DIY temp controller build

[ftlstrings]

Sorry, guess it only goes to 35, good enough I think, unless you like beer-cicles.

What is the voltage output of the 6020 (sent to the SSR)?

 

[T-Hops]

What ever the output of your transformer is.

 

[android]

In this SSR application, is a heatsink required? I can't tell if you have used one or not. If you have, where have you placed it?

Cheers,

Rhino

sorry, missed this. no heat sink is necessary.

 

[liljimmynorton]

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?

 

[android]

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).

 

[Pickngrin]

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?

 

[Azrack]

shildebr what automotive relay did you use please?

 

[Hang Glider]

...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).

 

[wheatgerm]

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.

 

[statman]

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.

 

[bmorgan]

I, too, reinvented the wheel. This is my 3rd Arduino project and I see no end in sight. I am a gadget freak and they're even more fun when you roll your own.

http://picasaweb.google.com/lh/photo/ErWIeMiPY08-rDCzplw7V5mqNgd6qJ4RhM9wu73rcO8?feat=directlink

 

[android]

that one looks pretty bad ass, nice work.

 

[vicegrip]

Thanks for the info android mine work great.
I used an old cellphone charger and an $5 SSR from ebay

 

[bmorgan]

Well done. You surely spent a fraction of what I did.

 

[rrittenhouse]

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.

You have kind of a valid point..to an extent. If something broke in the Johnson controller you would have to spend another $70 on a new controller. If something broke in this case you could do it much cheaper on a component-by-component basis. Plus people just love DIY and learning It may not be the best solution but its pretty darn cool.

 

[eastendershomebrew]

is it possible to make this into a 2 stage temp controlleR?

East enders

 

[android]

is it possible to make this into a 2 stage temp controlleR?

East enders

well, it will function as both, but of course you have to set the function to 'heat' or 'cool' on the thermostat. and i could swear i remember reading somewhere that if you use two SSRs or something, you can get it to function that way... but it's a vague memory.

what will you be using it for? if it's a fermentation chamber, you should be able to use one of the other without too many problems. i have a dual stage temp controller that i've used for fermenting and for kegerator temp control, and i've never had to have it set up as a simultaneous cold/heat unit. my basement is typically around 60 degrees, so i either turn it to heat to ferment warmer, or cool to ferment lagers. and if you will be using this for cold temps, make sure you get a thermostat that goes down that far. I cannot use mine for a kegerator, it only goes down to like 45 or so.

 

[android]

after re-reading the whole thread, i think it's on page 2 or 3 where someone mentions how they used two SSRs to do the simultaneous heat/cool. automotive relays to be exact.

 

[statman]

is it possible to make this into a 2 stage temp controlleR?

East enders

If you are talking about the Johnson unit, no-it is a single stage unit. They make a 2 stage electro mechanical unit and an electronic version but of course they are more money, like 140 to 200 or so.

 

[jmferris]

Sorry for the bump, but I am working out my temperature controller right now, and it is quite similar to your build. You say that the SSR does not require a heat sink for this application. Just wondering if you've noticed how hot it actually gets? I am doing a dual stage controller, so I will have two SSRs in the enclosure, obviously not both running at the same time.

Trying to figure out if I might want to wire a fan into the enclosure itself, or possibly just vent it. Just paranoid about anything that can run in an unattended state.

 

[statman]

Sorry for the bump, but I am working out my temperature controller right now, and it is quite similar to your build. You say that the SSR does not require a heat sink for this application. Just wondering if you've noticed how hot it actually gets? I am doing a dual stage controller, so I will have two SSRs in the enclosure, obviously not both running at the same time.

Trying to figure out if I might want to wire a fan into the enclosure itself, or possibly just vent it. Just paranoid about anything that can run in an unattended state.

hmmm, not sure what you are monitoring. Mine was a beer meister using a freezer. I can tell you that in my case, it was nuts on. I used a 4 degree range of 33 to 37, set point 35. (I like it cold) -and it never drifted outside of those parameters and tended to display set point temp most of the time-otherwise somewhere between 34 and 36. Make sure your probe connections are tight on the control. (apparently mine wasn't tight enough when I received/installed it-froze my beer. One other froze episode-make sure no one forgets to re-insert probes if you are leaving them hanging on the wall without anchoring. In short, no problem other than human error. (I didn't vent or fan the box.)

 

[jmferris]

hmmm, not sure what you are monitoring.

Specifically looking as to the temperature swings on the SSR itself. Due to it switching AC, my concern is actually that the junction box, itself, might become too hot as opposed to the contents of the fermentation chamber it will eventually be installed on.

The comments about leaving it unattended are related to not wanting to head out for the weekend and come back to a melted down junction box from excess heat build-up, or worse.

 

[IrregularPulse]

Nice project. Just one tip for the future when wiring stuff like outlets. Wrap the wire in the direction you are tightening the screw. This will pull the wire into and around the screw and apposed to try and twist itself out when you are tightening the screw down over the wire. AKA, bring the wire looped from the left to the right instead of right to left like in the picture above.

 

[android]

Nice project. Just one tip for the future when wiring stuff like outlets. Wrap the wire in the direction you are tightening the screw. This will pull the wire into and around the screw and apposed to try and twist itself out when you are tightening the screw down over the wire. AKA, bring the wire looped from the left to the right instead of right to left like in the picture above.

yes! thanks for mentioning this... i actually ended up putting a terminal adapter thingy on the end of this wire because i didn't like the way that looked.. but good advice on wiring it in the tightening direction.

 

[android]

Specifically looking as to the temperature swings on the SSR itself. Due to it switching AC, my concern is actually that the junction box, itself, might become too hot as opposed to the contents of the fermentation chamber it will eventually be installed on.

The comments about leaving it unattended are related to not wanting to head out for the weekend and come back to a melted down junction box from excess heat build-up, or worse.

i really wouldn't be concerned about it, but it's totally up to you if you want to put a vent/fan of some sort in there. mine has run fairly continuously for the last 6 months off and on and even when it's been controlling a heater for a week straight, when I go to move it, it only feels like ambient temperature. the plate that covers the junction box has a little opening on one side, so that sort of acts as a vent I guess... but it's never felt hot or even warm to the touch and like I said, I use this fairly often.

 

[jmferris]

i really wouldn't be concerned about it, but it's totally up to you if you want to put a vent/fan of some sort in there. mine has run fairly continuously for the last 6 months off and on and even when it's been controlling a heater for a week straight, when I go to move it, it only feels like ambient temperature. the plate that covers the junction box has a little opening on one side, so that sort of acts as a vent I guess... but it's never felt hot or even warm to the touch and like I said, I use this fairly often.

Thanks for taking the time to reply. I though that was what you were implying. I don't imagine that we are drawing enough current with this application to be a concern. I like the idea of a small air gap on the edge of the enclouse, as venting is just going to invite dust and I would need to create pressure from the inside (i.e. a fan) to help keep the dust out.

I guess the best way to find out will be when I put it together, after the SSRs make their way from the Orient.

 

[android]

plus, it's not like they'll both be running at the same time. if anything, with the dual controlling, it should spread the running between then SSRs and i bet it'll all be good.

 

[Augie62]

Can someone please send me the complete instructions?

Augie

 

[android]

Can someone please send me the complete instructions?

Augie

?? the instructions are outlined in this thread and you will have to follow a link or two on the first page for the original instructions and wiring diagram. updated photos are on page 3 with the finished product IIRC.

 

[rycov]

please tell me if i'm in the right direction. sorry about the ****ty windows paint drawing