• Skip to main content
  • Skip to primary sidebar

Homemade Circuit Projects

Need circuit help? Post them in the comments! I've answered over 50,000!

Blog | Categories | About | Contact | Calculators-online
You are here: Home / Water Controller / Pump Motor Timer Circuit Diagram with Dry Run Protection

Pump Motor Timer Circuit Diagram with Dry Run Protection

Last Updated on January 17, 2025 by Swagatam 19 Comments

In this post I have explained about a circuit which can be used to monitor and detect the presence of municipal water supply by operating a pump motor through an intermittent ON/OFF timer.

Table of Contents
  • Circuit Objective
  • Circuit Description

The timer keeps the pump motor ON for 15 seconds, if water is not detected, the pump is switched OFF for the next 15 minutes. After 15 minutes it repeats the water detection process, and this goes on until water is finally detected in the pipe.

Once water is detected, the timer is disabled and the pump motor is allowed to run continuously as long as the water supply is available.

The idea was requested by Mr. Aslam Iqbal, as I have explained below.

Circuit Objective

I need help constructing a circuit that controls a water pump using sensor probes and a relay timer. The pump should be activated every after 15 minutes, for a brief duration of 10-15 seconds through a preset timer relay. However, in case the sensor probes detect water flow, the pump should continue to run. After the first 10 to 15 seconds, the pump should automatically turn off if the water in the pipe becomes unavailable.

Related Post:
  • Safety Buoy Switch Circuit for Human Powered Submarine

Circuit Description

If you do not want to read the following description, you can watch the following video instead:

warning message: electricity is dangerous, proceed with caution

Referring to the diagram below, the working of the proposed Pump Motor Timer Circuit with Dry Run Protection circuit can be understood with the following points:

The heart of the circuit is the IC 555 which is configured as a standard astable multivibrator circuit with a PWM control.

In this mode the IC 555 generates a square wave output, with an ON and OFF timer periods of around 15 minutes, which are individually adjustable using the pot RV1.

Here, the pot VR1 adjusts the output PWM to fine-tune the 15 minutes ON/OFF time to 15 seconds OFF and 15 seconds ON time, at the IC output.

Related Post:
  • Simple Water Level Indicator Circuits (with Images)

Alternatively, you can also manipulate the values of the R1 and R2 to adjust the above duty cycle of the 555 output.

The relay connected with the output pin#3 of the IC555 responds to these set ON/OFF periods and keeps its contacts turned ON for 15 seconds and turned OFF for 15 minutes.

As a result, the attached motor remains switched ON for every 15 seconds and switched OFF for 15 minutes, as long as it is in the powered condition.

This takes care of the pump motor's ON/OFF switching cycle while it detects the availability of water in the municipal pipeline.

In an event water supply becomes available in the pipe, it is quickly detected by the sensor probes introduced across the relevant area of the pipe.

Related Post:
  • Programmable Automatic Starter Circuit for Diesel Water Pump

As soon as water bridges the probes, the +12V supply reaches the base of the T1 BC547 transistor, which instantly conducts and grounds the pin#2/6 of the IC 555.

Due to this the IC 555 is inhibited from its astable mode, causing a permanent logic high at its output pin#3.

This logic high locks the relay ON and the motor pump now starts operating without switching OFF, pumping out the available water supply from the source.

This goes on as long as water supply is available in the pipe line.

When water supply stops and becomes unavailable, the water across the probes is removed.

Related Post:
  • Municipal Water Supply Sensor Controller Circuit

You'll also like:

  • 1.  Ultrasonic Wireless Water Level Indicator – Solar Powered
  • 2.  Control Two Submersible Pumps Alternately
  • 3.  Water Softener Circuit Explored
  • 4.  Anti-Corrosion Probes for Water Level Controller
  • 5.  Analogue Water Flow Sensor/Meter Circuit – Check Water Flow Rate
  • 6.  Simple Water Level Indicator Circuits (with Images)

Filed Under: Water Controller Tagged With: Motor, Protection, Pump, Timer

About Swagatam

I am an electronics engineer and doing practical hands-on work from more than 15 years now. Building real circuits, testing them and also making PCB layouts by myself. I really love doing all these things like inventing something new, designing electronics and also helping other people like hobby guys who want to make their own cool circuits at home.

And that is the main reason why I started this website homemade-circuits.com, to share different types of circuit ideas..

If you are having any kind of doubt or question related to circuits then just write down your question in the comment box below, I am like always checking, so I guarantee I will reply you for sure!

Previous Post: « Automatic Door Controller Circuit Diagram using a Single Push-Button
Next Post: Convert any H-Bridge Inverter to Sine Wave H-bridge Inverter »

Reader Interactions

Comments

  1. Anto Das8 says

    November 3, 2024 at 9:27 pm

    Can we directly connect a 5v (DC) water pump to pin 3 of 555 and gnd

    Reply
    • Swagatam says

      November 4, 2024 at 9:02 am

      If the pump current rating is less than 100mA then, yes…

      Reply
  2. Anto Das8 says

    November 3, 2024 at 1:35 pm

    Can a water pump be employed instead of the relay,AC supply and motor

    Reply
    • Swagatam says

      November 3, 2024 at 1:57 pm

      The relay is used for switching the motor pump ON/OFF, without a relay that will not be possible….

      Reply
  3. Barclay Momin says

    July 16, 2024 at 12:47 pm

    When the power supply is 12 volts 500 MA, often the relay chatters when the load is the pump; what is the suggested ampere for the power transformer for the 40A relay?

    Reply
    • Swagatam says

      July 16, 2024 at 1:03 pm

      The relay coil current requirement may not be more than 100mA, so 500mA trafo is OK.
      The chattering can be stopped by adding a 220uF/25 capacitor right across the relay coil.
      Also make sure the power supply DC has a large filter capacitor of around 2200uF/50V

      Reply
  4. Barclay Momin says

    June 27, 2024 at 10:56 am

    I do not need the timer. I just want that the pump should stop when the tank is out of water. Accordingly, please modify the circuit.

    Reply
    • Swagatam says

      June 27, 2024 at 11:36 am

      You can try the first circuit from this article:

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

      Reply
  5. Carlos says

    June 15, 2024 at 5:18 pm

    The circuit is very good, but the problem is that the probes oxidize with electrolysis.

    Reply
    • Swagatam says

      June 16, 2024 at 8:05 am

      You can employ one of the ideas explained explained in the following article, to solve the corrosion problem:

      https://www.homemade-circuits.com/anti-corrosion-probes-for-water-level/

      Reply
  6. MOSES says

    May 16, 2024 at 5:15 pm

    COULD FLOAT SWITCH BE USED AS THE SENSING PROBE

    Reply
    • Swagatam says

      May 16, 2024 at 7:00 pm

      Sure, you can use any type of sensor which can detect water and conduct voltage.

      Reply
  7. Amir saraf says

    May 14, 2024 at 7:20 pm

    Hello

    It is a very interesting circuit.butI think it is better to amplify the IC output with a transistor before connecting it to the relay in order to increase the current. Also, a filter should be prepared to remove the noise of AC motors Thanks
    Amir Saraf

    Reply
    • Swagatam says

      May 15, 2024 at 8:53 am

      Hi, thanks for the suggestion.
      However, the IC 555 can handle upto 200mA current at its pin#3, so a 40 amp relay which might have a coil resistance of 100 Ohms can be easily handled by the 555 without any transistor.

      Reply
      • Amir saraf says

        June 12, 2024 at 2:53 pm

        Hi
        Thank you for your attention and response to my suggestion. In any case, the output has always been sensitive and not protected, so the output of the IC can provide the necessary current to move the relay, it is not bad if the output is shielded in some way. 
        Thanks

        Reply
        • Swagatam says

          June 12, 2024 at 5:16 pm

          Sure, If you are not comfortable with the direct relay connection with pin#3 of the IC, you can add a transistor stage for the relay at pin#3, for extra safety.

          Reply
  8. Aslam Iqbal says

    May 14, 2024 at 5:30 pm

    I am thankful for your prompt response on my specific need. Hope there may some users as well needing this circuit.
    With a feeling of proudness by way of your generosity and being naive on electronics, may I as ask, if possible, in this circuit, motor should also turn off when tank is full? I think it is possible with a little variation in the same circuit by adding a probe of tank full sensor.

    Reply
    • Swagatam says

      May 15, 2024 at 9:03 am

      You are welcome.
      The full tank motor auto switch off can be implemented by driving the relay through a transistor at pin#3 and then adding another BJT between the base and ground of the driver transistor. Then the base of this BJT can be configured with the probes for detecting the fully tank level.
      This will allow the motor to shut off as soon as the tank is full, however when the tank water drops below the probes, the motor will again start searching for water, which can be a problem.
      So the new water level controller should be set in way that once it turns off the motor, it should not switch ON the motor until the water level has dropped below a certain lower level.
      Implementing the above might require a separate water level controller circuit.

      Reply
  9. Jorge says

    May 14, 2024 at 11:11 am

    Hello, everybody!
    I don’t see the point of periodically checking to see if the water supply is available. If the sensor is in the water, the pump should be switched on. If there is no water, the sensor is not in the water, so the pump is switched off.
    I propose my variant of the scheme. The schematic can be downloaded from this link:
    " rel="ugc">comment image
    ———
    220V electric pump control, simple automation circuit on two transistors
    ———
    DP1 is a sensor of water level in the tank to be filled. If tank is not full DP2 contacts are closed and through them the voltage goes to the base of transistor VT 1. The key on the compound transistor VT1-VT2 opens and switches on the current to the relay winding K1, its contacts switch on the power supply to the pump. When the tank is full, the float of the sensor DP1 rises and its contacts open. The voltage is no longer supplied to the base of VT1. The key on the compound transistor VT 1-VT2 closes and switches off the current to the relay winding K1, its contacts switch off the power supply to the pump.
    DP2 is the water level sensor in the well. If the water level is sufficient for normal operation of the pump, the sensor contacts are open and the operation of the key on transistors VT 1 and VT2 is not affected.
    If the water level in the well is insufficient for normal operation of the pump, the DP2 sensor contacts are closed and shunt the base of transistor VT 1, shorting it to the minus supply. As a result, the transistor key VT1-VT2 remains closed regardless of the state of the DP1 sensor contacts. This will prohibit the pump from starting until there is enough water in the well for safe operation of the pump.
    Parts
    Relay K1 type BJ-118-1C. This is a relay with a 12V winding and 5A contacts at 230V. The relay can be replaced by another relay with 12V winding or other voltage.
    If the winding is not on 12V, then accordingly the supply voltage of the circuit must be different, – such as the nominal voltage of the relay winding. Capacitor C1 should be of voltage not lower than the supply voltage.

    Reply

Need Help? Please Leave a Comment! We value your input—Kindly keep it relevant to the above topic! Cancel reply

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

Primary Sidebar

circuit simulator image

Subscribe to get New Circuits in your Email



Categories

  • Arduino Projects (89)
  • Audio and Amplifier Projects (132)
  • Automation Projects (17)
  • Automobile Electronics (101)
  • Battery Charger Circuits (83)
  • Datasheets and Components (106)
  • Electronics Theory (143)
  • Free Energy (37)
  • Games and Sports Projects (11)
  • Grid and 3-Phase (19)
  • Health related Projects (25)
  • Home Electrical Circuits (12)
  • Indicator Circuits (14)
  • Inverter Circuits (88)
  • Lamps and Lights (142)
  • Meters and Testers (69)
  • Mini Projects (46)
  • Motor Controller (64)
  • Oscillator Circuits (28)
  • Pets and Pests (15)
  • Power Supply Circuits (108)
  • Remote Control Circuits (50)
  • Security and Alarm (64)
  • Sensors and Detectors (102)
  • Solar Controller Circuits (59)
  • Temperature Controllers (42)
  • Timer and Delay Relay (49)
  • Transmitter Circuits (29)
  • Voltage Control and Protection (40)
  • Water Controller (36)



Other Links

  • Privacy Policy
  • Cookie Policy
  • Disclaimer
  • Copyright
  • Videos
  • Sitemap

People also Search

555 Circuits | 741 Circuits | LM324 Circuits | LM338 Circuits | 4017 Circuits | Ultrasonic Projects | SMPS Projects | Christmas Projects | MOSFETs | Radio Circuits | Laser Circuits | PIR Projects |



Social Profiles

  • Twitter
  • YouTube
  • Instagram
  • Pinterest
  • My Facebook-Page
  • Quora
  • Stack Exchange
  • Linkedin


  • Recent Comments

    • Swagatam on 3 High Power SG3525 Pure Sine wave Inverter Circuits
    • Swagatam on Crystal Radio Sets with Amplifier Circuit
    • Alexander on 3 High Power SG3525 Pure Sine wave Inverter Circuits
    • Swagatam on 5V, 12V Buck Converter Circuit SMPS 220V
    • Swagatam on Crystal Radio Sets with Amplifier Circuit

    © 2025 · Swagatam Innovations