Note that comparison of this result with Example 4.13 shows that the chopper frequency (which is not specified in Example 4.13 ) has to be greater than 1 kHz to justify the assumption of continuous conduction in Example 4.13.
(C) while driving ,the chopper functions in the voltage step down mode. For this mode, The limiting condition for the commencement of discontinuous conduction is given by (4.27).this condition is rewritten, using V in place of E, as