Hello friends

Today I am back with another project called \$1 AUTOMATIC WATER LEVEL CONTROLLER.

It’s an automatic switching circuit that used to control an AC water pump. Operation of this circuit is simple.wen the water level goes below the limit the lower level sensor will detect it and activate the water pump.wen the water level reaches the upper limit the upper limit sensor detect it and switch of the water pump.

## Step 1: My Goal

“To make a cheap but efficient water level controller under \$1 budget to control AC water pump”

## Step 2: The Circuit

This is the driving circuit of the \$1 AUTOMATIC WATER LEVEL CONTROLLER.

To make this circuit you will need

1. BC 547 Transistor X 3 = 9 INR
2. 220 K Ohm & 5.4 K Ohm resistors = 1
3. 1N4007 Diode = 1
4. 12V relay = 12
5. One, 3-pin PCD connector & two, 2-Pin PCB connector = 25
6. Wires = 5
7. PCB = 12

Total = 66 INR

Total cost of this circuit is equals to 66Rs or 66INR (66.6 INR = 1 USD).that means this circuit is under the \$1 budget

12v relay is the main component of this circuit, so please use a relay with 7Amp or more. I am using a 12v relay.it can handle 7 Amp AC @240v.

## Step 3: The Sensor

To make sensor you don’t need anything special. Take three wires and name them like LOW, HIGH AND MAIN. Place “MAIN” on the bottom of the tank. Then place “LOW” above the outlet. Finally place “HIGH” on the top of the water tank

[ ~~~~~~~~~~~~] -------------------------------------- “HIGH”

[~~~WATER~~~ ]

[ ~~ TANK ~~~~~]

[~~~~~~~~~~~~ ]

[~~~~~~~~~~~~ ]--------------------------------------- “LOW”

[______________]--------------------------------------- “MAIN”

This is the placing order of the sensors

## Step 4: ​Connect Them All

Connect all wires to the main circuit board with help of circuit diagram. Double check all connections because playing with high voltage is DANGER

## Step 5: The Moment of Truth

This video show how \$1 AUTOMATIC WATER LEVEL CONTROLLER work

<p>Hi. Nice circuit. How large a tank will this work on (ie what is the maximum distance between the probes)?</p>
<p>is it applicable for 1 hp Submersible Pump as well?</p><p>pls repaly me as possible</p>
<p>Hi Vina, great project have just finished it but have a problem the relay activates when I touch the wires with my fingers but not in water. Will changing the resistor on the main terminal fix this, if you could help I would really appreciate it again a great project. I am using it to keep a fish pond full with a 12v solenoid valve.</p>
<p>Thank you for sharing this project.</p>
<p>Hi Vina , </p><p>Nice Useful Project !!</p><p> Please advice me the Ratings for the Power Supply for this Circuit while using A Relay of 12V / 7 Amps .</p><p>Thanks Again</p>
<p>Done..!, I've made it..after few try Wire (Probe) Connection Combination with MultiTester on Relay Connector, I got result like this :<br>1. Main - Lower - High = Relay Start Sound + Multitester Nail Moving, its indicating if water below Low Level Pump Motor Start &quot;On&quot; (NC State)<br>2. Main + Lower - High = Relay Stopping Sound + Multitester Nail Keep on Steady measurement like before (No.1), it's indication Pump Motor Still &quot;On&quot; (Still NC State)<br>3. Main + Lower + High = Relay Sound &quot;Clicking&quot; + Multitester Nail Moving to Beginning Value, it was indicate Pump Motor &quot;Off&quot; (NO State) and Loop again to No.1<br><br>Here some Spoiler for Pic :</p>
<p>thank you for trying my circuit :)</p>
<p>after real implement to water, i have a different result at step 3 that motor should stop after 3 wire connected, if I connected 3 wire directly per step it's worked!, but after i dipped 3rd water into water, relay still at NC state indicate motor still on, was it depend on water conductivity level..?</p>
<p>Q3:</p><p>yes, may be.water is not a poor conductor of electricity.the impurity and minerals are give the conductivity to water.may be filtered water can't conduct the tiny current given by the circuit.</p><p>update:</p><p>now i am trying to use a safer version of AWLC without touching water with probes or wires sooz i will fins a soilution</p>
<p>Ok thanks for your feedback vina..I think that's so cool you can make AWLC sensor without touching the medium..hmmm..sonic wave maybe..I will waiting fo your update:-)</p>
Sir I m waiting for ur response.. kindly help me through this
<p>i am sorry from the bottom of my heart :( i am busy with &quot;call of duty&quot; ( not the game.i mean the job)</p><p>Q1 :</p><p>i think, maybe there is an issue.the the circuit detect very minute current in the water.so maybe WLC get confused.try a test yourself :)</p><p>Q2:</p><p>yes.you can use same PS for 2 circuits f your power supply use same voltage and plenty of current .but in your case,you are going use 5v 1A power supply to power up 9V Indicator and 12v AWLC same time how is this possible?</p>
<p>Me thanx to you igniting an Inspiration:-D, if u don't mind I have two questions, first I have a circuit consist of four led Water Indicator using four Steel Bolt as water probe and has charged with 9V PS in my tank, so the questions, can I Join or share the probes with your circuit made..?, my plan will use DC-DC Step Up from 5V 1A later separately as PS, or they can be joined as share PS?, Newbie here so need more light:-D, thanks again. </p>
is it applicable for 1 hp Submersible Pump as well? and kindly give me a rough sketch on how to connect it with the starter box..
<p>sorry buddy.i don't know how to wire up a Submersible Pump jut because i cant find submersible pump near to my home.may be a local electrician can help you to wire up</p>
<p>hi!</p><p>i am making this circuit but confused with the current required to drive the circuit.</p><p>i am using a 12-0-12 v 500mA step down transformer .will this work???need help</p>
<p>this circuit only use 30 mA at idle stage and 250~300mA at full load(relay is on)</p><p>so you can use 12v 500mA power supply.</p><p>avoid using LEDs as indicator, they need 30mA current or use 1A power supply.</p>
<p>Hi!</p><p>Great ible, but if i need to control the well? when its full the pump could start and when its low the pump has his power off? what modification i need to make in this project?</p><p>Sorry my english!</p>
Hello, I believe the solution you are looking for is very simple. Build the circuit exactly the same, except when you are placing the wires in the water reservoir, reverse the wire positions so the low level will be the high wire and will turn the pump on, and the high level will be low water and will turn the pump off when it reaches the bottom. I haven't built this yet but I plan on it and trying it because that is what I am looking for too.
<p>Thank you for your positive feedback</p><p>It&rsquo;s an automatic switching circuit that used to control an AC water pump. Operation of this circuit is simple.wen the water level goes below the limit the lower level sensor will detect it and activate the water pump.wen the water level reaches the upper limit the upper limit sensor detect it and switch of the water pump.</p>
<p>This assumes that the water source is always available and will not allow a situation that can run the pump dry. I suggest you add an quad dual input nand gate IC, work out a karnaugh logic map that also takes into account the water levels in the source tank.</p>
<p>I know.but my relay work as expected</p>
<p>Thank You for Your Suggestion :)</p><p>i am happy to learn from error</p>
<p>Just use the relay in the normally closed position, not the normally open like the one in the schematic</p>
<p>Hi <a href="https://www.instructables.com/member/vina1991" rel="nofollow">vina1991</a>,</p><p>I want my controller activate the water pump when the water reached in the upper sensor and switch off when the water drops to lower sensor.</p><p></p>
<p>so just assume the (high sensor) as low &amp; (low sensor) as high as in this instructable, I mean Inverse. </p><p>[ ~~~~~~~~~~~~] -------------------------------------- &ldquo;Low&rdquo;</p><p>[~~~WATER~~~ ]</p><p>[ ~~ TANK ~~~~~]</p><p>[~~~~~~~~~~~~ ]</p><p>[~~~~~~~~~~~~ ]--------------------------------------- &ldquo;High&rdquo;</p><p>[______________]--------------------------------------- &ldquo;MAIN&rdquo;</p><p>This is the placing order of the sensors for yours type of case i think.</p>
<p>NO.</p><p>if the HIGH prob is still immersed in water,when water touch the LOW prob there is no action</p>
<p>use the same circuit just with a relay in the normally closed connection</p>
<p>ops! I forgotten that! BTW very nice work! Keep it up Bro!</p>
<p>ops! I forgotten that! BTW very nice work! Keep it up Bro!</p>
<p>ops! I forgotten that! BTW very nice work! Keep it up Bro!</p>
<p>ops! I forgotten that! BTW very nice work! Keep it up Bro!</p>
<p>ops! I forgotten that! BTW very nice work! Keep it up Bro!</p>
<p>ops! I forgotten that! BTW very nice work! Keep it up Bro!</p>
<p>ops! I forgotten that! BTW very nice work! Keep it up Bro!</p>
<p>with little modifications you can use same circuit for your use</p><p>usually we use NO leg of a relay as output but in this case we use NC as output</p>
<p>thanks, i'll give it a try</p>
<p>Try with safety buddy :)</p>
<p>Thank You!</p><p>I Will try this ASAP.</p>
<p>Try with safety buddy :)</p>
<p>Hello.</p><p>Vina1991, I believe that what RafaMemphis wishes to do is to maintain the level of water within limits in a well with an incoming flow by pumping water out of it. Therefore, his objective is to start the pump at the high level and stop it at the the low level. Basically, a sump or bilge pump.</p><p>RafaMemphis, perhaps you could add a mechanical float to your design, as is common in sump and bilge pumps. This would also avoid the problem of corrosion to the sensors.</p>
<p>Hi <a href="https://www.instructables.com/member/pbfleetwood" rel="nofollow">pbfleetwood</a>,</p><p>You understand what i need (start the pump at the high level and stop it at the the low level), but i need sensors on it because i will use for control a submersible pump installed in a 6&quot; tube. I use a eletronic relay to do this but cost 20\$ in here.</p>
<p>I was only hoping to clarify your question for the author of the ible, and I'm glad that I got it right; however, I do not know enough about electronics to answer your question.</p>
<p>Thank you for your help and support</p>
<p>Thanks for this vid. So only 12v would be in water.</p>
<p>When high and low sensor probe are in water, the potential difference across the coil is close to zero. I find it very well!</p>
They will be zero as both are behaving as same potential, just measure potential difference between any high or low probe with the common (main probe that at bottom of tank) , for ideal conditions it should not be more than 1.56 volt to decrease chance of electrolysis and if its not below 1.5 v then use steel or aluminium as probes....