power voltage and ampere help!!!

Discussion in 'Homework Help' started by rjng90, Feb 4, 2015.

  1. rjng90

    Thread Starter New Member

    Feb 4, 2015
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    Hi I have a LS100-12 power supply that provides up to 12V and 8.5A. it can power 2 things at a time.

    may i ask FIRSTLY, if it can be used to power SIMULTANEOUSLY a cooling fan: 'HYPER N520 12V, 0.31A' & a TEC 12710 (peltier module or thermoelectric cooler) of ratings 15.4 max voltage but operating voltage of 12V, 10A

    Secondly, both peltier and cooling fan operates at 12V, just nice the same as what the LS100-12 can provide. My concern is that the current rating for the peltier module is 10A. Does it mean that the power supply MUST provide 10A for the peltier to EVEN work? or does 8.5A suffice just that the peltier will not work at its maximum?

    Thirdly, the amperage of the cooling fan is 0.31A so will it be safe to connect it to the LS100-12 power supply? Will the power supply supply more than 0.31A (like 8.5A) to the cooling fan and damage it? I am clueless.

    Fourthly, if i have a peltier of rating 15.4V and 7A instead of the previously mentioned 15.4V and 10A, will it work too? which peltier is more advisable to be used such that nothing will spoil upon connection to the power supply?

    lastly, can BOTH appliances be used simultaneously under the same LS100-12 power supply ASSUMING the 2 appliances can function separately with the power supply?

    I hope someone can address my worries in this aspect. I am quite weak in terms of power and voltages and amperages ... thanks a bunch!
     
  2. WBahn

    Moderator

    Mar 31, 2012
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    http://www.hebeiltd.com.cn/peltier.datasheet/TEC1-12710.pdf

    If you just have the TEC sitting there looking stupid and you apply 12V to it for very long, you will probably damage it. You need to be able to carry the heat away from the hot side.

    These are normally used in a closed loop system where you have some means of sensing the temperature and controlling the TEC in response.
     
  3. rjng90

    Thread Starter New Member

    Feb 4, 2015
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    now my concern is not about peltier and overheating (I have heat sinks and fans) .., I just need to know based on the current and voltage ratings whether I can use the circuit components and appliances concurrently. Will a device burn/melt upon connecting the ls100-12 power supply with either/both the peltier and cooling fan, all 3 of the ratings as mentioned in my first post above. Hope someone can advise. Thank you :)
     
  4. rjng90

    Thread Starter New Member

    Feb 4, 2015
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    hi isit true that the fact that a power supply can provide 8.5 amps does NOT mean that it restricts the consumption of a 10A appliance to 8.5A? INSTEAD does it mean that the applicance will do its best to get its full 10A and is likely to damage the 8.5Amperage-rated power supply and possibly cause a fire? need some advice.
     
  5. WBahn

    Moderator

    Mar 31, 2012
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    That depends on the specifics of both the power supply and the appliance. As you exceed a certain amount of current, most supplies will suffer a drop in voltage as more current is demanded. That drop in voltage can cause problems in the appliance, particularly if they have control electronics that won't operate properly in an undervoltage condition. Your TEC itself shouldn't have that problem (but what you are controlling it with might). Many supplies are designed to self-limit to protect themselves, but others won't and will overheat, be damaged, or even destroyed with a prolonged overload. You should use an appropriately sized fuse intended to protect both.
     
  6. rjng90

    Thread Starter New Member

    Feb 4, 2015
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    hi i managed to get my TEC working the problem is that the Hyper N520 cooling fan has 3 wires, a red and a black and a yellow. I know how to connect the red and black but not sure how to connect the yellow wire (for DC rpm control) to control its speed. currently, based on this circuit diagram which is working, the speed of the fan is still slow. basically the fan is in parallel with the motorcontroller (connected to peltier) and both are in parallel to power supply. Where do i connect yellow wire to?
     
  7. rjng90

    Thread Starter New Member

    Feb 4, 2015
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    ok i just realsied yellow wire is to check speed of rpm. but i heard this N520 cooling fan is slow and silent, but does slow NECESSARILY means poor heat sink/fan in powering a peltier? just want to get the correlation right guys thanks!
     
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