How many watts is this?

Question

i know the equation watts = volts * amperes but i don't know which volts to use. now i'm looking at a converter. it's takes in 220 V and converts it to 15 V. it's 1 ampere. So which volts should i used in the equation? the 220 or 15?

Answer 1

if it is int the 220 V part of the circuit then you use 220 V, otherwise the 15V.

Answer 2

They will tell you at which voltage the ampereage is applied.

If it says' Output 15V. - 1Amp.` - that's 15Watts.

If it's 'Input 220V. - 1 Amp.' -  that's 220 Watts.

If they give you both, and they don't quite match up,

you can figure the heat loss from the difference.

Answer 3

You have input and output.

input 220v @ ?a  output 15v @ ?a

A power supply taking you 220 volts to 15 volts should step up the current approximately (220v/15v=14) 14 times.

220 input at 1 amp would provide about 15 volts at 14 amps. This would be a large unit  about the size of novel.

15 v at 1 a would require 220 v at .07 amps. the size of a wall charger.

Answer 4

all of the other comments are correct.

it is an ambiguous question.

in my experience, if a converter says it can "handle" 1 amp, it is usually referring to the output, being as it is the output device which determines the actual load.

Answer 5

you should know if your so freaking start! =]

Answer 6

Depends on where you measure the 1 amp. If it's on the input side then power = 220*1 = 220 watts.

If it's on the output side, then power = 15*1 = 15 watts.