The post explains a water level controller circuit which can be used for implementing an unmanned continuous drip irrigation to a home based garden. The idea was requested by Mr. Sandipan.

Technical Specifications

I’m implementing a drip irrigation for my balcony garden. One part of it is to automatic fill water a 5 liter/10 liter vessel (this is source of water for drip irrigation) from a bigger water tank (When I’m not at home for longer period of time like 15 days).So I break this project into several steps as follows

  • 1.      Implementing drip irrigation using a 5 or 10 liter vessel (say V1) as source of water. Probably smaller vessel will reduce the water pressure.

  • 2.       Have an automatic water pumping system to fill the vessel V1 periodically based on the water level in vessel V1 from a bigger water tank. If V1 is full motor should goes off and if water level in Vessel V1 is low to a certain point, motor should start to fill the vessel V1. I want to implement this pumping system using a homemade 6 Volt DC motor (DIY water pump using a dc motor).

  • 3.       Implement solar charging system to recharge the 6 volt lead acid declarable battery (so that if I’m out of my town for even 30 days, the battery should have enough juice to drive my small  water pump).

I’m done with step 1. When I was searching water level based automatic water pump, I came across your website. Let me tell you one thing, YOU ARE DOING WONDERFUL JOB. Now every day I open your site at least once to see different innovations of yours. I have seen your project:

But my requirement is a bit different as follows

  • a.       I need to operate a very small DC motor with 6 volt lead acid battery.

  • b.      At level below B (your diagram), motor should start fill my vessel V1 and when water reached at point A, motor should stop.

  • c.       Need to charge 6 volt lead acid battery using solar panel

Could you please help me with a circuit diagram?

Thank you


The Design

Referring to the figure below, the design may be configured by using a single IC 4093 for the proposed home drip irrigation and tank waer level control.

The water level control operation of the circuit is exactly identical to the one that's explained in this article.

As per the instructions provided in the above linked article, the motor is supposed to switch ON when the water in the tank has dropped below a particular level, which may be set by the user by installing sensor point C at the desired depth.

Circuit Operation

When the water pump starts, water is pumped inside the tank until it fills upto the brim, which prompts the motor to shut off through the signal as sensed by point A sensor.

The entire system can be seen powered through a 6V 10AH lead acid battery, which is charged by a suitably rated solar panel.

IC1 is a 7809 voltage regulator IC positioned to generate a regulated 9V charging input at a rate not exceeding 1 amp, to the battery.

Parts List for the discussed Solar drip irrigation for indoor gardens

R1 = 100K,R2, R3 = 2M2,R4, R5, R6= 1K,T1 = BC547,T2 = TIP122

IC1 = 7809

N1, N2, N3, N4 = 4093Solar Panel = 12V/1ampMotor = as per the intended specs

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