If I plan on using a window ac unti can I just wire this in place of the units original controls. I assume I would not need a relay since it would essentially be functioning as an ac in your house. Does anyone know if the window unit also uses the same voltage as a house system would?
i think there is a relay built into your thermostat wiring system in the furnace/ac, i'm not 100% sure about that, but I would guess that is the case. so, i think the relay would be necessary. it's not too hard to wire up and you could just plug the AC into the box if you wanted to and it might be a little less messy than if you tapped into the thermostat (although i think you might need to anyway, just to get it into a warm area so it doesn't kick off the unit).
__________________ primary: Schwarzbier kegged: A Lager, Irish Red, Oak Aged Dark Belgian
I just finished assembling one of these devices using a Ritetemp 8029. It isn't switching the freezer on, no matter what temp I set it at. I've double-checked the wiring (made sure I was plugging the freezer into the switched receptacle) and can't figure out what the problem is. I'm using a 5 volt DC adapter and a new SSR I bought through eBay (ie, direct from China). The freezer does power on when plugged into an unswitched outlet.
Any ideas?
Nevermind -- I just checked it yet again and as it turns out, the color coding on my DC adapter wires is the reverse of what I'd expected -- black is positive and red is negative. However, I am finding that if I can get the freezer to switch on the first time, if I set the thermostat lower than the internal temperature, and then can get it to switch off if I raise the target temp. However, I cannot get the freezer to switch back on if I drop the target temp again. Is there some sort of delay built into the thermostat?
...However, I am finding that if I can get the freezer to switch on the first time, if I set the thermostat lower than the internal temperature, and then can get it to switch off if I raise the target temp. However, I cannot get the freezer to switch back on if I drop the target temp again. Is there some sort of delay built into the thermostat?
There may be a delay - even in your freezer...I would wait 5 -10 minutes between switching actions, to verify, (and to minimize the strain on the compressor).
Just finished building mine. Got the fridge off Craigslist for free since it "wasn't cooling well." Ended up just needing a evap. fan motor. Got a used one off of eBay for $9. With the parts for this controller being around $40, I figure I got a temp controlled fermentation fridge for $50. Can't beat that.
Pic:
Looks a little sloppy, but I'll clean up the build tonight. Thanks for the plans and the link to the relay on eBay. Much appreciated.
Johnson Controllers (A19 type) can be had from ebay for < $30. That's where I bought mine. You do have to supply your own power cord, but that's it.
Its good you can do all of that stuff but those costs add up and that makes less time for the pretty stuff. For 70 bucks, why not buy the Johnson electronic (not mechanical) control with adjustable time-delay and differential and all you have to do is plug it in (and drop the probe inside). We are selling more and more of these. It takes 3 minutes to read the instructions and about 1 minute to program it.
Linear Mode
