§ 11-3 The ideal transformer
An ideal transformer is a useful approximation of a very
tightly coupled transformer in which the coefficient of coupling
is almost unity and both the primary and secondary inductive
reactance are extremely large in comparison with the
terminating impedance,( )
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If a=100
ZL=20k
Zin=2
If the amplifier internal impedance is
4000Ω and the speaker impedance is 8 Ω,
then we desire that
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The primary and secondary complex volt-amperes are equal.
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Example 2,Find the turns ratio a for the transformer in the
circuit of Fig,so that,(a) the power delivered to the 10 resistor
is 25 percent of that delivered to the 2 resistor for any
independent sinusoidal source connected to x-y,(b)
when an independent source is connected to x-y.
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2
sV
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Solution:
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2.7025.1
4.411.7
2
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