I'm just wondering.. You're putting the hot side against the sink, then how does the cool side conduct to inside the fridge?
I was thinking that too, I'll give it a try. More interestingly, what would happen if I used two PSUs? The chap who sold me the pelt said that it's possible to use a car battery charger, seing as it delivers lots of amps at 12v Yes, but at the moment it's not too bad. £15 for the pelt and the PSU was free. I have discovered that the heatsink is completely overkill for running the pelt at 5v, could have used a £10 one. I used to work at a pud, they get their frozen foodstuffs in big thick polystyrene chests, I'm going to pick up one of them, my carboard box isn't going to fit the bill. Yep, that's what I'm thinking The thought occured to me, but I looked at the minifridges you can buy, and they don't bother with that... I can live without a thermostat. I might mod in a timing circuit if it's getting too cold.
This is neat. You mad eyour own mini fridge. I'ma have to try this. But why did you use cardboard? You could have bought soem alum angle and sheet metal, and then you could have made a alum. box.
making a metal box would be retarded cos it would loss alot of the cold really quick without lots of insulation also that would increase the price alot and you can get a mini fridge for about AU$ 100 about 40 pounds you could make a metal box and put the polystyrene box inside that you could just put a larger piece of aluminum on the cool side (to increase the cooling surface area) or use a old passive cpu heatsink
I recommend a metl case inside of a insulating unit the metal will conduct heat quite well so all square inches will absorb the airs heat which is moved by the pelt. Keep in mind that the pelt will add heat to the room its in.
try to get a copy of this http://www.siliconchip.com.au/cms/A_30311/article.html and here you can get things like this http://www.dse.com.au/cgi-bin/dse.storefront/450c0fbd0d40a48e273fc0a87f9c0720/Product/View/M4500 which you could mod into your box and if you do want temp control http://www.oatleyelectronics.com/pdf/k140a.pdf
A quick trip to the local pub (where I used to work) and I managed to obtain some of the polystyrene boxes that the vegetables are delivered in. Tomorrow I will move to phaseII, assembly and beta testing.
I shouldnt worry too much about the multiple wires to the pelt cos AFAIK they are all ocnnected to the same trace on hte PSU's board.
not to mention the fact that the wires running to the pelt are normally no larger than psu wire to begin with. Peltiers are just fun to play with I guess. I had one for a while and it was neat just to see it freeze over on one side and make stuff super hot on the other side. Just so you know as well, imo you will never get your fridge cold effectively running that peltier at 5v. It may get cool, but not have enough cooling power to really deal with A) opening the fridge B) cooling other things down besides air. Remember that air is way easier to change the temperature of, water and liquids like in drinks take way longer and a good bit more energy. Just a side side note: imo it would be best to find a psu with a atx12v line to it, those normally are good at surviving high load on the 12v line, and will normally not just shut off if there is alot of power draw on it. Connect your peltier to that connector, besides the newer pci-e power wires, its probably your best bet. Find a local store with their cheapest atx12v powersupply, if it does not power your peltier right, take it back Good luck with the fridge.
I know you said you were too cheap to buy a real fridge. But dude people give **** away like that on Craigslist.org for free. It might have been fun to build, but I can't see it being too terribly practicle. I mean that pelt doesn't have enough juice to keep a glass of water cold as well as the surrounding air.
Indeedly true... My point was that one 12v wire isent designed to handle very much current on its own, that way if you put a few of them in parrallel the wires wont have a change of melting or heating up from too much current. (that kind of Amperage is Very big) -dont question me on my use of "amperage"
Amperage is a great word i used to use it in Physics class all the time to annoy my teacher. As long as the wires are equal or thicker than those of the pelt.
A peltier is all that most little mini-fridges have. To cool of the whole container, I'd mount either a big ol' heatsink or just a piece of steel to the cold side. That way it'd cool off a larger area and perhaps not freeze the peltier. I was gunna put a peltier into my computer and have a little minifridge built in, but I kinda broke my peltier, so that mod died a quick and painless death. PEACE
