Do i use the input voltage/amps or the output voltage/amps when calculating how much watts i am using?

Question

I am trying to figure out how many watts my ps2/mini tv are using but on the adapters it has input 100v-200v 1.2A, and that is a LOT of watts. Do i use the output which varies from 8-10v and 4-5A? Thanks for anyone who can help

Answer 1

i'd say the input terms , bec the output is the input+Internal Losses , so according to ur current rating u can say how many watts u are using with the 1.2 amps

Answer 2

The problem with adapters is that they give only the maximum loaded ratings. The actual power used by your system depends on the load so you should examine the ps2/mini tv for what they need. Should be on a plate on them or it may be in the literature that came with them.

Answer 3

Let me get this straight. The adaptor says 100v-200v 1.2A

and it says 8-10v and 4-5A.

The number of watts you use depends on what the unit is doing. In some modes it will use more power than others.

100v-200v 1.2A -- I think this is actually 100v-240v 1.2A, as 200v is not useful, whereas 240 means it will work in Europe. Most appliance are specd for 100-240v for that reason.

The 1.2a number will vary depending on the voltage you plug it into. At 240v it will use a lot less current than at 100v. So I would use 100*1.2 or 120 watts as the MAX input power.

DC power out, I'd take 9v and 5 amps, or 45 watts as the power output. But even 10v and 5a is only 50w

I have no idea why they are so different, it could be a game of specmanship. or a very inefficient supply.

Bottom line, use 120 watts.