verter or bootstrap circuit. This circuit has the ability to increase the
DC source voltage and to generate high voltage from a low-voltage
source. Figure 13.6 shows the basic circuit. When the IGBT is gated,
the inductor is charged with current. Then, when the IGBT is turned
off, the induced voltage from the inductor
di/dt
charges the capacitor
to a higher voltage.
13.4.The “H” Bridge
Four IGBTs can be combined to form a bipolar switching circuit that
is the basis for many motor drives and other applications. Figure 13.7
FIGURE 13.5Chopper at 50% duty cycle.
FIGURE 13.6IGBT boost converter.
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Switchmode Systems ...
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