
120 9
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Rectifiers and Converters
of 1.0 Vrms and a secondary voltage of 1.0 Vrms each side of center
tap and a resistive load of 1.0
Ω
, each secondary current is 0.707 Arms,
and the primary current is 1.0 A rms. Circuit voltamperes are 1.0 VA.
The transformer has a primary rating of 1.0 VA, but each secondary
must be rated at 0.707 VA. Thus, the transformer must have a VA rat-
ing of (1 + 0.707 + 0.707)/2 = 1.207 VA. It must be some 20% over-
sized for the circuit rating because of the half-wave currents in the
secondary sections.
Figure 9.3 shows the familiar bridge circuit. Here, the transformer
is fully utilized, since both windings carry sinusoidal ...