# Voltage, Watt, Current.... Resistance?

Discussion in 'General Electronics Chat' started by cheddy, Nov 1, 2007.

1. ### cheddy Thread Starter Active Member

Oct 19, 2007
87
0
Hey i'm just exploring the interdependency of electronic values please explain to me if my logic is correct here.

Let's say we have a power supply that supplies 12V and 100W.

P=E*I
100W=12V*I
I=8.3A

So another way to state 12V, 100W is that it's 12V 8.6A.

E=I*R
12V=8.3A*R
R=1.45ohm

Another way would be to say that the power supply can supply 12V just as long as the parallel power distribution resistance exceed 1.45ohms?

2. ### John Luciani Active Member

Apr 3, 2007
477
0
A better way to say it would be that the power supply can deliver 12V with a maximum
current of 8.3A.

When determing whether a power supply is suitable for an application it is usually
more convenient to use volts and amps rather than volts and ohms.

(* jcl *)

3. ### cheddy Thread Starter Active Member

Oct 19, 2007
87
0
I agree completely.

4. ### Salgat Active Member

Dec 23, 2006
215
1
Isn't Ohms law beautifully simple?

5. ### recca02 Senior Member

Apr 2, 2007
1,211
0
specification of current and voltage removes ambiguities since m/c may draw more current for a given power due to diff pf.