Guys/girls. So I am taking apart a NAS and fitting in into a small PC case for better cooling. ATM the NAS has a 12v 3a PSU. However, Tre has very generously sent me a 300w PC PSU because I need a way of powering up the lights on the case, fans and etc. Now obviously I am going to gut Tre's PSU and only keep what I need but my biggest concern is the NAS itself. I know this is a stupid question but I'm a worrier so I figured I would ask any way. If the NAS uses 12v @ 3a would it be safe to lop off the power connector and fit it to the PC PSU? obviously the PC PSU has a much higher AMP rating but if I'm correct in thinking the NAS will only use what it needs yes? So as stupid as I am for answering my own question (sorta) it would work and be safe so long as I get the polarity correct, yes? Obviously I could use two power sources but it would be much cleaner if I can use one.
The amperage is only drawn when needed. The voltage is the more important factor. I'd say it should be fine, but I am no electronics engineer.
I am no electronics engineer either but I've always found as long as the voltage is correct too many amps on the PSU just means it won't need to work very hard to power your NAS/device (too few amps will generally work for a while but it's over stressing your PSU and the PSU will probably fail pretty rapidly but this is unlikely to damage the device your powering)
You should be fine, except the PSU may not be rated for continuous load on a single rail. I was using an old PC PSU to power an ASIC rig via its 12V rails and despite being well within the limits it released the magic smoke thusly: That said, my ASIC box was pulling in a lot more than the 36W your NAS is rated for, so you'd probably be OK.
