enquiry on voltage amperage and power for assembly of device

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 with sufficient heatsinks) 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 5 questions on a step by step basis so as to avoid confusion. I am quite weak in terms of power and voltages and amperages ... thanks a bunch!

It would be wise to use a power supply that can supply more amps than the total that you could possibly use when everything is added together.

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. The applicance will do its best to get its full 10A and is likely to damage the power supply and possibly cause a fire.

I presume you are not also thinking of powering your Arduino from that power supply.


I don’t think you realize it is not up to you how much current the peltier draws or how much current the power supply delivers. Any power supply draws the amount of current
determined by Ohm’s Law based on the fact that I = V/R | Where “R” is the resistance
of the load. If you say the peltier needs 10 A then that’s what it will draw. You can’t connect a 1.2 ohm load to a 12 V power supply and expect it to behave like a 1.4 ohm load. You could limit the peltier current by inserting a power resistor in series with it.
1.4-1.2=0.211 ohms

12V/(0.211 ohms + 1.2 ohms) = 12 V / 1.411 ohms = 8.5 A

V R = I * R = 8.5 A * 0.211 ohms = 1.8 V

P= I * V = 8.5 A * 1.8 V = 15.25 Watts

R = 0.211 ohms/20 W

raschemmel: R = 0.211 ohms/20 W

Where could you buy one of those? :o

Amico 10 x 0.1 Ohm 5% Axial Lead Ceramic Cement Resistors 10W


$6.56 for free 2 days shipping.

Put 2 resistors in serial.

Put 2 resistors in serial.

(He means in SERIES)

raschemmel: (He means in SERIES)

Still won't dissipate 20W, though.