Continue to Site

Welcome to our site!

Electro Tech is an online community (with over 170,000 members) who enjoy talking about and building electronic circuits, projects and gadgets. To participate you need to register. Registration is free. Click here to register now.

  • Welcome to our site! Electro Tech is an online community (with over 170,000 members) who enjoy talking about and building electronic circuits, projects and gadgets. To participate you need to register. Registration is free. Click here to register now.

phazor question

Status
Not open for further replies.
for this signal
[latex]
I_s(t)=sin(t)
[/latex]
i have this equation
[latex]
I_L(1-CL+jCR+jcz)=I_s
[/latex]
then the next line is
[latex]
I_L(1-CL+jCR+jcz)=j
[/latex]

why they substitute j=I_s
 
for this signal
[latex]
I_s(t)=sin(t)
[/latex]
i have this equation
[latex]
I_L(1-CL+jCR+jcz)=I_s
[/latex]
then the next line is
[latex]
I_L(1-CL+jCR+jcz)=j
[/latex]

why they substitute j=I_s
[latex]
sin(t)=cos(\frac{\pi}{2}-t)=cos(t-\frac{\pi}{2})
[/latex]
the formula of the signal is
[latex]
Is=Acos(\omega t+\phi)
[/latex]
then we transform it to the phasor representation formula
[latex]
Is=Ae^{j\phi}
[/latex]
so we get
[latex]
Is=1e^{-j\frac{\pi}{2}}
[/latex]
and when we look at this expression as oilers formula we get
the Is=-j

so why its written Is=j
?
 
Last edited:
Hi,

Isnt that just j*w with w=1?
sin(t) is sin(w*t) or sin(1*t).

For ac analysis, s is made equal to j*w
and j*w is used to represent a sinusoidal source.
 
Last edited:
by what formula?

without formula it is well known in Electrical engineering that the difference between 2 which means ( 2 ± 0j ) and 2j which means ( 0 + 2j ), is that although they are representing the same magnitude, but the are 90 deg apart. If you added them together, they gives 2 + 2j in rectangular form , which equals to 2.83 with 45 deg or in polar form.

complex number is explained in:

Complex Number -- from Wolfram MathWorld

check Euler formula link, you may find the answer for your problem. :confused:
 
Last edited:
Status
Not open for further replies.

Latest threads

New Articles From Microcontroller Tips

Back
Top