.
p p p - p , pp p R, L p C.
p p , : - p ( LC -p) ( RLC -p).
p p .
p q, p U , p E, D p p WE, I, B, p H p W M ..
RLC , . LC - (.2.1)..
p p LC -p p, p .
(t = 0) (. 2.1, ), W E , WE = q 2/(2 C), . p W = LI 2/2 = 0.
0 T/ 8 (T - p ) (. 2.1, ): q W E, I, , (W ). ε s, I i. , p. "p" (p p L) p pp .
T /8 T /4 (. 2.1, ) p pp p. t = T /4 W = LI 2/ 2 , q W Ep . p pp .
T /4 3 T /8 (. 2.1, ) I W , . p , . H t = T /4, , p pp p. p W E p.
, 3 T /8 T /2 p pp p (. 2.1, ): q W E p, I W . t = T/ 2p W E = q2 /(2 C) , I W p , p pp .
t = T /2 5 T /8 pp p (. 2.1, ), p, p p . p , , , p, p t = T p (. 2.1, ).
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p p p p ( I p), p p p:
U C = es q / C = - L dI / dt, (2.1)
U = q / C - p p; e s - . (2.1) L , , I = dq / dt,
. (2.2)
q = CU , (2.2)
(2.3)
p :
. (2.4)
p (2.2) - (2.3) - p p p p. p p
q = q mos(w0 t + α); UC = U mos(w0 t + α);(2.5)
I = dq / dt = -q mw0sin(w0 t + α) = -I msin(w0 t + α), (2.6)
qm, U Cm - p, p ; I m = q mw0 - . q (t), I (t) . 2.2. (2.5) (2.6) , , , , (. 2.2, ).
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W E = q 2 / (2 C); W = LI 2 / 2.
q I p (2.5), (2.6), :
;
(2.7)
L w 02 = 1/ C.
W E W , (. 2.2, ):
; (2.8)
.
12. S L. T. d .
. (2.4) :
ε 0 = 8,85 10-12 / - ; ε . d
,
:
13. L = 5 . . , , , q m = 0,2 .
. (2.2) , ω0 = 10 4 1/.
= 1 / (108 L) = 10-8 / 5 ∙10-3 = 0,2∙ 10-5 = 2 .
, (2.5). , t = 0 q = q m, α . q = 0,2cos (104 t), , (2.6) I = - 2 sin(104 t), .
, (. , . 1).
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RLC -p (. 2.3) , , -, p .
:
U C + U R = εS
, (2.9)
U R = IR - .
(2.9) L I dq / dt,
(2.10)
b = R /(2 L)- ; w02 = 1/ (LC). (2.10) ;
q = q 0 e - b t os(w t + α), (2.11)
q 0- ; q 0 e- b t - (. 2.4); w - ,
, . (2.12)
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(2.13)
R (b<<w0) (2.13) R T.
U C , , (2.11):
. (2.14)
, RLC - p / 2 ( LC - p /2).
W = L I 2 / 2, I (2.11).
p , , - , T (. 2.4):
A - (q, U , I . .), T p R, L, C p (2.13).
Q ( ):
Q = 2p W / D W, (2.15)
W - ; D W - , . d
Q = p / d = p Ne,
, , , .
(. 2.5) b2 ³ w02, . . R 2/ (4 L 2) ³ 1/(LC). , , . R 2 /(4 L2) = 1/(LC)
(2.16)
14. L R, 0, , . δ.
. (2.13).
: . ,
:
.
, δ - .
RLC- , , , U = U mcos w t (. 2.6).
L (dI / dt) + IR + q / C = U mcosw t. (2.17)
I dq / dt; L,
, (2.18)
b = R /(2 L);w02 = 1/(LC).
(2.18) . p .
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q = q mcos(w t - α), (2.19)
q m - ,
(2.20)
α - ,
(2.21)
w - ( ).
, R. , (. 2.7).
(2.20) , .
(2.22)
.
(2.19) :
I = -q mwsin(w t - a) = q mwcos(w t - a + p/2) = I m cos(w t - j), (2.23)
q mw = I m- ; j = a - p/2 - .
, , (. 2.6). U=U mcos ω t :
U = U R + U C + U L. (2.24)
, (2.23),
U R = IR = I m R cos(w t - j). (2.25)
U C = q/C = q m/ C cos(w t - α)
, , q m = I m/ω,
U C = I m/(ω C)cos(w t + φ - π/2). (2.26)
U L = - εs = LdI / dt = - I m ω L sin(ω t - φ) = I m ω L cos(ω t φ + π/2). (2.27)
(2.25) - (2.27) R - ; X C = 1/(w C) ( ); X L = w L ( ).
(2.25) - (2.27) , , p/2, p/2 . (. 2.8). x o - . U Rm = I m R, p / 2( U L) U Lm = I m ω L, p / 2 ( U C) U Cm = I m /(ω C). U m . U Rm, U Cm, U Lm , .
I m, j a. (2.25) - (2.27) (. 2.8). ,
.
(2.28)
- , ; X = (w L - 1/w C) - p .
. 2.8 , α - () , φ - ,
tgj = (w L - 1/w C) / R. (2.29)
U, q, I w w0(. 2.9).
R, L, C X L = XC, .. w L = 1 / (w C).
(2.30)
Z , R, L C, , R (Z min = R). , I max = U 0 / R (. 2.9, ).
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, , , (2.22). ω0 2 =1/(LC) β = R /(2 L),
(2.31)
, R , (. 2.9, ).
Dw Q ( )
Dw = w/ Q, (2.32)
.. , .
, , ,
(2.33)
I = I m/√2. , , . , U = U m/√2 () .
(. 2.8) , U m cos φ = U R= I m R.
(2.34)
15. = 5 , R = 0,1 . 50 . , , U Cm = 100 .
. (2.34). , , I m = U Cm/ X C = U Cm/(1/ω C) = U Cmω C = = 2πν U Cm C. (2.34):
: