I understand the specs stamped on almost all of the DC power adapters I've seen, but I have one with some extra values that confuse me. Specifically, the adapter says:
INPUT: 100-240VAC, 50/60Hz max. 700mA, 50VA OUTPUT: 12VDC, 2A
I'm in the U.S., so the input is 120VAC at 60Hz. I'm using this to intermittently power a 12VDC solenoid that draws 540mA.
What I don't understand is the line in the middle. I know 50VA indicates apparent power, which is an upper bound on real power.
That seems plausible given that the real power at the output could be 48 Watts.
But I don't understand how that's consistent with the 700mA limit. If that that's an RMS current, then it could never reach 700mA at any voltage in the given range without exceeding the 50VA. So I guess the 700mA is the maximum instantaneous current draw. Is that right?
Does that "max" line contain useful information to someone (like me) who's trying to ensure the adapter can power a 12VDC solenoid that draws 540mA?