• Skip to main content
  • Skip to primary sidebar

Homemade Circuit Projects

Get free circuit help 24/7

Circuits for Beginners | Basic Circuits | LED Driver | Hobby Circuits | Transistor Circuits

New-Projects | Privacy Policy | About us | Contact | Disclaimer | Copyright

Home » Water Level Controller » 5 Useful Motor Dry Run Protector Circuits Explained

5 Useful Motor Dry Run Protector Circuits Explained

Last Updated on January 7, 2020 by Swagatam 192 Comments

electricity is dangerous warning message

The 5 simple dry run protector circuits presented here shows simple methods by which  insufficient water conditions inside an underground tank can be sensed without introducing probes inside the underground tank, and thus preventing any possibility of motor dry running. The circuit also incorporates an overhead water overflow control feature.

The idea was requested by one of the interested readers of this blog.

Technical Specifications

Do you have any idea of how to sense dry run motor by checking at the overhead tank inlet without checking at the underground tank since it takes more work in getting the wire from underground to motor place.

My requirement is motor should go off if no water is flowing at the tank inlet. Also motor should not off initially since it will take at least 5 seconds to push the water at the tank inlet.

My requirement is to switch off the motor when motor is not able to pump the water. This may be due to water level become less than certain threshold in the underground tank Or pump has malfunction.

My preference is not linking any wire from the underground tank to the circuit. My preference would be sensing the water flow in the overhead tank inlet. Hope you understood my requirement.

I would like to switch on the motor manually. If we replace the buzzer with a relay, then motor will be switched off immediately upon switching on motor,since it will few seconds for water to flow on the tank inlet.

We need to provide some time delay to sense the water flow at the tank inlet to avoid this problem. but I am not sure how to introduce a delay. Please help me on this.

Design #1

The circuit of the proposed underground water pump motor dry run protector can be understood with the help of the following details:

The circuit is powered with a 12V AC/DC adapter.

When the push-button is pressed momentarily, the BC547 transistor along with the BC557 relay driver stage is switched ON.

The 470uF capacitor and the 1M resistor forms a time delay network and locks the entire relay driver stage for some predetermined delay after the push button is released.

This delay interval can be adjusted by experimenting with the 470uF capacitor and/or the 1M resistor.

As soon as the relay activates, the motor is switched ON which instantly starts pulling water in the overhead tank.

The moment water inside the overhead tank pipe connects with its residual water, the submerged probe which is the positive probe gets linked with the probe that's introduced at the mouth of the pipe. This enables voltage from the lower probe to reach the base of the relevant BC547 transistor via the water, and the 1K resistor.

The above action now latches the relay driver stage such that even after the time delay lapses, the relay holds and sustains the operation.

Now the motor halts only under two conditions:

1) If the water level reaches the overflowing level of the overhead tank wherein the positive potential from the lower probe gets connected with the probe that's connected with the base of the upper BC547 transistor.

The condition switches ON the upper BC547 which instantly breaks the relay driver stage latch and the motor stops.

2) If the water inside the underground tank dries out, which obviously stops the water link inside the overhead tank pipe and breaks the relay driver latch.

An Automatic version of the above sump motor controller with dry run protection system may be witnessed below:

Using Logic Gates: Design #2

A fully automatic version can be also built using 6 NOT gates from the IC 4049 as shown below, this configuration can be expected to work much more accurately than the above transistorized version of the automatic underground submersible water pump dry run protection circuit.

CMOS tank overflow control with dry run sensing

Feedback from Mr. Prashant Zingade

Hello Swagatam,

How are you? Your Idea and logic are awesome. hats-off to you. I tried IC4049 version, It is working fine except one issue.(I done one modification base on your previous design and it is working now).

I am facing one issue in IC version like when we put it on auto mode, dry run function is not working. Please see attached simulated video file.

Case 1: I observe If water level reach below bottom level relay will on pump but it fail to sense dry run and pump will continue to on.

Case 2: In manual operation it works perfectly. Excuse for any typo.

Warm Regard

Prashant P Zingade

Solving the Circuit Problem

Hello Prashant,

Yes you are right.

To correct the situation we will need to connect the output of N6 to the base of the BC547 through a capacitor, you can try connecting a 10uF here.

Negative of the capacitor will go towards the base.

But the problem is, this operation will activate the system only once, and if water is not detected then the system will switch OFF the relay and remain switched OFF permanently until it is activated manually using the switch, and until the yellow sensor comes in contact with water yet again. Regards.

Update

Dry Run Protection for Motor Reed Switch: Design#3

The following diagram shows an effective dry run protection that can be added to the pump motor, in cases where water is unavailable in the tank and no water flows out from the pipe outlet.

Here the push-button is initially pressed to start the motor.

The 1000uF capacitor and the 56k resistor acts like a delay off timer and keeps the transistor switch ON even after the push button is released so that the motor keeps running for a few seconds.

During this time water can be expected to flow out from the pipe outlet, and this will fill up the small container introduced near the mouth of the hose pipe. This container can be seen having a float magnet and a reed switch relay arranged inside.

As soon as water starts filling inside the container the float magnet quickly rises at the top and reaches at a close proximity to  the reed relay, latching it ON. The reed relay now feeds a positive voltage to the base of the transistor ensuring that the transistor gets latched up and keeps the motor running.

However in an absence of water, the reed relay feedback is unable to turn ON, which causes the motor to shut down once the delay OFF time elapses after the predetermined amount of delay.

simple motor dry run circuit

Current Sensed Dry Run Protector Circuit: Design #4

In the above ideas the circuits mostly depend on detection of water which makes the designs a little outdated and cumbersome.

The following idea unlike the above depends on load sensing or current sensing for executing the dry run protection feature.Thus it is contactless, and does not rely on having a direct contact with the motor or water.

Here, the two transistors along with the associated components form a simple delay ON timer circuit. When SW1 is switched ON, the transistor T1 remains switched OFF because of C1 which initially grounds the base drive of T1 coming via R2, while C1 charges.

This keeps T2 switched ON and the relay also switches ON. The N/O of the relay switches ON the pump motor. Depending on the value of C2, the motor is allowed to run for sometime. In case there's no water, the motor runs unloaded with relatively low current passing through RX. Due to this RX is unable to develop sufficient potential across itself, which in turn keeps the opto-coupler LED switch OFF. This allows C1 to get charged fully unhindered during the stipulated period.

As soon as C1 is fully charged T1 switches ON, and this switches OFF T2 and also the relay. The motor is finally shut off protecting it from a dry run situation.

On the contrary suppose the motor gets the normal supply of water, and starts pumping it normally, this instantly loads the motor causing it to consume more current.

As per the calculated value of the resistor Rx, this develops sufficient voltage across it to switch ON the LED of the opto-coupler. Once the opto is activated C1 is inhibited from charging, and the delay ON timer is disabled. The relay now continues to supply the 220V to the motor allowing it to run as long as water is available.

Another Simple Motor Dry Run Protector Circuit: Design #5

Here;s yet another idea which explains a very simple overflow controller circuit which is able to implement and restrict overhead water overflow as well as dry running of the pump motor.

The idea was requested by Mr. S.R. Paranjape.

Technical Specifications

I came across your site while searching for Timer circuit. I am very surprised by seeing how much one individual can do!

I refer to your write up of Friday 20, 2012.

I have a similar problem. I have a designed a circuit, which appears to work on breadboard.I want to start pumping only if there is a need in upper tank and lower tank has enough water. Further if water in lower tank goes below certain level while pumping, the pumping should stop.

I am trying to find a way for satisfying my last condition. 

I want to start this circuit manually and when the circuit stops pumping action, it should also nullify my start action. This will stop the total operation of filling the upper tank.
Somehow I feel that combination of two relays( outside the circuit) in ON/Off part of total project should work. I am unable to figure how so far.

The above drawing may express what I want.Project/circuit is powered by the outer source. The output(that is used to stop umping) from the circuit should open the outer source, which was activated manually.

I hope you will excuse me in taking this root to pose my problem. If you find merit in my problem, you are welcome to put it on your blog.

I am attaching the circuit that I have devised.

As an introduction to myself- I am senior person(age 75 years) and has taken this as hobby to use my time interestingly.I was Professor of Statistics, University of Pune.

I enjoy reading your projects.

Thanking you

S.R.Paranjape

The Design

I appreciate the effort from Mr. S.R. Paranjpe, however the above design may not be correct due to many different reasons.

The correct version is shown below (please click to enlarge), the circuit functioning may be understood with the help of the following points:

The point "L" is positioned at some desired point inside the lower tank, which determines the tanks lower water level at which the motor is in the permitted zone of operation.

The terminal "O" is fixed at the topmost level of the upper tank or the overhead tank at which the motor should halt and stop filling the upper tank.

The basic switch ON sensing is done by the central NPN transistor whose base is connected to point "L", while the switch OFF action is performed by the lower NPN transistor whose base is connected to point "O".

However the above operations cannot initiate until the water itself is supplied with a positive potential or voltage.

A push-button switch has been included as requested for facilitating the required manual start function.

On pressing the given push button momentarily, allows a positive potential to enter the tank water via the push button contacts.

Assuming the lower tank level to be above the point "L" allows the above voltage to reach the base of the central transistor via the water, which instantly triggers the central transistor into conduction.

This triggering of the central transistor switches ON the relay driver stage along with the the motor, and it also latches the relay driver transistor such that now even if the push button is released sustains the operation of the circuit and the motor.

In the above latched situation, the motor halts under two conditions: either the water level goes below the point "L" or if the water is pumped until the overhead tanks upper limit is reached, that is at point"O"

With the first condition, the voltage from the relay driver collector is inhibited from reaching point "L" breaking the latch and the motor operation.

With the second condition, the lower BC547 gets triggered and breaks the latch by grounding the central transistors base.

Thus the overhead water level controller circuit is allowed to remain operational only as long as the water level is at or above point "L" or is below point "O", and also, the initialization is solely dependent on the pressing of the given push button.

IC 555 Dry run protection circuit

The dry run protection can be added to an existing IC 555 based controller circuit, a shown below:

The dry run function in the above design works in the following manner:

When the water level goes below the "low level" probe, causes the positive potential to be removed from pin#2 of the IC. This in turn causes pin#2 to go low, which instantly turns pi#3 high.

This high signal passes through the 470uF capacitor swithing ON the relay driver stage, and the pump motor is switched ON.

The relay driver and the pump remains switched ON only as long as the 470 uF charges, this may be for around 3 to 5 seconds.

Within this time span, if the pumps starts drawing water will allow the water sensor connected with the blue wires to be bridged by the pumped water.

The associated BC547 will now get the base bias and begin conducting, bypassing the 470 uF capacitor. This will enable the relay driver BC547 to conduct freely until the full tank level is reached.

On the other hand, if suppose there's no water, and the pump runs dry, will be unable to bias the upper BC547, and eventually the 470 uF will be charged full blocking any further base current to the relay driver stage. Due to this relay will be switched OFF preventing the dry run condition.

You'll also like:

  • 1.  GSM Pump Motor Controller Circuit using Arduino
  • 2.  Ultraviolet UV Water Filter/Purifier Circuit at Home
  • 3.  Making a Float Switch Circuit for a Corrosion-free Water Level Control
  • 4.  Rain Triggered Instant Start Windshield Wiper Timer Circuit
  • 5.  Capacitive Fluid Meter Circuit for Sealed Tanks
  • 6.  Simple Water Level Indicator Circuits (with Images)

About Swagatam

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!

Subscribe for the Latest Posts


 

Reader Interactions

Comments

    Your Comments are too Valuable! But please see that they are related to the above article, and are not off-topic! Cancel reply

    Your email address will not be published. Required fields are marked *

  1. Swagatam says

    You are welcome! I have updated the data, please check it.

    Reply
  2. Swagatam says

    water produces a high resistance to voltage, so no chance of any short circuit.

    Reply
  3. Swagatam says

    The probe which is submerged at the bottom can be put next to the probe situated near the pipe outlet, this will rectify all issues.

    Furthermore a 100uf capacitor may be added across base of BC557 and positive for avoiding relay break under interrupted water flow conditions from the pipe.

    Reply
  4. Soon says

    Hi Swagatam
    I Follow Ur blog last 6 month and i like
    I request u can u make a Water activated relay with 12 volt dc and 12 volt relay
    Simple when tank full the relay activated

    Reply
  5. Swagatam says

    Thanks Soon,

    You can make a relay driver circuit as shown in the following link (with some modification), and use the transistor base resistor free end and the positive supply as the two sensors placed just at the brim of the tank. The two terminals must not touch each other rather put close by such that they get bridged by the water just before over flowing, this will instantly activate the relay

    https://www.homemade-circuits.com/2012/01/how-to-make-relay-driver-stage-in.html

    The base resistor can be a 1K.

    Remember to use a Darlington paired transistors (two BC547 put in Darington form)

    Reply
  6. Swagatam says

    I have suggested the easiest possible method, 555 will be a complex circuit.

    Reply
  7. soon says

    Hi sir

    plz send me the circuit diagram of water activated relay 12 volt

    plzzzz help sir

    my email id – gadgetidea@gmail.com

    thnks
    SOON

    Reply
  8. Swagatam says

    Hi Prabir,

    Building it could be a lot time consuming and expensive, I would suggest that you buy LED strip or LED ribbon light of different colors and power them from any AC to DC adapter, that would be quick and simple.

    you can see the image here:

    http://www.sabson-led.com/v/vspfiles/assets/images/led-strip-lights.jpg

    Reply
  9. Swagatam says

    that's highly unlikely, unless there's something leaking into the base of the BC547.

    you can try the following:

    remove the capacitor entirely and then check….or alternatively connect the emitter of the BC547 through a 3V zener diode. anode will connect with ground and cathode with the emitter.

    Reply
  10. Swagatam says

    that means either your transistor is faulty, the connections are wrong or could be some other fault.

    3v zener will prevent leakage current from entering the base of BC547 until it exceeds 3v which can never happen unless a legitimate 3v is applied.

    no pull-down resistor is required.

    Reply
  11. Sriram Kp says

    Hello sir, In this same circuite, how to add the connection like if the water in the OHT is low means the motor have to start automatically? pls send the circuit diagram to my id. sriramsrikp@gmail.com

    Reply
    • Swagatam says

      Sriram, if possible i'll surely send it to you.

      Reply
  12. Sriram Kp says

    Am in first floor. the tank is on 4th floor. so the distance betweent the probes in the tank and the circuit in my floor is 15-18 meters. wil the circuit work correctly???

    Reply
    • Swagatam says

      you will need to place the circuit right beside the tank, otherwise it could create problems and incorrect results.

      Reply
  13. siddu says

    Hi sir
    that circuit what is the minimum distance between from circuit to tank

    Reply
    • Swagatam says

      Hi siddu, it shouldn't be too long not more than 5 meters.

      Reply
  14. Harun Rashid says

    Hello sir,
    I am Harun, Sir i want a automatic water level controller circuit for submersible / underground pumps use. Please send the circuit at: harunuvtsvharun@gmail.com

    Reply
    • Swagatam says

      Hello Harun, one example circuit is already presented in the above page, if you have any other specifications please provide a detailed explanation for the same.

      Reply
  15. Ajo Anto says

    Is here a possibility to eliminate the 557 pnp as the relay driver and to make use of buffer of bc 547 ??

    Reply
    • Swagatam says

      use two BC547 in Darlington mode and connect the relay in place of the collector 10k, this will allow you to remove the BC557 and its base resistor.

      Reply
  16. Vamsi Krishna says

    Hello sir, my name is vamsi. can u pls suggest me, In this same circuit, how to add the connection like if the water in the over head tank is low, the motor have to start automatically that means i need it to work as Fully automatic.can u pls send me the circuit diagram. my id. login2vamsi183@gmail.com.

    Reply
  17. Vamsi Krishna says

    Hello sir, i'm an electronics hobbyist. sir can u pls suggest me, In this same circuit, how to add the connection like if the water in the over head tank is low, the motor have to start automatically. that means i need it to works as fullyautomatic pls send the circuit diagram to my id. login2vamsi183@gmail.com. awaiting for ur needful reply. thank u…

    Reply
    • Swagatam says

      Hello Vamsi, you can make the following circuit:

      https://www.homemade-circuits.com/2011/12/how-to-make-simple-water-level.html

      and try connecting its relay contacts in parallel with the above circuit's relay contacts.

      Reply
    • Vamsi Krishna says

      Dear sir,
      i tried as u said. the differences of both the above given circuit is its sensors are connected to OHT. and which you said circuit is for, the sensors to connect to under ground tank. but actually what i need is., to the same above given circuit can you pls design with automatically starting also…THANKS

      Reply
    • Swagatam says

      Dear Vamsi,

      this circuit is fully automatic and is exactly as required by you:

      https://www.homemade-circuits.com/2015/09/automatic-submersible-pump-contactor.html

      Reply
    • Vamsi Krishna says

      Dear sir,
      in the same above circuit all i need is to work as fully automatic. the above design is semi automatic (manual start and auto cut off with dry dun) But can u pls design with adding auto start feature..? because our sump ( under ground tank ) is completely closed and tiled. and can not drop the sensors in it. so i think the above design is better putting sensors in OHT.so, kindly can u pls modify as per the request….
      THANK YOU.

      Reply
    • Swagatam says

      Dear Vamsi, I'll try to do it, and let you know….

      Reply
    • Vamsi Krishna says

      Dear Sir,
      Thanks for the response again. i'm sorry that i confused u. the design u posted for the bore well is very useful to me. but my request is the above circuit also for my sump motor purpose. so the modification i need about it like to work as fully automatic.thanks.

      Reply
    • Swagatam says

      Dear Vamsi, yes I understand, thanks, I'll try to do it soon..

      Reply
    • Swagatam says

      …please check out the new diagram

      Reply
    • Vamsi Krishna says

      Dear Sir,
      Thank you very much. i'll always be in touch with u regularly to discuss about more circuits designs..ill be back again after i prepared the circuit. THANK YOU VERY MUCH again.

      Reply
    • Vamsi Krishna says

      sir,
      what are the codes of three diodes 1N4007…? or IN4148 Zener…..? in the given new diagram.

      Reply
    • Swagatam says

      You are welcome, Vamsi

      Reply
    • Swagatam says

      for the relay it's 1N4007, remaining can be all 1N4148

      Reply
    • Vamsi Krishna says

      dear sir,
      the above given new circuit is also not working. as the same way i connected all the components through marking and checking thoroughly. can please check practically, or shell i change any values in the circuit…? Thanks..

      Reply
    • Swagatam says

      Dear Vamsi, just by connecting everything correctly will not necessarily make a circuit work. It might require many adjustments and tweaking.

      all these circuits are for those who know electronics very well and have plenty of practical experience.

      so you'll have to first learn how the transistors are supposed to functions, then build and confirm the stages step wise and only then finally you may be able to finish it successfully…it could be many long tutorial sessions for you….

      Reply
    • Vamsi Krishna says

      Thanks for the reply Sir……:)

      Reply
  18. Unknown says

    Hi Sir,
    Can you plz guide me. I wish to installing this circuit in my house automatic water level controller containing NE555 & CD4049 (simple water level controller) I wish to combine this circuit. would it work? And how to install its probes in OHT.

    Reply
    • Swagatam says

      I'll try to help you…

      Reply
    • Swagatam says

      you'll need to fabricate the probes as shown in the diagram..

      Reply
  19. Rahul Singh says

    sir
    what if the same motor is used for irrigation ie there is no any overhead tank and a rubber pipe is inserted in water pump mouth then how to detect if motor is running dry or not

    Reply
    • Swagatam says

      Rahul, you will need to place the sensor probes at the mouth of the pump pipe….as long as water is coming out from here, the circuit will stay switched ON, but the moment the pump stops throwing water, the pump will be switched off….preventing its dry run

      Reply
    • prashant zingade says

      I tried on simulator software. It start on push button. But it is not stoping replay when water touch to probe.

      Any advise or troubleshooting?
      Also if possible I will upload simulator video on YouTube and share link.

      Reply
    • Swagatam says

      which probes are you referring to?
      the one which is at the left just under the overhead tap is for latching the relay…..the latch will continue to hold until the water has filled upto the brim of the tank and until the right side probe comes in contact with water, then the latch will break.

      on the other hand in absence of water the relay will not be able to hold for more than a few seconds and the latch will break due to no water reaching the left side probes, and the motor will be stopped …

      this is how the dry run protection is implemented.

      Reply
    • prashant zingade says

      Yes I got you. Latch is break even after water touch brim of tank .
      If I'm not wrong top most bc547 will break latch. But in my case it is not breaking latch.

      Reply
    • Swagatam says

      when the tank becomes full, the positive supply comes in contact with the upper BC547 base, that triggers the BC547 and this in turn grounds the lower BC547 base…causing the relay to deactivate. this situation stops the motor and breaks the latch by stopping the water flow to the tank

      the simulation is simple and will work only if the water bridging across the sensor points are good.

      you can try a Dralington pair for the upper BC547 to increase its sensitivity.

      Reply
  20. Swagatam says

    check carefully, you will find it at extreme left of the design

    Reply
  21. Amarendra Sharma says

    Sir
    I have seen the blog "An Automatic version of sump motor controller with dry run protection system" in https://www.homemade-circuits.com/2013/07/underground-water-pump-motor-dry-run.html
    Can we put a switch in the circuit to run motor at any time in manual mode (water may not reach low level) and auto stop motor when tank is full.
    Hope you understand & Thanks
    Pls. reply: amarendra_co@yahoo.com

    Reply
    • Swagatam says

      Amarendra, you will have to momentraily cut the 12V supply which goes to the upper tank in order to initiate the motor…this can be done by a push-to-OFF kind of switch connected in series with this 12V line.

      but please note that this circuit will need to be perfectly optimized in order to make it respond to the various water linked sensors…otherwise you may find it difficult to get the expedited resulst from it.

      Reply
  22. Dmu says

    Sir,Fully Automatic version circuit is not working,i tryed 11 times on 6 boards,if any modification in this circuit please tell me sir,How to solve it? Thank you

    Reply
    • Swagatam says

      Dimu, it will not work unless you confirm and optimize each stage separately on table using sample water in a small container to simulate tank water,and then integrate each of the stages one by one for the final outcome….

      Since it is a transistorized circuit it might be be little inefficient and require some serious tweaking to make it work perfectly…..

      if possible I'll try to update an IC version of the same which will not require much adjustments and can be made to function quickly…

      Reply
  23. Dmu says

    Sir,Thank you for your reply, I am waiting for you to send the IC version circuit soon.

    Reply
    • Swagatam says

      sure…It might take a little time so kindly bear with me…

      Reply
    • Swagatam says

      I have updated it in the article, you can check it out

      Reply
  24. ragavan ganapathy says

    Dear Sir,

    Wish you a very HAPPY NEW YEAR sir, Stay happy always……

    Sir if possible can you please give this circuit with fully assembled in Bread Board ( practically) please, as I'm beginner I can understand in that easily.

    Thanks & Best Regards
    PG Ragavandir

    Reply
  25. ragavan ganapathy says

    my Email-ID is vijayragavandir@gmail.com

    Reply
    • Swagatam says

      Thank you Ragavan, Wish you too a Very Happy New Year!!

      I am sorry due to lack of time practical guidance may not be possible, however if you any specific queries I can help you to solve it here

      Reply
  26. ragavan ganapathy says

    Dear sir,

    Thanks for your reply, I tried doing first and second circuit but I failed, so only I asked you for bread board model. (I can understand you will be busy sir so only I requested if possible.) I Will try sir. So kind of you sir.

    Best Regards
    PG Ragavandir

    Reply
    • Swagatam says

      Thanks Ragavan, it is your learning phase, so you may have to go through some failures, all do…I am sure soon you will be able to overcome the failures and begin succeeding with the projects. all the best to you

      Reply
    • ragavan ganapathy says

      Dear Sir,

      Thanks for your positive words and faith on me.

      Soon will overcome sir.

      Thanks & Best Regards
      PG Ragavandir

      Reply
  27. prashant zingade says

    Its regarding IC version.
    If it is fully Automatic(i mean to say pump will when water level go below low level and stop at high level) then why push button is used.
    Correct me if I am wrong.

    Reply
    • Swagatam says

      the push button start is an added feature which allows the user to start the motor anytime he wants, without depending on the lower level detection.

      Reply
    • prashant zingade says

      One more quick question. How this IC version to be used in submersible pump. (There is stop and start button on board)

      Reply
    • Swagatam says

      for start stop contactor operations, you may have to employ the following concept

      https://www.homemade-circuits.com/2015/09/automatic-submersible-pump-contactor.html

      or the following

      https://www.homemade-circuits.com/2015/09/borewell-motor-pump-starter-controller.html

      Reply
    • prashant zingade says

      I am talking about IC version.
      1)What is value of cap connected to emitter of BC547 (OR positioned to left of N3).
      2)Please correct me if im reading circuit wrongly . From circuit diagram I think N1 and N2 (pin 1 &2), N3 and N4 (Pin 3 & 4) connected to each other ?Right

      Reply
    • Swagatam says

      the cap value is for the delay effect when the push button is used…it will need to be experimented, it could be around 22uF to 47uF

      input of one gate is connected with the output of the other gate for N1/N2, N3/N4

      Reply
  28. prashant zingade says

    Thanks, I will try this.

    Reply
  29. prashant zingade says

    One quick question. Can we use IC version with submersible pump. If yes then how , what are changes need to be done.
    Submersible control unit have RED and GREEN button. Green use to start pump and red used to stop. In such case where to fit circuit.

    Reply
    • Swagatam says

      I have answered your question, please refer to the previous comment….

      Reply
  30. prashant zingade says

    Yesterday I build and install transistor based circuit. I am facing some issue. When water touch to wire (or Sensor) water pump misbehaving, it stop and start constantly (In short fluctuate constantly), also my mother notice that pump start and stop automatically. Please advise.

    Reply
    • Swagatam says

      for the transistor version you will have to understand each stage and troubleshoot it yourself, it would be impossible for me to do it from here since there are many stages which may need careful adjustments.

      by the way in the above comments you said you wanted to build the IC version and you also said you wanted star/stop type of control for your motor, so I am a little confused.

      Reply
    • prashant zingade says

      Thanks for you comment.
      Can I try to increase value to cap of BC547(used to break latch/ used In OHT)

      Just few day before I saw IC version. Previously I was working on transistor version, It is done now. I will try for IC version and let you know if any issue.

      Can I have your Email ID ? so that I can share circuit diagram from which I created PCB

      Reply
    • prashant zingade says

      I'm taking about first circuit diagram. 3 transistor used.

      Reply
    • Swagatam says

      OK but you cannot control a start/stop contactor box using the first circuit?

      my email is

      admin
      @162.240.8.81

      Reply
    • Swagatam says

      if you increase the timing capacitor that might affect the dry run protection in case water is not available….because with increased delay the motor would keep operating for longer period of time before switching OFF

      Reply
  31. ragavan ganapathy says

    Dear Sir,

    Please check your mail, I implemented that IC circuit and mail photos in the given ID, Please have a look sir and tell me the corrections.

    Thanks & Best Regards
    P G Ragavandir

    Reply
    • Swagatam says

      Dear Ragavan, that would be impossible to check and implement…you must do it stage wise….first build only N3/N4, by connecting the associated parts along with the relay driver and the push switch stage.

      once this is confirmed then go for the other gates one after the other and test them with sample water inside a cup…

      so it has to be done in this way….and preferably do it on a veroboard not on bread board, because breadboard can be to messy and difficult to troubleshoot the connections.

      Reply
    • ragavan ganapathy says

      Dear Sir,

      Thanks for your reply, will do as you said sir

      Best Regards
      PG Ragavandir

      Reply
  32. Ian Clarke says

    I have just come across this site with these circuits and wonder if you can help me….. I have a similar requirement.
    I need a circuit to prevent a submersible bore pump (1100W) running dry, ie exhausting its water supply. I need the pump to shut off when the water level reaches about 1M above the pump intake, and start up again when the water level reaches about 3M above the intake. The pump body at earth potential would provide the common reference. The probes and associated wiring to the surface are already in place at those distances.
    Any help you can give would be much appreciated. I can build circuits but just do not have the knowledge to figure the actual circuitry out. Many thanks in anticipation.

    Reply
    • Swag says

      I’ll design it soon for you and let you know….

      Reply
    • Swag says

      I have posted the idea at the bottom of this post

      https://www.homemade-circuits.com/how-to-make-simple-water-level/

      Reply
  33. Mansoor says

    I need a dry run protection system for a submersible deep well pump that works by sensing the flow of water through the outlet pipe of the pump. I mean to say the circuit should be based on flow-sensor, and turns the pump off as soon as it detects that the flow of water has stopped. I do not want the system to be based on level sensors or probes. I simply need to turn the pump off when the flow sensor that is installed at any point on the outlet pipe of the pump, senses that there is no flow.

    Reply
    • Swag says

      You can try the following concept:

      https://www.homemade-circuits.com/municipal-water-supply-sensor-pump/

      ignore the probe and the connections.

      use a small motor with propellers as the flow sensors, connect the motor wires across the 1K end and ground line of the circuit

      Reply
    • Mansoor says

      after turning the pump on, the water takes few seconds to start flowing through the pipe. how would the transistor TIP122 be in ON state during that time? also, can you tell any other way, besides using a small motor with propellers, to sense the flow of water?

      Reply
      • Swag says

        a reed and magnet arrangement can be used instead of motor,I will try to update the drawing soon.

        Reply
        • Mansoor says

          ok. also please tell how the transistor would be in ON state at pump startup

          Reply
          • Swag says

            I have updated the diagram in the above article

            Reply
  34. Min Khant Naing says

    can i know the specific capacitance for design 2 ?
    as im still a student in electronics i cant estimate it
    and i hav tried transistor version but not working may be due to my lack of knowledge or transistors malfunctioning.
    so im going to try design 2 . so can i know cx written there to make a delay of 5second

    Reply
    • Swagatam says

      For a newcomer it can be a complex circuit, so I’ll recommend building it stage-wise, initially keep the N5, and N6 stages aloof and disconnected. Once the central N1—N4 latch is confirmed then go for the N5 stage, and then finally the N6 stage.

      For 5 seconds you can try a 470uF capacitor…or 220uF might also work…calculating accurately can be difficult, trial and error method is the quickest.

      Reply
      • min says

        sir
        only ic 4049 is recommended ? or can i use other not gate ICs?

        Reply
        • Swagatam says

          Any NOT gate IC will work

          Reply
  35. Min Khant Naing says

    in design 2 feed back i saw that he is facing one issue but it was solved making a modification
    do i need to do tht modification or can i jus use yr circuit diagram? i want to know if u hav updated tht diagram to fix tht issue
    with respect from this newbie sir thanks

    Reply
    • Swagatam says

      Yes it has been updated…the 10uF near N6 output is the updated part

      Reply
  36. Kaung says

    Can i use other not gate ic in design 2?sir

    Reply
    • Swagatam says

      yes will do!

      Reply
  37. Kaung Myat Kyaw says

    s://drive.google.com/file/d/1-y1kFMk73NbmwzPP-0SEJCtEGz8U31Ky/view?usp=drivesdk

    Sir i did automatic motor control with this 555Ic circuit? How can i modify this into dry run protection?

    Reply
    • Swagatam says

      Kaung, You can try the following updated circuit:

      https://www.homemade-circuits.com/wp-content/uploads/2019/08/automatic-water-lvl.jpg

      Reply
      • Kaung myat kyaw says

        Thank u for designing this circuit sir
        Is it also a delayed circuit? Sir

        Reply
        • Swagatam says

          Thanks Kaung, yes the dry run is with a slight delay.

          Reply
          • Kaung myat kyaw says

            For 5seconds delay what capacitance should i use?

            Reply
            • Swagatam says

              100uF near the push button should give 5 second delay

              Reply
  38. Koko says

    In design 2 sensor points simply mean wire dipped in the water right? Not real sensors? Sir

    Reply
    • Swagatam says

      yes, they are copper ends, tinned with solder.

      Reply
      • Koko says

        design 2 diode are 4007 or 4148 ? Sir or both ok?

        Reply
        • Swagatam says

          for relay 1N4007, rest all are 1N4148

          Reply
  39. Koko says

    In design two any othet transistor i can use instead of tp122 sir?
    I cant get tht transistor for now

    Reply
    • Swagatam says

      you can try 8050 or 2N2222

      Reply
  40. min khant naing says

    I tried 555 version with dry run
    It succeed in automatic water level control but failed in dry run protection.
    Also i dunt get why blue wire is connected to emitter.
    It started the motor when its under low level but didnt close off due to dry run after many seconds.
    This is my circuit
    s://drive.google.com/file/d/11GqLNGhYXf1lImdgnhQI61tMT5amqtrG/view?usp=drivesdk

    Reply
    • Swagatam says

      I have explained the working of the modification at the end of this post:

      https://www.homemade-circuits.com/underground-water-pump-motor-dry-run/

      You will have to optimize the part values to make the circuit run as per the explanation.

      The blue wire is connected with the ground line, which is also the emitter line of the relay transistor

      or you can try an external circuit like this:

      https://www.homemade-circuits.com/wp-content/uploads/2019/06/dry-run.jpg

      Reply
      • min khant naing says

        Can i also know the reason of diode at base of 557?sir

        Reply
        • Swagatam says

          it’s to ensure that the capacitor discharges only through the transistor and not through IC pin3

          Reply
      • min khant naing says

        Im sry for complaining again and again sir but can u tell me a way to remove 557 and use other devices instead of it sir. With much respect

        Reply
      • min khant naing says

        If dry run cut off power to ic 55 , pin 3 wil become low and motor wil turn off too. And the base of 557 get required negative signal and it wil turn on the 557 again. So the 55ic will regain its power and give out high at pin3 and motor will turn on again. Like this, im thinking confusingly sir. Can u pls explain and correct me who lack too much knowledge and think confused?
        With lots of respect sir
        Ihope u can help me im troubling with this project for over 2weeks now

        Reply
        • Swagatam says

          Yes that’s correct, I’ll have to redesign it then…

          Reply
      • min khant naing says

        im thinking about using 547 with a NOT gate at ase instead of 557 sir
        will it work sir
        but i dunt know if it will work because i dunt know the purpose of 4148 sir

        Reply
        • Swagatam says

          I’ll redesign it and let you know how to proceed…

          Reply
          • Swagatam says

            here’s the revised design, and should work as intended..

            https://www.homemade-circuits.com/wp-content/uploads/2019/08/dry-run.jpg

            Reply
            • min khant naing says

              it was very nice to hav u helping me sir! This new revised circuit is also easy to understand and u also didnt use 557 as i proposed. Im vert greatful to u sir.
              Sir as im not very familier with delays . May i know what i thought is right? Here’s wht i thought. The lower lvl water make pin 3 high . And tht charge capacitor. The capacitor only let current while charging.and during that time tht current make run the motor. After fully charge no more current and will turn off if there is no water at the water outlet. i hope its right sir

              Reply
              • Swagatam says

                It’s my pleasure min!
                Your assumption is absolutely correct. The circuit is supposed to work exactly in the same way!

                Reply
            • min khant naing says

              Sir in this revised version may i know where 4148 prevents discharging to? Is it pin 3? Im thinking when it discharge it wil be to the direction from where it was charged. And tht is pin 3 . So is it ok to discharge to pin3 now ?sir

              Reply
              • Swagatam says

                Hi min, the diode is not for discharging the capacitor, it’s to cut off the emitter voltage when the tank level reaches full level and the pin#3 become zero volt. Although the emitter would be well grounded through the capacitor even if the diode is not included, still for better accuracy I have included the diode.

                Reply
            • min khant naing says

              Oh isee ! Sir
              So when pin3 is zero it acts as a ground for emitter and the current from emitter will go to the ground and not go to other 547 to start the motor. Is tht it ?sir
              Im going to test it tdy thank u so much sir

              Reply
              • Swagatam says

                yes that’s right, however even if the diode link removed, the emitter would be still grounded through the capacitor due to opposite polarity of the capacitor, but adding the diode link makes it foolproof

                Reply
            • min khant naing says

              Also,in my opinion sir, when water out let doesnt sense water, it will turn off the transistor. So there is no current from tht transistor but there may be a current from pin 3 to start the motor. But having a diode on tht path prevents it? Is tht also right? Sir

              Reply
              • Swagatam says

                That’s correct, the only doubt is whether the trigger from the water will be strong enough to keep the relay ON or not

                Reply
            • Sison says

              Dear Swagathem,
              First i appreciate you for your simple desighn many of companies are produce commercially with micro controllers, but you provide us freely morover its working on first attempt.apprciate if you could provide whatsapp number or phone number.Also i have one quistion sir how long we can extend sensor wires?possible on first floor while unit on ground floor.Hope you will answer my quistion.Also need one buzzer activate while dry run .how to do?

              Reply
              • Swagatam says

                Thank you Dear Sison,

                Sorry, I discuss only from this commenting platform, I don’t use wattsapp for website queries.

                You can extend the probes as much as you like, just make sure to add a small capacitor at the base/emitter of the sensor transistor, or across the gate input and ground, if a gate is used

                Reply
            • Sisoncs Simon says

              Greetings…..
              Sir,
              When i assemble the circuit of 555 and 2nos bc148 circuit of water level controller with dryrun protection it work smoothly on breadboard.but unfortunately the dryrun not working when i assemble the circuit on pcb.But when i connect one 60kohm resistor between negative of electrolytic capacitor (470mfd)and powersupply negative on other end then work smoothly.i know this is not the proper method.why this happened?hope u will clear my doubt and do further modification also please give me a solution for false triggering too.there is no spilled flex on my pcb.its cleaned and dried.

              Reply
              • Swagatam says

                Sisoncs, sorry , I cannot see any 470uF in the diagram? Can you please pin point the section.

                Reply
            • Sisoncs Simon says

              Sir,
              The revised circuit here with 555 ic and 2nos of bc547 trans.The 470mfd electrolytic capacitor is parrllel to 1n4148 diode.here is your link.
              https://www.homemade-circuits.com/wp-content/uploads/2019/08/dry-run.jpg

              Reply
              • Swagatam says

                Sisoncs, OK got it! The 60K or any high value resistor across the negative of the 470uF and ground line will facilitate proper discharge of the 470uF so that the next relay ON/OFF cycle can happen correctly. But I cannot see any role of this resistor with regards to dry run. Because the dry run is solely controlled by the current delivered by the BC547 emitter.

                Reply
  41. min khant naing says

    I think my bc557 is faulty .
    Its not working properly when i trouble shoot it alone.
    If i use a not gate at base of 547
    Does 547 become 557 sir?
    Or other transistor i can use?

    Reply
    • Swagatam says

      yes, you can use two NPN to replicate a PNP

      Reply
  42. Muhammad Misbah says

    Hi swagatam!
    I want to automate my piston pump so that it only runs when there is muncipal water in the inlet of the pump. Problem is that all the water sensors I searched can sense air flow too that I dont want. So I request you to suggest me any suitable sensor or any other technique for sensing water in the inlet.
    Thank you.

    Reply
    • Swagatam says

      Hi Muhammad, you can try the concepts presented in this article:

      https://www.homemade-circuits.com/municipal-water-supply-sensor-pump/

      Reply
  43. Raaman says

    Hi sir 555 based dry run production circuit is not working sir …pls give me one good dryrun automatic circuit sir
    Thank you
    Raaman..

    Reply
    • Swagatam says

      Hi Raaman, it will definitely work, you will have to check the various points around the two BC547 transistors to make it perfect. Please let me know what results are you getting, and you must check it manually on table first before implementing it for the motor dry run…
      I hope you have made the following design:

      IC 555 dry run protection

      Reply
      • M.Raaman says

        Thanks sir now it’s working fine.
        But 555 ic and some times that 547 transister getting short..
        I don’t know the reason.pls help me sir …all my customers asking dry run motor off mechines only
        Iam assambled and selling decice circuit is only buzzer used for dry run.. pls give me good dry run production fully automatic circuit sir….thank you for your reply
        Your’s
        M.Raaman
        Shinetech electronics.

        Reply
        • Swagatam says

          Hi Raman, the IC may be getting damaged due to back EMF from the motor, please add the following protection to the IC:
          1) Connect the supply to pin4/8 of the IC 555 through a 100 ohm 1 watt resistor.
          2) Connect a 100uF/25V capacitor across pin4/8 and ground of the IC
          3) Add a 1N4007 diode across pin4/8 and ground of the IC. Cathode will go to pin4/8

          Please do this and check the response…make sure to use 12V supply Dc only.
          Connect a 1N4007 diode across collector/emitter of the BC547 also. Cathode will go to the collector.

          Reply
        • M.Raaman says

          Thanks sir
          Now it’s working fine..iam using ….SL100 for relay drive transister
          and 2222 transister for dry run production.. thank you
          Your’s
          M.Raaman
          Shinetech electronics

          Reply
          • Swagatam says

            That’s great Raman, appreciate your feedback!

            Reply
      • Pradeep kumar says

        hi Swagatham,
        one question – when the tank is full (relay is off, both Low and High in water), the 555 gets heated up and behaves eratically. Pls. suggest a solution. Thanks.

        Reply
        • Swagatam says

          Hi Pradeep, it could be due to the back emf transient from the motor which could be affecting the IC performance.

          To control this you can add the following snubber network:

          IC protection snubber circuit against moroe back emf transient

          Reply
          • Pradeepkumar Sivaraman says

            Thank you Swagatham. i will try this and update you.

            Reply
            • Swagatam says

              You are welcome Pradeep!

              Reply
            • Pradeepkumar Sivaraman says

              Thanks Swagatham. my 555 was faulty, i replaced with a new one. With dry-run, it works as expecte for my garden pump and i have not used the snubber. Thanks so much for your help.. and appreaciate you find time for helping everyone.. Take care. Thanks.

              Reply
              • Swagatam says

                Glad to know it’s solved Pradeep, the pleasure is all mine!

                Reply
            • Pradeepkumar Sivaraman says

              hi Swagatham,

              Am facing a problem with the circuit after it worked for around a month. I have sent to you a mail, could you pls. check and suggest.. Thank you.

              Reply
              • Swagatam says

                Hi Pradeepkumar, Please explain your problem, I’ll try to help you, I did not find any email from you so far….

                Reply
  44. Ajith kumar says

    Hay swagatham,
    I need a help in logic waterlevel controller circuit, How to connect a led indicater for dryrun cutoff, and thanks for the project, it’s working without any problems
    thanks a lot

    Reply
    • Swagatam says

      Hi Ajith, I am glad it’s working! for LED indication, you can connect an LED from +12V line to N2 output, make sure to put a series 1K resistor with the LED. This will show when the water connects…

      In the the same way you can add anther LED/1K across +12V and N3 output to show dry run cut off

      Reply
  45. Hameed K M says

    Sir,
    Before 4 years I made your circuit using IC 4049 and it was working perfectly except dry run and i contacted you and get some instructions. Now I am requesting you to design a WATER LEVEL CONTROLLER WITH DRY RUN PROTECTION Using Aurdiuno Uno (328P) because i saw one circuit with 328P and excellent working with minimum components.
    Thank You

    Reply
    • Swagatam says

      Sorry Hameed, I am good with Arduino so it can be difficult to design the mentioned circuit idea.

      Reply
      • Hameed K M says

        Thank you sir for replaying.
        Now i am going to try your 555 ic water level controller circuit. So please leave a link for last updated 555 ic circuit with dry run protection
        Thank you

        Reply
        • Swagatam says

          Hameed, please refer to the last diagram in the above article.

          Reply
  46. K. Shivakumar says

    All your circuit ideas r excellent. I am going to try CD 4049 IC with dry run protection. Hoping that this will work good. Any ready made pcb is avlble?. For 555 if version where to connect push button to start the motor. With the request can we make pcb of our own? .
    Shivakumar.

    Reply
    • Swagatam says

      Glad you are enjoying the articles, however I am sorry there’s no PCB designed for these projects so far.
      For the IC 555 circuit you can connect a push button between the positive line and the base of the upper BC547 transistor, through a 1k resistor.
      Sorry, due to lack of time it won’t be possible for me to design the PCB.

      Reply
  47. Philip K J says

    Hai Sir,
    I am Philip, I want to control my water pump motor automatically with dry run protection. now I am using BC548 transistor an four flot switches for the purpose.it is working very good condition but the problem is it have no dry run protection so many times motor become hot and O ring burning happened. so I am trying to make another circuit and finally find out your site and tried your IC555 circuit it is working but dry run protection not working then again tried your circuit using transistor BC547 and BC 557 but not working. I have a doubt that in your first design ( Design No.1) you mention earth point in two places 470mf cappasitor and BC547 emitor. But in fully automatic version the earth point is only in capacitor point no earth connection in relay point and other emitter points is it correct, please help me to make this circuit , or give some ideas for this purpose
    Thankyou Sir

    Reply
    • Swagatam says

      Hi Philip, all the circuits mentioned will work, but they will need to be done step-wise and stage-wise with correct understanding and adjustment of the different components. A few resistors may need to be adjusted slightly for proper results. The current passing through the water to the various sensors must be checked and correctly optimized for getting perfect results. If the sensors do not get proper current then the stages will not operate correctly. All these must be tested on a workbench with sample water content in glass or bowls. Only NPN BC547 need negative line connections, PNP BC557 do not need negative connections their emitters need positive connections.

      Reply
  48. Babu Yousuf says

    Hi Swagatam,
    Hope you are all doing good.
    Please do let me know most effective circuit for Automatic water level control with dry run protection. I have seen that more discussion on IC555 circuit. Shall I get the latest revised circuit from you ? I am using mono block pump and well water.
    If possible, please send it to my email.

    Thanks & Best Regards,
    Babu Yousuf.

    Reply
    • Swagatam says

      Hello Babu, all the circuits presented above are good, and can be adopted for the water level control application.
      For dry run protection you can refer to the following post:

      5 Useful Motor Dry Run Protector Circuits Explained

      Reply
      • Babu Yousuf says

        Dear Swagatam,
        Appreciate and thank you sir for your reply and your time.
        Can we modified IC555 circuit with 24V DC instead of 12V ? if it can be, what are the changes required to do in this circuit. How many A/mA transformer and wattage of resistors/diode and wire gauge (for sensor) to use ? Please advice.

        Reply
        • Swagatam says

          Thank you Babu, you can use 24V for the relay coil only, rest of the circuit will need to be operated with a 12V, derived from a 7812 IC.

          Reply
          • Babu Yousuf says

            Hi Sir,
            Wishing you and your family a Happy New Year 2021.
            Thanks for your quick response. I think I will go for your IC555 circuit as it is with 12VDC (without 7812 IC as per your circuit). Hope I will give you my feed back at the earliest.

            With Best Regards.

            Reply
            • Swagatam says

              No problem Babu, wish you too a Happy 2021.

              Reply
  49. Arjun S says

    IC 555 Dry run protection circuit

    This has a Flaw. When the leve is above HIGH and the motor is drawing current following happens

    output at PIN 3 is low. However since the motor outlet sensor (blue wires) would still be shorted hence the capacitor Bypass transistor BC547 base will still be on Bypassing the capacitor and inturn turning on the BC547 connected to relay and hence even though the water has reached HIGH the motor would not stop.

    So there needs few correction.
    1. the 1k resistor connected to collector of transistor and 12v supply needs to be connected to Pin 3 and collector.
    also the we need to have a Base emittor Resistor connected to the Transistor connected to relay without without which the motor will not stop running (This is due to capacitor which cahrges through the LED from the BC547 which is monitoring pump output)

    Reply
    • Swagatam says

      You can see a 1N4148 diode placed between the emitter of the upper BC547 and pin3. this diode will sink the emitter voltage to pin3 logic low. But a 0.6V may still be present towards the base of the lower BC547…this can be simply corrected by adding another 1N4148 in series with the emitter of the lower BC547.

      If we follow your idea of connecting the collector of the upper BC547 with pin3, then even though pin#3 will be logic low but the base/emitter of the upper BC547 will keep passing current to the lower BC547, keeping the relay permanently ON.

      A base emitter resistor for the lower BC547 may not be required since a logic low at pin3 will effectively ground the base, unless the IC 555 is a low quality one and has some serious offset voltage.

      Reply
      • Swagatam says

        …Your idea can be used if the blue wire positive is also taken from pin#3

        Reply
      • Arjun S says

        I have tried having another 4148. It doesnot work . i had tried it myself with few combination.

        when we try to implement such circuits at home we arent sure of the quality of components we get but its always safe to take in to consideration. just by having a resistor at bottom BC547 it worked exactly as intended and the relay want on permanently but only for RC time period. BE resistor bypassed excess current .

        Reply
        • Swagatam says

          A diode at the emitter of the relay transistor will definitely keep the relay switched OFF, if it is not working for you then you must investigate from where the switching potential is coming from?

          It may not work if you apply your idea of connecting the base and 12V of the other BC547 connected with water and collector with pin3, since it will keep leaking the whole 12V from water via base emitter of the transistor

          Reply
  50. Arjun S says

    Well i missed to mention this i have put a 2.2 K resistor at the base of bc547 resistor connected to blue wire. we we cnnot give 12v directly to base and with high current transistor may burn up. so thats obvious .

    Reply
    • Swagatam says

      That is not related to the issue. The water itself has a resistance of more than 5k at an inch distance, and the emitter already has a 10k in series the transistor can never blow.

      Even with 2.2k resistance the 12V will keep leaking from the emitter to the base of relay transistor.

      The +12V should be taken from the pin3 to solve this issue….not from the supply line.

      dry run protection

      Reply
  51. Babu Yousuf says

    Hi Swagatam,
    Hope you are doing good.
    I have tested your IC 555 based circuit in my table. It is working but there is a minor issue is that when dry run cut, the circuit doesn’t reset (even doing power off and on after a while ) unless I short the capacitor (to discharge). Could you please tell me how to solve this issue. Shall I provide a push button in parallel to the capacitor (to discharge) so that the circuit can be reset manually.
    Please, awaiting for your reply.

    Regards,
    Babu Yousuf

    Reply
    • Swagatam says

      Hi Babu, I think you can apply the following trick….take a BC547, connect its collector with the positive side of the cap and emitter with the negative side, and then connect the base of the transistor with the positive line via a 0.22uF series capacitor

      Reply
  52. Dipak Bhandari says

    Hi Swagatam,
    I want to put LED indication for overflow and dry run cutoff in IC 555 circuit, where can I place it ?

    Reply
    • Swagatam says

      Hi Dipak, for the tank full indication you can put an LED between the positive and the pin#3 of the IC, via a 4k7 resistor.
      For dry run indication you can put an LED in series with the upper BD547 base wire. If this LED does not light up after a few seconds and the relay switches OFF then it will indicate a dry run shut down.

      Reply
      • Dipak Bhandari says

        Thanks Swagatam for prompt reply, LED for tank full indication is fine but any other idea for dry run indication with LED “ON” condition where I can visually see from the distance that the pump is stopped due to dry run.

        Reply
        • Swagatam says

          Hi Dipak, there’s no other easy idea to monitor the dry run except putting an LED in series with the upper BC547 base…

          Reply
  53. SUJIT MAZUMDER says

    Dear Sir, I have tried your circuit with dry run along with 555 ic, but the relay not operating as the water level goes high or low. Only the relay being operated- for dry run! What is the function of 470 up electrolytic capacitor, as there is ac current is absent? And output of pin 3 of 555 being blocked. As a result relay driver not functioning. I’m not an expert. Please help me to build it. Thank you.

    Reply
    • Swagatam says

      Hi Sujit, try operating the circuit by touching the probes manually with the positive line, and check whether the relay operates or not. If the relay operates then it means the water is conducting the 12V supply to the respective probes….in that case try placing the positive probe very close to the pin2 and pi6 probes, so that when water reaches these probes, the 12V positive connects with the sensing probes adequately.
      The 470uF is a timing capacitor which allows the relay to operate for sometime until the 470uF charges fully then the supply to the transistor base is blocked by the 470uF. In the meantime if the pump starts pumping water the dry run transistor starts supplying the base current to the transistor so that the relay continues to remain switched ON

      Reply
  54. SUJIT MAZUMDER says

    Thank you for quick answering! If you don’t mind- please explain: at the over head tank, where the lower prob carries 12 volt DC, and whenever it completes cct with pin 2 and pin 6 at a time( both are receiving12 v dc), the relay not going off! 1M resistor getting heated. Please help me. Thanking you.

    Reply
    • Swagatam says

      You are Welcome! A 1 M resistor has a very high resistance and can never heat up, even if you connect it with 220 V mains AC. So it seems something’s may not be correct with your resistors, because it is impossible for a 1M to become hot.
      Please check the probe actions by manually connecting the 12V with the two sensor probes, alternately. This should set/reset the IC output ON/OFF alternately
      Once the actions are confirmed make sure that the 12V supply in water is held close to the two sensing probes so that the sensing probes are able to detect the 12V supply through water optimally.

      Reply
  55. Subhamoy says

    The barzer will ring just when the pump is off for a dry run. From which I can see that there is a problem with the pump. So please tell me how to set this buzer?

    Reply
    • Swagatam says

      Which circuit are you referring to?

      Reply
  56. Sison says

    Sir,Regarding the #4 idea how can we calculate the current sensing resistor Rx?
    to different loads.Appreciate if you could explain with 1hp motor as example.Thank you.

    regards.
    SISON
    Kerala

    Reply
    • Swagatam says

      Sison, the formula is

      RX = 2.5 / Normal Motor Current while it is pumping water

      Reply
      • Jorge says

        Hi! What the power (WATT) of RX, how I can calculate it?
        In this calculation (RX = 2.5 / Normal Motor Current while it is pumping water) current in amp, milliamp value?
        Thank you, sir!

        Reply
        • Swagatam says

          Current will be in Amps.
          Wattage = 2.5 x Normal Motor Current while it is loaded and pumping water.

          Reply
  57. Sison.c.s says

    Sir,
    Greetings..!!
    This is not a mail to pointing a fault or critisise you.This is for appreciate you for your effort to give us industry standard circuits to hobbyists around the globe.all were very nice and work properly at first time morover every doubt you clear through mail as express as possible.Your circuit of water level indicater with 4049 successfully install at 6 of my relatives house past 2years all of them working fine up today.Anyway appreciate great effort.Keep post more circuits.Thanks alot…!!!
    From Kerala
    With love
    Sison.c.s

    Reply
    • Swagatam says

      Thank you so much Sison, I appreciate your genuine feedback. Please keep up the good work!

      Reply
  58. Jorge says

    Hi, Swagatam!!!
    Design #4
    Question: maybe it is necessary to put a resistor of about 2-10 kilo ohms between the diode bridge and the optocoupler?
    May I use 4N35 optocoupler in this circuit?
    Thank you for response.
    Respectfully,
    Jorge

    Reply
    • Swagatam says

      Hi Jorge, yes you are right, may be a 100 ohm resistor should be enough. You can use any opto coupler which works with an LED and transistor internally, 4n35 will also do!

      Reply

Primary Sidebar



Categories

  • 3-Phase Power (15)
  • 324 IC Circuits (19)
  • 4017 IC Circuits (53)
  • 4060 IC Circuits (25)
  • 555 IC Circuits (98)
  • 741 IC Circuits (19)
  • Amplifiers (58)
  • Arduino Engineering Projects (82)
  • Audio Projects (95)
  • Battery Chargers (82)
  • Car and Motorcycle (94)
  • Datasheets (46)
  • Decorative Lighting (Diwali, Christmas) (33)
  • DIY LED Projects (89)
  • Electronic Components (97)
  • Electronic Devices and Circuit Theory (35)
  • Electronics Tutorial (109)
  • Fish Aquarium (5)
  • Free Energy (35)
  • Fun Projects (11)
  • GSM Projects (9)
  • Health Related (18)
  • Heater Controllers (28)
  • Home Electrical Circuits (101)
  • How to Articles (20)
  • Incubator Related (6)
  • Industrial Electronics (28)
  • Infrared (IR) (40)
  • Inverter Circuits (98)
  • Laser Projects (12)
  • LM317/LM338 (21)
  • LM3915 IC (25)
  • Meters and Testers (63)
  • Mini Projects (171)
  • Motor Controller (66)
  • MPPT (7)
  • Oscillator Circuits (24)
  • PIR (Passive Infrared) (8)
  • Power Electronics (33)
  • Power Supply Circuits (74)
  • Radio Circuits (9)
  • Remote Control (47)
  • Security and Alarm (61)
  • Sensors and Detectors (116)
  • SG3525 IC (5)
  • Simple Circuits (74)
  • SMPS (29)
  • Solar Controllers (61)
  • Timer and Delay Relay (54)
  • TL494 IC (5)
  • Transformerless Power Supply (8)
  • Transmitter Circuits (40)
  • Ultrasonic Projects (14)
  • Water Level Controller (45)

Circuit Calculators

  • AWG to Millimeter Converter
  • Battery Back up Time Calculator
  • Capacitance Reactance Calculator
  • IC 555 Astable Calculator
  • IC 555 Monostable Calculator
  • Inductance Calculator
  • LC Resonance Calculator
  • LM317, LM338, LM396 Calculator
  • Ohm’s Law Calculator
  • Phase Angle Phase Shift Calculator
  • Power Factor (PF) Calculator
  • Reactance Calculator
  • Small Signal Transistor(BJT) and Diode Quick Datasheet
  • Transistor Astable Calculator
  • Transistor base Resistor Calculator
  • Voltage Divider Calculator
  • Wire Current Calculator
  • Zener Diode Calculator

Facebook
Twitter
YouTube
Instagram
My Facebook-Page
Quora

© 2022 · Swagatam Innovations

We use cookies on our website to give you the best experience.
Cookie settingsAccept All
Privacy & Cookies Policy

Privacy Overview

This website uses cookies to improve your experience while you navigate through the website. Please visit the Privacy Policy Page for more info.
Necessary
Always Enabled
Necessary cookies are absolutely essential for the website to function properly. This category only includes cookies that ensures basic functionalities and security features of the website. These cookies do not store any personal information.
Non-necessary
Any cookies that may not be particularly necessary for the website to function and is used specifically to collect user personal data via analytics, ads, other embedded contents are termed as non-necessary cookies. It is mandatory to procure user consent prior to running these cookies on your website.
SAVE & ACCEPT