Automatic Water Level Controller With Indicator Project

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Automatic water level controller for submersible motor 


This Project Is Very Useful, Interesting, And Very Effective. This Automatic Water Pump Controller With Three Stage Level Indicator Provides the visual And Attractive LED Indication As Level Of Water in Water Tank. When Tank is Full Then Motor Stops Automatically, In This Circuit No Use Of Any Timer IC.

• This is an Automatic submersible Motor controller

•  The Main Advantage Of this Project Is To All Three LEDs Are Glowing One by One. Only One LED is Glowing At One Level And Other Two Are in Off state.

Schematic diagram

Click on image to large view


Water tank controller for submersible motor



In This Project No Need Of Any Capacitor, No Timer IC.  A Voltage Regulator IC LM7809, Some Resistors And Some NPN Transistors, Diode, LED And Relay used In This Circuit.

Connect The All Components As Shown In Image Diagram, The Value Of Resistors Are Should Not More Than 2kΩ.  And Not Less Than 1kΩ. R8 And R9 Should Not More Than 100 Ω. If All Values Are the same As I Recommend Then Circuit Working Will 100% Successfully.

Arrange The One Wire Which Is Connected to VCC from More Than Half Level (Not Necessary To Fix The VCC wire From Bottom). Second Wire Connect The Half Middle Of Tank Or Lower Than Half. And Third Wire Is Fix to Top Side Where You Want as Requirement.


First stage

At First When There Is No Water In-Tank. This Is time to start the motor and LED 1 is Glowing And Relay Is Activated. So Power to the motor is ON. Only The LED 1 will Glow At Till The water Level is About To Reach the Half Of the Tank. When the level of water has reached half level and Touches the middle wire of tank then the current from VCC supply through the water goes to BASE terminal of transistor Q1 and this will Turn ON.

Transistor Q1 is connected as NOT Logic Circuit, So When the input of this on the base is +ve (ON) then the output at COLLECTOR Terminal Will be LOW (OFF), In This Case only LED 2 is now glowing And LED 1 is getting OFF.

The transistor Q5 is Remain ON State Which Stay Relay Activated and motor get power.

Second and Third Stage

Now water is reached More than half and middle and wire is sunk in the water, Only LED 2 Is glowing and all are OFF

At The Time Of When Water Reached To The upper Wire And Touched That. As The Water Is Touched The Upper-Level Wire And Current At Base Of Q3 is Get Supply.  transistor Q3 in ON and LED 3 will Glow And On That Exact Time Transistor Q5 Will Get Turned OFF, Because Transistor Q3 And Q5 Are in Connected As Inverter Logic(Not GATE) Which Make The Output At Collector of Q3 is LOW, then Base Of Q5 In LOW input and Q5 Turned Off. This is The Reason Of Relay Deactivate When Tank Is Full. All Emitter Terminal Of Transistors Is Grounded(-ve supply). 

The Purpose of Voltage Regulator LM7809 is in this Circuit is to Divide The Supply In Two Section. One Is For Relay And Other is For the whole Circuit. If the LM7809 regulator Is not connected then The Maximum Power is get consumed by Relay And LED Not Glowing In Proper way.

Carefully Connects Terminals Of Transistors And Voltage Regulator ic LM7809. Relay Must Be More Than 20A. 

If Q5 BC547 Get Burn Or more Hot, then You Can Use 2N2222. 

You Can Use Tricolor Led At The Place Of 3 Different LEDs. But only Common Cathode Tricolor LED. This LED Make its Different Look.

2nd Schematic diagram

(suitable for both Motor- Submersible and Non-submersible)

automatic water level indicator pump controller circuit diagram


Must Watch Demo Video of this project…

Video is of 1st circuit

Must Read 2 Digit Digital Object Counter

BC547 Pin configuration


Must Read Simple ON OFF Touch Switch For Light/Fan

The power supply must 12 v DC.  If Power Supply Is LESS than 12v on the pin 1 of 7809 then the circuit may not correctly work.


LM7809 LM7805 7812 PIN



 1.5K- 9

 100 ohm-2 (optional)


 BC547 -5



 LED-3  Or Tricolor LED-1


 12v 20A-1

 Voltage Regulator IC



PCB layout

download Actul size printable image of PCB Layout

Download Gerber File



water level controller 3d image

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14 thoughts on “Automatic Water Level Controller With Indicator Project”

  1. I’ve been absent for a while, but now I remember why I used to love this blog. Thanks, I will try and check back more often. How frequently you update your website?

    1. please help me my dear i make this project for final year gradution project but when the tanker is empity no problem the pump automatically start,and achive the final max level it goes off. the main problem is that when the senser of the top maxlevel is lose the water the motor automatically start why b/c the pump atlist atart to full the tank below the midium but this project start to fill below the higher level please tell me the problem .

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  3. Hi there! This post couldn’t be written any better! Reading through this post reminds me of my previous room mate! He always kept talking about this. I will forward this article to him. Pretty sure he will have a good read. Thank you for sharing!

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