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

Discussion in 'General Electronics Chat' started by Cruiseomatic88, Mar 30, 2016.

  1. Cruiseomatic88

    Thread Starter Member

    Jun 30, 2014
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    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.
     
  2. Cruiseomatic88

    Thread Starter Member

    Jun 30, 2014
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    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?
     
  3. wayneh

    Expert

    Sep 9, 2010
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    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.
     
  4. Cruiseomatic88

    Thread Starter Member

    Jun 30, 2014
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    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.
     
  5. ronv

    AAC Fanatic!

    Nov 12, 2008
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    Can you post the AC/DC picture directly to the forum ? Use the upload file button.
     
  6. Cruiseomatic88

    Thread Starter Member

    Jun 30, 2014
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    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.
     
  7. wayneh

    Expert

    Sep 9, 2010
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    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?
     
  8. Cruiseomatic88

    Thread Starter Member

    Jun 30, 2014
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    Exactly. The AC comes in down towards the bottom by the two transistors with heat sinks. Large white connector.
     
  9. wayneh

    Expert

    Sep 9, 2010
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    You might pick up some info from this thread. There's at least one schematic in there and photos of similar boards. Might give a clue.
     
  10. Cruiseomatic88

    Thread Starter Member

    Jun 30, 2014
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    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.
     
  11. Cruiseomatic88

    Thread Starter Member

    Jun 30, 2014
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    Still no luck. Anyone have any ideas?
     
  12. wayneh

    Expert

    Sep 9, 2010
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    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.
     
  13. Cruiseomatic88

    Thread Starter Member

    Jun 30, 2014
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    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?
     
  14. N11778

    Member

    Dec 4, 2015
    39
    7
    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.
     
  15. Cruiseomatic88

    Thread Starter Member

    Jun 30, 2014
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    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.
     
  16. N11778

    Member

    Dec 4, 2015
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    post a pix of the run side of the board too. Please
     
  17. wayneh

    Expert

    Sep 9, 2010
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    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.
     
  18. InspectorGadget

    Active Member

    Nov 5, 2010
    211
    42
    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
     
  19. N11778

    Member

    Dec 4, 2015
    39
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    Is it ok to just turn the TEC on and off the one I have uses pwm and ramps the 12 volts.
     
  20. Cruiseomatic88

    Thread Starter Member

    Jun 30, 2014
    39
    0
    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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