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[ASK] 15 A powersupply with 12v~15v

Discussion in 'General Electronics Chat' started by Ragens, Feb 4, 2013.

  1. Ragens

    Ragens Member

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  2. ()blivion

    ()blivion Active Member

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    Forget computers, you are not doing anything with computers.
    You need to make a box, out of insulation, with one side the cold of your TEC, and the other the heat sink.

    Like this....
    TEC freezer.png

    Heat pump = peltier = TEC. All the same thing.

    Yes. Cold side of one, hot side of the other.

    TEC2_TOP.jpg

    6126_07_digital_storm_empowers_supreme_processor_performance_with_cryo_tec_cooling_system_full.jpg
     
  3. Ragens

    Ragens Member

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    okay here the story... i got mini cool box from my dad to use in college, then after few month the Peltier not function anymore so i can fix it by change the peltier but i think if i going to change the peltier better i use bigger Power(W) peltier to make it more cool(low temperature) or even can make ice... u post a picture of multistage peltier, i think i will not found that one in my country, so i will attach two peltier each other but can i use high Watt peltier to box then lower watt peltier to cool the peltier hot side or it need same Watt peltier? what effect the peltier cooling or function, current or voltage so i might know it need to set as parallel or series...

    i upload picture for my setup... pls guide me...

    here the box :

    inside the box
    DSC_0025 (1).jpg

    back of the box (i not use the powersupply circuit anymore and use other powersupply because it generate heat and reduce the cooling in the box)
    DSC_0028.jpg

    The thing is already old and found an open area when closing the box
    DSC_0029.jpg

    My AMD stock air fan
    DSC_0026.jpg

    Peltier
    DSC_0027.jpg

    position/location of peltier and air fan
    DSC_0030.jpg

    got open hole/leak when peltier in it position but never produce water at the back of the box only in the box got water produced
    DSC_0031.jpg
     
  4. dave

    Dave New Member

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  5. kubeek

    kubeek Well-Known Member

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    ONLINE

    where is the transfer side of the peltier located on the inside of the box?
     
  6. tcmtech

    tcmtech Well-Known Member Most Helpful Member

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    To make a two stage Pelter cooling system work you will need to have the higher wattage one cooling the lower wattage one. Overall cooling efficiency will be lower but the cold side temperature limit will be lower in exchange.

    Depending on the cooling efficiency of the higher wattage unit you may need a 2:1 or possibly a 3:1 wattage ratio between them which means that your present 150 watt cooler would be the large one and the smaller second one would need to be in the 50 - 75 watt rage if they are both of reasonable efficiency. If not you smaller one may have to be down in the 40 - 50 watt range.

    Also the larger cooler will need to have a good sized heat sink being that it will be trying to dump as much as 300 watts of heat energy at any one time when the system is running.

    As far as making ice it should be easy if your box is insulated well enough and you can keep your outside heat sink temperature as close to ambient temperature as possible.

    One issue I see is that using a common computer power supply is that its wattage rating is intended to be spread out over all of its outputs and not just one output such as the 12 VDC circuit. Trying to pull all or nearly all of the rated wattage off of the 12 VDC output alone will cause it to have a short life expectancy and typically very poor voltage regulation when it is working.

    Ideally you should have dedicated power supply if you are planning to be running higher wattages on a single output system.
     
  7. Ragens

    Ragens Member

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    inside the box got square line and 4 screw...

    like this? two stage peltier :
    Heat sink/fan(Hot side)
    ________
    |150Watt |
    |________| <- Cold side
    |75 Watt | <- Hot Side
    |________| <- Cold Side
    Insulated Box

    for heatsink and fan here is more specification:
    Material: Copper heatpipes, base w/ bonded aluminum fins
    Heat Sink Size: 92W x 95L x 64H
    Fan Size: 70 x 70 x 20mm
    Voltage: 12VDC
    Bearing: Dual Ball Bearings

    which one should i change? if both, how to choose?

    okay we back in main topic, so i need to fix the power supply first... i will post the schematic diagram after i finish draw it... i hope with the schematic i can get help to modified it to support higher wattage...
     
  8. ()blivion

    ()blivion Active Member

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    Yes. Just like that.
     
  9. Ragens

    Ragens Member

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    for the heat sink i cant find for 300 Watt... so i research CPU heat sink and make comparison between two product including price in my country...

    it state it can maximum cooling of 300 watt heat : Artic FreeZer 13 Pro - 139

    after see comparison chart from many website i found out this can beat in term of temperature : CoolerMaster Hyper 212 Plus - 99

    this suitable?
     
  10. tcmtech

    tcmtech Well-Known Member Most Helpful Member

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    Are you sure you even need that much cooling power to begin with for such a small unit?

    My full sized refrigerator with a built in freezer section at the top, which is probably a little bigger that your whole unit, only uses around 180 watts.
     
  11. Ragens

    Ragens Member

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    really? can you guide me through the setup? i got problem to freeze thing in the box to ice... when i on the box, after few hours there always has water flow under the box... its like the temperature cant maintain very well...
     
  12. Ragens

    Ragens Member

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    after reading back your post... i think i misunderstood you... u mean market refrigerator and not DIY right? that refrigerator use what kind of technology to make low temperature... as mine use peltier, most people will said that peltier not efficient because required lot of power and produce much heat, but this only thing i can think for price(cheap)...

    one more question... if i change full bridge diode/rectifier with Silicon Controlled Rectifier (SCR) how will it function/efficient/Volt-current loss... as i read through electronic device/component i found that SCR can change AC to DC...
     
  13. Ragens

    Ragens Member

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    after i search about power supply i found that some are use multiple rail and some use single rail... this is what you mean? better use single rail than multiple rail so it not divide the 12volt to multiple?
     
  14. Ragens

    Ragens Member

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    what is this thing?

    DSC_0026.jpg

    DSC_0027.jpg
     
  15. ronv

    ronv Well-Known Member Most Helpful Member

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    It looks like a thermal switch, It opens when it get to a certain temperature and closes when it cools down.
     
  16. Ragens

    Ragens Member

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    owh... still do not understand how it function... it can improve cooling power?
     

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