I am a programmer interested in interfacing a computer to the outside world, but I need a little information on the electrical side of things. At some point I will want to work with 50 of these solenoid valves: "http://cgi.ebay.com.au/ws/eBayISAPI.dll?ViewItem&item=400190081934&ssPageName=ADME:X:eRTM:AU:1123
" but at first will only connect 8 devices with the goal of being able to turn these devices on and off very fast.
1. Can I interface an Arduino to a board like this? http://denkovi.com/product/13/16-relay-board-for-your-pic-avr-project-5v.html
or do I need a chip to actually talk to the board.
2. From my initial research it looks like inductive loads can be a problem, what circuitry would I need to add to the board above to handle an inductive load? Is there a relay board that has the circuitry built in to handle deal with inductive loads?
3. At first I want to work with 5 or 6 solenoids, but as I get more comfortable with these devices I will want to scale up to around 50 or maybe even 100 relays. Would I be able to do this on an Arduino board? Would I be better off getting 8 channel USB boards and interfacing them to an old computer?