Timer based Water Level Controller Circuit

The explained circuit of a water level controller circuit is based on a adjustable timer circuit whose time delay is first adjusted to match the filling time of the tank, as the the tank fills, the timer delay also simultaneously lapses and its output switches OFF the water pump.

Circuit Specifications

Actually the circuit was requested to me by Mr. Ali Adnan who is one of the fans of this blog. Let's first hear what he had to say:

I like your blog very much. I have a problem which i think is common in every home, the problem is: I have a Water Pump (which pulls water from bore) installed at my home, when my brother switch on the water pump he always forget(u know bhulakar one:P) to switch it off back:( and water tank gets over flowed and water runs in upper portion of our house:(

I want you to help me to design a timer circuit to automatically turn off the pump at given time. I am not expert in electronics but i like to play with electronic and knows very well how to solder and always trying to do some little experiments with help of your blog. Please provide me the circuit for above sited problem with complete parts list and diagram.

Designing the Proposed Water Level Controller with Timer

The CIRCUIT DIAGRAM of this water level timer controller circuit utilizes a single versatile IC 4060 for generating the required time delay.

P1 is initially adjusted through some trial and error so that it exactly matches the filling time of the water tank which needs to be monitored.

The circuit is initiated by pressing the push button SW1 when the N/O contacts of the relay are bypassed.

This momentarily switches ON the transformer which powers the IC instantaneously.

This instantly triggers the transistor and also the relay which takes over and latches ON the circuit.

Now the circuit holds ON even after the push button is released, everything happens within half a second.

The above operation also simultaneously switches ON the pump motor which starts pushing water in the tank.

Once the timer counting finishes, pin #3 becomes high, T1 conducts and switches OFF T2 and the relay.

The relay contacts reverts to its original state switching OFF the motor as well as the the entire circuit, halting the motor pump and hopefully inhibits the tank from overflowing.

Parts procured by Ali Adnan

Parts List

• R1, R3 = 1M, 1/4 watt CFR
• R2 = 10K, 1/4 watt CFR
• R4(T1 base) = 22K, 1/4 watt CFR
• R4(T2 base) = 10K, 1/4 watt Cfr
• P1 = 1M preset horizontal
• C1 = 1uF/25V
• C2 = 1uF/25V non polar, any type will do
• C3 = 1000uF/25V
• D1, D2 = 1N4007,
• Relay = 12V/SPDT/contact current as per motor specification
• SW1 = Bell push type of button
• IC1 = 4060
• T1 = BC547
• T2 = 8050, or 2N2222
• TR1 = 0-12V/500mA

The above automatic water level controller with timer circuit was also built and appreciated by Mr.Raj Mukherji, one of my friends and a keen follower of this blog. I have explained more about his experience with the circuit.

Hi Swagatam,

Thank you very much for the timer circuit.

I have made the prototype on a general purpose PCB and so far found it to work accurately for my purpose: 5 min, 10 min and 15 min delay respectively (with the P1 set at 15.4 Kohms for 5 min delay etc). I am planning this weekend to house it in a 4x6 box and test it on actual load.

So far, I was looking at the above comments and would like to add something regarding the question raised by Mr. Khan on the relay. For my purpose, I am intending to use this timer on an AC 50 Hz, 220 - 240 volts, Crompton Greaves self priming mono-set pump, type - Miniwin II, 0.37 Kwatt/0.50 HP. So, I have purchased a 12 volt SPST relay which has a contact current tolerence of ~7 Amps. I think this is sufficient for my purpose and also for any kind of small pumps/loads. Isn't it?

I will definitely share with you the picture of the completed project.

Thank you,

Kind regards,

Raj Kumar Mukherji

My answer to Raj:

Hi Raj,

That's great! Thank you very much for the update.

A 7amp contact would mean a maximum capacity of 7*220 = 1540 watts, that's probably more than sufficient for the purpose.

I am sure the pictures that you will send will be loved by the other readers also, so please do send them here for publication.

Yes, surely the link will be very useful for the readers who would want to learn the timing calculation more accurately.

Thanks and Best Regards.

PCB Layout for the Above Circuit, Designed and Submitted By Mr. Raj Kumar Mukherji:

(Component-side view)

Pictures of the completed water level timer controller prototype, sent by Mr. Raj Kumar Mukherji:

The proposed water level timer/controller circuit  was further modified and enhanced Mr.Raj Mukherji, who is also an avid reader of this blog, and a keen electronic enthusiast.

Here's the feedback email that he sent to me explaining everything regarding the working of the circuit:

Finally I have managed to build, the model of this timer based water level controller project which is given below:

There were only three modifications I made:

1. Connected an LED to pin 7 in order to get a visual indication of the oscillation.
The LED starts to blink after 20 secs of powering the timer on
2. Used four diodes for full wave rectification instead of just a single diode for
smooth DC input
3. Added 22Mfd capacitor between pin 12 and 16 instead of 0.22Mfd because 0.22Mfd was
not allowing the oscillation to begin when the circuit was drawing power from the
transformer. However, 0.22Mfd did not make any problem when the power was fed from
a 9 Volt battery

I have found that with the given values of the R and C, the range of this timer is between 1 - 30 mins.

I have also found the formula to calculate the frequency of the timer (it is found to work correctly to a certain extent practically):

F in KHz = 1 / {2.3 x (R2+P1) x C1} where, R2 & P1 in K Ohms, C1 in Mfd

1 Time Period (TP) in milisecs = ------------ where, F in KHz, Q(n) as shown below. {F / Q(n)}

Pin7 = Q(4) -> divided by 16 Pin5 = Q(5) -> " " 32 Pin4 = Q(6) -> " " 64 Pin6 = Q(7) -> " " 128 Pin14 = Q(8) -> " " 256 Pin13 = Q(9) -> " " 512 Pin15 = Q(10) -> " " 1024 Pin1 = Q(12) -> " " 4096 Pin2 = Q(13) -> " " 8192 Pin3 = Q(14) -> " " 16384

Example: If P1 is set at 15 KOhms, R1 = 1 KOhm, C1 = 1 Mfd and we select the output from Pin3 (which is Q14) then:

1 1 1 F = -------------------- = ------------------ = ------------ = 0.0272 KHz {2.3 x (R2+P1) x C1} {2.3 x (1+15) x 1} 36.8

where, F = Clock frequency of the timer

Then, the frequency at Pin3 of the IC will be: 0.0272/16384 = 0.00000166 KHz

Therefore, Time Period (TP) of the timer is: 1/0.00000166 = 602409.6 miliseconds = 602.41 secs = 10.04 mins

[NOTE: Time Period = ON time + OFF time]

Hope this will help my co-readers to understand the working of the CD 4060 better.

Thank you,
With warm regards,
Raj Kumar Mukherji

Upgrading the Water Level Timer for Solar Panel Operation

The following diagram shows how the above circuit may be used with a solar panel supply, and with a DC motor connected at the output. The design was requested by Mr. Mehmet