Indirectly through work, I have come into some interest in working with temperature control. I happen to enjoy my beer at exactly 41 degrees. (Not really, but for the purpose of this experiment...).
I have decided to use a couple of TECs to achieve this. The result should be a self cooling coaster, though with the amount of equipment required, it will not be a small self contained coaster.
- Temperature selectable by potentiometer
- No temperature probe within the glass
- uses only materials and parts that i have on hand
- 2 x TECs (I don't recall the wattage)
- 1 x Computer PSU
- 1 x Arduino
- 1 x huge friggen heat sink
- 3 x computer fans
- 5 x transistors (two will be darlington arrangements)
- 3 x temperature probes
- 1 x pressure sensor
- 1 x Breadboard
The idea is that the arduino will read the temperature probes, and be able to, through the transistors, control the computer psu, the fans, and each TEC.
The reason the arduino will be controlling the psu is so that I can control the entire thing with one power switch.
I think I have everything required laying around at home...the TECs I bought some time ago for a different purpose, the computer PSU is coming from an older dead PC, I have a couple arduinos, big heat sink is scrap from work, computer fans I have, and I have a fair assortment of transistors.
The temperature probes I only have thermocouples, so I may look in to a non contact form of measuring the temperature of the glass.
I also have a pressure sensor that should be able to be used to tell if there is a glass sitting on the coaster. When there is no glass on there, only the fans will run until the heatsink is down to a decent temperature, then everything can shut off. The heatsink I have is not the best design for this, but it was free so I will make do.
The circuits for this are simple, but I will post schematics at some point. The physical part of this will not be anything pretty, so I won't be bothering with build drawings, I'll just post some photos as I'm putting it together.
More to come later...