Electronica

1) En el circuito siguiente:

[pic]

2r

[pic]h





Req:

















a) Hallar PR (t) en el instante VL (t) = 8v
b) Pmax L (t) = ?
c) P L (t) = ? en el instante PR (t) = 20w


Circuito Equivalente :
















a) i(t) = [pic] ( i(t) = [pic] ( i(t) = [pic] ….. I

( Pero VL (t)= L[pic]i(t) 
VL (t) = [pic] 
VL (t) = [pic]
VL (t) = [pic] …. II

( Dato: VL (t) = [pic]


En II :
[pic] ( [pic]



( Hallando PR (t) :

PR (t) = R [pic] i2(t) PR (t) = 4(3(1-e- 60t)) 2

PR (t) = 36(1-e(-60x0.007)) 2


b)









Reemplazando :

( (P L (t))’ = 0 ( (36(e -60t - e -120t))’ = 0
( 36 (-60e -60t - 120e -120t) = 0 ( -60 (e -60t - 2e -120t) = 0
( e -60t - 2e -120t = 2 ( [pic]
( e 120t . e -60t = 2 ( e 60t = 2
( [pic] ( t2 = 0.012 seg

( Pmax L (0.012) = 36 (e(-60 x 0.012) - e(-120 x 0.012)) Pmax L (0.012) = 9 var


c)








( PR (t)=20 w
( 36 (1 – e-60t)2 = 20
( t3 = [pic]
( t3 = 0.023 seg


( PL (0.023) = 36 (e(-60 x 0.023) - e(-120 x 0.023)) PL (0.023) = 6.8 var


























2) En el circuito siguiente:


D E D C


6Ω

C C C BB A + - A


( Hallando Leq :x simetría l = [pic] ( Hallando Req: x nodos:












a) Hallar PR (t) en el instante VL (t) = 16v
b) Pmax L (t) = ?
c) P L (t) = ? en el instante PR (t) = 50w

Circuito Equivalente :












a) i(t) = [pic] ( i(t) = [pic] ( i(t) = [pic] ….. I

( Pero VL (t) = L[pic]i(t) VL (t) = [pic] 
VL (t) = [pic]
VL (t) = [pic] …. II

( Dato: VL (t) = [pic]


En II :
[pic] ( [pic]


( Hallando PR (t) :

PR (t) = R [pic] i2(t) PR (t) = 5[pic] PR (t) = [pic]……III
PR (0.134) = [pic]


b)
















Reemplazando :

( (P L (t))’ = 0 ( [pic]’ = 0( [pic] ( [pic]
( [pic] ( [pic]
( [pic] ( [pic]
( [pic] ( t2 = 0.416 seg


( Pmax L (0.416) = [pic] Pmax L (0.416) = 20.0 var


c)








( PR (t) = 50 w
( [pic]
( t3 = [pic]
( t3 = 0.938 seg


( PL (0.938) = [pic] PL (0.938) = 13.2 var


3) En el circuitosiguiente:

D E D C




C C C B





B A + - A


( Hallando Leq :x simetría ( Hallando Req: x nodos:















a) Hallar PR (t) en el instante VL (t) = 30v
b) Pmax L (t) = ?
c) P L (t) = ? en el instante PR (t) = 100wCircuito Equivalente :












a) i(t) = [pic] ( i(t) = [pic] ( i(t) = [pic] ….. I

( Pero VL (t) = L[pic]i(t) 
VL (t) = [pic] 
VL (t) = [pic]
VL (t) = [pic] …. II

( Dato: VL (t) = [pic]


En II :
[pic] ( [pic]


( Hallando PR (t) :

PR (t) = R [pic] i2(t) PR (t) =11[pic] PR (t) = [pic]……III
PR (0.802) = [pic]


b)















Reemplazando :

( (P L (t))’ = 0 ( [pic]’ = 0
( [pic] ( [pic]
( [pic] ( [pic]
( [pic] ( [pic]
( [pic] ( t2 = 0.567 seg


( Pmax L (0.567) = [pic] Pmax L (0.567) = 145.5 var


c)...