<1>2004200467 Jin-ho Cho<2>2007102861 Jeong-min Cho<3>2007102860 Eun-jin Cho<4>2007101329 Song-hee Cha<5>2003202089 Sun-woong Jin

(1) Thévenin's theorem and Norton’s theorem

(2) Loading Effect (In OP AMP circuit) -Ex)Voltage source -Ex)Current source (3) Load

In electrical circuit theory, Thévenin's theorem(or Norton) for linear electrical networks

states that any combination of voltage sources, current sources and

resistors with two terminals is electrically equivalent to a single voltage source V(or current source) and a single series resistor R

Ex)

VAB= 7.5V = Vth

R1 || (R2+R3) = 2kΩ = Rth

Vth/Rth = 3.75mA

The gain of an amplifier generally depends on its source and load terminations, so-called loading effects that reduce the gain.

※

※Loading Effect

If an electric circuit has a well-defined output terminal, the circuit connected to this terminal is the load.

The term 'load' also refer to the power consumed by a circuit

Vs=10V

IL

Imax=1A 10W power consumed

RL VL IL

1MΩ

1kΩ

10Ω

10V

10V

10V

1V

10uA

10mA

1A

10A

Overload

1Ω

Imax=1A