I have created one circuit which consists of 2 BC transistors low rating any values, one is NPN and other one is PNP, Relay and battery or battery eliminator with 1.5 to 3V.
In this circuit PNP and NPN transistors together to form SCR gate or we can use SCR gate instead of two transistors. Gate wire of this circuit is at the top level of the tank. Other two line wires are at the bottom of the tank. Function: Initially over head tank will be filled, so wires also connected to each other by water. Water will complete the circuit and so, relay will be off in 'F' end, so motor will be off. Even after the water level drops down from 'Level A' the circuit will be 'on', so Relay will be 'off' at the 'F' end. When water level drops down below the 'Level B', circuit will be (open) 'off', so Relay becomes 'on' at 'F' end and water pump will turn 'ON'. When water level rises it will touches the two wires but still the circuit will be (open) 'off' condition. so Relay will be (on) at 'F' end and motor will be 'ON' to fill the water. When water level reaches 'Level B', all the wires will be touched by water and forms (closed) circuit. And Relay will be (off) at F end, this makes motor turn off.

I have tested this experiment and succeeded.

I will upload the image and video in coming days. Currently, I'm busy with another project. However, you can do this project by referring the image.

Step 1:

My other works:



<p>Hi Sujith...can you share your FB id?</p>
My FB id is 'sjth.88@gmail.com' or 'Sujith Achary' both will work
<p>My FB id is 'sjth.88@gmail.com' or 'Sujith Achary' both will work</p>
<p>Hello sujith,</p><p>very nice simple circuit, btw how 'bout the relay.., is it engaged all the time?, and what kind/type of relay using on this?, coz stable rated voltage n current needed to drive on relay. thanks.</p>
I have used simple relay which costs 80Rs in the market. And I dont know how stable it is or can it be engaged for all the time. However, I'm seeking for help from electronic students and lecture how to keep relay engaged all the time without effecting the performance of the relay. Here relay is the main driving part. If relay doesn't work then circuit will not work. Also transistors if we engage all the time the life of the transistors will reduce. So, I want suggestion on that from anyone who is viewing this circuit diagram.
<p>Yes..I saw you've used an arrangement of darlington pair Tr, it would be nice if you add a PotRes to control sensitivity of water conductivity, AFAIK water have some resistance to be compensate 'bout amount of current to deliver electrical signal. and bout the Tr I have an idea to change it with pair of Tr + HeatSink to avoid break it at longer time. have you tried this circuit at real Condition sujith..?</p>
<p>I have tried this circuit with mug of water. I put water in the mug and dipped the wires and tested it. Instead of Water Pump I connected other end of the relay to the CLF Lamp. </p><p>First I attached all the three wires in the mug as shown in the above image. Then, I have filled the mug with drinking water. At this time CLF lamp was not glowing. Then slowly I decreased the water level in the mug. When water level was reducing, CLF lamp was not glowing. But when water level was empty in the mugg, CLF lamp started glowing. Then I have manually pored the water into the mug, slowly. When I continued to pore the water, wire(A) and (B) as shown in the above image are dipped in the water but CLF lamp continued to glow. When water level touched the third wire(C), that is when water level reached the top of the mug, CLF lamp turned OFF by the relay automatically. So, I thought of using this circuit for Water Pump, so that when water level in the water tank is full water pump will not work but when water level is empty in the water tank, water pump will work until the water fills in the water water tank(touches the wire (C)).</p>
Thank you for your interest in my project
<p>Hi Sujith,</p><p>Did you have any difficulty with how far apart the wires are? Non-distilled water is a conductor but not a fantastic one. Clever circuit by the way!!!</p>
You can use 28 feet length wire. Since wire is long, power may reduce at the other end. So, you can increase the source voltage.
Sorry fro the delay. <br><br>It is a simple test circuit. I have used normal water because I wanted to implement this project for my home use. I'm not electronic student so I don't know the piratical hazards of this circuit. So, I have not yet implemented for my house water tank.
I didn't try with distilled water. However nobody will use distilled water for drinking purpose. Nobody will store distilled water in tank. This circuit can be used for home or commercial use
Sujith,<br> I am sorry: you missed my point. I know nobody drinks distilled water and I did refer to <em>non-distilled</em> water being a conductor. What I wanted to know is: how far apart could you put the exposed wire electrodes for it still to work? 10cm? 50cm? 500cm?<br> Kind regards<br> Rex
I have checked it with 1 inch distance. It is not exact 1 inch it may more than that or less. But it will work. My suggestion is to use SCR gate instead of two transistors because you can add heat sink to SCR this is to avoid heating of electronic components due to continuous power supply
<p>If any have queries or suggestions please update it here.</p>

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