need to build soil moisturizer level detector...

[ahmed hassan]

i need to build soil moisturizer level detector to complete my study project...
the supply required is 12Vdc for this circuit. the function of the circuit is to detect the moisturizer of the soil...
when the soil is dry, the signal (power supply) will give to the water pump to supply water to the soil...
below is the my whole project block diagram:

PV cell (12V solar panel) -  charge controller (12Vdc) - rechargeable battery (12Vdc, 10A @ 20A) -  soil moisturizer level detector (12Vdc) - inverter (12Vdc to 240Vac) - water pump (240Vac)

please and hopefully someone will help me..i really appreciate it...thank you very much...
you also can reach me at:
[email protected]

 

[Hero999]

http://www.faludi.com/2006/11/02/moisture-sensor-circuit/

 

[ahmed hassan]

the circuit maybe meet my demand...but, i need some time to show it to my supervisor lecturer first to verify that the circuit can be use in my project. As you know, my project kind of complex (maybe for me only ) so i need to plan first...
by the way, thanks...if any, i will tell you...

 

[KMoffett1]

Why 12V battery to inverter to 240VAC pump? The inverter stage will waste power.  Just use a 12V water pump directly from the battery.

http://www.faludi.com/2006/11/02/moisture-sensor-circuit/
Since your sensor probes will always be in moist soil, this circuit will cause the electrodes to corrode over time due to electrolysis from the DC current between them.  A better circuit would one one that uses AC for the detection circuit. Like:http://www.electronicsforu.com/efylinux/circuit/cir80.gif. Also use stainless steel rod or wire for the probes...as copper is toxic to plants.

Ken

 

[Hero999]

I agree, especially with your point about the AC pump, it sounds like a silly idea.

You could use an automotive windscreen washer pump which is a pretty standard part you can probably pcik up for next to nothing from a scrapyard.

 

[KMoffett1]

Windshield washer pumps won't work.  They have plastic motor bearings. They're meant to run for only a second or two at a time.  If you try to run them for much more than that the bearings will melt.  I tried several different ones.  Been there...done that...smelled the burnt nylon.

Ken

 

[Hero999]

I've just Googled for 12V pumps and they seem pretty easy to get hold of and start at reasonably low prices too.
http://www.towsure.com/product/832-Submersible_Pump_(12_Volt)

It's certainly cheaper to buy a 12V pump than it would be to make/buy and inverter and a mains powered pump.