Day 20 Sinusoids and Phasors (NO LAB)

We started the day with talking about phasors and sinusiods. We went with f = 1/T and w = 2pif. Our white board work below shows an example done in class with the right transformations.

White board work of a sin wave of V(t). It is shifted up .03 with an amp of .17

White board work continued with a clear picture of the interpretation of V(t).

White board work of the equation of the sine wave.

We then talked about the phasor graph and did an example below.

White board work of the phasors on the graph.

More detalied explantion for phasor where C  = sqrt(X^2 + y^2) and the phase angel tan-1(y/x),
x = rcosphi and y = rsinphi. We can switch from REKT to polar and use REKT for +- and Polar for multiplication and division.

White board work of stuff stated above.

We then move onto an example to try. We first transformed phasor to time domain and then added the relative components together and then back to phasor.

White board work of the transformation of phasor to time domain for addition then back to phasor for answer.

More white board work continued with the phasor answer taken to negative 1 power.

White board work continued with the -1 of the phasor which we get to be .02 @ -45.

We move onto examples of going time domain to phasor for many problems.

White board work of many examples of time domains to phasors. If sine add -90 to it. If negative sine add 90.

We then move onto the more examples.

White board work of V =  j8e-j20.

More white board work of examples of phasors and time domain. It was important to use the magnitude by taking the sqrt( real^2 + fake^2) and then the tan-1(fake/real) for angle.

White board work that used importation information named above and then translated back to time domain.

More white board work.

White board work with the angles and mags drawn.

Another example to try with real numbers and components.

White board work with real components and numbers we found L = .1H V = 1/L di/dt, i = integral of v. V = 12 cos(60t+45) and finally then do the phasor transformation and then back to time domain, we subs 90 since it was sin.

Last part of the day we talked about our E44 projects. Mine is here drawn out with beautiful pictures and notes. It will be the best fly killer by laser ever.

Beautiful picture of penmanship and artistically ability used to convey a wonderful idea of having less flies in the world.

In summary there was no lab today. We spent the whole day talking about phasors and time domain and did a lot of examples. Some notes to take are that if it is sine sub 90 from phi, if sine is negative add 90. If it is cosine leave alone. Rect is for addition and subtraction and polar is for multiplication and division. Lastly talked about my project "Fly Killer, by lazer".