I have been using ardunios and relays together since my first arduino project. I have been looking for a relay board but the only one I could find was the Liquidware Relay squid, which was pretty expensive at 69$.
I decided to design one of my own, I call it Open Squid. It uses 4 OMRON G5LEs.
Here is my blog post about it.
I would like to sell it as a kit. What do you think would be a good price, 25$.
Futurlec sells some pretty sweet boards, they don't bolt up to an Arduino but the price is tough to beat:
WARNING: Shipping from Futurlec is about 14 days, they're reliable and I've bought a lot of stuff from them, but fair warning on the shipping taking a while.
A search like below turns up some adaptable relay boards.
http://www.electronickits.com/kit/complete/elec/ck1601.htm
http://www.electronics123.com/s.nl/it.A/id.446/.f
http://www.mcmelectronics.com/product/KEMO-ELECTRONIC-B210-/28-6348
http://www.qkits.com/serv/qkits/diy/pages/QK74.asp
Thanks for posting options but I was looking for feedback on the board that I designed. I can get the costing down but that just depends on volume.
There is a drop-in replacement that would allow 230ac but those relays cost 3 times as much as the current ones that I am using.
I'd be more interested in it if I could just push it on top of the arduino, like most of the shields you get, those long standoffs look kind of awkward and how do you attach it to the arduino pins?