Is my peltier maxing out the power supply?

Harlequin

Harlequin

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Mar 4, 2005
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I'm working on a peltier-cooled external drive. The power-supply for the external drive says the output is 1.5A at 12V and 1.5A at 5V. My multimeter shows that the peltier, when connected, is drawing 12V 2A from that supply. (It will happily draw 3-4A on a larger supply). Furthermore, because of this load, the 12 supply voltage drops from 12.3V down to 11.8V when I switch on the peltier.

My question: Is the peltier over-taxing the supply in a way that could damage the supply or shorten its life? Will a switch-mode regulated supply produce more current than it is safely rated for if a current-hungry device is attached? Or do they simply not produce more than they're rated for (in which case I'm fine), or do they shut down when over-taxed? (which case I'm also fine).

Is the 2A actually within spec because there is little loading on the 5V and it's really the overall wattage that is the limit, meaning it's rated for 25.5 Watts (adding wattage of 12V to 5V), which sounds about right for the draw of the peltier + idle drive?

(Unfortunately I can't measure the load on the 5V line without risking disconnecting the drive while it's running)

The voltage remains within the specified tolerance despite the load, so I'm thinking it's ok, but I don't know much about these adaptors, so I'm wondering if there are any power supply gurus out there...

Or to put it another way, how could a switch-mode power supply get damaged? If it's by overheating, then it might be less of a problem, because the supply will soon be peltier cooled [grin], otherwise, I'll have to add "replace the power supply" to the To-Do list :)
 
A Peltier will max out your PSU, in fact, a lot of people have dedicated a PSU to a single peltier!
 
Schpanky:
But is maxing out the PSU a problem for the PSU?
Ie, for all I know, someone might want to avoid maxing out the first PSU by using a second because they won't be getting the maximal amount of power/cooling out of the peltier if the PSU isn't up to it, rather than because there are any actual problems with maxing out the PSU if you're happy to have your peltier underperform (as I am).

Peach:
Several reasons. Mainly because I want to do a watercooling mod for the hell of it, but don't want as big a project as a full case mod. Partly because I want silent cooling. Partly because I have all sorts of cooling parts kicking around that I like, and would like to use, but are probably a bit under-powered for a modern computer.
 
I would say to go get a dedicated PSU for the pelt. I would think it would be nescessary as you don't want to max your PSU. Heck, for what I know, it could explode if you max it out. Only from what I have seen of people's pelt systems, they all had a dedicated PSU for the pelt, so I would go for the dedicated PSU.

Just my $0.02. I am no expert on the subject by any means though. I only make my suggestion based on what I've seen others do.
 
Oh I would kill for that PSU. I want to pelt cool, but I am poor and lacking in power and money :[
 
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