The best Temperature Controller for Fermentation?

Can you share your experiences using temperature controllers with me?

My first attempt at controlling my lager fermentation via my refrigerator failed miserably. My fridge either sets itself at 40 degrees (too low) or 80 (too high).

To remedy, I'm going to have to get a temp controller to keep my temps constant.

Looking at morebeer and amazon, there are a ton of temp controllers to choose from... Any recommendations, things to watch out for?

My first choice is the Ranco digital temp controller from amazon. It's cheap! like 60 bucks and has some good ratings.

Many thanks,

Oh, and in the time being I've turned off the fridge put a bunch of ice in there. Not very scientific, but at this point anything between 50 and 70 will do.

I use one of these for my keezer and the two stage type for my fermentation fridge. The two stage lets me have a fermwrap tywrapped to the back of the fridge to raise the ambient heat in the winter and be able to control the fridge at the same time. Great for the spring/fall when it's cold in the morning/night but warm during the day.

http://www.etcsupply.com/ranco-etc1....html?osCsid=4c5b4177f6356bdfd1ef0fb30bbd528e

I built one similar to the one in this thread:

https://www.homebrewtalk.com/f51/diy-temp-controller-build-133364/

It's the only one I've used, but it works perfectly and I'm getting ready to build another one for fermentation (I bought a lot of 3 thermostats for next to nothing on ebay). If you can get some good advice about one that's ready-made and will last, I would go that way--unless you are building multiples and have some experience with electronics. Ask yourself: 1. Have I been shocked by 110 VAC? 2. Do I own a multi-meter?

I can't help you much with a specific model because I've only ever used homemade controllers, but the Rancos and the Johnsons both tend to get solid reviews. One thing to consider, though, is getting one with short-cycle prevention. Basically, it keeps your compressor from turning on and off in quick succession, which is especially useful if you are trying to keep a tight temperature range.

I have the Johnson 419, it will control heating or cooling. So far it's worked great.