The Fourier transform gives a frequency-domain description of an aperiodic time-domain
function.
Depending on the nature of the time-domain signal, there are few ways to find the Fourier
Transform
If the time-domain signal is a well-behaved pulse of finit

Instantaneous power is the product of the instantaneous terminal voltage and current, or p = vi
- The positive sign is used when the reference direction for the current is from the positive
to the negative reference polarity of the voltage
- The frequency

The general equation for a sinusoidal source is v = Vmcos(a)t + 4>) (voltage source), or i = Im
cos(ar + (j>) (current source), where Vm (or Im) is the maximum amplitude, a> is the
frequency, and <f) is the phase angle
The frequency, a>, of a sinusoidal r

The Laplace transform is a tool for converting time domain equations into frequency-domain
equations, according to the following general definition:
- .cfw_f(t)= Integral of f(t)e^-s tdt = F(s)
- where f(t) is the time-domain expression, and F(s) is the f

A frequency selective circuit, or filter, enables signals at certain frequencies to reach the output,
and it attenuates signals at other frequencies to prevent them from reaching the output.
The passband contains the frequencies of those signals that are

A periodic function is a function that repeats itself everv T seconds
A period is the smallest time interval (T ) that a periodic function can be shifted to produce a
function identical to itself
The Fourier series is an infinite series used to represent

Active filters consist of op amps, resistors, and capacitors. They can be configured as low-pass,
high-pass, bandpass, and bandreject filters. They overcome many of the disadvantages associated
with passive filters
A prototype low-pass filter has componen

The two-port model is used to describe the performance of a circuit in terms of the voltage and
current at its input and output ports
No independent sources are inside the circuit between the ports
No energy is stored inside the circuit between the ports

We can represent each of the circuit elements as an s-domain equivalent circuit by Laplacetransforming
the voltage-current equation for each element
Resistor: V = RI
Inductor: V - sLl - LI()
Capacitor: V = (1/sC)I + V/s
We can perform circuit analysis

When analyzing balanced three-phase circuits, the first step is to transform any A connections
into Y connections, so that the overall circuit is of the Y-Y configuration
A single-phase equivalent circuit is used to calculate the line current and the phas