Filtry elektryczne

Zpodł

Zpodł

Zpodł

Zpoprz

Zpoprz

Zpoprz

Tłumienność

U

I

a = ln 1 = ln 1

U

I

2

2

[ a] = 1 N = 8,686 dB → 1 dB = , 0 115 N

U

I

a

1

1

(

)

20log

20log

dB =

=

U

I

2

2

F i l t r d o l n o p r z e p u s t o w y L

L

2

2

L

C

C

C

2

2

ω

2

0 =

LC

R

u

u

1( t)

C

2( t)

U ( s) 1

1

1

U ( s

1

) =

=

U ( s) =

U ( s

2

)

sC

sRC

1

+ 1

s

1

1

τ +1

R + sC

1

U ( s) =

U ( s) ⇔ s 2

>> 1

s

1

τ

τ

1

1

U ( jω ) =

U ( jω ) =

U ( jω ) 2

jω RC +1 1

jωτ +1 1

−1+ jωτ

−1+ jωτ

=

(

=

jωτ + )

U

jω

U

jω

1 (− jωτ + ) (

)

(

)

1 1

2

ω τ +1 1

2

U ω

1

( ) =

U ω

( )

2

ω τ

1

2 2 +1

gdzi e ω = 1 RC =1 τ

0

| k | , a 1

a

| k |

0 , 7 0 7

a

0 , 2 9 3

0

ω

ω

0

F i l t r g ó r n o p r z e p u s t o w y C

2

C

2

C

L

2 L

2 L

ω

1

0 = 2

LC

C

u

u

1( t)

R

2( t)

U ( s

1 )

sRC

sτ

U ( s) =

R =

U ( s) =

U ( s

2

)

sRC

1

+

s

1

1

1

τ +1

R + sC

U ( s) = sτ U ( s) ⇔ sτ < 1

2

1

j

j

2 2

U ( jω

ωτ

) =

U ( j ) =

+

U ( jω

2

)

j

1

ωτ

ω

ωτ ω τ

+

2 2

1

1

ω τ +1

ωτ

U ω

( ) =

U ω

( )

2

ω τ

1

2 2 +1

gdzi e ω = 1 RC =1 τ

0

| k | , a 1

a

0 , 7 0 7

| k |

a

0 , 2 9 3

0

ω

ω

0

F i l t r p a s m o w y L

C

C

1

1

1

L 1

L

C

2

1

ω = ω ω

0

1 2

| k | , a

| k |

1

a

0 , 7 0 7

0

ω

ω

ω

ω

1

0

2