AC/DC Thermoelectic fridge control board. Impossible to find.

Thread Starter

Cruiseomatic88

Joined Jun 30, 2014
39
I have a problem. I have a control board for a thermoelectric fridge and I need about 3 more. The one I have runs on dual power, door light, and thermostat with three fans. I seen Haier makes the same board but it is only AC power then converts to DC. I talked to Haier and Encompass who is their supplier. Nothing. Local Haier service center said I should call Haier back and ask for a engineer. So I did. Tried to explain everything to "Chris" who could careless because I wasn't a "ASC" as he puts it. They don't talk to anyone but them. So I'm never buying their crap again but I need the boards. Nearest part number I have is RF-5210-75. Here is what I have:
https://drive.google.com/open?id=0B9rL-HjX1H5nMGEtVkNzdUtkSVk
https://drive.google.com/open?id=0B9rL-HjX1H5nb1V5T0NHTHNwOUE
There are only 2 fridges that are dual power, Koolatron KCR-40B and Avanti. Tried Koolatron and they will not release part numbers or any info. Haven't been able to get ahold of Avanti yet but I think theirs uses an adapter and the same with the Black and Decker BNA17B which is only AC power.
Does anyone know what the part number is to my board or is the one I listed have DC capability just doesn't have the connection? Alot of the pictures for these boards is so pixelated I can't make anything on them out hardly.
Thanks.
 

Thread Starter

Cruiseomatic88

Joined Jun 30, 2014
39
If I can't find the right board, Can I use Part number rf-5210-60 and then use a 120 watt inverter to power the ac from dc? And if so, If the inverter is off, Would leaving the inverter connected when plugged in to ac damage it?
 

wayneh

Joined Sep 9, 2010
16,399
I believe that you can run an AC-only unit off of 12v by using an inverter. It's not 100% since it can depend on both the inverter and the fridge, but it would surprise me if it didn't work.
 

Thread Starter

Cruiseomatic88

Joined Jun 30, 2014
39
It would work, But I don't want to lug around an inverter and have cables running. What I'm looking for is either that board I posted pictures of if someone knows what its part number is so its a direct connection and less loss(Inverters and wall bricks are famous), or worst case use the ac-only board and install an inverter into the fridge somehow so I can just plug it into either ac or dc and don't need a "setup" In other words, Idiot proof. I have two I need to build and the future owners want them for "prepping" and camping. What I also got to thinking is, Get the AC board, plug it in and find where the 12vdc comes in at, Then just tap two leads on there and run them to a connector on the back. So, it can run on either or plug into 120 and act as a power supply. The board I have now does that and they're made by the same company. Just throwing ideas out.
 

ronv

Joined Nov 12, 2008
3,770
It would work, But I don't want to lug around an inverter and have cables running. What I'm looking for is either that board I posted pictures of if someone knows what its part number is so its a direct connection and less loss(Inverters and wall bricks are famous), or worst case use the ac-only board and install an inverter into the fridge somehow so I can just plug it into either ac or dc and don't need a "setup" In other words, Idiot proof. I have two I need to build and the future owners want them for "prepping" and camping. What I also got to thinking is, Get the AC board, plug it in and find where the 12vdc comes in at, Then just tap two leads on there and run them to a connector on the back. So, it can run on either or plug into 120 and act as a power supply. The board I have now does that and they're made by the same company. Just throwing ideas out.
Can you post the AC/DC picture directly to the forum ? Use the upload file button.
 

Thread Starter

Cruiseomatic88

Joined Jun 30, 2014
39
IMG_20160330_002806.jpg IMG_20160330_002905.jpg
This is the board I need to get more of. It would be the safest and most reliable way to get what I need done. This board comes with koolatron model kcr-40b. However, They're not playing nice with part numbers or suppliers.
 

wayneh

Joined Sep 9, 2010
16,399
That jumper block labeled "DC IN": Is that where 12V DC might be supplied? And the red and black wires are for the TEC? I don't see where AC comes in?
 

Thread Starter

Cruiseomatic88

Joined Jun 30, 2014
39
Close, But no cigar. Only two fans and it appears the NTC has two wires where mine only has one. The board has two prongs but are soldered together as one. I've found every other board but the one I have. I can't find a schematic on rf-5210-11 or 60 which would help.
 

wayneh

Joined Sep 9, 2010
16,399
I thought you might be trying to determine where the DC power on the board might be hacked into when you don't have AC. I can't do that for you. You may not have another viable option.
 

Thread Starter

Cruiseomatic88

Joined Jun 30, 2014
39
You are right, to a point. My board uses a transistor to switch between AC and DC. If I get another board similar, how would I tap a DC input?
 

N11778

Joined Dec 4, 2015
174
Looks like a single sided board. Which makes it easy to Draw us a Schematic and post it.
Include part number of the chips.
Value of resistors and caps etc.
****>>>>>> should be easy to hack in the 12v. <<<<<<++++
A hand drawn diagram on scratch paper will work.
 

Thread Starter

Cruiseomatic88

Joined Jun 30, 2014
39
Not good with drawing schematics but I'll give it a shot. It would be easy if the 12v went in at one point but this is something else. I'll try to get it up tonight.
 

wayneh

Joined Sep 9, 2010
16,399
The schematic in the link I posted earlier might help, as a bit of a roadmap. It may match up better than you expect.

One shortcut I'd be tempted to look at is to pick an IC, find its power pins, and trace upstream from there. The ICs are likely to be powered from the DC power supply with fairly minimal parts in between, just some regulation and filtering perhaps. You don't need to trace out all of the sensor signal conditioning and so forth, you only need to focus on the power.
 
Well we know that the existing board runs off 12V, and the existing power supply just generates 12V from line voltage.

What the TS needs are additional control boards that run at 12V, right?

And the replacement 120VAC-input boards won't do because there's no way to know if they use 12V as an intermediate, or some other voltage, or even an AC voltage.

Do I have this all correct?

It seems to me the only good schematics of the current board would do is to try to reverse-engineer and reproduce it. And that's not going to work because it probably has an MCU on it with software that can't be read out.

Why not use a 12V temperature controller like below? You may have to add additional delay circuitry to get the fans to run longer on the outside to cool it off but I think it would work if you're building new coolers or refurbishing old ones with broken circuits. You haven't really told us what you're trying to do.

http://www.amazon.com/DROK-Digital-Thermostat-Temperature-Controller/dp/B00GFF5YXM

http://www.amazon.com/All-Purpose-Fermentation-Temperature-Controller-Thermostat/dp/B008KVGWT4
 

Thread Starter

Cruiseomatic88

Joined Jun 30, 2014
39
Inspector Gadget has it right.
Haven't had a chance to reverse engineer it yet, But I did get a hold of Koolatron again today and spoke with someone different who gave me the email to one of their engineers. I sent him an email with the problem and waiting for a reply. And what I'm trying to do is quiet simple. I could use a 12VDC thermostat and mount a PS in as well with some diodes and relays so it could run on either voltage. But that's a lot to mount in a small space. What I want is dual voltage peltier/fan controller in one package. The TEC that is used is TEC1-12708. I would need at minimum a 10 amp PS. Not to mention, The board I have although a switcher, is quiet. Most aren't. Look up a Koolatron KCR-40B and what it does. Thats what I'm looking for but to do it to a couple other boxes without the fake freon coils.
 
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