1. Han Q Le© ECE 3336 Introduction to Circuits & Electronics Lecture Set #8 Method for Linear Circuit: Phasor Part 1: Background Dr. Han Le ECE Dept.

2. Han Q Le© Phasors: AC Circuits – Background Concepts Note: The main lecture is in the Mathematica file – this is only for basic discussion

3. Han Q Le© Outline Time-varying circuits and signals Introduction to mathematical techniques: – Harmonic functions – Complex analysis – Fourier analysis and transform – Phasors Applications of mathematical techniques to physical problems and circuits

4. Han Q Le© It is more natural to have time- varying signals & circuits than time-constant circuits

5. Han Q Le© An example of signal

6. Han Q Le© Certain mathematical tools and techniques are highly useful for certain types of problems For NVM and MCM, linear algebra (the math principle) and matrix (the tool) is highly useful For time-varying signals and AC circuits, it will be Fourier transform (the math principle) and phasor (the tool) Again, it is important to use the tool rather than get lost or tangled with the tool Mathematical tools and techniques

7. Han Q Le© So, phasor is worth learning because it makes things so easy

8. Han Q Le© Outline Time-varying circuits and signals Introduction to mathematical techniques: – Harmonic functions – Complex analysis – Fourier analysis and transform – Phasors Applications of mathematical techniques to physical problems and circuits

9. Han Q Le© Fourier transform Harmonic function Complex numbers &analysis Phasors

10. Han Q Le© Link to Mathematica file

11. Han Q Le© Outline Time-varying circuits and signals Introduction to mathematical techniques: – Harmonic functions – Complex analysis – Phasors – Fourier analysis and transform Applications of mathematical techniques to physical problems and circuits

12. Han Q Le© Applications of mathematical techniques Fourier transform Harmonic function Complex number &analysis Phasors Signal and AC circuit problems RLC or any time-varying linear circuits. Applicable to linear portion of circuits that include nonlinear elements Signal processing signal analysis (spectral decomposition) filtering, conditioning (inc amplification) synthesizing