode is called ‘Free wheeling diode’ or ‘Flyback diode’ which is used to eliminate sudden voltage spikes seen across inductive loads at the time of switching ON or OFF the power supply.

  7. 1. For submersible pumps, there will be 2 buttons, in which one is to start the motor and the other is to stop. The starting switch connects starting capacitor for approx a second to get the initial torque to the motor [ = = ]. When the red switch got pushed, it disconnects the supply to the contactor and the motor stops. now, please try to provide the circuit, in which the relay should trip in a second to start the motor when water is at low level and the stop switch can be connected to relay in series to stop supply to the contactor. it may need 2 relays undoubtedly.
    2. the present circuit for monoblock motors is working fine, but when any other switch like a calling bell switch is pressed, the motor is getting started irrespective of water level in the tank. what to do? :)

  8. Hi admin.. I want to add a circuit that cuts off the supply to the motor automatically when water does not get sucked up to the tank by the pump, due to some fault like air lock. Please suggest me an idea as to what I should do for this.

    • Hey Sandeep,
      You need to add an extra dry run circuit for that, it can be achieved by a simple logic. We’ll publish it soon. So stay tuned and by the way follow us on facebook and google plus.

      • hi sir i really like the circuit but kindly explain on how to connect the relay from the out put of the 555 down to the connection to the motor?,,please sir i need your explanation.

  9. Im having a bit of a problem with this circuit so please help me out!!!
    I bought and connected all the components as mentioned above and soldered them on a breadboard.
    I used a 6-0-6 transformer and rectifier. the high level probe is working correctly as when I touch Vcc and high sensor it shuts the motor but when i touch Vcc and low it still runs but it should stop. And also motor is running when Vcc is not in contact with any of them which is fine. there is no possibility of faulty components as i made two different circuits and in both problem is the same. plz get back at me, its urgent.

  10. Hi dear sir.
    This cuircuit is only for over head tand but i want to make the water level using under ground tank nd upper tank both. So can u help me on that ?? Or send me the cuircuit on my mail.

  11. Please I need a detailed diagram ad description on this topic so I understand it cos it is part of my project work. Thank you for your effort so far.

  12. nice project !! who can we add probs of ground water tank to show level and also cut off if no more water in ground tank ??

  13. Hi admin i have made diz projects its working well wid my homemade mini water pump bt i want to add relay to domestic water pump so hw much amp do i need n i want to add some led n manual switch so plz help me out… N thank u for diz wonderful projects m very happy ..

  14. Hello sir !
    Sir i have a question??
    Will it work with home 3-phase motor for the purpose of Water leve indication in my home tank ?? If changes, then do let me know sir, Thank you in advance!

  15. Hai
    This project is very good.
    When I dip the wire (Up) It gets bubble (melting) what is the problem ? I connected the resistor (BR-BK-GR) in place of 100 ohm working good, plz solve it

  16. i need ckt which can stop my submercible automatically in 5,10,15,20 min automatically by setting variabke pot adjustmebt
    plz mail me

  17. hi , this is yash from agra ,i m a student of class 12 and i want to know the working of every part as i have nit understood. So plz help me out.

  18. Sir,if i use 6v relay
    then can i use 9v dc supply?
    distance between upper & lower tank is 35 m in my home then this circuit can work?
    Reaply me plz

  19. i have built this circuit but relay making trrr sound but while i keep my hand on vcc it works well what may be the cause ?

      • sir ! as you suggested i placed a 100*25 capacitor its working but the problem is, it is switching of when vcc touched at trigger(low) pin only so that its getting of at low level prob only and start immidietly water leaves the low level probe so that there is no chance of rising of water to top level what can i do now pls help me I became completly crazy about this circuit i trying this since 3 day whole day

    • if u connect it to the controlled 6v dc or 12v dc power supply with bridge rectifier, it won’t give that sound. try it and let me know.

  20. Hi srinivas i using a mobile charges its giving volatage around 7 and i have checked that by directly connect with relay its working fine but through the circuit its not operating

    • sir relay problem solved by placing a capacitor but its getting of when vcc touch with low level prob only so it get on just immidietly water leaves the low level wire it is also of when touch with up level wire and its not waiting for empty

  21. How much current is required from power supply?? circuit is working fine when probes are connected to Vcc but in water its unable to work. There is no current flowing through water when i checked with DMM. only voltage reading is the same as supplied. I am using 12V DC, 2A supply.

  22. I have replaced the ic its woking while manipulating with wire fine but in the water its not conducting what migt be the problem i checked with copper and aluminium

  23. The circuit is working fine but i’m getting some problems. I’ve used bc547 instead of bc548 and 1n4148 diode instead of 1n4007. The relay does not switch on when the water level goes below the low probe and after experimenting for a couple of times i figured it out that if you touch low probe(while up probe is outside the water) and keeping Vcc probe inside the water the relay energizes. Can anyone sort it out? I’d be glad for any suggestions. Thank you.

  24. This circuit is working properly with out connect in water tank but when i’m gonna connect in tanks it’s not working .
    The distance of circuit and tank is 8m . I’m using 1.5sqmm and then 30swg copper insuleted wire for Sensor . So what ‘ll I do ?

  25. Thanks for the circuit! it works fine! though pin3 didn’t go HIGH when water level went below middle probe. but that ha been corrected by connecting 10k resistor from pin2 to ground. Thanks once again for the good work. God bless you!

  26. I finally figured out the problem. Putting a 2K2 or above valued resistor from pin 2 to ground will work out and i think most of the people commenting that the circuit is not working must have been facing the same problem since the voltage at pin 2 is not dropping as it used should have been which is solved by putting a resistor. Cheers

  27. Dear Sir,
    Thank you for your circuit sir it is great. But i have some problems,so please help me.My problems are-
    1.In my house there are underground tank from which water is pumped to overhead tank,but sometimes underground tank becomes empty and if i use this circuit that can lead to a problem. So how to modify the circuit sir?
    2.Sir how to protect the motor from dry run?
    If you have any confusion i am ready to help you. But please help me. I also forgot to mention this is the most simplest circuit for this purpose, it is great. I like the simplicity of the circuit.
    Thanks in advance.


  29. I have found the high sensor to be extremely sensitive. I can trip the high line just with my finger even when I am not touching the rest of the circuit in any way. Sometimes, measuring the voltage on the high line with my Fluke voltmeter trips it. That has an impedence of about 10Mohms. Any suggestions on how to make the circuit less sensitive?

  30. Nice post and its interesting,can u please tell me if this circuit is practical for 2m height water tank,u know, water is’nt a good conducter…..

  31. I am a Senior citizen staying in Mysore.
    I have an open 1000 litre water tank (1.T) in my compound with bottom at (-) 3ft.
    Water flows into this tank at the top at odd hours in the night and hence automation is required.
    Just before the pipe enters the tank, there is a T junction with another pipe, to a 500 litre tank (0.5T), 50 ft. away, whose bottom is (-) 2 ft. There is an overhead tank (OHT) on the terrace at +25 ft.
    There is a tap at the end of the pipe entering 1.0T.
    Now when water starts flowing into the 1.T tank, it has to be closed after it fills up and then only water enters the 0.5T as there is not much pressure to flow on both ends. Once this 0.5T fills up water has to be pumped up to the OHT. However filling to the OHT can be done leisurely in the day time.

    Ideally what I want is:
    In my bed room which is 50 ft. away at +15 ft. an indicator that shows water has filled up the 1.T tank.
    Another indicator that shows water has filled up the 0.5T tank.
    Another indicator that shows water has filled up the OHT.
    Manual and Automatic starting/stoppage of all three water flows from my bedroom.

    Please let me know if it is possible for you to get it executed it by some agency and if so what may be an approx. cost. If the cost is very high, then part automation has to be done.

    • Dear Sir,

      I think, by using solenoid valves with the help of sensor circuits, all the 3 tanks can be operated automatically. What is the type of motor you are using to lift the water to the 3rd tank?

  32. what we use micro controller using ic 555 can we use a single ic and capacitor whose powers are 2200 uf n 1000 uf
    and what is the actual work of relay …
    i read somewhere that relay is a process of that use magnetic field and close a switch off power n relay is used for a close switch which have closed for the another switch because of the circuit demands to a higher electric field

  33. Hi, I have a problem that when the circuit is connected to the tank the relay produce a buzzer type sound on touching one of the wire goes to tank or coming in contact with moisture or earth. It means to say that the fluctuation occur with relay. Also want a solution for submersible motor where maximum 3sec pussing is required to switch on the motor.

  34. please sir, I Dont understand what u mean by Vcc, I was thinking it’s the positive terminal Of My battery while the negative terminal Of My battery goes to My ground. And again for P and N towards the motor circuit represent the positive And neutral terminals Of the AC electricity for the pump. Thank u

  35. Hi admin,I successfully assembled this controller.Now,my question is that;can I use it with a submersible pump if the relay is 12v30a?Please suggest me details.

    • Not suitable for submersible pumps as it will have cintactor_controlled operation, and needs tripping from starting to running in less than 1 second.

    • Hi Nideesh G,
      Draw your Block diagram as follows


  36. if i want to off the motor at the top level the top level of water. then, what should i have to do with 2nd pin of 555 timer.
    plz.let me know.!!

  37. Hi…

    . At any time 6v is presenting in water….it may give problem for child .when they r using water direct from tap like drinking face washing ….

  38. hi…………….
    In above circuit I am confuse that , how would I gave supply to the motor and control it by relay. I mean at which point of ckt. I can give supply.

  39. Hi,
    If the water level goes below the Low level Pin 2 becomes low and the o/p becomes high in turns the motor is ON.
    The water is keep on pumped to the tank. Now when the water level reaches the Low lwvel Probe then the Pin 2 is going to be High and Motor is going to be switched Off before it reaches “high level and then Off”.
    Pls assist If I am wrong anywhere here

  40. hi sir..
    its really nice sir i tried wit tis circuit nd i succeeded in it.. i need a help sir i need a projct tat is made with timer circuit.. could u help me wit should on and off in a perticular time dily or weekly… pls help me sir..

  41. Dear Admin
    I have two issue with this circuit:
    1- How to operate it with 230V supply to turn on off motor
    2- To make it multilevel indicator: is this possible to attach motor turn on off mechanism with that circuit.

    Kindly send me the appropriate details to make it.

  42. this is very helpful for home use. can u give me an idea for its P.C.B. from where i get this pcb. i want to make this project.

  43. Hallow.
    The ckt is working normally.But some problems are there at the time of installation. 1.When the probs. are within 2 meters length from the ic then the ckt works normal. 2. But when the porob length increased to 10 meter from the ic then the relay chatters continuously.That means the motor going on and off continuously.. it is very hermfull. What will be the solution-?
    My pump motor situated at ground floor, and the circuit will fixed at gr.fl. But the overhead tank situated at 10 meter height from gr.fl.Am I explain the problem clearly-?

  44. It’s vary good project, only prblm is VCC which is dipped into water get bubbles and gradually melted completely,what’t solution plz advice

  45. Hi Kaleel,
    Thanks for the circuit diagram, sorry to say that the I haven’t tested it yet. I am a very beginner in Electronics and bare with me if my question is dump. I just wanted to simulate Low water level, the idea is to allow the user to switch on the relay/Motor by pressing a push button. Some time my mother want to switch on motor without waiting till its empty/low.

    To add that logic I am thinking of adding a two pin push button, one end of the button connects to ground and other end of the button connects to IC 555’s pin 2 (the connection to low level prob). I assume when the button is on, GND is connected to Pin 2 and register a zero voltage, even if the prob low is touched in water and trigger the relay.

    I might be wrong, if any one can tell whether it will work it will be really helpful. Thanks in advance.

    Sony Arouje

    • I was wrong in my question. Let me reframe my question.

      If I connect a push button switch between the connection to Probe low. That means when I switch off the button there will be no current flowing from probe in water to Pin 2 of IC 555 and I assume that simulates a low water effect.

      • Hi, you are absolutely correct. I already did this an year back and still it is working fine. the switch should be Push-to-break switch. go ahead….it works.

        • Thank you so much Srinivas for confirming it.

          Another question, at my home the water tank is above the second floor. Is it possible to wire the probe so long from the circuit? a lengthy wire connecting the probe and the circuit cause any noise and thus cause any issues.


          • I made it with 12V DC and its above 3rd floor. i didn’t get any problem except one. The problem i am getting is, it starts the pump motor once in a while when any other electrical switch nearby the probes’ path is switched on ,but not all the times. I have used a heavy 3-core cable to resist from atmospheric conditions.

            The before mentioned push-to-break switches, i have arranged at every floor. so, from any floor, we can switch on the motor just by pushing the button as and when required.

          • Thanks Srinivas for your quick reply. I got all my questions answered.

            Sony Arouje

  46. Hello sir i hope you are fine. I am done this circuit connection in two different general purpose board
    But both circuit are not working properly both circuit having same problem.i used 5 volts dc relay and 5volts dc mobile charger my problem is that the relay is making continuously tarr sound (means continues on off in less delay time) and also if any sensor wire is having less moment then also same problem is present if i touched the either vcc or gnd then circuit is working properly and give perfect output i cant identify the problem i already effort to remove the error but i cant pass so now your turn for help me

  47. this circuit works. use carbon rods from old dry cell as electrodes. Normal copper wires reacts with water And dissolve with time. I did some modifications to circuit. Is there any way i can add a image of my circuit to this ??

    • Hi Kasun,

      Sure, you can add your circuit or images so that it will be useful for others too. I will make sure to credit the image/circuit with your name. Send the image to our email By the way, using of carbon rods was a valuable suggestion. Thank You.

  48. Sir,
    Can we change this circuit to another way
    That, when the water level raise and reach at the top the motor should automatically turn on and the water level goes down the motor should turn off,
    Can you say…

  49. I implemented this with my son for a science project. If you use a very short wire between tank low and 555 trigger pin 2 to low this works. If you use a longer wire, even if it is high quality the pump rarely turns off once the low wire is above the water line. Touching a finger to the wire is often enough to turn pump off. Something more is needed that a strait wire from tank low to 555 to force trigger below 1/3 Vcc when disconnected from the charge in the water. It is floating above the 1/3Vcc. Maybe a pull down resistor would keep trigger pin 2 from floating above 1/3 Vcc. Has anyone implemented this, see the same thing and have feedback?

  50. hi! this is cheap, easy and almost what i need, in my case, i need to star the motor when the water reach the top of the tank, and turn it off when the water reach the lower level, i guess just inverting the high and low sensors in the tank its not gonna do the job? any insights? help! in the meanwhile im gonna test it on a protoboard… thanks in advance!

  51. Hey can you please tell me its simulation in MATLAB. As I cannot connect tank with any electrical component.

  52. where we have to connect (up) high level LED and Low Level Indicator as per my Knowledge for (up) high level indicator, LED should connect at the collector side of Q1 transistor but power supply and then 10k resistor but what about low level indicator.

  53. Will the motor stop just after crossing the “LOW” position or it will stop after the water rises up to the “UP position

  54. pin2 is 0 V so out put pin’s volt is hight.So,low water level gets hight then botton prob is coverd with water.Is pin 2 volt hight again & does pin 2 volt that is hight cause pin3 off?

  55. I have made this circuit and it works. But how to prevent turning on the motor when ac voltage is lower than normal (when voltage drips less than 230v)..?. Running motor in low voltage may burn motor windings…?. Any body suggest a protection circuit please…

  56. Is there a way to reverse this circuit easily? In other words, I would like to have a sump pump come on when the water is high and go off when the water is low. I can do this by connecting up a SPDT relay in such a way that when the water is low (normal), the relay is energized but disconnects power to the pump, but then the relay is energized all the time.

  57. I am using the same above circuit in my home, pump getting trip before high level switch closing in some operation cycle what is the cause, is it voltage problem or relay malfunction?

  58. hiiiii..
    i want to make a water cutoff device for a water purifier in a membrane. when there is no waste water from membrane then it cutoff the input water. please help me and please text me i my email address i.e.

  59. thanks for your circuit it works. please urgently can you advice me on what to do because i want my pump to ON during high level and OFF during low level

  60. hi admin. I have built the auto water level controller and works fine… I have used a 1 and half amp transformer a and 30 amp relay. the project is 12 volts. the 100 ohms resistor on pin 3 of if 555 is heating up. the transistor that is connected to 100 ohms resistor also heats up. the on / off is not always satisfying… what could be the reason that heats up the two components? please help me figure it out. could it be the transformer? will a 300 milli amp transformer make a difference?

  61. Hi Friend. I have an under ground tank. I need to on the pump when the under ground tank is full.
    Could you please forward me circuit diagram with component details with the same NE 555 timer IC for this case?

    • Sweeti and All: This circuit is not just a project, by implementing in daily life, it will save a lot of power, water, as well as time. go ahead and recommend this circuit whoever is using mono-block pump sets to lift ground water to overhead tank.

  62. Hi Mr. Habeesha, I have installed this circuit for my mono block pump and also installed it at almost 46 houses…..I strongly recommend you to design another circuit that can automatize submersible pumps, which will have a Contactor Relay to switch between starting winding and running winding.

  63. Hi, sir I want to know whether this circuit work on submersible pumps as well. As I have 1 HP submersible around 150 feet nderground kindly guide me through the schematics and the required component.. Thank you.

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