, .
. 5.14 .
, ( ). . . 5.14
. - , ( ) , "" . , .
t, t = 0 . , m (-2), :
w(t) = wo + mt.
:
Dw = m×t.
y(t) = wot + mt2/2.
:
u(t) =
. (Dw << wo) :
Dw×t = m×t2.
. 5.15 .
.5.15 - . . 5.16 B>>1.
1. Dw, Um× . . 5.16
, . ( ) , . , . - () - () .
- () :
U(t) = Uo + ks(t), t = const, T = const.
|
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s(t), . 5.17
:
u(t) = (1+M cos Wt)f(t),
f(t) wo, ( ):
f(t) = Uo + Un cos nwot.
:
u(t) = (1+M cos Wt)Uo+ Un cos nwot (1+M cos Wt) =
u(t) = Uo + UoM cos Wt + Un cos nwot +
+ 0.5M Un cos (nwo+W)t + 0.5M Un cos (nwo-W)t.
, , . 5.17. , , . nwo nwoW, ( ). .
. 5.17
- ( , pulse width modulation, PWM), (), :
t(t) = to + ks(t), U = const, T = const.
, . 5.18
. 5.18 - .
, , , . , , . . 5.18 , 8.
. 5.19 . . 5.20 .
. 5.20 . , . , , . 5.20 , .
, - ( ) , , , .
() , . () ().
() , , , . .
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6.1 6.1
.
:
ua(t) = u(t) + juh(t),
uh(t) u(t), u(t) (1/πt):
uh(t) = (1/π) u(t') dt'/(t-t').
:
y(t) = arg(ua(t)).
. ωt:
j(t) = y(t) - ωot.
ω:
j(t) = y(t)/dt - ωo.
, , , .
, 90:
u1(t) = u(t) cos(ωot) = Um cos(ωot+j(t) cos(ωot) = ½ Um cos j(t) + ½ cos(2wot+j(t)),
u2(t) = u(t) sin(ωot) = Um cos(ωot+j(t) sin(ωot) = - ½ Um sin j(t) + ½ sin(2wot+j(t)).
, :
ua(t) = ½ Um cos j(t) - ½j Um sin j(t).
, , , .