A Conversation for Complex Numbers - an Introduction

Electrical Engineers call it j not i

Post 1

highamexpat


Takes me back to when I was studying electrical engineering quite a few years ago. the letter i is reserved for current so we electrical engineers call it j not i.

it's very useful for carrying out calculations on inductive and capacitive circuits where the resistance is the real part and the inductance is -j & capacitance is +j (inductive current lags the resistive current by almost 90 degrees & vice versa for capacitive.

We also generally convert it to polar coordinates which simplifies multiplication and division if my memory serves me well.


Electrical Engineers call it j not i

Post 2

Gnomon [195]

..but makes addition and subtraction much harder.smiley - smiley


Electrical Engineers call it j not i

Post 3

Icy North

Hi highamexpat,

I too studied electrical engineering many years ago - so long in fact, that I forgot to mention this. Many thanks for posting it here!

Those co-ordinate systems always confuse the hell out of me. Did you use those Smith charts, which we plotted things on? If I had some now, I'd give them to my daughter to colour in.

smiley - cheers Icy


Electrical Engineers call it j not i

Post 4

highamexpat

Hi icy

I never had much problem with with Argand diagrams or complex numbers though Calculus was another story.

I found a great calculator which let you input in the form a+jb & it would do any calculation you wanted & switch between cartesian or polar coordinates at the push of a button.

Never had anything to do with Smith diagrams (that I can remember) the worst ones were those logic charts for Boolean algebra. i could never get my head round them.

Cheers highamexpat


Electrical Engineers call it j not i

Post 5

Muddy90

Blimey

This conversation brings back memories, I spent an age racking my brain over this then I to discovered that calculator.


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