I am working on designing a Boost PFC based on the TIDA-00779 reference design. I have a question regarding the In-rush current protection. In the reference design a PTC B470N is used, along with a by-pass circuit is used for the same. My question is, can I replace the PTC with a 47 Ohm, 10W through hole resistor with enough delay, before the relay is turned on, to charge caps?