I've implemented the presented 80W PFC boost pre-regulator in the following application note without using the applied fuse at the input. Surely I will add the fuse to the finalized tested circuit. But it was recommended to me not to use the fuse for early tests because it doesn't protect the semiconductor devices from failure and if you use the fuse, besides losing the main components, now you also lose the fuse without any advantage. Is it correct?
The reason for most failures is due to the "gate staying ON for a long time" and resulting in high current flow, core saturation, short circuit of the input terminal, and burning of the diode bridge, MOSFET, CS resistors, and IC.
Does the fuse protect the circuit from these failures and explosions during initial tests or do you recommend continuing testing without a fuse?
https://www.st.com/resource/en/application_note/cd00195944-solution-for-designing-a-transition-mode-pfc-preregulator-with-the-l6562a-stmicroelectronics.pdf