BASIC COOLING CLOSED-LOOP CONTROL

[Dutch]

From Wednesday's meeting a number of questions came out.
Here is the first of three posts I will make.
This is a very basic [and inexpensive] closed-loop control for cooling [or heating].
A simple two-chambered enclosure is required [much better if insulated]. The first chamber contains some form of passive chilling medium [evaporative cooling or ice e.g.] while the second contains the carboy. When cooling is required a small fan forces air into the cooling chamber and in turn into and through the fermentation chamber finally exiting to the right.
The fan is controlled by a simple 12VDC temperature regulator available in EBAY for less than 15$ [which also includes the temperature probe]. The whole system can be powered by a used tower PC power supply and surplus computer muffin fan[s].
Contact me for a simple schematic or I can post one.
Following technical problems to post overview - should get straightened out shortly

[Dutch]

Controller information.
The industrially hardened version comes from RANCO - it is bulletproof. Model for simple single-stage cooling is RANCO ETC-111000 DIGITAL TEMPERATURE CONTROL 120 - 240V and is currently offered on EBAY for around 45$ w free shipping.
Another option:
There are a number of people who offer this simple case-free controller on EBAY. The best so far that I have seen is a seller by the name of http://myworld.ebay.com/tomtop_uk/&_trk ... 1439.l2754
They offer the 120 volt version at about 15$ w free shipping.
The 12 VDC version is offered by a number of vendors for about the same price. I am currently using one of these to control the unpowered slave-fermenter on my system and it works well. The model STC 1000 has a ten amp contact rating here others made only have a five amp rating. Care must also be taken during wiring as these models use the European terminal board standards which are sort of small and leads should be soldered/tinned to make best connection.
I have made a number of simple aluminum enclosures for thee units at the machine shop and will bring another to the next meeting.
These controllers can be applied to any existing freezer or refrigerator by simply plugging the appliance into a pigtail attached to the controller and placing the temperature probe inside the appliance.,
Feel free to ask any questions..

[Michael Erwin]

Don Armstrong has a good example of the this system, he calls the Chilly Willy, it's like the Son of Fermenator. Google that, you'll find good pictures and plans.

[john mills]

Lots of talk about the Ranco.
I prefer the Johnson Controls A419. Lots of easy features to change. Heat to cold, temp differential adjustment to control temp swing, cycle time override so compressor doesn't burn up cycling off/on if you set temp diff too tight. All with the easy to read digital display.