I would suggest doing some research on PID algorithms (http://en.wikipedia.org/wiki/PID_controller
), since you will likely need something like that to control the temperature/feedback.
Of course, I'm not sure how much automation you will be able to achieve, given that the still will require, yeast and a food source to be added, beyond water.
will do some reading up like you suggest.
Im not interested in automating the brewing process, thats easy and takes care of itself mostly. Its the distillation process that i want to automate. So that is after the brewing has been done. its basically pouring "beer" into a 25L kettle and boiling it, trapping the steam and cooling the steam down.
I think the water is for cooling, not for the product...
Correct. the water is for cooling.
If for cooling, you really don't need an automated valve...
Well i think that its not entirely necessary, it would make things much much better. As it takes 2-3 hours to get up to temperature that doesnt need to be cooled and from 50-80 degrees jumps really fast, having it automatically come on would save me having to check it every 5 mins for 2 hours. Then, once it gets going the water needs to be adjusted as it get closer the the end of the run the temperature increases closer to 90 and more water is required.
The other tap is to switch the output of the alcohol. The first 500 or so mL contains nasties and needs to be cut off into a separate container. Also if it switches 3 ways, i could catch the tail end of the run in a separated jug too. Improving the quality furthermore. As for counting 500mL, i was thinking last night that i may not need a flow meter, just a simple switch that is operated when the liquid bridges two contacts set at the 500mL mark in a jar.
will need the alcometer to test the alcohol coming out and switch to the tails jug at about 70-80%ABV the 80-95%ABV will be the main "good stuff" used for drinking.