Bueno, de acuerdo con ' Ley de Faraday ' en una serie de circuitos RLC:
$$ \ text {V} _ {\ space \ text {C}} \ left (t \ right) +0+ \ text {V} _ {\ space \ text {R}} \ left (t \ derecha) - \ text {V} _ {\ space \ text {in}} \ left (t \ right) = - \ text {V} _ {\ space \ text {L}} \ left (t \ right) \ tag1 $$
Ahora, sabemos algunas cosas:
- $$ \ text {I} _ {\ space \ text {C}} \ left (t \ right) = \ text {I} _ {\ space \ text {in}} \ left (t \ right) = \ text {V} _ {\ espacio \ text {C}} '\ left (t \ right) \ cdot \ text {C} \ tag2 $$
- $$ \ text {V} _ {\ space \ text {R}} \ left (t \ right) = \ text {I} _ {\ space \ text {R}} \ left (t \ right) \ cdot \ text {R} = \ text {I} _ {\ space \ text {in}} \ left (t \ right) \ cdot \ text {R} \ tag3 $$
- $$ \ text {V} _ {\ space \ text {L}} \ left (t \ right) = \ text {I} _ {\ space \ text {L}} '\ left (t \ right ) \ cdot \ text {L} = \ text {I} _ {\ space \ text {in}} '\ left (t \ right) \ cdot \ text {L} \ tag4 $$
Entonces, obtenemos:
$$ \ text {V} _ {\ space \ text {C}} '\ left (t \ right) +0+ \ text {V} _ {\ space \ text {R}}' \ left ( t \ right) - \ text {V} _ {\ space \ text {in}} '\ left (t \ right) = - \ text {V} _ {\ space \ text {L}}' \ left (t \ right) \ space \ Longleftrightarrow \ space $$
$$ \ text {I} _ {\ space \ text {in}} \ left (t \ right) \ cdot \ frac {1} {\ text {C}} + 0+ \ text {I} _ {\ space \ text {in}} '\ left (t \ right) \ cdot \ text {R} - \ text {V} _ {\ space \ text {in}}' \ left (t \ right) = - \ text { I} _ {\ space \ text {in}} '' \ left (t \ right) \ cdot \ text {L} \ space \ Longleftrightarrow \ space $$
$$ \ text {V} _ {\ space \ text {in}} '\ left (t \ right) = \ text {I} _ {\ space \ text {in}} \ left (t \ right) \ cdot \ frac {1} {\ text {C}} + \ text {I} _ {\ space \ text {in}} '\ left (t \ right) \ cdot \ text {R} + \ text {I} _ {\ space \ text {in}} '' \ left (t \ right) \ cdot \ text {L} \ space \ Longleftrightarrow \ space $$
$$ \ text {V} _ {\ space \ text {in}} '\ left (t \ right) = \ text {I} _ {\ space \ text {in}}' '\ left (t \ right) \ cdot \ text {L} + \ text {I} _ {\ space \ text {en}} '\ left (t \ right) \ cdot \ text {R} + \ text {I} _ {\ space \ text {in}} \ left (t \ right) \ cdot \ frac {1} {\ text {C}} \ tag5 $$
Suponiendo que las condiciones iniciales son iguales a \ $ 0 \ $ y que utiliza transformada de Laplace :
$$ \ text {s} \ cdot \ text {v} _ {\ space \ text {in}} \ left (\ text {s} \ right) = \ text {s} ^ 2 \ cdot \ text {i} _ {\ space \ text {in}} \ left (\ text {s} \ right) \ cdot \ text {L} + \ text {s} \ cdot \ text {i} _ {\ space \ text {in}} \ left (\ text {s} \ right) \ cdot \ text {R} + \ text {i} _ {\ space \ text {in}} \ left (t \ right) \ cdot \ frac { 1} {\ text {C}} \ space \ Longleftrightarrow \ space $$
$$ \ text {i} _ {\ space \ text {in}} \ left (\ text {s} \ right) = \ frac {\ text {s} \ cdot \ text {v} _ {\ space \ text {in}} \ left (\ text {s} \ right)} {\ text {L} \ cdot \ text {s} ^ 2 + \ text {s} \ cdot \ text {R} + \ frac {1} {\ text {C}}} \ tag6 $$
Utilizando el ' Teorema de convolución ' de la transformada de Laplace:
$$ \ text {I} _ {\ space \ text {in}} \ left (t \ right) = \ int_0 ^ t \ mathscr {L} _ \ text {s} ^ {- 1} \ left [\ text {v} _ {\ space \ text {in}} \ left (\ text {s} \ right) \ right] _ {\ left (\ text {y} \ right)} \ cdot \ mathscr {L } _ \ text {s} ^ {- 1} \ left [\ frac {\ text {s}} {\ text {L} \ cdot \ text {s} ^ 2 + \ text {s} \ cdot \ text { R} + \ frac {1} {\ text {C}}} \ right] _ {\ left (t- \ text {y} \ right)} \ space \ text {d} \ text {y} = $$
$$ \ int_0 ^ t \ text {V} _ {\ space \ text {in}} \ left (\ text {y} \ right) \ cdot \ mathscr {L} _ \ text {s} ^ {- 1} \ left [\ frac {\ text {s}} {\ text {L} \ cdot \ text {s} ^ 2 + \ text {s} \ cdot \ text {R} + \ frac {1} {\ text { C}}} \ right] _ {\ left (t- \ text {y} \ right)} \ space \ text {d} \ text {y} \ tag7 $$
Y \ $ \ mathscr {L} _ \ text {s} ^ {- 1} \ left [\ frac {\ text {s}} {\ text {L} \ cdot \ text {s} ^ 2 + \ text {s} \ cdot \ text {R} + \ frac {1} {\ text {C}}} \ right] _ {\ left (t- \ text {y} \ right)} \ $, es igual a: