I'm a second year student at university, and wanted a simple power supply to test a couple pet projects without going all the way to the lab. I picked up a Power-One MPU150-4350 on the cheap at a second-hand electronics store. The output specifications section seems to state that, for the 3.3V output (V1), 3A is the minimum load while 30A is the maximum.
I know that running a switched mode power supply without a load can produce inaccurate output voltages and even damage the system, although I don't understand exactly why this is the case. However, having to always pull at least three amps from a 3.3V rail seems excessive to me.
What is the minimum load I can put on each of the outputs without damaging the power supply?
Will running a switched mode power supply without a load for short periods of time damage it? Or just produce unstable output voltages?
Why don't switching power supplies like low currents?
If you only know the answer to one of these please don't hesitate to post. Anything that helps gets +1.
Edit This article will be very helpful for beginners (like me), the answer below is an in-depth and very useful explanation of why SMPSs can fail due to over-voltage when not sufficiently loaded.