12v solenoid valve + automatic moisture sensor

[frostymantin]

Here's a pic of an automatic soil moisture sensor that switches on and off a solenoid valve to care for thirsty plants in outdoors and greenhouse.

any suggestions what is the easiest design for it? how much power it would take per season? what control electronics to use for the switch?

 

[growshopfrank]

frosty you know that you are taking the high road here
seen folks use booster packs for power weather proofed oc
most solenoids wont work with just gravity for pressure there is a vendor on ebay that sells the correct ones
here is one link for a sensor search around there are plenty of others
http://www.campbellsci.ca/leaf-wetness

for power calculations it would vary by delivery rate and duty cycle
a small DC rated relay would control switching

link for solenoid http://www.ebay.com/itm/1-2-Gravity...588?pt=LH_DefaultDomain_0&hash=item4600567c1c

 

[frostymantin]

frosty you know that you are taking the high road here
seen folks use booster packs for power weather proofed oc
]

Brilliant thanks! i'll find out about the relay and sensor and gravity solenoid options.

What did you mean about booster packs for power weather proofed oc... what is oc and what kind of booster packs please?

 

[frostymantin]

I've also seen these humidity sensor + relay http://www.ebay.co.uk/itm/DC-12V-3-...al_Components_Supplies_ET&hash=item43bbce8985
available on ebay... i wonder if i can have one to control the solenoid valver and then put in a couple of other for redundancy in case they are unreliable... given the price it would be easy.

 

[SecondAttempt]

Hopefully Frank chimes in with an answer but I believe "oc" = of course. It's my belief he believes you want to set up an outdoor spot, perhaps a self watering guerrilla op, using a 12V jump start box to power the solenoid...

Seems like an elegant solution... Bobblehead was using a gravity fed solenoid system last I knew so he may have some input for you.

Good luck, let us know what you go with and how it works out.

 

[rives]

There are two basic types of solenoid valves - direct acting and pilot operated. Pilot operated uses the supply pressure to help open the valve, and don't work with low pressure. Direct acting just use the coil's operating force to open the valve and work well with gravity-fed, low pressure or even vacuum applications.