Alternating Current 1
In ac,the current magnitude and direction is constantly changing.The current(magnitude and direction) can be represented by means of a graph.
The top quadrant represents current in one direction and the bottom quadrant represents current in the other direction.
Since the current magnitude is always changing, it is necessary to identify an average current, or a dc equivalent.
This avearge value is called the average current or Irms (the green line). This is called root mean square, which is really a complicated way of saying "average".
How do the numbers work?
Easy!
Assume that Imax = 20A.
(This would be the peak on the graph)
Calculate the average, Irms.
(This would be the peak on the graph)
Calculate the average, Irms.
Equation
20 = 1,41(Irms)
Irms = 14,18A
You must learn the above equation.