I bought the plastic solenoid valves recently from Adafruit - http://www.adafruit.com/products/997
Before having them connect through Arduino and control through relays, I had this powered by a 12V power supply connection. When I power them ON, I didn't notice anything. The valve didn't seem to be open.
I haven't connected them to an Arduino or to a water supply.
Should I do anything to make it work. The product description mentions that it needs a minimum pressure (water pressure) to make it work.
The power supply mentions 12V DC, 2A, Max 24W. Please help. I'm a novice in electronics.