thanks Michael, the changes required to run it on a 240/120 system wouldn't be that big, from what I can work out it would be something like this http://www.mediafire.com/view/?pred9es9i5tw1n7, switch the 240 with the SSR and use the 120 for the rest of the unit, it won't look as neat as the 240v only and the box might need to be larger but the box it is in is only 171mm X 121mm X 80mm (6.7" X 4.8" x 3.15") so its really small anyway.

I'm a sparky by trade but have done my advance diploma of electrical engineering here in australia but I don't know what that means in the US. My job is to test and calibrate protection relaying systems for electrical distribution and transmission systems.

cheers steve

Okay, so I've been looking at something like this to control a fermentation chamber, and this seems as good a place as any to ask about it.

I'm building a keezer/fermentation cabinet based off Mylo's design. What I'm thinking is 3 separate fermentation chambers in the top, with enough room for 2 carboys in each (I may eventually go to 10 gallon batches, and I figure I can split them into 2 carboys and ferment side-by-side. Also allows room for experimentation.)

So I'm just gonna be running fans for temp control, they'll pipe up cool air to cool the chamber, and then I was going to put in removable, insulated dividers, because I'll probably just stick a brew belt on the carboys to keep them from getting too cold (and really, that'll be down the road a little bit, because I'm not lagering or anything). Onto the part that's actually relevant to this thread: I'm debating between a FermTroller (which is already programmed and just needs to be installed and have temp probes attached) or doing it with an Arduino. I'm not sure which way to go.

I know you said the BrewTrollers were pretty high quality, Mylo, but I'm thinking I may eventually want to set it up to be controlled via the web, and Arduino offers a few more options on that front. There's an ethernet controller for the FermTroller, which also might work, but the firmware doesn't support it yet and I don't know anything about coding at this point in time (this is part of the reason I'm thinking of just going with the FermTroller anyways.). Down the road I might want to upgrade each carboy to have independent-ish temp control as well, so I'd need support for 6 different zones (6 inputs and 6 outputs). So I dunno which way to go.

Honestly, the more I write, the more it seems like the Fermtroller is probably the more logical choice, but I figured I would let some of the experts weigh in.

I really like the Webcontrol board (http://amzn.to/rQxjZ6) for my fermentation control. You can do a lot of pretty complicated stuff without much work. I've got one hooked to an 8 relay board. It uses the one wire temp sensors (like the Fermtroller/Brewtroller does).

It still requires some electronics knowledge, like the Fermtroller would.

Another options it the BCS-460 (http://www.embeddedcc.com/index.php/pro ... ystem.html)

So with that, you would basically run your temp probes through the board itself (the Webcontroller) and then run your input/outputs through the relay board to control fermentation? And how advanced does your knowledge of electronics need to be? I know enough to follow directions (I wired a Ranco 2-stage for my current fermentation freezer) but that seemed pretty easy.

Also, for right now, there's gonna be a max of 3 carboys going at any one time, and I may just keep it that way for simplicity sake...I just kinda liked the idea I could go to 10 gallon batches if I wanted to, but I'm also wondering if the box (which actually extends outside the footprint of the freezer I have) will physically support that much weight.

That is beautiful work. I love the simplicity of it. What are the advantages and disadvantages of a single vessel system like this?