Friday, March 26, 2010

Hangin Out With The Geek Out

Ok, here's a fair warning. Things are about to get a little technical. In the name of Emeril... BAM!

In prep for the HERMS system, which should be starting in about a week or two, I decided to visualize what the inside of the control box should look like so I can plan what parts I need. For a refresher the HERMS system works by taking the mash from the mash tun and circulating through a copper coil submersed in hot water. When the temperature needs to be raised, I have two valves that will actuate and send the wort into the submersed coil. When the temperature is set, the valves return to normal positions which bypasses the coil in the hot liquor tank (HLT), and continuously circulates the mash keeping the temperatures across the mash nice and uniform.

I was running into some headaches with this design. Trying to figure out how to economically convert my 120V AC power to 12V DC power was one. Thanks to suggestions over at, and my continuing stubbornness to throw away old electronics, I was able to dig out an old PC power supply which will perfectly fit the bill. This also makes it easy to mount and power a small computer fan on the side of the box to keep things cool.

I also decided to add a single pole double throw switch (I think thats what it's called) in between the valves and the PID controller so I can take over the valves from the controller if need be.

The circulation pump will just have an on/off switch.

The second PID controller is solely to monitor the temperature of the HLT for now. Depending on how much of my budget is left over, I'm going to rig a propane burner to be controlled by it. I still have more research to do on that subject however.

I've also read recommendations to put fuses inline of my controllers for protection. I still need to look into that as well.

Whew. That's why I went to Engineering school.

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