This is my first forum post and I'm not sure if I should be starting a new topic or joining an old one. I'm a new user to these forums (to any forums actually), and an electronics and Arduino n00b, so I apologize in advance for any accidental stupidity on my part
I just got my Arduino a few weeks ago and planned to build an aquarium management system as my first real project. One key thing I wanted in the system was the ability to perform a 30% water change every week. To do this, I figured I'd get the Arduino to control a solenoid valve connected to my tap water supply and a pump to remove water from the aquarium and store in a reservoir. Considering both run off a wall socket at 240 V (I live in Asia), I initially assumed that relays were my best bet (I breadboarded the example circuit(http://www.arduino.cc/playground/uploads/Learning/relays.pdf
) from the Arduino website and it worked fine).
However, I recently discovered optocouplers and after some research, I found that they were comparable in price to my relays and draw less current. Also, if I understand them right, I would not need a snubber diode or a transistor. The fact that they are solid state makes them even more compelling.
My question is, would it be advisable to stick with a relay circuit, or to use high voltage optocouplers instead. If so, are there any that can output 240V and 3A? Also, any futher explanations into their functionality and limitations would be great! Any advice or recommendations are greatly appreciated!