"Hawke" wrote in message
news:NWm5k.1360$_n.847@fe95...

wrote in message
...
On Jun 15, 7:21 am, wrote:
how do you imagine imaginary
numbers - positive and negative phasors and vectors - +j -j - I KNOW
they mean something, but its just chicken tracks to me.

Andrew VK3BFA.

And if I have stuffed up the cutting and quoting bit above and got the
names wrong - sorry, no offense meant.


Don't worry about it. Just accept it.

Don't let the name imaginary bother you. Use the term complex
instead.

With DC in the steady state, the power is Voltage times Current.

With AC the power is the Voltage times the Current that is in phase
with the voltage. P = E I cos theta. If theta is 45 degrees then Cos
theta is 1/ 2^.5

Now if you think of a 45, 45, 90 triangle , then the current that is
in phase can be represented by one of the legs of the triangle. The
total current is represented by the hypotenuse. So what is the other
leg of the triangle? It is the current that is 90 degrees out of
phase with the voltage. It is orthogonal to the in phase current.
That is you can change the value without affecting the other leg
( you do affect the total current, but not the in phase current )

Now if you can see that, then all that stuff about complex numbers is
just a way to do the calculations instead of drawing triangles. Got
two vectors you want to add. Just draw one and then draw the second
with the beginning of it at the end of the first.
Or you can break both vectors into two parts that are orthogonal and
add the " real " parts and then add the "imaginary" parts.And you end
up with the same total length and direction, but you did not have to
draw the two vectors.

I hope that is clear to you. It is to me.

Dan
AD7PI


Thanks for proving my original point far better than I ever could. What is
clear to you is completely incomprehensible to most of the rest of us.
That
is the way it works. Six foot eight inch basketball players have no
trouble
dunking either. They wouldn't be able to understand why you can't except
that you are lacking something they have. That's the way it is with math.
Those who can comprehend it have something the rest of us don't have.

What most of them had was better teachers. My Russian neighbors are math
whizzes. They had great teachers.

But I
learned long ago that the math guys were often very, very bad at all kinds
of other things and different ways of thinking. Only a very few lucky
people
can comprehend higher math and do everything else well too. You don't want
to compete with those guys unless you happen to be one of them. It's like
the time I was watching a lecture on cable TV and it was an advanced
computer science class. I'm no dummy but I couldn't understand a thing the
teacher was saying. It was so far over my head it was a joke. But for the
people that can comprehend it that were in the class it made perfect
sense.
It's a case of one having to know one's limitations, I guess.

I'd give it 90% teachers, 10% personal limitations. And 50% individual
interest. g

--
Ed Huntress