ebay aquarium temp controller build

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It appears that it would be worse in achieving the main goal of fermentation temperature control- stable temperatures. More cycles means more temp overshoots. Controlling temp overshoot/hysteresis could be problematic even with a PID.

thank god we're not preforming rocket surgery than! ;)

We are trying to control an ambient temperature around a mass of 5+ gallons of fluid. Overshoot, hysteresis, PID control loops are all moot points considering the amount of thermal mass the fluid represents compared to the amount of ambeint air. You're waaaay overthinking this. Although everything you say is true, it's not a practical approach.

Now if you had one single carboy in a room the size/volume of a house...now that's a different story.

I digress. :mug:


PS Welcome to HBT
 
can I use this to control the temperature of my keezer, or am I better off just buying a controller that the home brew stores sell for my keezer?

-=Jason=-
 
I use it for my kegerator and it works fine. still haven't found a good spot for the sensor though...someone put theirs in s vial with water to help reduce drastic temperature changes from opening the door and such. It just slows down the response time. good idea I think.
 
You're waaaay overthinking this. Although everything you say is true, it's not a practical approach.
It's for a fermentation chamber...a little big I know, but it'll just cycle less.

I was not suggesting PIDs or other impractical nonsense in a temp control system. I was stating the futility of applying more and more sophisticated means to compensate for the side effects of the root problem which is an improperly sized element of the system.

My initial input to this thread was merely to clarify/correct your rebuttal to a previous poster's comment that your heater seemed oversized. In your reply you stated that on oversized heater will just "cycle less". This post was worded, at least to my eye, to suggest that a larger heater is advantageous due to it cycling less (which it won't), or having a lower duty cycle.

I merely stated, for future readers gathering components, that a more appropriate/practically sized heater will function better- no matter how much you over or under think it. While I like to use Tim "the toolman" Taylor's overkill engineering method as much as anyone, this is not a good case to apply it.

Cliff
 
i dont want to jump into this arguement but i think a little clarification might help. The size of the heater doesnt matter as far as number of cycles cause the fridge is loosing temp at the same rate no matter how fast or slow it is brought up to temp. however, by using a smaller heater it will run longer which would slowly raise the temp slightly over the rate the firdge losses heat unlike a big heater which will blast heat really fast. Truely this all depends on your temp settings. My concern with a big heater is it may get too hot if its not adjustable. I use to have a large coiler heater that would pump out heat so hot anything in front of it would melt if exposed for more than 30 sec! fire hazzard to the nth degree
 
I use it for my kegerator and it works fine. still haven't found a good spot for the sensor though...someone put theirs in s vial with water to help reduce drastic temperature changes from opening the door and such. It just slows down the response time. good idea I think.

i just tape some folded paper towel to one of the kegs and tuck the sensor inside of that. works great, especially if you have a keg that doesn't go as quickly as the others.
 
The size of the heater doesnt matter as far as number of cycles cause the fridge is loosing temp at the same rate no matter how fast or slow it is brought up to temp. however, by using a smaller heater it will run longer which would slowly raise the temp slightly over the rate the firdge losses heat unlike a big heater which will blast heat really fast.

Your explanation for why the number of cycles over time will be the same regardless of heater size sounds more like a proof of a theorem on why it will cycle less. I explained this theory earlier that as the size of the heater approaches the heat loss of the system, the number of cycles approaches 1 and the duty cycle approaches 100%.

Cliff
 
ok so I read the thread from start to finish,

I shall buy my black box at radio shack,
I'll buy the oulets at lowes and extension cord

so I have this all wired up and complete. I plug the unit into my wall set my temp them just plug my keezer into the cooling outlet?

really that simple?

also I was thinking of mounting this all assembly to the inside of my keezer does anyone foresee any problems going that route? should a waterproof box then be used instead?

-=Jason=-
 
still haven't found a good spot for the sensor though.

This is a good issue for hashing out the pros and cons. If there is only one fermentation vessel being controlled, it seems the optimal placement is in (or on) the vessel. If in one chamber there are multiple vessels, at possibly multiple stages of fermentation, placement becomes more problematic. A good case could be made for multiple small chambers, depending on how exact you want temperatures.

Cliff
 
so I have this all wired up and complete. I plug the unit into my wall set my temp them just plug my keezer into the cooling outlet?

really that simple?

also I was thinking of mounting this all assembly to the inside of my keezer does anyone foresee any problems going that route? should a waterproof box then be used instead?

-=Jason=-

I just came here to find out which model of ebay controller to buy, but I think in this thread it most advised against putting the controller in the freezer (for various reasons). The only other gotcha I remember being mentioned was to double check the delay setting for the cooling side to prevent fast cycling of the freezer. I am not sure if cutting powering to the freezer, which the controller will do, will defeat the the freezer own fast cycling prevention circuit. It may depend on the make/model of freezer, as well. The method of wiring into the freezer's starting capacitor (that was proposed elsewhere) to maintain the freezers defrosting controls (by leaving the freezer powered at times) may also bypass the freezers fast cycling prevention.
 
I'll have to search for the specific Magic Chef Freezer I have and see how to best set it up then.

-=Jason=-
 
EDIT:I found a seller selling 10 of the 110-120 V models http://cgi.ebay.com/Digital-PID-Tem...ltDomain_0&hash=item2a0c0f9dc2#ht_2172wt_1139


here is a link to the seller http://myworld.ebay.com/hktrading2010/
-=Jason=-

I am not sure which model that one is, as the description is a little vague. I found this thread while looking for another thread where the various ebay controllers were explained in detail. There were more than a few who went solely by lowest price, only to find out it was a different model that looked similar.
I think the difference was that one (the $2 more one) had relays for both a heating and cooling circuit. The heating circuit is only needed if your climate/ambient temp is below your ferm temps.
I thought this one is the one people were buying, but many ebay links are now expired (and so will this one in one month).
http://cgi.ebay.ca/Mini-Digital-Tem...ultDomain_0&hash=item1e5fd1d0ba#ht_4382wt_905

Cliff
 
I'll have to search for the specific Magic Chef Freezer I have and see how to best set it up then.

-=Jason=-

Jason,
I think that if you are using the simple wiring strategy of plugging the freezer into an outlet box which is wired to the controller, you will not have any issues. The caveat being that you double check the cycling delay parameter on the controller. I think it is adjustable and preset to something sane, but that info is from memory from reading other posts here and elsewhere.
Cliff
 
I am not sure which model that one is, as the description is a little vague. I found this thread while looking for another thread where the various ebay controllers were explained in detail. There were more than a few who went solely by lowest price, only to find out it was a different model that looked similar.
I think the difference was that one (the $2 more one) had relays for both a heating and cooling circuit. The heating circuit is only needed if your climate/ambient temp is below your ferm temps.
I thought this one is the one people were buying, but many ebay links are now expired (and so will this one in one month).
http://cgi.ebay.ca/Mini-Digital-Tem...ultDomain_0&hash=item1e5fd1d0ba#ht_4382wt_905

Cliff

Cliff, it would seem the two units I just purchased do in fact work for both heating and cooling

here is a tid bit taken from the product description.
Relay contact capacity (Heating): 10A (max) 250 V

- Relay contact capacity (Cooling):10 A (max) 250 V

(Is not simultaneously control cooling and heating, cooling or heating optional)
 
Jason,
I think that if you are using the simple wiring strategy of plugging the freezer into an outlet box which is wired to the controller, you will not have any issues. The caveat being that you double check the cycling delay parameter on the controller. I think it is adjustable and preset to something sane, but that info is from memory from reading other posts here and elsewhere.
Cliff

cool, yeah I don't plan to get into re-wiring anything in the freezer, was just looking for a plug and play option and I think this is it.

now should freezer be set on coolest setting to allow the newly built unit to cool that low?


-=Jason=-
 
now should freezer be set on coolest setting to allow the newly built unit to cool that low?

-=Jason=-

The freezer setting is just maxed out, or at least set colder than the lowest temp you want to achieve.
The controller you bought looks like the one people had doubts about because the schematics were different than the description. Hard to tell because the photo of the schematics is so small/fuzzy. The other ebay guy, globalconn, has detailed pics of the schematic. He also has two other models, one with a compressor and defrost circuit, to add to the confusion.
Cliff
 
Cliff I have an email to the seller asking him what this unit does and if I can't wire both a heating and cooling I like to cancel my order.

I'll have to wait and see what happens

-=Jason=-
 
still no responce from the seller I guess the time zone has some thing to do with it... FML I do think I purchased a single phase unit that can only heat or cool but not both.

-=Jason=-
 
I got an email back, those controls can only control heat or cooling not both... FML>.... now it see about him not shipping them and refunding my money back..

I'm going to edit my posts to remove the bad links so no one else makes the mistake I did.


-=Jason=-
 
jason, are you planning to use this for fermentation or keg serving? i use mine on my keezer and have never needed to use the heating side of things.
 
jason, are you planning to use this for fermentation or keg serving? i use mine on my keezer and have never needed to use the heating side of things.

one is for keezer so I guess its fine, but the other was going to get hooked up to a mini fridge converted into fermentation box

I guess I can sell one and buy a dual heat/cool unit.


-=Jason=-
 
A couple people asked awhile back what could be done to replace the sensor if it got broken. Looking at the other single stage controller listed by the seller, the sensor is "NTC sensor (10 kΩ / 25 °C, B value 3435 K)". I imagine this is about the same, especially given that one poster awhile back mentioned that a 10k resistor read 25°C on the controller. Given that, wiring up a simple thermistor like this should offer a decent replacement for the sensor on the controller.

http://www.jameco.com/webapp/wcs/stores/servlet/Product_10001_10001_1871852_-1

Of course, I'm sure it's not to hard to find this a single version somewhere (digi-key).
 
I was under the impression that you could have a heating and cooling component plugged in and the controller would alternate between the two circuits to maintain the set temperature. This is not correct then? It either heats or cools, but does not alternate?
 
I was under the impression that you could have a heating and cooling component plugged in and the controller would alternate between the two circuits to maintain the set temperature. This is not correct then? It either heats or cools, but does not alternate?

OrangeHero, that is correct the Original unit has both heating and cooling, there was a single stage unit that looked different with only 2 buttons, but now they are making single stage units with 4 buttons that looks like the dual stage units.

I was one of unlucky ones who got duped into buying a single stage thinking it was dual. unfortunately I bought 2 units :( I can use one for my keezer, but for my fermentation box I'd like a 2 stage unit so it will kick on the heater to get up to temp.

-=Jason=-
 
sorry. noob question. where does it actually heat/cool from. i want to step up to all grain and would like to also start paying more attention to temp control. does it come from the wire you have off the right side of that temperature read out? what does that attach to? thanks!
 
I finally finished building my controller.
12062010067.jpg

12062010065.jpg

12062010061.jpg


I will be doing an ale next and I am going to use a stand up refrigerator as
a fermentation chamber hocked up to this controller.
Now my question; what would I use for heating that is not going to melt the
inside of the Refrigerator?

Thank you.
 
I use a 75 watt bulb in one of those holders that has the metal shield, got it at Menards for about $4. It's held 49° temp, doing a lager, for three weeks and the temp here has gotten down to 9°. The chest freezer is in my garage. I also run a small computer fan to circulate the air.

tom
 
Thanks for the suggestions, but isn't light supposed to be bad for your brew?
Wouldn't running a light bulb to keep the temp. up negatively effect the beer?

Schupaul, what kind of heating pad would that be?

Thank you.
 
Thanks for the suggestions, but isn't light supposed to be bad for your brew?
Wouldn't running a light bulb to keep the temp. up negatively effect the beer?

Schupaul, what kind of heating pad would that be?

Thank you.

It's UV light that is bad for the beer. Incandescent bulbs essentially produce no UV light. I've had a 40W light bulb heater in my fermentation fridge for years with no illeffects. You can always cover it with foil, too.

Or get one of the ceramic bulbs that are used to produce heat and no light at all.
 
I bought this temp controller several months ago and didn't find an appropriate fridge for ferm. chamber till last week, free, of course.

I wired up the controller with a cord off an old cable box, but no power.
I used an old wall wart, no power.

Do I need the probe and outputs wired in first?

Fridge is all cleaned and painted and ready to go and now this glitch is killin me:confused:

Thanks guys.



Pics after solved.
 
It says it's the correct one- '110VAC, 50Hz/60Hz' marks below the power screws.
Not getting anything.

:mad:
 
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