HOLD-UP TIME EXTENDING CIRCUIT AND CONVERTER COMPRISING THE SAME

摘要

PURPOSE: A hold-up time expander circuit and a converter including the same are provided to expand hold-up time without changing the capacity of a direct current link capacitor. CONSTITUTION: One or more switches operates in order to create output voltage. An leaking inductor(Llk) switches one and more switches into zero-voltage. A hold-up time expander circuit(30) controls switching frequency of one or more switches according to input voltage. The hold-up time expander circuit comprises an input voltage sensing part and a frequency setting part. The input voltage sensing part senses the input voltage. The frequency setting part controls impedance according to the input voltage. The switching frequency is determined according to the impedance. A switch control part(10) operates one and more switches.