(. 4.9) iR , . . = iR.
(2) , . , i,
u = iR, I m, Um = ImR, I, U = IR.
i = u/R; Im = Um/R; I=U/R.
, .
i = ωt, i = Im sinωt (. 4.10).
u = iR = ImR sin ωt = Um sin ωt, . . : = ωt = ai. (1).
(. 4.14) , . i, q, , , . . =.
, , = , i = 0 ( , ). , 90. , , .
. , . 90 (1) (. 4.15).
= Umsinωt. (2.1) (1.6),
i = dq/dt = Cdu/dt = Cd(Um sin ωt)/dt = ωCUm cos ωt =Im sin (ωt + 90 ), (1) Im = UmωC. √2, I = Uω, I = U/XC,
X = 1/(ω).
I=U/XC; (4.5)
= 1/(ω)= 1 /(2πf); = U/I. (4.6)
(4.5) , (4.6) .
(4.5) . , , , , , q = 0, = 0, i = Im (. 4.15), i = / = 0/ = 0, .
= ui pit) (. 4.16).
, , (. . ) . Qc,
|
|
p= i = Um sin ωt I m cos ωt = Um Im /2 sin 2ωt = UI sin 2ωt = Qc sin 2ωt, ..
Qc =UI = I2 Xc
(. 4.17) eL = Ldi/dt. , , . . = .
,
i = Im,
di/dt = O ( ,
), eL=0tu= £/,=0.
,
90.
, ,
.
. . 90 (1) (. 4.18).
i = Im sin ωt. = eL = Ldi/dt = Ld (Im sin ωt) / dt = ωLIm cos ωt = Um sin (ωt +90), (1) Um = ωLIm. √2, U = ωLI,
I=U/(ωL)=U/XL; (4.7)
XL =ωL=2 πfL; XL = U/I. (4.8)
(4.7) , (4.8) .
.
i = Im di/dt = 0, eL = Ldi/dt = 0.
, 90(. 4.19). , 90, , , . . (2).
=i .
, , ( ) , QL, , :
QL==UI = I2XL.