what is the different?

[AMD]

hi all...
just wondering for quite some time (more than a year xtually.. hehehe)...
well, what if the different between PSU (power supply unit) and a battery?
i'm still confiusing... is it depends on what kind of application that we use and
how to determind it best?

[sich]

PSU should be refer to circuits like what we have in a PC. The PSU in PC converts AC power to DC 12V and 5V to supply the mobo, drives and so on. So my understanding about a PSU is the system/circuit that prepares the required power supply(s) for another system/circuit and monitor the output to maintain its value.

[AMD]

hmm.. so, PSU is a designated hardware unit to meet electronic/electrical equipment...
I have seen many PSU that being used on equipment with different spec...
let say, I have an equipment that will consume 2A current and using 5V voltage. I have 2 PSU to choose..
1) PSU#1 5V 2A
2) PSU#2 5V 4A
which one is better for me to use? I believe both PSU can be use right, but is there any known side effect that may rise?

[sich]

I don't know what equipment u want to supply with the PSU, It's better to get the one with the power rating higher than your need. Always give a space before hitting the limit. Lets say if ur equipment's efficiency will reduce over time (like electric motor, automation system...), the power needed to run the equipment will increase for it to produce the same result if compare to a brand new unit. Besides, usually efficiency will drop when it reaches the max value - could be due to overheat issue. However, it depends on the specs of materials, chips, topology & etc in the unit.
Since there're 2 choices and only 1 is higher than the power you need and if cost is not a matter, i'll suggest u to get the 4A one.