350 Introduction to Electrical Power and Power Electronics
result in component damage. A freewheeling diode D shown in Figure 13.12b can
eliminate any such sparking and negative voltage transients by providing a circulat-
ing current path when the switch is opened.
The basic converter—called the main power train—in the LPC box constitutes
the bulk of the LPC design, around which many bells and whistles are added to make
the LPC suitable for the user load. The input voltage may vary over a wide range in
some poor-quality power buses. If the LPC output voltage is required to be constant
with variable voltage input, a feedback voltage regulator is used in the design with
a PWM converter with duty ratio control. If the input voltage variation is ...