Pi Filter

6

10

C

1

10

6

10

C

2

10

L

1

R

rect

100

R

choke

100

R

load

3000

input amplitude

100

rectifier

full wave

half wave

t

max

0.25

zoom in

A pi filter is used to attenuate noise in power and signal lines. This Demonstration shows the output voltage from a DC power supply with a pi filter, which consists of an inductor (choke) between a pair of capacitors, as shown in the schematic in the upper-left corner. You can vary all the component values, including load resistance and internal resistances of the rectifier/input supply and the choke.