MALFUNCTION PREVENTING CIRCUIT DEVICE FOR DRIVING POWER SOURCE GENERATING PART

摘要

PURPOSE:To obtain a driving power source generating circuit which makes little erroneous operation even if a commercial frequency is used by providing a comparator which is operated at a low speed before a high-speed operating switching control circuit and using the output of said comparator as a phase controlling voltage. CONSTITUTION:A rectangular wave generated from an oscillator 32 is charged in a capacitor 34 and then inputted in the inverting input terminal of a comparator 36. On the other hand, a phase controlling voltage E for determining the duty of an output wave shape is applied to the non-inverting input terminal of the comparator 36. A comparator 33 compares the output of the comparator 36 with a triangular wave voltage charged in the capacitor 34 and, since a sudden change is developed in its output, no erroneous operation will take place on its rising.