Home » Water Level Controller » 5 Simple Water Level Controller Circuits
5 Simple Water Level Controller Circuits

5 Simple Water Level Controller Circuits

The article explains 5 simple automatic water level controller circuits which can be used for effectively controlling the water level of a water tank by switching the pump motor ON and OFF. The controller responds depending upon the relevant levels of water in the tank and the position of the immersed sensor points

I received the following simple transistorized circuit contribution from Mr.Vineesh, who is one of the keen readers and followers of this blog.

He is also an active hobbyist who likes to invent and make new electronic circuits. Let's learn more about his new circuit which was sent to me via email.

1) Simple Automatic Water Level Controller Using Transistors

Please find the attached circuit for a very simple and cheap water level controller. This design is only a basic portion of my own marketed product having unsafe voltage cutoff, dry run cut off and LED & alarm indications and overall protection.

Anyway, the given concept includes automatic water level control and high /low voltage cut off. 

It is not a new design since we can find 100s of circuits for over flow controller in many sites and books.

But This ckt is simplified with least no: of cheap components. water level sensing and high voltage sensing is doing with same transistor.

I used to put all my ckts in observation for a few months and found this ckt OK. but recently some problems highlighted by some customer,which i will definitely write down the end of this mail.


When the water level in over head tank is sufficient , points B & C are closed through water and keeps T2 in ON condition , so T3 will be off , resulting the motor in off condition.

When water level lowers below B &C, T2 gets off and T3 on, which switches the relay and pump ON (pump connections not shown in ckt). Pump get off only when water rises and touch the point A only , because point C becomes neutral condition when T3 get ON.

The pump switches on again only when the water level comes down below B & C . Presets VR2 is to be set to a high voltage cut off, say 250V when the voltage rises above 250V during pump ON condition, T2 gets ON, and relay off.

Preset VR1 is to be set to a low voltage cut off say 170V. T1 will be ON until zener z1 loses its breakdown voltage when voltage lowers to 170V, Z1 will not conduct and T1 stays OFF, which delivers a base voltage to T2 , resulting relay off.

T2 is handling the major role in this ckt. (high voltage cut off boards available in market can be easily integrated to this ckt)

Electronic components in this circuit worked very fine, but recently some problems were observed:

1) Minor deposits on sensor wire due to electrolysis in water, needed to be cleaned in 2-3 months( this problem is minimized now by applying ac voltage to sensor wire by means of additional circuit, which will be send to you later)

2) Due to relay contact terminal sparks, generated every time during initial current pull of pump, contacts get worn out gradually.

This tends to heat the pump because off in-sufficient current flow to pump (observed, new pumps works fine. older pumps heats up more) .For avoiding this problem, additional motor starter must be used, so that relay's function is limited to control the motor starter only, and pump never heats up.

transistor automatic water level controller circuit


R1,R11 = 100K
R2,R4,R7,R9,= 1.2K
R3  -10KR5 = 4.7K
R6 = 47K
R8,R10 = 10E
R12 = 100E
C1 = 4.7uF/16V
C2 = 220uF/25 V
D1,D2,D3,D4 = 1N 4007
T1,T2 = BC 547
T3 = BC 639( try 187 )
Z1,Z2 = Zener 6.3 V,VR1,
RL = Relay 12V 200E, > 5 AMP CONT ( According  to pump HP)

2) IC 555 Based Automatic water Level Controller Circuit

The next design incorporates the versatile work horse IC 555 for implementing the intended water level control function in rather very simple and yet effective manner.

automatic simple IC 555 water level controller circuit

Referring to the above pictorial schematic, the IC 555 working can be understood with the following points:

We know that when the voltage at pin#2 of the IC 555 drops below 1/3rd Vcc, the output pin#3 is rendered high or active with the supply voltage.

We can also observe that pin#2 is held at the bottom of the tank to sense the lower threshold of the water level.

As long as the 2-pin plug remains submerged in water, the pin#2 is held at the Vcc supply level, which ensures that pin#3 stays low.

However as soon as the water drops below the lower 2-pin plug position, the Vcc from pin#2 disappears, causing a lower voltage than 1/3rd Vcc to generate at pin#2.

This instantly activates pin#3 of the IC switching ON the transistor relay driver stage.

The relay in turn switches ON the water pump motor which now begins filling the water tank.

Now as the water starts filing, after some moments the water again immerses the lower two pin plug, however this does not revert the IC 555 situation due to the internal hysteresis of the IC.

The water keeps climbing until it reaches the upper 2-pin plug, bridging water between its two pins. This immediately switches ON the BC547 attached with pin#4 of the IC, and it grounds the pin#4 with the negative line.

When this happens the IC 555 is quickly reset causing pin#3 to goes low and consequently switching OFF the transistor relay driver and also the water pump.

The circuit now reverts to its original condition and waits for the water to  reach the lower threshold to begin the cycle.

3) Fluid Level Control Using IC 4093

In this circuit we employ a logic IC 4093. As we all know water (in it’s impure form) that we get in our homes through our house water supply system, has a low resistance to electrical energy.

In simple words, water conducts electricity albeit very minutely. Normally the resistance of tap water might be in the range of 100 K to 200 K.

This resistance value is quite enough for electronic for exploiting it for the project described in this article that is for a simple water level controller circuit.

We have used four NAND Gates here for the required sensing, the whole operation may be understood with the below given points:

automatic water level controller circuit using IC 4093
IC 4093 pinout details

IC 4093 Pinouts

How the Sensors are Positioned

Referring to the above diagram, we see that point B which is at the positive potential is placed somewhere at the bottom section of the tank.

Point C is placed at the bottom of the tank, while point A is pinned at the top most section of the tank.

As long as water remains under point B, potentials at point A and point C remain at negative or ground level. It also means that the inputs of the relevant NAND gates are also clamped at logic low levels because of the 2M2 resistors.

how to install water level sensor probes inside tank

The outputs from N2 and N4 also remain at low logic, keeping the relay and motor switched OFF. Now suppose the water inside the tank starts filling and reaches point B, it connects point C and B, input of gate N1 becomes high making the otput of N2 also high.

However due to the presence of D1, the positive from the output of N2 does not make any difference to the preceding circuit.

Now when the water reaches point A, input of N3 becomes high and so does the output of N4.

N3 and N4 gets latched due to the feedback resistor across the output of N4 and input of N3. The high output from N4 switches ON the relay and the pump starts emptying the tank.

As the tank gets vacated, the position of water at some point of time goes below point A, however this does not affect N3 and N4 as they are latched, and the motor keeps running.

However once the water level reaches below point B, point C and the input of N1 reverts to logic low, output of N2 also becomes low.

Here the diode gets forward biased and pulls the input of N3 also to logic low, which in turn makes the output of N4 low, subsequently switching OFF the relay and the pump motor.

Parts List 

R1 = 100K,
R2, R3 = 2M2,
R4, R5= 1K,
T1 = BC547,
D1, D2 = 1N4148,
RELAY = 12V, 400 OHMS,
SPDT Switch
N1, N2, N3, N4 = 4093

Prototype Images

The above discussed circuit was successfully built and tested by Mr. Ajay Dussa, the following images sent by Mr. Ajay confirm the procedures.

tested prototype for automatic water level controller circuit
test results for simple water level controller circuit
Front view PCB for water level controller assembly design

4) Automatic Water Level Controller Using IC 4017

The concept explained above can be also designed using the IC 4017 and a few NOT gates as shown below. The working idea of this 4rth circuit was requested by Mr. Ian Clarke

Here's the Circuit Requirement:

"I have just discovered this site with these circuits and wonder if you possibly can guide me….. I have a very similar necessity.
I want a circuit to avert a submersible bore pump (1100W) functioning dry, ie exhausting its water supply. I need the pump to shut off when the water level reaches approximately 1M above the pump intake, and start up again as soon as it reaches about 3M above the intake.

The pump body at earth potential would likely impart the typical reference. The probes and associated wiring to the surface area had been in place at those ranges.

Any assistance you can render would be much acknowledged. I will be able to put up circuits but hardly possess the understanding to figure the specific circuitry out. Many thanks in eager expectation."

IC 4017 based automatic water level control circuit

Video Clipping:

Circuit Operation

Let's assume the setup is exactly as shown in the above figure, In fact this circuit needs to be initiated in the existing position that's shown in the figure.

Here we can see three probes, one having common ground potential attached at the bottom of the tank and is always in contact with water.

The second probe is around 1 meter above the tank bottom level.

The uppermost probe above 3 meters above the bottom of the tank level.

In the shown position, both the probes are at the positive potentials via the respective 2M2 resistors, which renders the output of N3 positive, and the output of N1 negative.

Both these outputs are connected with pin#14 of the IC 4017 which is used as a sequential logic generator for this application.

However during first power switch ON the initial N3 positive output does not have any effect on the IC 4017 sequencing, because at switch ON the IC gets reset through C2 and the logic is unable to shift from its initial pin#3 of the IC.

Now let's imagine water beginning to fill the tank and reaching the first probe, and this causes the output of N3 to go negative, which again has no impact on the output of IC 4017.

As the water fills and finally reaches the uppermost probe, this causes the output of N1 to go positive. Now this impacts the IC 4017 which shifts its logic from pin#3 to pin#2.

Pin#2 being connected with a relay driver stage, activates it and subsequently activates the motor pump.

The motor pump now starts drawing water out of the tank and keeps emptying it until a time when the tank level begins receding and goes below the upper probe.

This reverts the output of N1 at zero, which does not impact the IC 4017 output, and the motor keeps running and emptying the tank, until finally the water goes below the lower probe.

When this happens, the N3 output turns positive, and this impacts the IC 4017 output which shifts from pin#2 to pin#4 where it is reset through pin#15 back to pin#3.

The motor stops here permanently... until the time when the water again starts filling the tank  and its level yet again rises and reaches the uppermost level.

5) Water Level Controller Using IC 4049

Another simple water level controller circuit which is 5th in our list for controlling tank overflow can be  built using a single IC 4049 and used for the intended purpose.

The circuit provided below performs a dual function, it includes an overhead water level control features and also indicates the different levels of water while the water fills the tank.

Circuit Diagram

How the Circuit Functions

As soon as the water reaches the uppermost level of the tank, the last sensor positioned at the relevant point triggers a relay which in turn switches the pump motor for initiating the required water evacuating action.

The circuit is as simple as it could be. Use of just one IC makes the entire configuration very easy to build, install and maintain.

The fact that impure water which happens to be the tap water that we receive in our homes offers a relatively low resistance to electricity has been effectively exploited for implementing the intended purpose.

Here a single CMOS IC 4049 has been employed for the necessary sensing and executing the control function.

Another interesting associated fact that’s associated with CMOS ICs has helped in making the present concept very easy to implement.

It is the high input resistance and sensitivity of the CMOS gates which actually makes the functioning completely straightforward and hassle free.

As shown in the above figure, we see that the six NOT gates inside the IC 4049 are arranged in line with their inputs directly introduced inside the tank for the required sensing of the water levels.

The ground or the negative terminal of the power supply is introduced right at the bottom of the tank, so that it becomes the first terminal to come in contact with water inside the tank.

It also means that the preceding sensors placed inside the tank, or rather the inputs of the NOT gates sequentially come in contact or bridges themselves with the negative potential as the water gradually rises inside the tank.

We know that NOT gates are simple potential or logic inverters, meaning their output produces exactly the opposite potential to the one that’s applied to their input.

Here it means as the negative potential from the water bottom comes in contact with the inputs of the NOT gates through the resistance offered by the water, the output of those relevant NOT gates sequentially start producing opposite response, that is their outputs start becoming logic high or become at the positive potential.

This action immediately lights up the LEDs at the outputs of the relevant gates, indicating the proportionate levels of the water inside the tank.

Another point that’s to be noted is, all the inputs of the gates are clamped to the positive supply through a high value resistance.

This is important so that the gates inputs are initially fixed at the high logic level and subsequently their outputs generate a logic low level keeping all the LEDs switched off when there’s no water present inside the tank.

The last gate which is responsible for initiating the motor pump has its input positioned right at the brim of the tank.

It means when the water reaches t the top of the tank and bridges the negative supply to this input, the gate output becomes positive and riggers the transistor T1, which in turn switches the power to the motor pump through the wired relay contacts.

The motor pump stats and begin evacuating or releasing the water from the tank to some other destination.

This helps the water tank from overfilling and spilling, the other relevant LEDs which monitors the level of the water as it climbs also provides important indication and information regarding the instantaneous levels of the rising water inside the tank.

Parts List

  • R1 to R6 = 2M2,
  • R7 to R12 = 1K,
  • All LEDs = Red 5mm,
  • D1 = 1N4148,
  • Relay = 12 V, SPDT,
  • T1 = BC547B
  • N1 to N5 = IC 4049

All the sensor points are ordinary brass screw terminals fitted over a plastic stick at the required measured distance apart and connected to the circuit through flexible conducting insulated wires (14/36).

Upgrading the Relay Circuit

The above discussed circuit appears to have one serious drawback. Here the relay operation might continuously keep switching the motor ON/OFF as soon the water level reaches the overflowing threshold, and also immediately when the upper level reduces slightly below the topmost sensor point.

This action may not be desirable for any user.

The drawback can be eliminated by upgrading the circuit with an SCR and transistor circuit as shown below:

How it Works

The above intelligent modification ensures that the motor is switched ON as soon as the water level touches the point "F", and hereafter the motor keeps running and pumping the water out even while the water level drops below the point "F" .... until it finally reaches below the point "D".

Initially when the water level goes above the point "D" the transistors BC547 and BC557 are turned ON, however the relay is still inhibited from switching ON because the SCR is switched OFF during this time.

AS the tank fills and the water level rises upto the point "F" output of gate N1 turn positive latching ON the SCR, and subsequently the relay and the motor also switch ON.

The water pump begins pumping water out from the tank which results in emptying the tank gradually. The water level now drops below the point "F" switching OFF N1, but the SCR keeps conducting being in the latched situation.

The pump keeps running causing the water level to drop continuously until it reduces below the point "D". This instantly switches OFF the BC547/BC557 network, depriving the positive supply to the relay, and eventually switching OFF the relay, the SCR and the pump motor. The circuit returns to its original situation.

Making a Customized Water Level Controller

This customized ideal tank overflow controller circuit idea was proposed and requested to me by Mr. Bilal Inamdar.

The designed circuit attempts to enhance the above simple circuit into a more personalized form.

The circuit is exclusively designed and drawn by me.

Objective of the circuit

Well simply I want add a acrylic sheet bellow my tank which will contain tube lights. In short acrylic ceiling. The tank level can't be observed because of the sheet. This is Also needed for terrace tank 1500 Ltrs to observe level indoors without going outside.

How it will help

It will help in many scenarios like to observe terrace tank level, to observe and operate overhead tank level and to observe underground tank water level and operate the motor. Also it will save precious water from wasting due to overflow (go green). And release the tension caused due to human error ( forgetting to turn the pump on &filling the water also turn off the motor)

Application area :-

Overhead tank
Size - height = 12" width = 36" length = 45"
the tank is used for drinking, washing & bath.
The tank is 7 foot above the flooring.
The tank is kept in the bathroom.
Material of the tank is plastic (or PVC or fiber whatever non conductive)
The tank have three connection
Inlet 1/2", outlet 1/2" and whirlpool (overflow) 1".
The water fills from inlet. The water comes from outlet for use. The overflow connection prevent water overflowing on the tank and channelized it to drainage.
The hole of outlet is lower and the overflow and inlet is higher on the tank (ref height)

Scenario :-

The tank probes and level
|_A probe (overflow)
|__ok level
|_D probe (Medium)
|__low level
|_B probe
|__very low level
|_C common probe

As per the scenario I will now explain how the circuit should work

Circuit notes:-

1) Input of the circuit 6v AC/DC (for backup) to 12 AC/DC (for backup)
2) The circuit should mainly work on AC ( my mains is 220-240vac) with use of transformer or adaptor this will avoid probe rusting which occurs due to positive negative stuff.
3) The dc will drives from 9v battery easily available  or from aa or aaa battery.
4) We have lots of power cut so please consider backup dc solution.
5) the probe used are aluminum wire 6mm.
6) The resistance of water changes as per location so the circuit must be universal.
7) There must be a sound which is musical as well as different for very high and very low. It can go bad so next sound is preferable. A buzzer is not suitable for big room 2000 sqft.
8) The reset switch must be a normal door bell switch which can be put in existing electric board.
9) There must be at least 6 led
Very high, very low, ok, low, mid, motor on/off. The mid must be considered for future expansions.
10) The circuit should indicate led of light gone when there is no AC current.
And switch to dc back. or add two led for indication On AC and On battery.

Circuit functions.

1) Probe B - if the water goes below this a indication led of very low must glow. The motor should start. The alarm should sound. The sound must be unique for very low level.
2) if the reset switch is pressed than the sound must go off everything else remains the same ( circuit armed, led glowing, motor)
3) if the water touch probe B the sound must be killed automatically. The very low indication led turn off the Low indication led turn on nothing else
4) Probe D - if the water touch probe The low indicator turn off. The ok level led turns on
5) Probe A - if the water touches this probe the then the motor turns off.

The ok level led goes off and the very high level led glows.

The bell/ speaker turns on with different tune for very high. Also if the reset button is pressed in this case than also there must be no other effect rather than killing the sound.

Last but not least the circuit diagram should be expandable to E,F,G etc for very big tank (like mine on terrace)

One more thing I m not able to know how the mid level should be indicated.

Too tired to write more sorry. Name of the project (just a suggestion) Perfect Water Tank level automation or perfect tank water level controller.

Parts List 
R1 = 10K,
R2 = 10M,
R3 = 10M,
R4 = 1K,
T1 = BC557,
Diode = 1N4148
Relay = 12 volt, contacts as per pump current rating.
All Nand gates are from IC 4093

Circuit functioning of the above configuration

Assuming the water content to be at point A, the positive potential from point "C" in the tank reaches the input of N1 through water, making the output of N2 go high. This triggers N3, N4, transistor/relay and horn#2.

As the water comes down, below point "A" the gates N3, N4 maintain the situation due to the latching action (feedback from its output to input).

Therefore horn#2 remains switched ON.

However if the upper reset switch is pressed, the latch is reversed and maintained to negative, switching OFF the horn.

In the meantime, since point "B" is also at positive potential, keeps the output of the middle single gate low, keeping the relevant transistor/relay and horn#1  switched OFF.

The output of the lower two gates is high but has no effect on the transistor/relay and horn#1 because of the diode at the base of the transistor.

Now suppose, the level of the water falls below point "B", the positive from point"C" is inhibited and this point now goes logic low via the 10M resistor (correction required in the diagram which is showing 1M).

The output of the middle single gate immediately becomes high and switches ON the transistor/relay and horn#1.

This situation is maintained as long as the water threshold is below point B.

However horn#1 can be switched OFF by pressing the lower PB, which reverts the latch made from the lower couple of gates N5, N6. The output of the lower two gates becomes low, pulling the base of the transistor to ground via the diode.

The transistor relay switches OFF and hence horn#1.

The situation is maintained until the water level again rises above point B.

Parts List for the above circuit is given in the diagram.

Circuit functioning of the above configuration

Assuming the water level to be at point A, the following things can be observed:

The relevant input pins of the gates are at high logic due to the positive from point "C" coming via the water.

This produces a logic low at the output of the upper right gate, which in turn makes the output of the upper left gate high, switching ON the LED (bright glow, showing the tank is full)

The input pins of the lower right gate is also high, which makes its output low and therefore the LED marked LOW is switched OFF.

However this would have made the lower left gate output high, switching ON the LED marked OK, but due to the diode 1N4148 it keeps its output low so that the "OK" LED remains OFF.

Now suppose the water level falls below point A, the upper two gates reverts their position switching OFF the LED marked HIGH.

No voltage flows through 1N4148 and so the lower left gate switches ON the LED marked "OK"
As the water falls below the point D, the OK LED still glows because the lower right gate still remains unaffected and continues with a low output.

However the moment water goes below point B, the lower right gate reverts its output because now both its inputs are at logic low.

This switches ON the LED marked LOW and switches OFF the LED marked OK.

Parts List for the above circuit is given in the diagram

IC 4093 PIN-OUT Diagram

Please remember to ground the input pin of the remaining three gates which are not used.

In all three ICs would be required constituting 16 gates, only 13 will be used and 3 will remain unused, the above precaution must be followed with these unused gates.

All the relevant sensor points coming out from different circuits must be joined together and terminated to the appropriate tank sensor points.

Wrapping it up

This concludes our articles regarding the 5 best automatic water level controllers which can be customized for switching ON/OFF a pump motor automatically in response to the upper and lower water thresholds. If you have any other ideas or doubts please feel free to share them through the comment box below


About the Author

I am an electronic engineer (dipIETE ), hobbyist, inventor, schematic/PCB designer, manufacturer. I am also the founder of the website: https://www.homemade-circuits.com/, where I love sharing my innovative circuit ideas and tutorials. If you have any circuit related query, you may interact through comments, I'll be most happy to help!

76 thoughts on “5 Simple Water Level Controller Circuits”

  1. Hi
    Thanks for replying.
    I’m learning a lot from you.
    But I want to make waterlevel controller which can remember its previous state even after power cut without using battery.
    If possible Could you please help me in making this.

  2. Hi
    The above ic555 water level controller circuit is very simple and cost effective to make, however i have a doubt. In practical conditions if there is power cut when motor is on. Will it remember it’s previous state and again start the motor by itself.

  3. Good day Sir,

    i am using a water level controller circuit in my dog’s drinking bowl for almost a week by now and its just working great and i just really love watching it working, as the dog consumed the water it will just automatically fill up to the preset level. i am using a very small submersible aquarium water fountain motor, i put it inside a 25 liters bucket with lid in a rack just above the dog’s bowl the water runs thru an aquarium air hose which has a very small hole just enough to fill the bowl slowly and it doesn’t bother the dog while he’s drinking

    my concern is that, is there any effect on my dog’s health in the long run with this set up? i didn’t see any unusual reaction with my dog while drinking.

    i am using a mineral water ( no chlorine added ) with a small additional amount of tap water because i don’t know why my probe doesn’t conduct with pure mineral water alone.


    • Hi Amor, a Dog’s gut is much stronger and immune compared to humans, so I don’t think it will affect the animal in any manner, still to be fully sure you can confirm it with a specialist or a vet.

  4. Design and Implement a circuit that could give the status of 4 filling tanks when any two of the tanks need filling. The indication shall be implemented using a LED.

  5. Dear Sir,

    Circuit is working nicely sir with a slight change, thanks for your support so kind of you.

    Will be in touch with your permission sir.

    Thanks & Best Regards
    PG Ragavandir

    • Dear Sir,

      Greeting for the day, sir I'm looking for a circuit which Pump Motor get 'ON' & 'OFF'by using Remote or by mobile message for around 10 Km surrounding, it will be used for Farmers for there land (which they can be bit tension free). if possible can you help me for supporting them please.

      Thanks & Best Regards
      PG Ragavandir

    • Dear sir,

      Thanks for the response & support, sir I tried what you told but same problem again, now I came to know that after the motor getting 'ON' automatically after 1 hour 30 min because of the BATTERY, If we change new battery to the circuit immediately, again the circuit is working normally.

      Sir in this case whether I can use transformer? if so please tell me how to connect transformer and which one? If you say I will send photo sir. Eagerly waiting for your reply.

      Thanks & Best Regards
      PG Ragavandir

    • Dear Ragavan, battery is actually not recommended since it can discharge and cause instability, a transformer power supply is ideally recommended for this circuit.

      alternatively you can buy a 12V/1amp AC/DC adapter from the market and simply connect its (+)(-) wires at the points where you had previously connected the battery supply, that's all you need to do for the wiring

    • Dear Sir,

      I'm happy for your continuous support, will test and come up with a good result soon sir. thank you very much.

      Thanks & Best Regards
      PG Ragavandir

  6. Customizing for 1 Hp Water Pump Motor

    Dear Sir,

    Thanks for sharing this valuable information, Hats-off to you.

    As per this circuit it is working very well, but when it is connected to Half or One HP motor, when it goes beyond 'B' motor getting ON and when it touch 'A' motor is getting OFF, and then now it is in standby for 1 hour and 30 minis motor is in OFF condition only, but same all three points (A,B,C) are immersed, after 1 hour and 30 minis motor is switched ON automatically if it is even all three are immersed and it is not getting switched off till we OFF manually, can you please help how to rectifies this issue. I'm using every thing as you told.

    Thanks & Best Regards
    PG Ragavandir

    • Thank you Raghavan, I appreciate your enthusiasm,

      check the circuit again by replacing the motor with a 100 watt bulb, if it works normally then the problem could be in the relay, or due to instability.

      Make sure the relay contacts are rated to handle at least 30 amp current and for this the BC547 driver transistor will need to be upgraded to 2N2222, and also connect 0.22uF capacitors in parallel with R2, R3 and across base/emitter of T1.

      also if the water is turbulent in the tank, then the sensors might fail to detect the connections across the terminals….to prevent this you can immerse the contacts within a plastic pipe so that the water column inside the pipe provides stable water levels for the sensing.

    • My apologies for not replying as i was not sure if the question was directed at me. A JQX – 15F (90) works well but I prefer the smaller footprint such as RT424006 but they are only rated at 8amps whereas the JQX is rated up to 40 amps depending on the one you get. Regards, Mike.

  7. Using BC337 and BC327 transistors and three relays

    My water project is up and running thanks to your circuits. Sensing probes are always a problem and I used a simple method in the pharmaceutical industry since 1979. Simply use 2mm 316 stainless welding rod forced through a 1.5mm drilled hole in a good quality plastic fitting. It never rusts and is small enough not to be affected by too much water motion. In addition, your circuit can be driven by 3 or 4 volts, so , I used second hand 5 volt cell phone chargers to power them. These are obtainable locally for ZAR 10. These give plenty power to drive 6 volt relays and of course they have been designed almost bullet proof and are compact. I have the project on facebook (Mike Ellis Kloof) and made the project public, so you can see it if you want. But essentially I am collecting water off our roof and ditching the first 400 litres as a first flush. As soon as the tank is filled a 0.55Kw pump is switched on and that sensing circuit also powers another relay to switch on a second sensing circuit on the 2×5000 litre main tanks. When the main tanks are full their sensor redirects the water to the ground at the back of our property. The main tank feed is then used via a pressure controlled pump to feed the house. This pump is also protected by one of your circuits to switch off in the event the tanks get empty. Thank you once more for your circuit which I have acknowledged on Face Book. The circuit I used for 40 years at my work , used BC337 and BC327 transistors and three relays. It was also bullet proof, but the cost of the relays made it expedient to use your circuit. Once more thank you for your effort to make life easier for us. Kind regards, Mike.

    • Thanks so much Mike, that's amazing, you have turned my designs into reality.

      I appreciate your efforts a lot, in future if you have any queries regarding any new circuit-idea please feel free to drop a comment, I'll be always there to help you.

  8. Dear Mr. Swatagam. Many thanks for your well designed circuits. I wish to pump water in a similar fashion from a tank collecting rain water. Will the high resistivity of the water be too high for this circuit to work and if so is there a way of amplifying the signal to make it work? Our rain water has a conductivity of 5 to 6 microsiemens/ cm compared with our municipal supply at 200-300 microsiemens per cm. I have to pump the rain water from a 750 litre collection tank near the house to a position above and behind the house to fill two 5000 litre tanks. Thanking you, Mike Ellis. Durban. South Africa.

    • Thanks Mike, Rain water will also have some impurity in it since it has to go through many pollutants in the atmosphere, and this will be enough for conducting electricity to some extent. But if there's a lot of movement in the water then the sensitivity of the probes can get affected…to remedy this you can add a pipe enclosure around the probes, meaning use a long pipe inside the tank, and keep the probes inside this pipe such that the water column inside the pipe can be used for the conduction and detection.

  9. Is it necessary to change resistance or transistor value if i use ic4017? Another thing u have not provided pcb layout, is there any software to make layout?

    • the resistance wattage can be 1/4 watt but the configuration will change entirely.

      for the PCB you can contact any qualified PCB designer, he will do it for you.

  10. Sir can i use ic 4017 here? Another thing i did not understand why u have not used 1n4007 as a free wheel diode?

    • Kaushik,

      you can use IC 4017 or any other suitable configuration for implementing the idea….you can use 1N4007 diode for the relay coil if the relay coil resistance is much lower or if the relay is rated to handle more than 20 amps

  11. Hi,

    very helpfull post!
    Can you help me telling me how to deal with the circuit running reversing the relay?
    I need it to run at the NC position because I have a Preassure sensor to activate the pump and I want to disable the system when no water is at the bottom level sensor opening it. When the both sensors are powered then the relay become open instead of closed. Thanks!!!!

    • Hi, thanks, if you want to reverse the relay and the motor operations, you just need to apply the indicated N/O phase supply to the N/C contact of the relay

    • Thanks foir your reply!
      I did that, but I guess I need to explain myself better.

      The system needs to operate the opposite way you planned, I need to power the relay coil when NO water is in the tank but turn it off when water reaches the top sensor so the pump get in phase. Then gates get latched (relay power is still off) until water reaches the bottom sensor where reley coil is powered and pump circuit opens. I just not want to get the relay powered all the time because almost 99,9% of the time the UGT tank would be filled. I think that its better to activate to shut the system of in case of no water is present.

      Thanks again!!!!

    • If you don't' the relay to be powerd all the time then you can try replacing the BC547 with a BC557 and connect the relay/diode assembly across its collector and negative supply…the emitter will go to the positive supply….rest everything can remain exactly as given in the diagram

  12. Hi Swagat,

    It is really good to get all these information. I have same requirement of water indicator which I am going to make now.

    I have one query regarding the wireless receiver, that my building is quite high and the receiver will be around 500 meters + distance from the OHT.

    Can you please able to provide me the desing of the receiver to cover that big distance.

    • Naveen, a contactors is also a form of relay, but these are much heavier in terms of current capacity than the conventional relays, and therefore better suited to handle high current loads

  13. Sir I want to connect it with the water tank having 440 v supply .what modifications should I make…..what relay contacted should I use…

  14. hello,
    If I want to connect this circuit for the water tank that works with 220v what changes should I make? practically must control a pump that operates at 220v.

    Advance many thanks.

    • hello, the above circuit is meant for 220V operation, see the relay connections it's configured with mains voltage.

      the circuit will need to be powered from a 12V adapter.

  15. sir why we use 4 nand gates in this circuit, i mean why we would not use two nand gates, and how diode become forward biased.
    sir please explain me about diode working.
    i shall be very thankful to u.

    • Faisal, I have explained the circuit functioning in the article above, for learning how the NAND and the diode work you may have to learn their basic tutorials first

    • Arun, I have seen it, but could not study it fully due to lack of time.

      As for the single terminal sensor, it is not possible according to me.

      you can try float switch mechanism for a corrosion free operation.

  16. स्वचालित जल स्तर नियंत्रक सर्किट एक सरल इंजीनियरिंग परियोजना है. यह स्वतः ही टैंक पानी के स्तर के आधार पर और घरेलू पानी पंप सेट बंद कर सकता है. आप कम महंगा घटकों का उपयोग कर अपने घर या कॉलेज में इस मोटर चालक सर्किट लागू कर सकते हैं. परियोजना की अनुमानित की लागत के बारे में $ 5 केवल है. इस जल स्तर नियंत्रक सर्किट का मुख्य लाभ यह स्वचालित रूप से किसी भी उपयोगकर्ता संपर्क के बिना पानी पंप है कि नियंत्रण है.
    इस पंप नियंत्रक सर्किट का दिल एक पूर्वोत्तर आईसी 555 है; यहाँ हम 555 मज़दूर आईसी अंदर फ्लिप फ्लॉप चालाकी है. हमारी परियोजना दो जल स्तर सेंसर, तल पर शीर्ष पर तय की एक और अन्य के होते हैं. इस सर्किट का कार्य करना एक द्वि स्थिर mutlivibrator लगभग समान है. इस सर्किट का अनुकरण भी कम दिया जाता है. निश्चित रूप से यह आप अपने शैक्षिक परियोजना करने में मदद मिलेगी.
    आवश्यक घटक
    बिजली की आपूर्ति (6V)
    पूर्वोत्तर 555 मज़दूर आईसी
    प्रतिरोधों (100Ωx2, 10kΩ)
    रिले (6V, 30A)
    ईसा पूर्व 548 ट्रांजिस्टर X2
    1N4007 डायोड
    स्वत: पानी की टंकी स्तर नियंत्रक का कार्य
    दूसरे पिन (ट्रिगर पिन) में वोल्टेज Vcc कम से कम 1/3 है जब इसके उत्पादन उच्च जाता है यानी हम, 555 टाइमर आईसी की संपत्ति पता है.
    इसके अलावा, हम 4 पिन (PIN रीसेट) पर एक कम वोल्टेज लगाने से आईसी वापस रीसेट कर सकते हैं.
    इस परियोजना में 3 तारों पानी की टंकी में डूबा रहे हैं. हमें दो जल स्तर नीचे (कम) स्तर और प्रमुख (उत्तर प्रदेश) के स्तर को परिभाषित करते हैं. तार या जांच की एक Vcc से है.
    नीचे स्तर से जांच आईसी 555 का ट्रिगर (2) पिन से जुड़ा है. यह पानी से कवर किया जाता है तो जब 2 पिन पर वोल्टेज Vcc है.
    जल स्तर नीचे चला जाता है, 2 पिन ट्रिगर पिन पर पानी यानी वोल्टेज से (अछूता) काट दिया जाता Vcc से भी कम हो जाता है. तो फिर 555 का उत्पादन अधिक हो जाता है.
    555 का उत्पादन एक BC548 ट्रांजिस्टर को खिलाया जाता है, यह रिले का तार energizes और पानी पंप सेट चालू है.
    पानी का स्तर बढ़ जाता है, वहीं शीर्ष स्तर की जांच के पानी से कवर किया और ट्रांजिस्टर पर हो जाता है. इसकी कलेक्टर वोल्टेज Vce को जाता है (सैट) = 0.2.
    4 पिन पर कम वोल्टेज आईसी रीसेट करता है. तो 555 का उत्पादन 0V हो जाता है. इसलिए मोटर स्वचालित रूप से बंद हो जाएगा.
    इस परियोजना के साधारण प्रदर्शन के लिए यदि आप के बजाय रिले के 555 के उत्पादन में सीधे एक डीसी मोटर का उपयोग कर सकते हैं.
    व्यावहारिक कार्यान्वयन के लिए, आप एक रिले का उपयोग करना चाहिए. रिले की रेटिंग लोड (मोटर) के हिसाब से चुना जाता है. 32 एम्पीयर रिले सबसे अच्छा घरेलू अनुप्रयोगों के लिए अनुकूल है.
    यह भी पढ़ें: रिले कनेक्ट करने के लिए कैसे: रिले एनीमेशन के साथ काम करना
    नीचे स्तर और शीर्ष स्तर स्विच पर माउस क्लिक आप पानी नीचे स्तर पर है जब मोटर काम शुरू होता है और पानी शीर्ष स्तर की मोटर पर पहुंचता है जब कामकाज बंद हो जाता है देख सकते हैं कि एनीमेशन से, पानी का स्तर दिखा.
    यह भी पढ़ें:

    संख्यात्मक जल स्तर सूचक
    पानी की टंकी ओवरफ्लो तरल स्तर सेंसर अलार्म सर्किट
    अब, यहाँ अपने जल स्तर नियंत्रक परियोजना है. इस परियोजना आप के लिए उपयोगी था? अपने विचारों को साझा करने और परियोजना के बारे में कोई संदेह स्पष्ट करने के लिए नीचे दिए गए टिप्पणी बॉक्स का उपयोग करने के लिए मत भूलना

  17. Hello Swag,

    You're doing wonders on this blog. I believe my carrier will be enhanced here especially if I manage to get a design software.


    • Good day,

      I am interested in circuit design and simulation as well but I don have equipment to take my desire to another level. Could someone help me with the design software preferably multisim because I have once used it so its easy for me.

      My email is nherera.tn@gmail.com if willing to use it.


    • you can put two 1N4007 diodes in series with the relay coil for cutting down 1.2 volts, this will keep the relay from getting unnecessarily warm.

  18. hi, swagatam
    i have made your project but i have some trouble due to probe. i have used GI Iron Rod as probe it has electrolyzed after some time and i need to change it every time so could you give me the right things which can be better for probe. i am waiting for your suggestion plz.

    • Hi Vesh,

      The probes should be in the form of small leads such as a screw or a nail etc, rod is too big to be a sensor.
      You can try to get the sensor leads plated with chromium or tin…tinning could be a easier option, or simply look for tin plated metals and use them as the electrodes.

Leave a Comment