Download 생체계측 #5

<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
IL
RL
Vs=10V
10W power
consumed
IL
1MΩ 10V
10uA
1kΩ
10V
10mA
10Ω
10V
1A
1V
10A
1Ω
Imax=1A
VL
Overload
Imax=1A