Engr. Pepugal & Engr. Largo: September 2015

9/26/15

FIRST ORDER CIRCUITS: SOURCE FREE RC AND RL CIRCUIT

FIRST ORDER CIRCUIT
-A circuit that can be simplified to a Thevenin's or Norton's equivalent connected to either a single equivalent inductor or capacitor.

THE SOURCE-FREE RC CIRCUIT
-an electric circuit composed of resistors and capacitorsdriven by a voltage or current source. A first order RC circuit is composed of one resistor and one capacitor and is the simplest type of RC circuit.

IN SOLVING THE RC CIRCUIT

$V(t)=V_0 e^{-\frac{t}{RC}} \ ,$

The time required for the voltage to fall to

is called the RC time constant and is given by

SOURCE FREE RL CIRCUIT
-is an electric circuit composed of resistors and inductorsdriven by a voltage or current source. A first order RL circuit is composed of one resistor and one inductor and is the simplest type of RL circuit.

IN SOLVING THE RL CIRCUIT

$i(t) = i(0)e^{-\frac{R}{L} t} = i(0)e^{-\frac{1}{\tau} t}$

$\tau = {L \over R}$

SAMPLE RL CIRCUIT

9/19/15

MAXIMUM POWER TRANSFER

MAXIMUM POWER TRANSFER THEOREM

maximum power transfer theorem states that, to obtain maximum external power from a source with a finite internal resistance, the resistance of the load must equal the resistance of the source as viewed from its output terminals.

(RTH=RL)

PROVE THAT RL=RTH

Computing the Power Transfer is equal to V2/4(RL)