eBay Temp Controller Problem

I recently picked up one of the eBay temperature controllers to build my own thermostat unit. Shortly after it arrived in the mail, I wired it up inside of a project box and I was so excited when I powered it up and the unit was working right away! At least, I thought it was working.

Currently, the display and controls all work just as expected. Unfortunately, when the list is on for either heating or cooling, it is doing neither. Using a voltage meter, it seems that the power is not being switched on for either heating or cooling at the unit itself.

Does anyone have any troubleshooting they can recommend, or any experience with them that might suggest a configuration problem? ANY help would be appreciated!

What is the brand?

Sorry, I guess I should have included more information.

The brand is Elitech and the model number is STC-1000.

EDIT: (More info)

Using a voltage meter, I get power between the ground and pins 5 & 7. I do not get power between ground and 6 or 8, regardless of heating or cooling being on.

What version did you get the 110v or the 220v? If you got the 220v it will power on but running on 110v will not turn the relays on. You have to replace the 220v transformer with a 110v one its pretty easy i did it on one of my units.

I thought that the auctioneer would send the appropriate voltage version based on country, but looking back at the auction, it seems that it was not actually spelled out that way. The description lists the "Relay contact capacity" as 220v, so it sounds like I do indeed have the wrong voltage version.

So now that we have determined that I simply have the wrong version, do you happen to have or know of a guide for switching the transformer? Also, where could I get a replacement transformer? Radio Shack?

Some of the e-bay sellers are good about sending the model with the correct voltage, and some are not. It pays to read carefully and to make a note of which model you need in the notes section when you pay. I don't think radioshack is going to have the transformer you need. Look in the last ~10 or so pages of the e-bay controller thread for info on buying and replacing the transformer. There was a member that bought a few of them and was willing to sell the extras at his cost to those that needed them, but I'm not sure if he still has any of them left. Are you sure you ended up with the 220v model? You can open it up and check the voltage on the transformer.

from your description i can't tell for sure but it sounds like you are expecting the relay output to produce a voltage output.... not going to happen. The relay outputs are just switches. you need to provide a source and load in series with the relay terminals to have an effect.

LakewoodBrew said:

from your description i can't tell for sure but it sounds like you are expecting the relay output to produce a voltage output.... not going to happen. The relay outputs are just switches. you need to provide a source and load in series with the relay terminals to have an effect.

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I thought the same thing after re-reading the post, which is why I asked if he's sure it's the 220v version. He may be thinking that the relay being rated for 220v @ x amps means that the controller is a 220v model.

LakewoodBrew said:

from your description i can't tell for sure but it sounds like you are expecting the relay output to produce a voltage output.... not going to happen. The relay outputs are just switches. you need to provide a source and load in series with the relay terminals to have an effect.

Click to expand...

Sorry is my terminology isn't perfect. My experience with electronics is limited.

I'm not sure exactly what you're suggesting. You seem to know more about this than I do, so perhaps if I provided more information on the way it's wired, you could help direct me.

Currently, I have it wired the same way as in this diagram from the eBay Aquarium Temp Controller thread:


I do have constant power running into ports 5 and 7, with the outputs (6 and 8 respectively) going to electrical outlets that are not connected together. In an attempt to isolate the problem, I have removed the outlet and I'm checking the wiring with a very simple illuminating voltage tester. When it makes a connection and power flows through that connection, it lights up.

In my testing, for example, when the heat turns on, the light for heat on the display is a solid dot. When connecting the voltage tester to the screws on the unit, connecting pins 2 and 5 lights up but connecting pins 2 and 6 do not. Also, there are people talking about the unit audibly clicking when either heat or cooling turns on, but I hear no noise when it engages either function.

EDIT:
Here's the picture of the transformer inside the unit. Perhaps this would help?

that wiring is correct. There is a sticker on the bottom of the unit. It will either say 110v or 220v next to terminal 1&2. Also there is a compressor delay built in (default is 3 mins). The cooling dot should be blinking during the delay and testing terminals during that delay would of course show no current. I don't think that would be the case of the heat side however.

The sticker says 220VAC next to the 1&2 terminals. Sounds like that's my problem.

I am taking the compressor delay into consideration when testing. From my testing there isn't the delay on the heat side. I do wait until the compressor delay ends on the cooling side before testing the connections.

Vlar said:

The sticker says 220VAC next to the 1&2 terminals. Sounds like that's my problem.

Click to expand...

Thats it.

goto this thread.
https://www.homebrewtalk.com/f51/ebay-aquarium-temp-controller-build-163849/index151.html
Get intouch with infection he might still have some 110v transformers left.

Chrisl77 said:

goto this thread.
https://www.homebrewtalk.com/f51/ebay-aquarium-temp-controller-build-163849/index151.html
Get intouch with infection he might still have some 110v transformers left.

Click to expand...

Thanks for the tip. I've PM'd him. Any idea how much the cost? Debating just buying a new unit (110v!) instead of buying the replacement transformer.

The cost of the transformer is very small. Something like $2.50 when purchased in quantities of 5. What hurts is shipping. You will have to pay for the shipping to infection and then from him to you, if he wants to break even.

I bought 5 of them to verify that the transformers would work in the 220 V model. I ended up selling all of them. I believe the final shipped price was about $13.50.

You will also have to cut away part of the case to get the 110 v transformer to fit. There are pictures in the main thread showing this.

I did see the pictures you posted and I greatly appreciate them. It sounds like even with the cost of shipping from the supplier to infection, shipping from infection to me, and the unit itself, it is still cheaper than a new controller and much faster!

Time to brush up on my soldering skills.

I am interested in buying one of these amazingly cheap ebay units, but was wondering what it would do in the event of a power outage. Is the user setting lost? and if so, what would be the default temp that it would reset to?

idkleine said:

I am interested in buying one of these amazingly cheap ebay units, but was wondering what it would do in the event of a power outage. Is the user setting lost? and if so, what would be the default temp that it would reset to?

Click to expand...

I unplug my entire fermentation chamber, including the controller, from its power source quite often. Settings are not affected and the controller powers up to a working condition after a power outage.

raouliii said:

I unplug my entire fermentation chamber, including the controller, from its power source quite often. Settings are not affected and the controller powers up to a working condition after a power outage.

Click to expand...

Yep, they hold the numbers, even if it's been unplugged for months. I have three units I use around the house, one in my keezer, one that I use for fermentation temp control, and one to power my ghetto sous-vide machine. And I just fired up the sous-vide up after 3 weeks and my last cooking settings were still there.

Another bit of information:

The STC-1000 stores its ON / OFF state during a power outage (or being unplugged) and recovers to the same condition when power returns. Very nice feature.

My CH54, single-stage farenheit controller, doesn't function this way. It always recovers to an ON condition when power returns or it is plugged in. Not so nice feature. Good when you want it ON but bad if you wanted it OFF.

They both hold their settings while not provided with power.